**2.3 Microphthalmia**

A variety of disorders in which axial length is at least two standard deviations below normal is called microphthalmia. It is frequently associated with secondary orbital and ocular deformity including cataract and coloboma. It is frequently associated with various genetic conditions such as trisomy 13, Goldenhar's syndrome (Kherani & Robb, 2008).

#### **2.4 Colobomas**

4 Complementary Pediatrics

Normal infant eyes are 2 diopters hyperopic. This increases slightly to around age 7, then decreases to age 9-12 years when emmetropia is reached. Normal eyes have diminutive

The congenital eye anomalies may appear in isolation or as part of a systemic syndrome. It may be genetically proven in some cases. Either germ line or somatic mutations can cause eye abnormalities. They may result from disruption, deformation, intrauterine infection or teratogenic exposure. Some anomalies significantly affect visual acuity. On the other hand, there are some anomalies which are noticed incidentally on routine eye check with no

Infantile hemangiomas are the most common eyelid tumors in infancy. They have a bright red or purple appearance. Superficial ones typically blanch with pressure. At birth, they may be clinically undetected. However, they typically enlarge in the first 12 months followed by a slow involution during the first decade. Vision loss is related to amblyopia because of induced astigmatism or visual deprivation due to ptosis. Steroid treatment

Choristomas (congenital dermoids) are masses of normal tissue found in an abnormal location. They induce astigmatism and cause refractive amblyopia. They may be excised to

A variety of disorders in which axial length is at least two standard deviations below normal is called microphthalmia. It is frequently associated with secondary orbital and ocular deformity including cataract and coloboma. It is frequently associated with various genetic

conditions such as trisomy 13, Goldenhar's syndrome (Kherani & Robb, 2008).

refractive changes after 13 years (Mutti, 1992).

significance to the patient (Kherani & Robb, 2008).

(intralesional and/or oral) is the first line of therapy (Levin, 2003).

**2. Congenital eye anomalies** 

**2.1 Infantile hemangiomas** 

Fig. 1. Capillary hemangioma

improve cosmetic appearance and avoid amblyopia.

**2.2 Epibulbar dermoids** 

**2.3 Microphthalmia** 

It results from failure of the embryonic fissure to close along the inferonasal side of the optic cup during embryogenesis. It is frequently associated with microphthalmia. The visual prognosis is linked to the degree of optic nerve and macular involvement.

#### **2.5 Persistant fetal vasculature (persistant hyperplastic primary vitreus)**

It occurs sporadically and unilaterally in full-term health infants. The affected eye is microphthalmic with a shallow anterior chamber. A vascularized membrane behind the lens is typical. If the eye is not severely microphthalmic, surgical intervention may have a good prognosis (Levin, 2003).

### **3. Optic nerve disease in children**

The optic nerve is approximately 50 mm long from the globe to the chiasm. It can be subdivided into four segments: Intraocular (optic disc, optic nerve head), intraorbital, intracanalicular and intracranial segment. Optic nerve is surrounded by the vascular pia, arachnoid and dura mater. The subarachnoid space is continuous with the cerebral subarachnoid space and contains the cerebrospinal fluid. The optic nerve carries approximately 1.2 million afferent nerve fibres which originate in the retinal ganglion cells (Kanski 2011).

Common congenital optic disc anomalies are present as follows: Tilted disc, optic disc pit, optic disc drusen (hyaline bodies), optic disc coloboma, morning glory anomaly, hypoplastic optic nerve and myelinated nerve fibres (Nicholson et al., 2011). Optic disc drusen is a common anomaly with a prevalence of 0.3% of the population. In buried drusen which are the most commonly encountered type, they mimic papilloedema. Exposed optic disc drusen are rare types and more easily diagnosed. They are usually innocent, but rarely may lead to visual field defects or optic disc neovascularisation. Ultrasound is important for the differential diagnosis by showing calcific deposits associated with drusen (Kanski 2011).

Optic neuritis is an inflammatory, infective or demyelinating process affecting the optic nerve. It can be classified both ophthalmoscopically and etiologically as follows. Papillitis is characterized by hyperemia and edema of the optic disc, associated with peripapillary flame-shaped hemorrhages. Neuroretinitis is characterized by papillitis in association with inflammation of the retinal nerve fibre layer and a macular star. The optic nerve head is normal in retrobulbar neuritis, because the optic nerve head is not involved. Optic neuritis may be seen due to demyelinating disease, parainfectious, infectious such as sinus-related, or associated with cat-scratch fever, syphilis, Lyme disease, cryptococcal meningitis and non-infectious such as sarcoidosis, systemic lupus erythematosus, polyarteritis nodosa and other vasculitides (Dale et al., 2009).

Papilloedema is swelling of the optic nerve head secondary to raised intracranial pressure. It is nearly always bilateral, although it may be asymmetrical. Systemic findings such as headaches, deterioration of consciousness, nausea and vomiting, may be seen in patients with papilloedema. Transient obscurations lasting a few seconds are frequent in

Pediatric Ophthalmology / Eye and Disorders 7

less severe photopic ERG abnormalities. Perimetry is useful in monitoring the progression of disease. Perimetry initially demonstrates small mid-peripheral scotomas that gradually coalesce to form the classical annular scooma that correlates in location and shape to the

Although the photoreceptor cell death of retinitis pigmentosa cannot at be arrested or reversed currently, some vision threatening complications (cataract and macular edema) can be successfully managed. Additional molecular and surgical therapies targeting various stages of the disease are under investigation. (gene and stem cell-based therapies, prosthetic retinal implants, germ and somatic cell gene replacement, allele-specific targeting strategies

Retinopathy of prematurity (ROP) is a disease of premature babies. The disease is a potentially blinding disorder affecting primarily the retinas of the premature infants. Three epidemics of ROP have been described. The first one was seen in the 1950s in the industrialized countries. The reason was uncontrolled oxygen therapy and inadequate neonatal intensive care. With developing technology in the western countries, the incidence of the surviving extremely low birth weight babies increased. This increase in survival resulted in another epidemic. This epidemic of ROP was the second epidemic, which was characterized by extremely low birth weight babies with ROP. Currently there is an ongoing epidemic in the third world countries. The characteristics of this third epidemic are the

Uncontrolled oxygen therapy and premature birth are the most important risk factors for ROP. Babies born at or before 31 weeks of gestational age, or weighing 1500 grams or less are under high risk for ROP. Systemic problems associated with prematurity may also be considered to be independent risk factors. Sepsis, anemia and growth retardation are the

The retina is not completely vascularized at birth. Especially the temporal quadrant of the retina lack blood vessels in the neonates and the retinal vessels development continues until the end of the first month of age. Vascular endothelial growth factor (VEGF) is very important for the retinal vasculature development. If uncontrolled and high oxygen therapy is applied in a premature infant, the production of VEGF may increase resulting in the development of ROP. Under physiological conditions, VEGF production is stimulated by hypoxia. Therefore, it is not exactly known why high oxygen levels lead to increased VEGF levels. The possible explanation for this inconsistency is the high variations encountered during uncontrolled oxygen supply. High oxygen levels suppress VEGF initially. This is followed by an exaggerated VEGF production, after cessation of the oxygen therapy. To prevent such variations in oxygen blood levels, oxygen supply should be given in a more

extent of fundus pathology (Kanski, 2011).

and retinal transplantation etc.)

**5. Retinopathy of prematurity** 

**5.1 Risk factors and pathogenesis** 

most significant of these systemic associations.

steady level, according to the needs of the infants.

mixture of the first and second epidemics (Gilbert, 2008).

**4.3 Treatment** 

patients with papilloedema. Horizontal diplopia due to 6th nerve palsy may accompany the clinical picture.

Optic nerve glioma is the most common primary neoplasm of the optic nerve. A low-grade form of this neoplasm, called benign optic glioma, occurs most often in the pediatric patients. On the other hand, the aggressive form of optic glioma, is most common in adults. Many children with optic nerve glioma are also known to have neurofibromatosis type 1. Another optic nerve tumor is meningioma. Meningiomas are believed to arise from arachnoid cap cells, and they are usually attached to the dura.

Optic atrophy is the final common morphologic endpoint of any disease process that causes axonal degeneration in the optic nerve. There are two types; primary and secondary. Primary optic atrophy may be caused by lesions affecting the visual pathways from the retrolaminar portion of the optic nerve to the lateral geniculate body. Secondary optic atrophy is preceded by long-standing swelling of the optic nerve head.
