Posterior Eye Segment Diagnostic Methods

**47**

**Chapter 4**

**Abstract**

**1. Introduction**

Wide-Field Retinal Imaging in

*Mustafa Değer Bilgeç, Nazmiye Erol and Seyhan Topbaş*

Wide-field retinal imaging has become an important standard of care imaging modality in many retinal disorders both in adults and children. The recently developed wide-field retinal imaging systems enable approximately 200° imaging of retina. In this chapter, we would like to review the use of wide-field retinal imaging in disorders such as retinal vascular diseases, uveal and retinal inflammatory diseases, intraocular tumors, peripheral retinal pathologies, and retinal disorders in children such as retinopathy of prematurity, familial exudative vitreoretinopathy, and Coats' disease. Also, we would like to address the rapidly expanding role of peripheral retinal imaging in treating systemic diseases. The use of wide-field imaging technologies in screening, diagnosis, treatment, and documentation of retinal pathologies and the new information provided by wide-field angiography

for retinal vascular diseases and macular problems will be discussed.

angiography, optomap, scanning laser ophthalmoscope

ultra-wide-field photography and angiography [6].

**Keywords:** retinal imaging, wide-field, ultra-wide-field, wide-angle, fluorescein

Wide-field retinal imaging gives the opportunity to simultaneously visualize the central and peripheral retina in a single session. Older wide-field retinal imaging systems had significant downsides such as the requirement of a contact lens and a clear ocular media [1]. Acquiring images from the far peripheral retina was difficult, requiring a skilled technician and demanded difficult tasks from the patient such as performing extreme gazes. Systems that utilized image montaging could only capture up to 75° of the retina and were disadvantaged due to frequent montage errors [1–3]. New-generation devices were able to obtain up to 140° at one session [1–3]. The Optos Optomap Panoramic 200A imaging system (Optos® camera,Optos PLC, Dunfermline, UK) revolutionized wide-field retinal imaging by increasing the field of view to 200° [4]. This system implements a scanning laser ophthalmoscope technology with an ellipsoid mirror and covers approximately 82% of the retina in a single image by forming a virtual scanning head within the patient's eye [1]. Compared with conventional digital imaging systems, ultra-wide-field fluorescein angiography (UWFA) using the Optos system captures twice as much retinal area [5]. Heidelberg (Heidelberg Engineering, Germany) introduced a noncontact lens that attaches to the Heidelberg Spectralis and Retinal Angiography systems allowing

Endowed with high resolution and multimodal capabilities, ultra-wide-field imaging is destined to become the standard-of-care in retinal imaging. These

Adults and Children

### **Chapter 4**

## Wide-Field Retinal Imaging in Adults and Children

*Mustafa Değer Bilgeç, Nazmiye Erol and Seyhan Topbaş*

### **Abstract**

Wide-field retinal imaging has become an important standard of care imaging modality in many retinal disorders both in adults and children. The recently developed wide-field retinal imaging systems enable approximately 200° imaging of retina. In this chapter, we would like to review the use of wide-field retinal imaging in disorders such as retinal vascular diseases, uveal and retinal inflammatory diseases, intraocular tumors, peripheral retinal pathologies, and retinal disorders in children such as retinopathy of prematurity, familial exudative vitreoretinopathy, and Coats' disease. Also, we would like to address the rapidly expanding role of peripheral retinal imaging in treating systemic diseases. The use of wide-field imaging technologies in screening, diagnosis, treatment, and documentation of retinal pathologies and the new information provided by wide-field angiography for retinal vascular diseases and macular problems will be discussed.

**Keywords:** retinal imaging, wide-field, ultra-wide-field, wide-angle, fluorescein angiography, optomap, scanning laser ophthalmoscope

### **1. Introduction**

Wide-field retinal imaging gives the opportunity to simultaneously visualize the central and peripheral retina in a single session. Older wide-field retinal imaging systems had significant downsides such as the requirement of a contact lens and a clear ocular media [1]. Acquiring images from the far peripheral retina was difficult, requiring a skilled technician and demanded difficult tasks from the patient such as performing extreme gazes. Systems that utilized image montaging could only capture up to 75° of the retina and were disadvantaged due to frequent montage errors [1–3]. New-generation devices were able to obtain up to 140° at one session [1–3].

The Optos Optomap Panoramic 200A imaging system (Optos® camera,Optos PLC, Dunfermline, UK) revolutionized wide-field retinal imaging by increasing the field of view to 200° [4]. This system implements a scanning laser ophthalmoscope technology with an ellipsoid mirror and covers approximately 82% of the retina in a single image by forming a virtual scanning head within the patient's eye [1]. Compared with conventional digital imaging systems, ultra-wide-field fluorescein angiography (UWFA) using the Optos system captures twice as much retinal area [5]. Heidelberg (Heidelberg Engineering, Germany) introduced a noncontact lens that attaches to the Heidelberg Spectralis and Retinal Angiography systems allowing ultra-wide-field photography and angiography [6].

Endowed with high resolution and multimodal capabilities, ultra-wide-field imaging is destined to become the standard-of-care in retinal imaging. These


**Table 1.**

*Classification of wide-field devices according to their working principles.*

devices have also found their place in research applications and have the potential to be utilized in telemedicine [7]. Wide-angle imaging systems using different systems are summarized in **Table 1**.

### **2. The history and evolution of retinal imaging**

Hermann von Helmholtz was the founder of the first direct ophthalmoscope in 1851 [8]. The first available fundus camera, produced by Carl Zeiss in 1955, had a 20° field of vision. Development of fluorescein angiography (FA) in 1961 brought another format to retinal imaging [9]. The first camera that was able to visualize beyond the equator was developed by Oleg Pomerantzeff in 1977 and this device could image 148° of the retinal area. A disadvantage of this modality was the requirement of a contact lens and transscleral illumination [10]. In the meantime, montage methods had been developed to image the peripheral retina such as the 75° views compiled for the ETDRS seven-standard fields [1, 3]. A further development in the wide-field imaging systems was the introduction of RetCam (Clarity Medical Systems, Inc., Pleasanton, CA, USA) by Bert Messie in 1997 which was able to image up to 130°. This device which brought significant convenience in pediatric retinal imaging was quickly popularized [9]. The main disadvantage of this device is its optical method of illumination, necessitating a clear media. In 2003, Medibell introduced the Panoret-1000 (Medibell Medical Vision Technologies, Inc., Haifa, Israel), incorporating a non-mydriatic camera which could image up to 100° of the retina. However, this technique was technically demanding as it required technicians for image acquisition. In general, although it was able to capture high-resolution images of the retina, it did not perform well in dark pigmented fundus due to decreased transscleral illumination [9, 11]. A milestone in wide-field retinal imaging systems was the development of Optos in 2005 (Optos® camera,Optos PLC, Dunfermline, UK) which, by utilizing an ellipsoidal mirror, was capable of capturing up to 200° of the internal viewing angle of the retina [4]. Both UWFA and fundus autofluorescence are available. Furthermore, this UWFA system allowed better detection of peripheral capillary non-perfusion. An indocyanine green (ICG) angiography upgrade was also recently made available [6, 9]. In 2005, Giovanni Staurenghi developed the handheld Staurenghi 230 SLO Retina Lens (Ocular Staurenghi 230 SLO Retina Lens; Ocular Instrument Inc., Bellevue, WA, USA) which was later incorporated into a confocal scanning laser ophthalmoscopy system by Heidelberg. Addition of this lens increased the original field of view of Heidelberg Retinal Angiography (HRA) Spectralis system from 100° to 150° of the retina [12].

In summary, apart from Optos, other notable systems for wide-field imaging include the Pomerantzeff Camera/Equator-plus, Panoret-1000, the Staurenghi lens, HRA Spectralis and RetCam 3 system [11–15]. Each of the former devices has its specific inherent limitations such as the requirement of a contact lens, illumination difficulties, low resolution, optical aberrations limiting angiographic view, incapability to obtain ultra-wide-field retinal images, and absence of ultra-wide-field

**49**

in **Table 2**.

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

simultaneously [16].

• Enhanced resolution

• Faster image processing time

• Ease of image duplication and manipulation

• Possibility of image transmission via electronic route

• Simultaneous imaging of central and peripheral retina [17].

**5. Multimodal imaging with digital wide-field systems**

**lens system**

CSLO

CSLO using Staurenghi Lens

Contact SD-OCT with

• Faster image acquisition

ditional fundus camera

photo image is acquired [18].

**Platforms/devices Type of** 

WFI Heidelberg Spectralis Non-contact SD-OCT with

autofluorescence imaging. Although the montage method using standard fundus photography is also able to obtain wide-angle images of the retina, the final

**3. Advantages of modern digital wide-field imaging systems**

assembled image may not be synchronous as none of the images have been captured

• Better acquisition in eyes with hazy ocular media (such as cataract) than a tra-

**4. Confocal scanning laser ophthalmoscopy imaging (CSLO) systems**

CSLO systems use laser light to illuminate the retina, instead of bright flashes of light. This reduces scatter of light in images acquired. Two different wavelengths of laser are used (532 nm-green, 633 nm-red). Green laser provides more detailed information about the superficial layers of the retina and the retinal vessels. Red laser (633 nm) owing to a longer wavelength gives more detailed information about deep retinal layers and choroid. Images can be evaluated separately or a composite

A great advantage offered by many of the present WFI and UWFI systems is the possibility of simultaneous acquisition of fundus fluorescein angiography (FA), indocyanine angiography (ICGA), red-free photography, fundus photography, fundus autofluorescence (FAF), including blue-light fundus autofluorescence (BAF), infrared autofluorescence (IRAF) or green-light fundus autofluorescence (GAF). The main features of commercially available WFI systems are summarized

**Principle Field of view Available application**

FFA, ICGA, FAF(BAF and

IRAF)

150° FFA,ICGA, FAF(BAF and IRAF)

55°(105°with HRA2)

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

autofluorescence imaging. Although the montage method using standard fundus photography is also able to obtain wide-angle images of the retina, the final assembled image may not be synchronous as none of the images have been captured simultaneously [16].

## **3. Advantages of modern digital wide-field imaging systems**

• Enhanced resolution

*Novel Diagnostic Methods in Ophthalmology*

are summarized in **Table 1**.

**Table 1.**

**2. The history and evolution of retinal imaging**

*Classification of wide-field devices according to their working principles.*

devices have also found their place in research applications and have the potential to be utilized in telemedicine [7]. Wide-angle imaging systems using different systems

Confocal scanning laser ophthalmoscope(CSLO)-based systems Optos, Heidelberg Optics-based systems RetCam, Panoret 1000 Contact lens-based systems Staurenghi, Rodenstock lens

Hermann von Helmholtz was the founder of the first direct ophthalmoscope in 1851 [8]. The first available fundus camera, produced by Carl Zeiss in 1955, had a 20° field of vision. Development of fluorescein angiography (FA) in 1961 brought another format to retinal imaging [9]. The first camera that was able to visualize beyond the equator was developed by Oleg Pomerantzeff in 1977 and this device could image 148° of the retinal area. A disadvantage of this modality was the requirement of a contact lens and transscleral illumination [10]. In the meantime, montage methods had been developed to image the peripheral retina such as the 75° views compiled for the ETDRS seven-standard fields [1, 3]. A further development in the wide-field imaging systems was the introduction of RetCam (Clarity Medical Systems, Inc., Pleasanton, CA, USA) by Bert Messie in 1997 which was able to image up to 130°. This device which brought significant convenience in pediatric retinal imaging was quickly popularized [9]. The main disadvantage of this device is its optical method of illumination, necessitating a clear media. In 2003, Medibell introduced the Panoret-1000 (Medibell Medical Vision Technologies, Inc., Haifa, Israel), incorporating a non-mydriatic camera which could image up to 100° of the retina. However, this technique was technically demanding as it required technicians for image acquisition. In general, although it was able to capture high-resolution images of the retina, it did not perform well in dark pigmented fundus due to decreased transscleral illumination [9, 11]. A milestone in wide-field retinal imaging systems was the development of Optos in 2005 (Optos® camera,Optos PLC, Dunfermline, UK) which, by utilizing an ellipsoidal mirror, was capable of capturing up to 200° of the internal viewing angle of the retina [4]. Both UWFA and fundus autofluorescence are available. Furthermore, this UWFA system allowed better detection of peripheral capillary non-perfusion. An indocyanine green (ICG) angiography upgrade was also recently made available [6, 9]. In 2005, Giovanni Staurenghi developed the handheld Staurenghi 230 SLO Retina Lens (Ocular Staurenghi 230 SLO Retina Lens; Ocular Instrument Inc., Bellevue, WA, USA) which was later incorporated into a confocal scanning laser ophthalmoscopy system by Heidelberg. Addition of this lens increased the original field of view of Heidelberg Retinal Angiography (HRA) Spectralis system

In summary, apart from Optos, other notable systems for wide-field imaging include the Pomerantzeff Camera/Equator-plus, Panoret-1000, the Staurenghi lens, HRA Spectralis and RetCam 3 system [11–15]. Each of the former devices has its specific inherent limitations such as the requirement of a contact lens, illumination difficulties, low resolution, optical aberrations limiting angiographic view, incapability to obtain ultra-wide-field retinal images, and absence of ultra-wide-field

**48**

from 100° to 150° of the retina [12].


## **4. Confocal scanning laser ophthalmoscopy imaging (CSLO) systems**

CSLO systems use laser light to illuminate the retina, instead of bright flashes of light. This reduces scatter of light in images acquired. Two different wavelengths of laser are used (532 nm-green, 633 nm-red). Green laser provides more detailed information about the superficial layers of the retina and the retinal vessels. Red laser (633 nm) owing to a longer wavelength gives more detailed information about deep retinal layers and choroid. Images can be evaluated separately or a composite photo image is acquired [18].

## **5. Multimodal imaging with digital wide-field systems**

A great advantage offered by many of the present WFI and UWFI systems is the possibility of simultaneous acquisition of fundus fluorescein angiography (FA), indocyanine angiography (ICGA), red-free photography, fundus photography, fundus autofluorescence (FAF), including blue-light fundus autofluorescence (BAF), infrared autofluorescence (IRAF) or green-light fundus autofluorescence (GAF). The main features of commercially available WFI systems are summarized in **Table 2**.



**Table 2.**

*The main features of commercially available WFI systems.*

### **6. Wide-field fundus autofluorescence (FAF) imaging**

Autofluorescence is based on the excitation of fluorophores within the retina. The main fluorophore is lipofuscin, found in the retinal pigment epithelial cells [19]. For some diseases, autofluorescence provides valuable information in the differential diagnosis. An ultra-wide-field scanning laser ophthalmoscope with FAF capability was recently introduced. The importance of peripheral retinal evaluation was highlighted in reports showing distinct peripheral FAF changes in diseases that were previously assumed to be isolated to macula [20]. Wide-field FAF imaging

#### **Figure 1.**

*Typical FAF appearance of multifocal central serious chorioretinopathy. Hyperfluorescent areas are indicative of chronic subretinal fluid and secondary RPE changes.*

**51**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

central serous chorioretinopathy [22] (**Figures 1–3**).

**7.1 Healthy eyes**

**Figure 3.**

**7.2 Diabetic retinopathy**

marked peripheral ischemia.

**7. Applications of wide-field imaging in clinical practice**

provides valuable information in pathologies such as AMD, posterior uveitis, and choroidal melanoma [21]. Wide-field imaging also provides valuable clinical data in

*FAF image of a patient with retinitis pigmentosa showing annular hypo and hyper autofluorescent areas.*

In order to evaluate the pathological angiography findings in various diseases, first of all, it is necessary to evaluate the normal retinal findings in wide-field angiography.[23, 24] Perfused vascular border distance decreases after 60 years of age in all quadrants [24]. Normal peripheral retinas infrequently show granular background fluorescence [23]. **Figure 4** shows wide-field images of healthy eyes.

Vascular abnormalities in diabetic retinopathy, particularly non-perfusion, occur in the peripheral retina; therefore, evaluation of the retinal periphery is of vital importance [25]. With the advent of wide-field imaging systems in recent years, it is possible to evaluate peripheral retina which cannot be visualized by conventional imaging systems in diabetic patients. Peripheral avascular areas, neovascularization, and vascular leakages are evaluated. UWFA was found superior to simulated seven-standard field images in a previous study not only in terms of the visualized total retinal area (3.2 times) but also in terms of the total area of retinal non-perfusion (3.9 times), neovascularization (1.9 times), and panretinal photocoagulation (3.8 times) [26]. Moreover, this study has demonstrated that the seven-standard field image technique has failed to identify positive findings that were present in UWFA in 10% of the patients [26]. Detecting peripheral retinal ischemia is essential as studies have shown that peripheral ischemia may precede diabetic macular edema [27, 28]. In patients with retinal ischemia, macular edema was 3.75 times more than those without ischemia [28]. Patients with diabetic retinopathy with large ischemic areas had more treatment-resistant macular edema [27]. It is stated that ultra-wide-field imaging may provide some additional data in the diagnosis because it contains a larger area [29–32]. **Figure 5** shows UWFA image of a diabetic patient with

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

#### **Figure 3.**

*Novel Diagnostic Methods in Ophthalmology*

**Platforms/devices Type of** 

*The main features of commercially available WFI systems.*

**6. Wide-field fundus autofluorescence (FAF) imaging**

**lens system**

RetCam 3 Contact Optical light

Autofluorescence is based on the excitation of fluorophores within the retina. The main fluorophore is lipofuscin, found in the retinal pigment epithelial cells [19]. For some diseases, autofluorescence provides valuable information in the differential diagnosis. An ultra-wide-field scanning laser ophthalmoscope with FAF capability was recently introduced. The importance of peripheral retinal evaluation was highlighted in reports showing distinct peripheral FAF changes in diseases that were previously assumed to be isolated to macula [20]. Wide-field FAF imaging

source to obtain high resolution

UWFI Optos Non-contact CSLO-based 200 FFA,FAF (GAF,IRAF),ICGA

**Principle Field of view Available application**

130° FFA, ICGA

*Typical FAF appearance of multifocal central serious chorioretinopathy. Hyperfluorescent areas are indicative* 

*FAF shows a hyper-autofluorescent gravitational tract in chronic central serous chorioretinopathy.*

**50**

**Figure 2.**

**Figure 1.**

**Table 2.**

*of chronic subretinal fluid and secondary RPE changes.*

*FAF image of a patient with retinitis pigmentosa showing annular hypo and hyper autofluorescent areas.*

provides valuable information in pathologies such as AMD, posterior uveitis, and choroidal melanoma [21]. Wide-field imaging also provides valuable clinical data in central serous chorioretinopathy [22] (**Figures 1–3**).

### **7. Applications of wide-field imaging in clinical practice**

#### **7.1 Healthy eyes**

In order to evaluate the pathological angiography findings in various diseases, first of all, it is necessary to evaluate the normal retinal findings in wide-field angiography.[23, 24] Perfused vascular border distance decreases after 60 years of age in all quadrants [24]. Normal peripheral retinas infrequently show granular background fluorescence [23]. **Figure 4** shows wide-field images of healthy eyes.

#### **7.2 Diabetic retinopathy**

Vascular abnormalities in diabetic retinopathy, particularly non-perfusion, occur in the peripheral retina; therefore, evaluation of the retinal periphery is of vital importance [25]. With the advent of wide-field imaging systems in recent years, it is possible to evaluate peripheral retina which cannot be visualized by conventional imaging systems in diabetic patients. Peripheral avascular areas, neovascularization, and vascular leakages are evaluated. UWFA was found superior to simulated seven-standard field images in a previous study not only in terms of the visualized total retinal area (3.2 times) but also in terms of the total area of retinal non-perfusion (3.9 times), neovascularization (1.9 times), and panretinal photocoagulation (3.8 times) [26]. Moreover, this study has demonstrated that the seven-standard field image technique has failed to identify positive findings that were present in UWFA in 10% of the patients [26]. Detecting peripheral retinal ischemia is essential as studies have shown that peripheral ischemia may precede diabetic macular edema [27, 28]. In patients with retinal ischemia, macular edema was 3.75 times more than those without ischemia [28]. Patients with diabetic retinopathy with large ischemic areas had more treatment-resistant macular edema [27]. It is stated that ultra-wide-field imaging may provide some additional data in the diagnosis because it contains a larger area [29–32]. **Figure 5** shows UWFA image of a diabetic patient with marked peripheral ischemia.

#### **Figure 4.**

*Various wide-field images in different adults with healthy eyes. Composite color photo (a), pars plana view at temporal gaze (white arrows) (b), normal FAF image (c), and normal FA image (d).*

#### **Figure 5.**

*UWFA image of a patient with diabetic retinopathy showing marked peripheral ischemia, patches of neovascularization at disc and elsewhere.*

#### **7.3 Retinal vascular occlusions**

#### *7.3.1 Branch retinal vein occlusions*

Branch retinal vein occlusion (BRVO) is a significant cause of vision loss and is the second most common retinal vascular disease after diabetic retinopathy. BRVO can be categorized as ischemic or non-ischemic [33]. Wide-field FA can be used to

**53**

**Figure 6.**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

*7.3.2 Central retinal vein occlusions*

with CRVO in the acute phase.

imaging system.

**7.5 Retinal detachment**

**7.4 Choroidal lesions including tumors**

identify vascular abnormalities, peripheral capillary non-perfusion, and neovascularization [34, 35]. Capillary non-perfusion on wide-field angiography heralds the development of macular edema in patients with BRVO [36]. Increased production of VEGF has been proposed to cause macular edema by increasing capillary perme-

Central retinal vein occlusion (CRVO) is a relatively less frequent cause of vision loss than BRVO. CRVO is classified into ischemic and non-ischemic types depending on the extent of retinal ischemia. As the detection of the extent of retinal ischemia is crucial in prognostication, peripheral retinal imaging is of significant value. Conventional FA systems may be limited in peripheral retinal assessment compared to UWFA. As such, considering that ischemic CRVO is, by definition, the presence of non-perfusion greater than 10 disc diameters, UWFA may be more efficient than conventional FA in differentiating ischemic from non-ischemic CRVOs [37]. Furthermore, wide-field FA allows detection of a greater area of overall non-perfusion enabling earlier and targeted laser photocoagulation [37–39]. In view of these considerations, UWFA is anticipated to improve the management of CRVO. **Figure 7** shows a wide-field fundus photography and UWFA of a patient

Wide-field imaging systems ease the evaluation and follow-up of peripheral temporal lesions [40]. SLO images can be distinguished as malignant or benign lesions. Typically, malignant lesions appear dark with a red laser, but appear bright with a green laser [41]. Wide-field fundus imaging may allow documentation of growth of a choroidal tumor and associated serous retinal detachment [42]. **Figures 8** and **9** show two different choroidal tumors imaged by ultra-wide-field

Wide-field imaging may be used to supplement fundus examination for characterizing and documenting retinal detachments [7, 43]. Use of wide-field systems in the diagnosis and evaluation of retinal detachments is, however, controversial. The gold

*UWFA image of the inferior temporal region in a patient with BRVO showing a delineated area of peripheral* 

*ischemia (arrow) and areas of blocked fluorescence due to hemorrhage (arrow head).*

ability [36]. **Figure 6** shows UWFA image of a patient with BRVO.

#### *Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

identify vascular abnormalities, peripheral capillary non-perfusion, and neovascularization [34, 35]. Capillary non-perfusion on wide-field angiography heralds the development of macular edema in patients with BRVO [36]. Increased production of VEGF has been proposed to cause macular edema by increasing capillary permeability [36]. **Figure 6** shows UWFA image of a patient with BRVO.

### *7.3.2 Central retinal vein occlusions*

*Novel Diagnostic Methods in Ophthalmology*

**52**

**Figure 5.**

**Figure 4.**

**7.3 Retinal vascular occlusions**

*neovascularization at disc and elsewhere.*

*7.3.1 Branch retinal vein occlusions*

Branch retinal vein occlusion (BRVO) is a significant cause of vision loss and is the second most common retinal vascular disease after diabetic retinopathy. BRVO can be categorized as ischemic or non-ischemic [33]. Wide-field FA can be used to

*UWFA image of a patient with diabetic retinopathy showing marked peripheral ischemia, patches of* 

*Various wide-field images in different adults with healthy eyes. Composite color photo (a), pars plana view at* 

*temporal gaze (white arrows) (b), normal FAF image (c), and normal FA image (d).*

Central retinal vein occlusion (CRVO) is a relatively less frequent cause of vision loss than BRVO. CRVO is classified into ischemic and non-ischemic types depending on the extent of retinal ischemia. As the detection of the extent of retinal ischemia is crucial in prognostication, peripheral retinal imaging is of significant value. Conventional FA systems may be limited in peripheral retinal assessment compared to UWFA. As such, considering that ischemic CRVO is, by definition, the presence of non-perfusion greater than 10 disc diameters, UWFA may be more efficient than conventional FA in differentiating ischemic from non-ischemic CRVOs [37]. Furthermore, wide-field FA allows detection of a greater area of overall non-perfusion enabling earlier and targeted laser photocoagulation [37–39]. In view of these considerations, UWFA is anticipated to improve the management of CRVO. **Figure 7** shows a wide-field fundus photography and UWFA of a patient with CRVO in the acute phase.

### **7.4 Choroidal lesions including tumors**

Wide-field imaging systems ease the evaluation and follow-up of peripheral temporal lesions [40]. SLO images can be distinguished as malignant or benign lesions. Typically, malignant lesions appear dark with a red laser, but appear bright with a green laser [41]. Wide-field fundus imaging may allow documentation of growth of a choroidal tumor and associated serous retinal detachment [42]. **Figures 8** and **9** show two different choroidal tumors imaged by ultra-wide-field imaging system.

### **7.5 Retinal detachment**

Wide-field imaging may be used to supplement fundus examination for characterizing and documenting retinal detachments [7, 43]. Use of wide-field systems in the diagnosis and evaluation of retinal detachments is, however, controversial. The gold

### **Figure 6.**

*UWFA image of the inferior temporal region in a patient with BRVO showing a delineated area of peripheral ischemia (arrow) and areas of blocked fluorescence due to hemorrhage (arrow head).*

standard in diagnosing retinal detachment remains a dilated binocular indirect examination with scleral depression. **Figure 10** shows a patient with retinal detachment.

### **7.6 Age-related macular degeneration (AMD)**

Detection of peripheral autofluorescence is a potential area of research and its significance is currently being investigated in different studies [44, 45]. In a previous study, peripheral FAF abnormalities were found to be 68.9% and several distinct FAF patterns were identified: granular (46.2%), spotted (34.0%), and nummular (18.1%). An abnormal FAF pattern was observed more frequently in neovascular compared to non-neovascular AMD or normal eyes, but the clinical

#### **Figure 7.**

*Wide-field fundus photograph and UWFA image of the left eye of a patient with CRVO illustrating widespread retinal hemorrhage and disc staining. Peripheral ischemia in this patient may have been missed by conventional FA due to limited field of view.*

#### **Figure 8.**

*A case of choroidal malignant melanoma, composite photograph (a), UWFA (b), red laser (c), and green laser/red-free (d) images.*

**55**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

significance of these findings is, at present, uncertain [45]. **Figure 11** shows various

*Wide-field fundus photograph of a choroidal metastatic tumor with exudative retinal detachment in a patient* 

Wide-field imaging of retinopathy of prematurity (ROP) is usually performed using RetCam technology. Optos test is performed more often in older children to document the late sequelae of ROP. Even if it seems difficult, Optos imaging of newborns with ROP can also be performed using the "flying baby" position [46]. Wide-field imaging for telemedicine-based screening of ROP has recently gained popularity [47]. RetCam can be used immediately after laser treatment to identify untreated areas in ROP cases [48]. The RetCam technology is also useful in the diagnosis and follow-up of retinoblastoma. UWF imaging with Optos has been shown to be useful in the diagnosis of Coats' disease. Wide-field imaging is critical for the detection of areas of non-perfusion and telangiectasias, in addition image-guided targeted panretinal photocoagulation to these areas [49, 50]. Familial exudative vitreoretinopathy (FEVR) is a condition of abnormal vascularization of the retinal periphery. UWFA has also been employed to conceptualize an updated version of FEVR classification [51]. **Figures 12–15** show images of pediatric patients

peripheral FAF abnormalities in different AMD patients.

*Macula-off retinal detachment with a horse-shoe tear at 10 o'clock.*

**7.7 Pediatric retinal diseases**

**Figure 9.**

**Figure 10.**

*with lung cancer.*

with different retinal diseases.

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

#### **Figure 9.**

*Novel Diagnostic Methods in Ophthalmology*

**7.6 Age-related macular degeneration (AMD)**

standard in diagnosing retinal detachment remains a dilated binocular indirect examination with scleral depression. **Figure 10** shows a patient with retinal detachment.

Detection of peripheral autofluorescence is a potential area of research and its significance is currently being investigated in different studies [44, 45]. In a previous study, peripheral FAF abnormalities were found to be 68.9% and several distinct FAF patterns were identified: granular (46.2%), spotted (34.0%), and nummular (18.1%). An abnormal FAF pattern was observed more frequently in neovascular compared to non-neovascular AMD or normal eyes, but the clinical

*Wide-field fundus photograph and UWFA image of the left eye of a patient with CRVO illustrating widespread retinal hemorrhage and disc staining. Peripheral ischemia in this patient may have been missed by* 

*A case of choroidal malignant melanoma, composite photograph (a), UWFA (b), red laser (c), and green* 

**54**

**Figure 8.**

*laser/red-free (d) images.*

**Figure 7.**

*conventional FA due to limited field of view.*

*Wide-field fundus photograph of a choroidal metastatic tumor with exudative retinal detachment in a patient with lung cancer.*

#### **Figure 10.** *Macula-off retinal detachment with a horse-shoe tear at 10 o'clock.*

significance of these findings is, at present, uncertain [45]. **Figure 11** shows various peripheral FAF abnormalities in different AMD patients.

#### **7.7 Pediatric retinal diseases**

Wide-field imaging of retinopathy of prematurity (ROP) is usually performed using RetCam technology. Optos test is performed more often in older children to document the late sequelae of ROP. Even if it seems difficult, Optos imaging of newborns with ROP can also be performed using the "flying baby" position [46]. Wide-field imaging for telemedicine-based screening of ROP has recently gained popularity [47]. RetCam can be used immediately after laser treatment to identify untreated areas in ROP cases [48]. The RetCam technology is also useful in the diagnosis and follow-up of retinoblastoma. UWF imaging with Optos has been shown to be useful in the diagnosis of Coats' disease. Wide-field imaging is critical for the detection of areas of non-perfusion and telangiectasias, in addition image-guided targeted panretinal photocoagulation to these areas [49, 50]. Familial exudative vitreoretinopathy (FEVR) is a condition of abnormal vascularization of the retinal periphery. UWFA has also been employed to conceptualize an updated version of FEVR classification [51]. **Figures 12–15** show images of pediatric patients with different retinal diseases.

#### **Figure 11.**

*Various peripheral FAF abnormalities in different AMD patients. Hypo-autofluorescent lesions with hyperautofluorescent borders (a), nummular hypo-autofluorescent lesions (b), hyper-autofluorescent lesions (c), and hypo-autofluorescent lesions (d) at peripheral retina.*

#### **Figure 12.**

*Color fundus photograph reveals zone II, stage 2 retinopathy of prematurity with plus disease (from RetCam).*

#### **7.8 Uveitis**

UWFA is useful in evaluating disease severity, progression, and treatment response in intermediate or posterior uveitis [52]. The UWFA showed a view of capillary dropout and leakage in the peripheral retina. This was first demonstrated in two case series of patients with retinal vasculitis imaged with UWFA [53, 54]. In a study about Behçet retinal vasculitis, it was found that UWFA detected active vasculitis not otherwise detectable in 84.8% of eyes [55]. Multimodal UWF imaging will likely assume a more prominent role in the diagnosis and follow-up of patients with retinal vasculitis and posterior uveitis [7]. **Figures 16–18** show images of different uveitis patients in wide-field imaging.

**57**

**Figure 15.**

**Figure 13.**

**Figure 14.**

**7.9 Miscellaneous diseases**

UWFA shows peripheral perfusion abnormalities not previously recognized in myopic eyes. Retinal vasculature in the peripheral retina is significantly altered in eyes with axial myopia. This may be associated to a mechanical stretching [56].

*UWFA image of the right (a) and left eye (b) of a patient with FEVR. Marked peripheral retinal non-perfusion and NVE (a) and severe macular dragging due to falciform retinal fold (b) is noted.*

*A RetCam image of a retinoblastoma case showing a large retinal mass encompassing the retinal arcuates.*

*Wide-field fundus photograph (left panel) of a patient with Coats' disease showing macular circinate exudates, telangiectatic vessels in the upper nasal retina. UWFA image (right panel) of the same patient* 

*showing telangiectatic vessels and peripheral non-perfusion.*

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

#### **Figure 13.**

*Novel Diagnostic Methods in Ophthalmology*

*hypo-autofluorescent lesions (d) at peripheral retina.*

**56**

ferent uveitis patients in wide-field imaging.

**7.8 Uveitis**

**Figure 12.**

**Figure 11.**

UWFA is useful in evaluating disease severity, progression, and treatment response in intermediate or posterior uveitis [52]. The UWFA showed a view of capillary dropout and leakage in the peripheral retina. This was first demonstrated in two case series of patients with retinal vasculitis imaged with UWFA [53, 54]. In a study about Behçet retinal vasculitis, it was found that UWFA detected active vasculitis not otherwise detectable in 84.8% of eyes [55]. Multimodal UWF imaging will likely assume a more prominent role in the diagnosis and follow-up of patients with retinal vasculitis and posterior uveitis [7]. **Figures 16–18** show images of dif-

*Color fundus photograph reveals zone II, stage 2 retinopathy of prematurity with plus disease (from RetCam).*

*Various peripheral FAF abnormalities in different AMD patients. Hypo-autofluorescent lesions with hyperautofluorescent borders (a), nummular hypo-autofluorescent lesions (b), hyper-autofluorescent lesions (c), and*  *A RetCam image of a retinoblastoma case showing a large retinal mass encompassing the retinal arcuates.*

#### **Figure 14.**

*Wide-field fundus photograph (left panel) of a patient with Coats' disease showing macular circinate exudates, telangiectatic vessels in the upper nasal retina. UWFA image (right panel) of the same patient showing telangiectatic vessels and peripheral non-perfusion.*

#### **Figure 15.**

*UWFA image of the right (a) and left eye (b) of a patient with FEVR. Marked peripheral retinal non-perfusion and NVE (a) and severe macular dragging due to falciform retinal fold (b) is noted.*

#### **7.9 Miscellaneous diseases**

UWFA shows peripheral perfusion abnormalities not previously recognized in myopic eyes. Retinal vasculature in the peripheral retina is significantly altered in eyes with axial myopia. This may be associated to a mechanical stretching [56].

#### **Figure 16.**

*Diffuse vasculitic leakage and neovascularization at disc (NVD) in a case with Behçet's disease (a) and diffuse vasculitic leakage and macular edema in a patient with idiopathic retinal vasculitis (b).*

#### **Figure 17.**

*Wide-field fundus photograph and UWFA image of the left eye of a patient with Eales disease. Peripheral ischemia in the nasal and temporal quadrants accompanied by collateral formation and NVD.*

#### **Figure 18.**

*Wide-field fundus photograph and UWFA images of the right eye showing mid-peripheral linear lesions (Schlaegel lines) and secondary peripapillary CNV. This patient was diagnosed with multifocal choroiditis.*

**59**

**Figure 19.**

**9. Future directions**

*Limited view in the lower quadrant due to eyelash artifacts.*

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

**8. Limitations of wide-field imaging systems**

peripheral hard drusen formation [57].

artifact caused by eyelashes.

artifacts [60].

UWFI has shown a significant association between Alzheimer's disease and

The eyeball is a three-dimensional structure. Since a two-dimensional image is obtained with a wide-field system, there are peripheral aberrations in the image. Because of the ellipsoid mirror used, lesions in the retinal periphery appear larger, with a slight distortion [58]. As this distortion and enlargement are variable in different directions, capturing should be done at the same direction as possible [24]. The Optomap system displays an area of 200° in the horizontal plane, while the vertical plane displays an area of 170° [58]. Evaluation of the retinal periphery, especially in the lower quadrant due to eyelashes, is difficult [1, 59]. **Figure 19** shows an image

Limitations of the Optos include laser artifacts, abnormal colors, and lack of stereopsis [9]. Also, resolution of the macula area is lower than that of standard fundus cameras [1]. Wide-angle retinal imaging with the use of a contact lens, such as the Staurenghi lens, expanded the view to 150° but is technically more challenging and requires high patient cooperation [12]. HRA is an alternative to Optos system in peripheral retinal imaging and each has its own advantages and disadvantages. A recent study has demonstrated that UWFA with the Optos system is able to capture a significantly wider total retinal area when compared to the Heidelberg noncontact system particularly in the nasal and temporal quadrants [60]. Although it was not found statistically significant, Heidelberg system was able to obtain a wider area in the superior and inferior quadrants. In contrast, Optos showed more peripheral distortion and greater variability in image quality, largely due to eyelash

The future goal in retinal imaging is to capture a high-resolution image of the whole retina with the finest details. Devices that allow ultra-wide-field retinal imaging may be miniaturized, thus enhancing portability. These systems may also be integrated with smartphones, therefore facilitating telemedicine applications.

*Novel Diagnostic Methods in Ophthalmology*

**58**

**Figure 18.**

**Figure 17.**

**Figure 16.**

*Wide-field fundus photograph and UWFA image of the left eye of a patient with Eales disease. Peripheral* 

*Diffuse vasculitic leakage and neovascularization at disc (NVD) in a case with Behçet's disease (a) and diffuse* 

*vasculitic leakage and macular edema in a patient with idiopathic retinal vasculitis (b).*

*Wide-field fundus photograph and UWFA images of the right eye showing mid-peripheral linear lesions (Schlaegel lines) and secondary peripapillary CNV. This patient was diagnosed with multifocal choroiditis.*

*ischemia in the nasal and temporal quadrants accompanied by collateral formation and NVD.*

UWFI has shown a significant association between Alzheimer's disease and peripheral hard drusen formation [57].

### **8. Limitations of wide-field imaging systems**

The eyeball is a three-dimensional structure. Since a two-dimensional image is obtained with a wide-field system, there are peripheral aberrations in the image. Because of the ellipsoid mirror used, lesions in the retinal periphery appear larger, with a slight distortion [58]. As this distortion and enlargement are variable in different directions, capturing should be done at the same direction as possible [24]. The Optomap system displays an area of 200° in the horizontal plane, while the vertical plane displays an area of 170° [58]. Evaluation of the retinal periphery, especially in the lower quadrant due to eyelashes, is difficult [1, 59]. **Figure 19** shows an image artifact caused by eyelashes.

Limitations of the Optos include laser artifacts, abnormal colors, and lack of stereopsis [9]. Also, resolution of the macula area is lower than that of standard fundus cameras [1]. Wide-angle retinal imaging with the use of a contact lens, such as the Staurenghi lens, expanded the view to 150° but is technically more challenging and requires high patient cooperation [12]. HRA is an alternative to Optos system in peripheral retinal imaging and each has its own advantages and disadvantages. A recent study has demonstrated that UWFA with the Optos system is able to capture a significantly wider total retinal area when compared to the Heidelberg noncontact system particularly in the nasal and temporal quadrants [60]. Although it was not found statistically significant, Heidelberg system was able to obtain a wider area in the superior and inferior quadrants. In contrast, Optos showed more peripheral distortion and greater variability in image quality, largely due to eyelash artifacts [60].

**Figure 19.** *Limited view in the lower quadrant due to eyelash artifacts.*

### **9. Future directions**

The future goal in retinal imaging is to capture a high-resolution image of the whole retina with the finest details. Devices that allow ultra-wide-field retinal imaging may be miniaturized, thus enhancing portability. These systems may also be integrated with smartphones, therefore facilitating telemedicine applications.

A novel smartphone-based wide-field retinal camera capable of capturing highquality fundus images was previously described [61]. Nonphysician operators may also be trained to acquire retinal images for remote evaluation [62].

Different diagnostic tools embedded in one device will offer more cost- and time-efficient systems. A multimodal device combining conventional wide-field fundus photography, OCT, FA, FAF, ICGA, adaptive optics, and OCT angiography would be a step forward in retinal diagnostic testing. Incorporating a treatment utility such as laser photocoagulation into a multimodal diagnostic tool would be revolutionary in retina clinical practice.

### **10. Conclusion**

The use of wide-field imaging systems for clinical applications and researches is increasing. In the future, the role of these imaging systems in the diagnosis, followup, and treatment of retinal diseases will continue to be demonstrated in comparative studies.

### **Acknowledgements**

The authors would like to thank Dr. Eray Atalay for his help in final proof reading of the manuscript.

### **Conflict of interest**

The authors declare that they do not have any financial conflict of interest related to the study.

### **Notes/thanks/other declarations**

All images used in the section are from our archives of Optos and Retcam device.

### **Author details**

Mustafa Değer Bilgeç1 , Nazmiye Erol1 and Seyhan Topbaş 2 \*

1 Ophthalmology Department, Eskisehir Osmangazi University Medical School, Eskisehir, Turkey

2 Private Umit Hospital Ophthalmology Department, Eskisehir, Turkey

\*Address all correspondence to: stopbas@ogu.edu.tr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**61**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

> [8] Mark HH. On the evolution of binocular ophthalmoscopy. Archives of Ophthalmology. 2007;**125**(6):830-833. DOI: 10.1001/archopht.125.6.830

DOI: 10.1007/978-3-319-17864-6

[10] Pomerantzeff O. Wide-angle noncontact and small-angle contact cameras. Investigative Ophthalmology & Visual Science. 1980;**19**(8):973-979

[11] Shields CL, Materin M, Shields JA. Panoramic imaging of the ocular fundus. Archives of Ophthalmology. 2003;**121**(11):1603-1607. DOI: 10.1001/

[12] Staurenghi G, Viola F, Mainster MA, Graham RD, Harrington PG. Scanning laser ophthalmoscopy and angiography

with a wide-field contact lens system. Archives of Ophthalmology. 2005;**123**(2):244-252. DOI: 10.1001/

[13] Pomerantzeff O. Equator-plus camera. Investigative Ophthalmology.

[14] Reeves GM, Kumar N, Beare NA, Pearce IA. Use of Staurenghi lens angiography in the management

Ophthalmologica. 2013;**91**(1):48-51. DOI: 10.1111/j.1755-3768.2011.02200.x

[15] Dhaliwal C, Wright E, Graham C, McIntosh N, Fleck BW. Widefield digital retinal imaging versus binocular indirect ophthalmoscopy for retinopathy of prematurity screening: A two-observer prospective, randomised comparison. The British Journal of

of posterior uveitis. Acta

archopht.121.11.1603

archopht.123.2.244

1975;**14**(5):401-406

[9] Leung EH, Rosen R. Fundus imaging in wide-field: A brief historical journey. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 1-25.

[1] Witmer MT, Kiss S. Wide-field imaging of the retina. Survey of Ophthalmology. 2013;**58**(2):143-154. DOI: 10.1016/j.survophthal.2012.07.003

[2] Sim DA, Keane PA, Rajendram R, Karampelas M, Selvam S, Powner MB, et al. Patterns of peripheral retinal and central macula ischemia in diabetic retinopathy as evaluated by ultrawidefield fluorescein angiography. American Journal of Ophthalmology. 2014;**158**(1):e141, 144-153. DOI: 10.1016/j.ajo.2014.03.009

[3] Diabetic Retinopathy Study. Report Number 6. Design, methods, and baseline results. Report Number 7. A modification of the Airlie House classification of diabetic retinopathy. Prepared by the Diabetic Retinopathy. Investigative Ophthalmology & Visual

[4] Manivannan A, Plskova J, Farrow A, McKay S, Sharp PF, Forrester JV. Ultrawide-field fluorescein angiography of the ocular fundus. American Journal of Ophthalmology. 2005;**140**(3):525-527.

[5] Friberg TR, Gupta A, Yu J, Huang L, Suner I, Puliafito CA, et al. Ultrawide angle fluorescein angiographic imaging: A comparison to conventional digital acquisition systems. Ophthalmic Surgery, Lasers & Imaging.

Science. 1981;**21**(1 Pt 2):1-226

DOI: 10.1016/j.ajo.2005.02.055

[6] Patel M, Kiss S. Ultra-widefield fluorescein angiography in retinal disease. Current Opinion in Ophthalmology. 2014;**25**(3):213-220. DOI: 10.1097/ICU.0000000000000042

[7] Nagiel A, Lalane RA, Sadda SR, Schwartz SD. Ultra-widefield fundus imaging: A review of clinical applications and future trends. Retina. 2016;**36**(4):660-678. DOI: 10.1097/

IAE.0000000000000937

2008;**39**(4):304-311

**References**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

### **References**

*Novel Diagnostic Methods in Ophthalmology*

revolutionary in retina clinical practice.

**10. Conclusion**

tive studies.

**Acknowledgements**

ing of the manuscript.

**Conflict of interest**

related to the study.

**Notes/thanks/other declarations**

**60**

**Author details**

Eskisehir, Turkey

Mustafa Değer Bilgeç1

provided the original work is properly cited.

, Nazmiye Erol1

\*Address all correspondence to: stopbas@ogu.edu.tr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Ophthalmology Department, Eskisehir Osmangazi University Medical School,

A novel smartphone-based wide-field retinal camera capable of capturing highquality fundus images was previously described [61]. Nonphysician operators may

Different diagnostic tools embedded in one device will offer more cost- and time-efficient systems. A multimodal device combining conventional wide-field fundus photography, OCT, FA, FAF, ICGA, adaptive optics, and OCT angiography would be a step forward in retinal diagnostic testing. Incorporating a treatment utility such as laser photocoagulation into a multimodal diagnostic tool would be

The use of wide-field imaging systems for clinical applications and researches is increasing. In the future, the role of these imaging systems in the diagnosis, followup, and treatment of retinal diseases will continue to be demonstrated in compara-

The authors would like to thank Dr. Eray Atalay for his help in final proof read-

The authors declare that they do not have any financial conflict of interest

All images used in the section are from our archives of Optos and Retcam device.

also be trained to acquire retinal images for remote evaluation [62].

2 Private Umit Hospital Ophthalmology Department, Eskisehir, Turkey

and Seyhan Topbaş

2 \* [1] Witmer MT, Kiss S. Wide-field imaging of the retina. Survey of Ophthalmology. 2013;**58**(2):143-154. DOI: 10.1016/j.survophthal.2012.07.003

[2] Sim DA, Keane PA, Rajendram R, Karampelas M, Selvam S, Powner MB, et al. Patterns of peripheral retinal and central macula ischemia in diabetic retinopathy as evaluated by ultrawidefield fluorescein angiography. American Journal of Ophthalmology. 2014;**158**(1):e141, 144-153. DOI: 10.1016/j.ajo.2014.03.009

[3] Diabetic Retinopathy Study. Report Number 6. Design, methods, and baseline results. Report Number 7. A modification of the Airlie House classification of diabetic retinopathy. Prepared by the Diabetic Retinopathy. Investigative Ophthalmology & Visual Science. 1981;**21**(1 Pt 2):1-226

[4] Manivannan A, Plskova J, Farrow A, McKay S, Sharp PF, Forrester JV. Ultrawide-field fluorescein angiography of the ocular fundus. American Journal of Ophthalmology. 2005;**140**(3):525-527. DOI: 10.1016/j.ajo.2005.02.055

[5] Friberg TR, Gupta A, Yu J, Huang L, Suner I, Puliafito CA, et al. Ultrawide angle fluorescein angiographic imaging: A comparison to conventional digital acquisition systems. Ophthalmic Surgery, Lasers & Imaging. 2008;**39**(4):304-311

[6] Patel M, Kiss S. Ultra-widefield fluorescein angiography in retinal disease. Current Opinion in Ophthalmology. 2014;**25**(3):213-220. DOI: 10.1097/ICU.0000000000000042

[7] Nagiel A, Lalane RA, Sadda SR, Schwartz SD. Ultra-widefield fundus imaging: A review of clinical applications and future trends. Retina. 2016;**36**(4):660-678. DOI: 10.1097/ IAE.0000000000000937

[8] Mark HH. On the evolution of binocular ophthalmoscopy. Archives of Ophthalmology. 2007;**125**(6):830-833. DOI: 10.1001/archopht.125.6.830

[9] Leung EH, Rosen R. Fundus imaging in wide-field: A brief historical journey. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 1-25. DOI: 10.1007/978-3-319-17864-6

[10] Pomerantzeff O. Wide-angle noncontact and small-angle contact cameras. Investigative Ophthalmology & Visual Science. 1980;**19**(8):973-979

[11] Shields CL, Materin M, Shields JA. Panoramic imaging of the ocular fundus. Archives of Ophthalmology. 2003;**121**(11):1603-1607. DOI: 10.1001/ archopht.121.11.1603

[12] Staurenghi G, Viola F, Mainster MA, Graham RD, Harrington PG. Scanning laser ophthalmoscopy and angiography with a wide-field contact lens system. Archives of Ophthalmology. 2005;**123**(2):244-252. DOI: 10.1001/ archopht.123.2.244

[13] Pomerantzeff O. Equator-plus camera. Investigative Ophthalmology. 1975;**14**(5):401-406

[14] Reeves GM, Kumar N, Beare NA, Pearce IA. Use of Staurenghi lens angiography in the management of posterior uveitis. Acta Ophthalmologica. 2013;**91**(1):48-51. DOI: 10.1111/j.1755-3768.2011.02200.x

[15] Dhaliwal C, Wright E, Graham C, McIntosh N, Fleck BW. Widefield digital retinal imaging versus binocular indirect ophthalmoscopy for retinopathy of prematurity screening: A two-observer prospective, randomised comparison. The British Journal of

Ophthalmology. 2009;**93**(3):355-359. DOI: 10.1136/bjo.2008.148908

[16] Klufas MA, Yannuzzi NA, Pang CE, Srinivas S, Sadda SR, Freund KB, et al. Feasibility and clinical utility of ultra-widefield indocyanine green angiography. Retina. 2015;**35**(3):508-520. DOI: 10.1097/ IAE.0000000000000318

[17] Yannuzzi LA, Ober MD, Slakter JS, Spaide RF, Fisher YL, Flower RW, et al. Ophthalmic fundus imaging: Today and beyond. American Journal of Ophthalmology. 2004;**137**(3):511-524. DOI: 10.1016/j.ajo.2003.12.035

[18] Erol N. Wide angle imaging: Technique, indications and assessment (analysis). Turkiye Klinikleri Journal of Ophthalmology. 2015;**8**(2):30-37

[19] Delori FC, Dorey CK, Staurenghi G, Arend O, Goger DG, Weiter JJ. In vivo fluorescence of the ocular fundus exhibits retinal pigment epithelium lipofuscin characteristics. Investigative Ophthalmology & Visual Science. 1995;**36**(3):718-729

[20] Heussen FM, Tan CS, Sadda SR. Prevalence of peripheral abnormalities on ultra-widefield greenlight (532 nm) autofluorescence imaging at a tertiary care center. Investigative Ophthalmology & Visual Science. 2012;**53**(10):6526-6531. DOI: 10.1167/iovs.12-9909

[21] Heussen FM, Puliafito CA, Sadda SR. Wide-field autofluorescence. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 49-57. DOI: 10.1007/978-3-319-17864-6

[22] Pang CE, Shah VP, Sarraf D, Freund KB. Ultra-widefield imaging with autofluorescence and indocyanine green angiography in central serous

chorioretinopathy. American Journal of Ophthalmology. 2014;**158**(2):362-371. e362. DOI: 10.1016/j.ajo.2014.04.021

[23] Lu J, Mai G, Luo Y, Li M, Cao D, Wang X, et al. Appearance of far peripheral retina in normal eyes by ultra-widefield fluorescein angiography. American Journal of Ophthalmology. 2017;**173**:84-90. DOI: 10.1016/j. ajo.2016.09.024

[24] Singer M, Sagong M, van Hemert J, Kuehlewein L, Bell D, Sadda SR. Ultrawidefield imaging of the peripheral retinal vasculature in normal subjects. Ophthalmology. 2016;**123**(5):1053-1059. DOI: 10.1016/j.ophtha.2016.01.022

[25] Shimizu K, Kobayashi Y, Muraoka K. Midperipheral fundus involvement in diabetic retinopathy. Ophthalmology. 1981;**88**(7):601-612

[26] Wessel MM, Aaker GD, Parlitsis G, Cho M, D'Amico DJ, Kiss S. Ultrawide-field angiography improves the detection and classification of diabetic retinopathy. Retina. 2012;**32**(4):785-791. DOI: 10.1097/IAE.0b013e3182278b64

[27] Patel RD, Messner LV, Teitelbaum B, Michel KA, Hariprasad SM. Characterization of ischemic index using ultra-widefield fluorescein angiography in patients with focal and diffuse recalcitrant diabetic macular edema. American Journal of Ophthalmology. 2013;**155**(6):1038-1044 e 1032. DOI: 10.1016/j.ajo.2013.01.007

[28] Wessel MM, Nair N, Aaker GD, Ehrlich JR, D'Amico DJ, Kiss S. Peripheral retinal ischaemia, as evaluated by ultra-widefield fluorescein angiography, is associated with diabetic macular oedema. The British Journal of Ophthalmology. 2012;**96**(5):694-698. DOI: 10.1136/ bjophthalmol-2011-300774

[29] Kernt M, Hadi I, Pinter F, Seidensticker F, Hirneiss C, Haritoglou C,

**63**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

et al. Assessment of diabetic retinopathy using nonmydriatic ultra-widefield scanning laser ophthalmoscopy (Optomap) compared with ETDRS 7-field stereo photography. Diabetes Care. 2012;**35**(12):2459-2463. DOI:

findings in fellow eyes of patients with branch retinal vein occlusion. International Journal of Inflammation. 2013;**2013**. DOI: 10.1155/2013/464127

[35] Prasad PS, Oliver SC, Coffee RE, Hubschman JP, Schwartz SD. Ultra wide-field angiographic characteristics of branch retinal and hemicentral retinal vein occlusion. Ophthalmology. 2010;**117**(4):780-784. DOI: 10.1016/j.

[36] Noma H, Minamoto A, Funatsu H, Tsukamoto H, Nakano K, Yamashita H, et al. Intravitreal levels of vascular

endothelial growth factor and interleukin-6 are correlated with macular edema in branch retinal vein occlusion. Graefe's Archive for Clinical and Experimental Ophthalmology. 2006;**244**(3):309-315. DOI: 10.1007/

[37] Tsui I, Prasad PS. Wide-field retinal imaging of central retinal vein occlusions. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 83-91. DOI: 10.1007/978-3-319-17864-6

[38] Spaide RF. Peripheral areas of nonperfusion in treated central retinal vein occlusion as imaged by widefield fluorescein angiography. Retina. 2011;**31**(5):829-837. DOI: 10.1097/

[39] Tsui I, Kaines A, Havunjian MA, Hubschman S, Heilweil G, Prasad PS, et al. Ischemic index and neovascularization in central retinal vein occlusion. Retina. 2011;**31**(1):105-110. DOI: 10.1097/

[40] Jain A, Shah SP, Tsui I, McCannel TA. The value of Optos Panoramic 200MA imaging for the monitoring of large suspicious choroidal lesions.

IAE.0b013e31820c841e

IAE.0b013e3181e36c6d

Seminars in Ophthalmology.

ophtha.2009.09.019

s00417-004-1087-4

[30] Silva PS, Cavallerano JD, Sun JK, Noble J, Aiello LM, Aiello LP. Nonmydriatic ultrawide field retinal imaging compared with dilated standard 7-field 35-mm photography and retinal specialist examination for evaluation of diabetic retinopathy. American Journal of Ophthalmology. 2012;**154**(3):549-559. e542. DOI:

10.2337/dc12-0346

10.1016/j.ajo.2012.03.019

jdiacomp.2014.08.009

[32] Silva PS, Cavallerano JD, Sun JK, Soliman AZ, Aiello LM, Aiello LP. Peripheral lesions identified by mydriatic ultrawide field imaging: Distribution and potential impact on diabetic retinopathy severity. Ophthalmology. 2013;**120**(12):2587- 2595. DOI: 10.1016/j.ophtha.2013.05.004

[33] Rogers S, McIntosh RL, Cheung N, Lim L, Wang JJ, Mitchell P, et al. The prevalence of retinal vein occlusion: Pooled data from population studies from the United States, Europe, Asia, and Australia. Ophthalmology. 2010;**117**(2):313-319, e311. DOI: 10.1016/j.ophtha.2009.07.017

[34] Tsui I, Bajwa A, Franco-Cardenas

SD. Peripheral fluorescein angiographic

V, Pan CK, Kim HY, Schwartz

[31] Rasmussen ML, Broe R, Frydkjaer-Olsen U, Olsen BS, Mortensen HB, Peto T, et al. Comparison between early treatment diabetic retinopathy study 7-field retinal photos and nonmydriatic, mydriatic and mydriatic steered widefield scanning laser ophthalmoscopy for assessment of diabetic retinopathy. Journal of Diabetes and its Complications. 2015;**29**(1):99-104. DOI: 10.1016/j.

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

*Novel Diagnostic Methods in Ophthalmology*

Ophthalmology. 2009;**93**(3):355-359. DOI: 10.1136/bjo.2008.148908

chorioretinopathy. American Journal of Ophthalmology. 2014;**158**(2):362-371. e362. DOI: 10.1016/j.ajo.2014.04.021

[24] Singer M, Sagong M, van Hemert J, Kuehlewein L, Bell D, Sadda SR. Ultrawidefield imaging of the peripheral retinal vasculature in normal subjects. Ophthalmology. 2016;**123**(5):1053-1059. DOI: 10.1016/j.ophtha.2016.01.022

[25] Shimizu K, Kobayashi Y, Muraoka K. Midperipheral fundus involvement in diabetic retinopathy. Ophthalmology.

[26] Wessel MM, Aaker GD, Parlitsis G, Cho M, D'Amico DJ, Kiss S. Ultrawide-field angiography improves the detection and classification of diabetic retinopathy. Retina. 2012;**32**(4):785-791. DOI: 10.1097/IAE.0b013e3182278b64

[27] Patel RD, Messner LV, Teitelbaum B, Michel KA, Hariprasad SM. Characterization of ischemic index using ultra-widefield fluorescein angiography in patients with focal and diffuse recalcitrant diabetic macular edema. American Journal of Ophthalmology. 2013;**155**(6):1038-1044 e 1032. DOI: 10.1016/j.ajo.2013.01.007

[28] Wessel MM, Nair N, Aaker GD, Ehrlich JR, D'Amico DJ, Kiss S. Peripheral retinal ischaemia, as evaluated by ultra-widefield fluorescein angiography, is associated with diabetic macular oedema. The British Journal of Ophthalmology. 2012;**96**(5):694-698. DOI: 10.1136/

bjophthalmol-2011-300774

[29] Kernt M, Hadi I, Pinter F,

Seidensticker F, Hirneiss C, Haritoglou C,

[23] Lu J, Mai G, Luo Y, Li M, Cao D, Wang X, et al. Appearance of far peripheral retina in normal eyes by ultra-widefield fluorescein angiography. American Journal of Ophthalmology. 2017;**173**:84-90. DOI: 10.1016/j.

ajo.2016.09.024

1981;**88**(7):601-612

[16] Klufas MA, Yannuzzi NA, Pang CE, Srinivas S, Sadda SR, Freund KB, et al. Feasibility and clinical utility of ultra-widefield indocyanine green angiography. Retina. 2015;**35**(3):508-520. DOI: 10.1097/

IAE.0000000000000318

[17] Yannuzzi LA, Ober MD, Slakter JS, Spaide RF, Fisher YL, Flower RW, et al. Ophthalmic fundus imaging: Today and beyond. American Journal of Ophthalmology. 2004;**137**(3):511-524.

DOI: 10.1016/j.ajo.2003.12.035

[18] Erol N. Wide angle imaging: Technique, indications and assessment (analysis). Turkiye Klinikleri Journal of Ophthalmology. 2015;**8**(2):30-37

[19] Delori FC, Dorey CK, Staurenghi G, Arend O, Goger DG, Weiter JJ. In vivo fluorescence of the ocular fundus exhibits retinal pigment epithelium lipofuscin characteristics. Investigative Ophthalmology & Visual Science.

[20] Heussen FM, Tan CS, Sadda SR. Prevalence of peripheral abnormalities on ultra-widefield greenlight (532 nm) autofluorescence imaging at a tertiary care center. Investigative Ophthalmology & Visual Science. 2012;**53**(10):6526-6531. DOI:

[21] Heussen FM, Puliafito CA, Sadda SR. Wide-field autofluorescence. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 49-57. DOI: 10.1007/978-3-319-17864-6

[22] Pang CE, Shah VP, Sarraf D, Freund KB. Ultra-widefield imaging with autofluorescence and indocyanine green angiography in central serous

1995;**36**(3):718-729

10.1167/iovs.12-9909

**62**

et al. Assessment of diabetic retinopathy using nonmydriatic ultra-widefield scanning laser ophthalmoscopy (Optomap) compared with ETDRS 7-field stereo photography. Diabetes Care. 2012;**35**(12):2459-2463. DOI: 10.2337/dc12-0346

[30] Silva PS, Cavallerano JD, Sun JK, Noble J, Aiello LM, Aiello LP. Nonmydriatic ultrawide field retinal imaging compared with dilated standard 7-field 35-mm photography and retinal specialist examination for evaluation of diabetic retinopathy. American Journal of Ophthalmology. 2012;**154**(3):549-559. e542. DOI: 10.1016/j.ajo.2012.03.019

[31] Rasmussen ML, Broe R, Frydkjaer-Olsen U, Olsen BS, Mortensen HB, Peto T, et al. Comparison between early treatment diabetic retinopathy study 7-field retinal photos and nonmydriatic, mydriatic and mydriatic steered widefield scanning laser ophthalmoscopy for assessment of diabetic retinopathy. Journal of Diabetes and its Complications. 2015;**29**(1):99-104. DOI: 10.1016/j. jdiacomp.2014.08.009

[32] Silva PS, Cavallerano JD, Sun JK, Soliman AZ, Aiello LM, Aiello LP. Peripheral lesions identified by mydriatic ultrawide field imaging: Distribution and potential impact on diabetic retinopathy severity. Ophthalmology. 2013;**120**(12):2587- 2595. DOI: 10.1016/j.ophtha.2013.05.004

[33] Rogers S, McIntosh RL, Cheung N, Lim L, Wang JJ, Mitchell P, et al. The prevalence of retinal vein occlusion: Pooled data from population studies from the United States, Europe, Asia, and Australia. Ophthalmology. 2010;**117**(2):313-319, e311. DOI: 10.1016/j.ophtha.2009.07.017

[34] Tsui I, Bajwa A, Franco-Cardenas V, Pan CK, Kim HY, Schwartz SD. Peripheral fluorescein angiographic findings in fellow eyes of patients with branch retinal vein occlusion. International Journal of Inflammation. 2013;**2013**. DOI: 10.1155/2013/464127

[35] Prasad PS, Oliver SC, Coffee RE, Hubschman JP, Schwartz SD. Ultra wide-field angiographic characteristics of branch retinal and hemicentral retinal vein occlusion. Ophthalmology. 2010;**117**(4):780-784. DOI: 10.1016/j. ophtha.2009.09.019

[36] Noma H, Minamoto A, Funatsu H, Tsukamoto H, Nakano K, Yamashita H, et al. Intravitreal levels of vascular endothelial growth factor and interleukin-6 are correlated with macular edema in branch retinal vein occlusion. Graefe's Archive for Clinical and Experimental Ophthalmology. 2006;**244**(3):309-315. DOI: 10.1007/ s00417-004-1087-4

[37] Tsui I, Prasad PS. Wide-field retinal imaging of central retinal vein occlusions. In: Kozak I, Arévalo JF, editors. Atlas of Wide-Field Retinal Angiography and Imaging. 1st ed. Switzerland: Springer International Publishing; 2016. pp. 83-91. DOI: 10.1007/978-3-319-17864-6

[38] Spaide RF. Peripheral areas of nonperfusion in treated central retinal vein occlusion as imaged by widefield fluorescein angiography. Retina. 2011;**31**(5):829-837. DOI: 10.1097/ IAE.0b013e31820c841e

[39] Tsui I, Kaines A, Havunjian MA, Hubschman S, Heilweil G, Prasad PS, et al. Ischemic index and neovascularization in central retinal vein occlusion. Retina. 2011;**31**(1):105-110. DOI: 10.1097/ IAE.0b013e3181e36c6d

[40] Jain A, Shah SP, Tsui I, McCannel TA. The value of Optos Panoramic 200MA imaging for the monitoring of large suspicious choroidal lesions. Seminars in Ophthalmology.

### 2009;**24**(1):43-44. DOI: 10.1080/08820530802520384

[41] Kernt M, Schaller UC, Stumpf C, Ulbig MW, Kampik A, Neubauer AS. Choroidal pigmented lesions imaged by ultra-wide-field scanning laser ophthalmoscopy with two laser wavelengths (Optomap). Clinical Ophthalmology. 2010;**4**:829-836

[42] Coffee RE, Jain A, McCannel TA. Ultra wide-field imaging of choroidal metastasis secondary to primary breast cancer. Seminars in Ophthalmology. 2009;**24**(1):34-36. DOI: 10.1080/08820530802520194

[43] Kornberg DL, Klufas MA, Yannuzzi NA, Orlin A, D'Amico DJ, Kiss S. Clinical utility of ultrawidefield imaging with the optos optomap compared with indirect ophthalmoscopy in the setting of non-traumatic rhegmatogenous retinal detachment. Seminars in Ophthalmology. 2016;**31**(5):505-512. DOI: 10.3109/08820538.2014.981551

[44] Reznicek L, Wasfy T, Stumpf C, Kampik A, Ulbig M, Neubauer AS, et al. Peripheral fundus autofluorescence is increased in age-related macular degeneration. Investigative Ophthalmology & Visual Science. 2012;**53**(4):2193-2198. DOI: 10.1167/ iovs.11-8483

[45] Tan CS, Heussen F, Sadda SR. Peripheral autofluorescence and clinical findings in neovascular and non-neovascular age-related macular degeneration. Ophthalmology. 2013;**120**(6):1271-1277. DOI: 10.1016/j. ophtha.2012.12.002

[46] Patel CK, Fung TH, Muqit MM, Mordant DJ, Brett J, Smith L, et al. Non-contact ultra-widefield imaging of retinopathy of prematurity using the Optos dual wavelength scanning laser ophthalmoscope. Eye (London,

England). 2013;**27**(5):589-596. DOI: 10.1038/eye.2013.45

[47] Scott KE, Kim DY, Wang L, Kane SA, Coki O, Starren J, et al. Telemedical diagnosis of retinopathy of prematurity intraphysician agreement between ophthalmoscopic examination and image-based interpretation. Ophthalmology. 2008;**115**(7):1222-1228e 1223. DOI: 10.1016/j.ophtha.2007.09.006

[48] Kang KB, Orlin A, Lee TC, Chiang MF, Chan RV. The use of digital imaging in the identification of skip areas after laser treatment for retinopathy of prematurity and its implications for education and patient care. Retina. 2013;**33**(10):2162-2169. DOI: 10.1097/ IAE.0b013e31828e6969

[49] Tsui I, Franco-Cardenas V, Hubschman JP, Schwartz SD. Pediatric retinal conditions imaged by ultra wide field fluorescein angiography. Ophthalmic Surgery, Lasers and Imaging Retina. 2013;**44**(1):59-67. DOI: 10.3928/23258160-20121221-14

[50] Kang KB, Wessel MM, Tong J, D'Amico DJ, Chan RV. Ultra-widefield imaging for the management of pediatric retinal diseases. Journal of Pediatric Ophthalmology and Strabismus. 2013;**50**(5):282-288. DOI: 10.3928/01913913-20130528-04

[51] Kashani AH, Brown KT, Chang E, Drenser KA, Capone A, Trese MT. Diversity of retinal vascular anomalies in patients with familial exudative vitreoretinopathy. Ophthalmology. 2014;**121**(11):2220- 2227. DOI: 10.1016/j.ophtha.2014.05.029

[52] Campbell JP, Leder HA, Sepah YJ, Gan T, Dunn JP, Hatef E, et al. Widefield retinal imaging in the management of noninfectious posterior uveitis. American Journal of Ophthalmology. 2012;**154**(5):908-911, e902. DOI: 10.1016/j.ajo.2012.05.019

**65**

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

> [60] Witmer MT, Parlitsis G, Patel S, Kiss S. Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis((R)) noncontact ultra-widefield module versus the Optos((R)) Optomap((R)). Clinical Ophthalmology. 2013;**7**:389-394. DOI:

10.2147/OPTH.S41731

[61] Maamari RN, Keenan JD, Fletcher DA, Margolis TP. A mobile phone-based retinal camera for portable wide field imaging. The British Journal of Ophthalmology. 2014;**98**(4):438-441. DOI: 10.1136/

bjophthalmol-2013-303797

[62] Fijalkowski N, Zheng LL,

Henderson MT, Wang SK, Wallenstein MB, Leng T, et al. Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP): Five years of screening with telemedicine. Ophthalmic Surgery, Lasers and Imaging Retina. 2014;**45**(2):106-113. DOI: 10.3928/23258160-20140122-01

[53] Tsui I, Kaines A, Schwartz S. Patterns of periphlebitis in intermediate

fluorescein angiography. Seminars in Ophthalmology. 2009;**24**(1):29-33. DOI:

Schwartz S. The use of ultra wide field fluorescein angiography in evaluation and management of uveitis. Seminars in Ophthalmology. 2009;**24**(1):19-24. DOI:

[55] Mesquida M, Llorenc V, Fontenla JR, Navarro MJ, Adan A. Use of ultra-widefield retinal imaging in the management of active Behcet retinal vasculitis. Retina. 2014;**34**(10):2121-2127. DOI: 10.1097/IAE.0000000000000197

[56] Kaneko Y, Moriyama M, Hirahara S, Ogura Y, Ohno-Matsui K. Areas of nonperfusion in peripheral retina of eyes with pathologic myopia detected by ultra-widefield fluorescein angiography. Investigative Ophthalmology & Visual Science. 2014;**55**(3):1432-1439. DOI:

[57] Csincsik L, Mac Gillivray TJ, Flynn E, Pellegrini E, Papanastasiou G, Barzegar-Befroei N, et al. Peripheral retinal imaging biomarkers for Alzheimer's disease: A pilot study. Ophthalmic Research. 2018;**59**(4): 182-192. DOI: 10.1159/000487053

[58] Oishi A, Hidaka J, Yoshimura N.

obtained with a wide-field scanning ophthalmoscope. Investigative Ophthalmology & Visual Science. 2014;**55**(4):2424-2431. DOI: 10.1167/

[59] Mackenzie PJ, Russell M, Ma PE, Isbister CM, Maberley DA. Sensitivity and specificity of the optos optomap for detecting peripheral retinal lesions. Retina. 2007;**27**(8):1119-1124. DOI: 10.1097/IAE.0b013e3180592b5c

Quantification of the image

iovs.13-13738

10.1167/iovs.13-13706

uveitis using ultra wide field

10.1080/08820530802520186

[54] Kaines A, Tsui I, Sarraf D,

10.1080/08820530802520095

*Wide-Field Retinal Imaging in Adults and Children DOI: http://dx.doi.org/10.5772/intechopen.84215*

*Novel Diagnostic Methods in Ophthalmology*

England). 2013;**27**(5):589-596. DOI:

[47] Scott KE, Kim DY, Wang L, Kane SA, Coki O, Starren J, et al. Telemedical diagnosis of retinopathy of prematurity intraphysician agreement between ophthalmoscopic examination and image-based interpretation.

Ophthalmology. 2008;**115**(7):1222-1228e 1223. DOI: 10.1016/j.ophtha.2007.09.006

[48] Kang KB, Orlin A, Lee TC, Chiang MF, Chan RV. The use of digital imaging in the identification of skip areas after laser treatment for retinopathy of prematurity and its implications for education and patient care. Retina. 2013;**33**(10):2162-2169. DOI: 10.1097/

IAE.0b013e31828e6969

[49] Tsui I, Franco-Cardenas V,

10.3928/23258160-20121221-14

[50] Kang KB, Wessel MM, Tong J, D'Amico DJ, Chan RV. Ultra-widefield imaging for the management of pediatric retinal diseases. Journal of Pediatric Ophthalmology and Strabismus. 2013;**50**(5):282-288. DOI: 10.3928/01913913-20130528-04

[51] Kashani AH, Brown KT, Chang E, Drenser KA, Capone A, Trese MT. Diversity of retinal vascular anomalies in patients with familial exudative vitreoretinopathy. Ophthalmology. 2014;**121**(11):2220- 2227. DOI: 10.1016/j.ophtha.2014.05.029

[52] Campbell JP, Leder HA, Sepah YJ, Gan T, Dunn JP, Hatef E, et al. Widefield retinal imaging in the management of noninfectious posterior uveitis. American Journal of Ophthalmology. 2012;**154**(5):908-911, e902. DOI:

10.1016/j.ajo.2012.05.019

Hubschman JP, Schwartz SD. Pediatric retinal conditions imaged by ultra wide field fluorescein angiography. Ophthalmic Surgery, Lasers and

Imaging Retina. 2013;**44**(1):59-67. DOI:

10.1038/eye.2013.45

[41] Kernt M, Schaller UC, Stumpf C, Ulbig MW, Kampik A, Neubauer AS. Choroidal pigmented lesions imaged by ultra-wide-field scanning laser ophthalmoscopy with two laser wavelengths (Optomap). Clinical Ophthalmology. 2010;**4**:829-836

[42] Coffee RE, Jain A, McCannel TA. Ultra wide-field imaging of choroidal metastasis secondary to primary breast cancer. Seminars in Ophthalmology. 2009;**24**(1):34-36. DOI:

10.1080/08820530802520194

[43] Kornberg DL, Klufas MA, Yannuzzi NA, Orlin A, D'Amico DJ, Kiss S. Clinical utility of ultrawidefield imaging with the optos optomap compared with indirect ophthalmoscopy in the setting of non-traumatic rhegmatogenous retinal detachment. Seminars in Ophthalmology. 2016;**31**(5):505-512. DOI: 10.3109/08820538.2014.981551

[44] Reznicek L, Wasfy T, Stumpf C, Kampik A, Ulbig M, Neubauer AS, et al. Peripheral fundus autofluorescence is increased in age-related macular

degeneration. Investigative Ophthalmology & Visual Science. 2012;**53**(4):2193-2198. DOI: 10.1167/

[45] Tan CS, Heussen F, Sadda SR. Peripheral autofluorescence and clinical findings in neovascular and non-neovascular age-related macular degeneration. Ophthalmology. 2013;**120**(6):1271-1277. DOI: 10.1016/j.

[46] Patel CK, Fung TH, Muqit MM, Mordant DJ, Brett J, Smith L, et al. Non-contact ultra-widefield imaging of retinopathy of prematurity using the Optos dual wavelength scanning laser ophthalmoscope. Eye (London,

iovs.11-8483

ophtha.2012.12.002

2009;**24**(1):43-44. DOI: 10.1080/08820530802520384

**64**

[53] Tsui I, Kaines A, Schwartz S. Patterns of periphlebitis in intermediate uveitis using ultra wide field fluorescein angiography. Seminars in Ophthalmology. 2009;**24**(1):29-33. DOI: 10.1080/08820530802520186

[54] Kaines A, Tsui I, Sarraf D, Schwartz S. The use of ultra wide field fluorescein angiography in evaluation and management of uveitis. Seminars in Ophthalmology. 2009;**24**(1):19-24. DOI: 10.1080/08820530802520095

[55] Mesquida M, Llorenc V, Fontenla JR, Navarro MJ, Adan A. Use of ultra-widefield retinal imaging in the management of active Behcet retinal vasculitis. Retina. 2014;**34**(10):2121-2127. DOI: 10.1097/IAE.0000000000000197

[56] Kaneko Y, Moriyama M, Hirahara S, Ogura Y, Ohno-Matsui K. Areas of nonperfusion in peripheral retina of eyes with pathologic myopia detected by ultra-widefield fluorescein angiography. Investigative Ophthalmology & Visual Science. 2014;**55**(3):1432-1439. DOI: 10.1167/iovs.13-13706

[57] Csincsik L, Mac Gillivray TJ, Flynn E, Pellegrini E, Papanastasiou G, Barzegar-Befroei N, et al. Peripheral retinal imaging biomarkers for Alzheimer's disease: A pilot study. Ophthalmic Research. 2018;**59**(4): 182-192. DOI: 10.1159/000487053

[58] Oishi A, Hidaka J, Yoshimura N. Quantification of the image obtained with a wide-field scanning ophthalmoscope. Investigative Ophthalmology & Visual Science. 2014;**55**(4):2424-2431. DOI: 10.1167/ iovs.13-13738

[59] Mackenzie PJ, Russell M, Ma PE, Isbister CM, Maberley DA. Sensitivity and specificity of the optos optomap for detecting peripheral retinal lesions. Retina. 2007;**27**(8):1119-1124. DOI: 10.1097/IAE.0b013e3180592b5c

[60] Witmer MT, Parlitsis G, Patel S, Kiss S. Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis((R)) noncontact ultra-widefield module versus the Optos((R)) Optomap((R)). Clinical Ophthalmology. 2013;**7**:389-394. DOI: 10.2147/OPTH.S41731

[61] Maamari RN, Keenan JD, Fletcher DA, Margolis TP. A mobile phone-based retinal camera for portable wide field imaging. The British Journal of Ophthalmology. 2014;**98**(4):438-441. DOI: 10.1136/ bjophthalmol-2013-303797

[62] Fijalkowski N, Zheng LL, Henderson MT, Wang SK, Wallenstein MB, Leng T, et al. Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP): Five years of screening with telemedicine. Ophthalmic Surgery, Lasers and Imaging Retina. 2014;**45**(2):106-113. DOI: 10.3928/23258160-20140122-01

**67**

**Chapter 5**

**Abstract**

A Brief Overview of Ophthalmic

Ultrasound is one of the oldest imaging modalities. Sound waves are emitted into the body, and the returning echoes can be interpreted. It has become widely used because it can easily be done at bedside with a relatively small apparatus and does not expose the patient to any ionizing radiation. While this technique has seen widespread acceptance in other fields such as cardiology or obstetrics and gynecology, the general use in ophthalmology has been somewhat limited. However, recent advancements in ultrasonic arrays can be a powerful tool in the evaluation of ophthalmic pathology. Such systems can quickly generate very high detail images and 3D reconstructions without the need for extensive manual scanning. The application of this technology includes evaluation of traumatic eye injuries; assessing presence and location of an intraocular foreign body; evaluation of intraocular tumors, including small tumors that have not yet caused visual distortion; evaluation of retinal detachment; and evaluation of vascular disease. The goal of this article is to briefly review the history and development of ultrasound and to provide an overview of the most current systems and applications of ultrasound use in

**Keywords:** ultrasound, 3D reconstruction, ultrasonic biomicroscopy, Doppler

recent advancements, ultrasound has a rich history dating back centuries.

One of the most common and well recognized technologies in modern medicine is ultrasonography. Its use has been used in many medical fields, and new methods and devices using ultrasound are frequently emerging. While there have been many

Some consider the earliest investigation into ultrasound beginning with the ancient Greeks [1]. Pythagoras invented the sonometer to study music; Boethius compared the waves generated by dropping a pebble into water to sound waves. In 1880, French scientists and brothers, Pierre and Jacques Curie, discovered piezoelectricity [2]. When certain materials (such as some crystals) are exposed to an electric field they undergo mechanical changes. The reverse is also true: when piezoelectric materials have mechanical force exerted on them they generate an electric charge. Thus, these crystals can both transmit and receive sound. Such piezoelectric devices are the basis of ultrasound transducers [3]. When voltage is applied to the transducer sound waves are emitted; when the reflected waves are

*David B. Rosen, Mandi D. Conway, Charles P. Ingram,* 

Ultrasound Imaging

ophthalmologic clinical evaluation.

ultrasonography, ultrasonic array

**1. Introduction**

*Robin D. Ross and Leonardo G. Montilla*

### **Chapter 5**
