**7. Childhood cataract**

The lens is a biconvex structure that hangs behind the iris. Its diameter is about 3.5 mm at birth and it grows to about 10 mm by adulthood. There are three structural elements that

Pediatric Ophthalmology / Eye and Disorders 11

Dense cataracts require early surgery when the child is 4–6 weeks of age to prevent the development of stimulus deprivation amblyopia. If the severity is asymmetrical in bilateral cataracts, the eye with the denser cataract should be addressed first. Surgery may not

The exact definition of glaucoma is still a subject of debate. What that did not change over years is that raised intraocular pressure is the most important risk factor for glaucoma development. Glaucoma is generally the disease of adults, occurring most frequently over

Primary congenital glaucoma (PCG) is the most common reason for raised intraocular pressure in child. It occurs in 1:10000 births and more commonly in boys. 75% of the cases are bilateral. Although autosomal recessive cases have been described, most cases of PCG are sporadic. Glaucoma develops due to the anomalous development of the anterior chamber angle. Raised intraocular pressure, cloudy cornea, large appearance of the eye (buphthalmos), optic nerve alterations due to high intraocular pressure and special bio-

PCG has 3 subtypes; true, infantile and juvenile PCG. Intraocular pressure is elevated during intrauterine life in true PCG, whereas the disease started before 3 years of age in infantile PCG. Infantile cases are the most frequently encountered ones. Treatment is surgical in all cases of PCG. Medications may also be used concomitant with the surgery. The initial evaluation must be performed under general anaesthesia. Enlargement of the eye

There is no consensus on when the initial eye examination in a healthy child should be performed and how often the examinations should be repeated in the presence of normal eyes. Premature infants at risk of retinopathy of prematurity must be screened by an ophthalmologist. Many congenital ocular abnormalities may be diagnosed by simple observation by a pediatrician, if they are aware of the possible congenital ocular diseases.

In developed countries, the initial eye examination by an ophthalmologist is commonly performed at 6 months of age. At this age, the alignment of the eyes and the near focussing

in pediatric age group should be referred to an ophthalmologist (Idrees, 2006).

require in partial cataracts if opacity is not central.

40 years of age. However, it may also develop in children.

microscopic signs are diagnostic features of PCG.

**8. Childhood glaucoma** 

Fig. 4. Buphthalmos in PCG

**9. Pediatric eye examination** 

constitute the lens: capsule, epithelium and fibers. The crystalline lens is a transparent structure that helps to refract light to be focused on the retina, along with the cornea. The lens is capable of changing its shape in order to modify the focal distance of the eye, so that it can focus on objects at different distances, thus allowing a clear image of the object to be formed on the retina (Kanski, 2011).

Cataract is the opacification of the crystalline lens. Cataracts result from protein denaturation, increased molecular weight of proteins, water vesicles between lens fibers, increasing proliferation and migration of the lens epithelium. Childhood cataract occurs worldwide and is an important cause of childhood blindness in many countries. Congenital cataracts occur in about 3 in 10 000 live births. Two-thirds of cases are bilateral. The cause of the cataract can be identified in about half of the cataractous eyes. Unilateral cataracts are usually isolated sporadic incidents, without a family history or systemic disease and effected infants are usually full-term and healthy. Cataract can be associated with ocular abnormalities, trauma, or an intrauterine infection such as rubella. Bilateral cataracts are often inherited and associated with other diseases. They require a full metabolic, infectious, systemic and genetic workup. The common causes are hypoglycemia, trisomy (eg, Down, Edward and Patau syndromes), myotonic dystrophy, infectious diseases (eg, toxoplasmosis, rubella, cytomegalovirus and herpes simplex [TORCH]) and prematurity. Isolated hereditary cataracts account for about 25% of the cases. The mode is most frequently autosomal dominant, but may be autosomal recessive or X-linked (Mickler, 2011).

Fig. 3. Bilateral conjenital cataract

Detailed eye examination is required for the density and morphology of the any lens opacity. Potential impact on visual function of cataract is assessed on the basis of the appearance of the red reflex and the quality of the fundus view on direct and indirect ophthalmoscopy. A very dense cataract occluding the pupil will preclude any view of the fundus. In case of pediatric cataract serology should be done for intrauterine infections. Urinalysis for reducing substance after drinking milk (galactosaemia) and chromatography for amino acids (Lowe syndrome) should be performed. Other investigations include fasting blood glucose, serum calcium and phosphorus and galactokinase levels. Children who have calcium and phosphorus anomalies severe enough to cause cataracts are usually having associated severe systemic problems. Referral to a pediatrician may be warranted for dysmorphic features or suspicion of other systemic diseases. Chromosome analysis may be useful in this context. It is important to examine parents and siblings to reveal a possible etiology (Krishnamurthy & Vanderveen, 2008).

Dense cataracts require early surgery when the child is 4–6 weeks of age to prevent the development of stimulus deprivation amblyopia. If the severity is asymmetrical in bilateral cataracts, the eye with the denser cataract should be addressed first. Surgery may not require in partial cataracts if opacity is not central.
