**7. Personal experience with SD-OCT in DME**

The personal experience in using SD-OCT for the management of DME is illustrated by several cases (**Figures 1**–**8**).

In this case, the OCT aspect of the macula favored intravitreal injection of anti-VEGF in AO, given the absence of PHT and the high amount of fluid within the retina OS. In OD, early Spectral Domain Optical Coherence Tomography in the Diagnosis and Monitoring of Diabetic… http://dx.doi.org/10.5772/intechopen.78681 47

**Figure 1.** OD diffuse mild thickening of the macular region. OS large ovoid spaces of low reflectivity (liquid content) separated by hyperreflective septae located in the neurosensitive retina that represent intraretinal cystoid-like cavities; hyperreflective deposits with posterior shadowing (hard exudates, hemorrhages) in the neurosensory retina; no evidence of PHT; significant increase of the macular thickness, mainly centrally—on the account of the cystoids cavities.

parameters, into three categories: sponge-like swelling, cystoid edema and serous retinal detachment [5]. A fourth category was added by Trichonas et al., posterior hyaloid traction (PHT) [6]. A more detailed classification was proposed by Koleva-Georgieva, and it is based on quantitative and qualitative OCT data: retinal thickness, retinal morphology, retinal

point of adhesion

Early subclinical ME Macular thickening nondetectable clinically

Retinal morphology Simple noncystoid ME Increased retinal thickness; reduced retinal reflectivity;

No MT Complete PVD/no PVD/no ERM

Cystoid ME Well-defined intraretinal cystoids spaces

Retinal thickness increased on OCT

foveal depression; no cystoid spaces

over the hyperreflective line of EPR

Questionable MT Incomplete PVD with no detectable distortion of retinal surface contour at the point of adhesion Definite MT Incomplete PVD with distortion of retinal surface contour at the

IS/OS and ELM with disrupted integrity

irregularities of the layered retinal structure; flattening of the

Hyporeflective area under the detached neurosensory retina and

Established ME Retinal thickening and morphological signs of edema

OCT-Angiography (OCT-A) enables the noninvasive visualization of 3D retinal capillary network. It correlates very well with fluorescein angiography (FA), and it is able to show even more capillaries in the pericentral macula than FA and to separate and individualize the

The personal experience in using SD-OCT for the management of DME is illustrated by sev-

In this case, the OCT aspect of the macula favored intravitreal injection of anti-VEGF in AO, given the absence of PHT and the high amount of fluid within the retina OS. In OD, early

topography, macular traction, foveal photoreceptor status (**Table 3**) [8].

Retinal thickness No macular edema Normal macular thickness

Serous macular detachment

Retinal outer layers IS/OS and ELM intact IS/OS and ELM intact IS/OS and ELM with disrupted integrity

**Table 3.** OCT classification of macular edema (after Koleva-Georgieva).

**6. OCT-angiography**

Vitreo-macular interface

46 OCT - Applications in Ophthalmology

eral cases (**Figures 1**–**8**).

superficial and deep capillary plexus.

**7. Personal experience with SD-OCT in DME**

treatment in the stage of mild edema had positive outcome. In OS, the high degree of macular disorganization prevented a significant improvement in vision (**Figure 2**).

In this case, intravitreal anti-VEGF injections alone would probably not lead to the resolution of edema, because vitreo-macular traction is also involved in its pathophysiology. Therefore, pars plana vitrectomy with dissection of the posterior hyaloid from the macular area was indicated (**Figures 3** and **4**).

In this case, anti-VEGF injections are indicated in AO, but with a much better prognosis in LE where edema is mild, as compared to RE in which the macula is disorganized (**Figures 5** and **6**).

In this case, beside anti-VEGF injections, pars plana vitrectomy appears reasonable in order to release the traction exerted by the posterior hyaloid on the macula.

Even if macular edema is mild, intravitreal anti-VEGF would prevent its progression toward more advanced stages with cystoid degeneration of the macula (**Figure 7**).

On the ground of the OCT aspect, intravitreal anti-VEGF injections are indicated in OD, but not in LE in which retinal atrophy is present (**Figure 8**).

**Figure 2.** Moderate increase of the macular thickness in a diffuse manner, most likely caused by PHT: posterior hyaloid appears as a highly reflective band adherent to the underlying retina.

**Figure 4.** OD marked increase of the macular thickness, large cystoid cavities in the neurosensory retina separated by moderately reflective septae; OS slight increase of the macular thickness with diminishing of the foveal profile and

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**Figure 5.** Focal macular edema OU: OD—beside the cystoid cavities within the neurosensitive retina, PHT is revealed;

OS—smaller cystoid cavities with hyperreflective deposits and loss of normal foveal contour.

tendency to flattening of the macular retina (early macular edema).

**Figure 3.** Diffuse DME in AO in a young patient with type 1 diabetes. Fluid is present within the neurosensitive retina in the fovea (dark spaces). PHT is not present; therefore, intravitreal anti-VEGF injections were indicated with good outcome.

Spectral Domain Optical Coherence Tomography in the Diagnosis and Monitoring of Diabetic… http://dx.doi.org/10.5772/intechopen.78681 49

**Figure 4.** OD marked increase of the macular thickness, large cystoid cavities in the neurosensory retina separated by moderately reflective septae; OS slight increase of the macular thickness with diminishing of the foveal profile and tendency to flattening of the macular retina (early macular edema).

**Figure 5.** Focal macular edema OU: OD—beside the cystoid cavities within the neurosensitive retina, PHT is revealed; OS—smaller cystoid cavities with hyperreflective deposits and loss of normal foveal contour.

**Figure 3.** Diffuse DME in AO in a young patient with type 1 diabetes. Fluid is present within the neurosensitive retina in the fovea (dark spaces). PHT is not present; therefore, intravitreal anti-VEGF injections were indicated with good

**Figure 2.** Moderate increase of the macular thickness in a diffuse manner, most likely caused by PHT: posterior hyaloid

appears as a highly reflective band adherent to the underlying retina.

48 OCT - Applications in Ophthalmology

outcome.

**Figure 6.** OD diffuse macular edema with preservation of the foveal contour and hyperreflective deposits in the neurosensory retina; OS mild focal macular edema.

> In LE (not vitrectomized) there is a slightly increase in macular thickness related to the traction of the posterior hyaloid on the macula. In RE, vitrectomy released the vitreo-macular

> **Figure 8.** OD aspect following pars plana vitrectomy and dissection of the posterior hyaloid: mild diffuse macular edema, with normal foveal profile; OS mild macular edema with reflective posterior hyaloid adherent to the macula.

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For many years, the only therapy of DME was laser photocoagulation which was indicated exclusively on clinical criteria, defined by Early Treatment Diabetic Retinopathy Study (ETDRS) as clinically significant macular edema [9]. Currently, therapeutic approaches of DME expanded, including anti-VEGF and steroid intravitreal injections and vitreo-retinal surgery [9]. The selection of the optimal therapy is correlated with the pathogeny of DME,

In most circumstances, DME is the consequence of internal blood-retinal barrier break-down with subsequent accumulation of fluid in the retina. Macular thickness and fluid topography are precisely evaluated by OCT. In these DME categories, the first line treatment is represented in our practice by intravitreal anti-VEGF injections. In refractory cases intravitreal

**8. Importance of OCT in selecting the appropriate therapy for DME**

traction and macular thickness is almost within the normal range.

which is best elucidated by OCT.

steroids are considered.

**Figure 7.** OD severe macular edema with considerable thickening of the macular area, cystoid cavities within the retina with involvement of the outer retinal layers and disorganization of the retinal pigmented epithelial line, PHT; OS retinal atrophy at the level of the foveal region.

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**Figure 8.** OD aspect following pars plana vitrectomy and dissection of the posterior hyaloid: mild diffuse macular edema, with normal foveal profile; OS mild macular edema with reflective posterior hyaloid adherent to the macula.

**Figure 6.** OD diffuse macular edema with preservation of the foveal contour and hyperreflective deposits in the

**Figure 7.** OD severe macular edema with considerable thickening of the macular area, cystoid cavities within the retina with involvement of the outer retinal layers and disorganization of the retinal pigmented epithelial line, PHT; OS retinal

neurosensory retina; OS mild focal macular edema.

50 OCT - Applications in Ophthalmology

atrophy at the level of the foveal region.

In LE (not vitrectomized) there is a slightly increase in macular thickness related to the traction of the posterior hyaloid on the macula. In RE, vitrectomy released the vitreo-macular traction and macular thickness is almost within the normal range.
