**8. Childhood glaucoma**

10 Complementary Pediatrics

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

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).

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

formed on the retina (Kanski, 2011).

Fig. 3. Bilateral conjenital cataract

etiology (Krishnamurthy & Vanderveen, 2008).

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

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 biomicroscopic signs are diagnostic features of PCG.

Fig. 4. Buphthalmos in PCG

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