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Visual electrodiagnostic tests can contribute significantly to pediatric ophthalmology. The tests are objective, safe, relatively swift, and easy to administer. They can give unique insight into the functional integrity of different levels of the visual pathway. The indicates retinal function, the expresses pigment epithelium function, and the reflects optic pathway function beyond the eye to the visual cortex. These tests complement, and supplement, other visual methods of assessment. Thus,depending on the clinical context, an abnormal ERG may suggest the necessity for metabolic screening, and an abnormal VEP in association with a normal ERG can indicate the need for structural imaging studies.

The American Academy of Pediatrics states that 75% of learning during the early years is processed through vision; because vision is a learning sense, children with visual impairment may not learn to perform many tasks as quickly as those with normal vision. Children with subnormal vision often look and act like any other child in the classroom and on the playground making it difficult to distinguish them from normally sighted children. Children with low vision may wear thick glasses or even dark glasses, but they will run and jump as fearlessly as their playmates.

Janet and Marc thought their life was as close to perfection as any family’s life could be. Married for 8 years, they had one daughter, Missy, age 5, and Brian, age 3 months, their long-awaited son. At Brian’s 3-month routine well-baby checkup, the pediatrician remarked that Brian might have strabismus because his eyes appeared to turn in and weren’t “working together,” as Janet later described it. The pediatrician was very reassuring, however, and told Marc and Janet that he would like the baby to be examined by a pediatric ophthalmologist “just to be on the safe side.” Marc had recently started a new and more responsible job so it was decided that Janet would take Brian for the eye examination herself, to minimize the amount of time Marc was away from the office.

This chapter covers disorders characterized by ophthalmoscopically visible changes in structures deep to the neurosensory retina. A prominent component of many of these conditions is the accumulation of yellowish material within and beneath the retinal pigment epithelium (RPE) associated with a progressive loss of macular RPE cells. A number of toxic and inflammatory conditions can also cause dots and spots at the level of the RPE, but these conditions can usually be distinguished by history from those in this chapter and are considered elsewhere in this volume (Chapter 11). Choroideremia, gyrate atrophy, and some forms of congenital stationary night blindness are also associated with ophthalmoscopically visible abnormalities in structures beneath the photoreceptors. However, these diseases share some psychophysical, electrophysiological, and symptomatic features with the photoreceptor degenerations and are discussed in Chapter 5. Last, myopia (Chapter 12) can be associated with several abnormalities at the level of the RPE that can be ophthalmoscopically similar to the entities discussed in this chapter.

Retinitis pigmentosa (RP) is a general term used to refer to a group of related inherited diseases typically characterized by poor vision in dim light, constricted visual fields, bone spicule-like pigmentation of the fundus, and electroretinographic evidence of photoreceptor cell dysfunction. These diseases can be inherited as an autosomal dominant, autosomal recessive, or X-linked recessive trait. Mitochondrial inheritance has also been described, often as part of a syndrome. It has been estimated that RP affects approximately 1 in 3700 people in the United States. Inherited retinopathies affect approximately 1 in 2000 individuals worldwide. Approximately 20% of these cases are autosomal dominant,and 6%to 9% are X-linked. The remaining 71% to 84% are either autosomal recessive or isolated “simplex” cases. The latter may represent autosomal recessive disease, a new autosomal dominant mutation,or an environmental phenocopy. In the United Kingdom, X-linked RP appears to be more common than in the United States.

The human vitreous is a complex extracellular matrix composed of 98% water and 2% solid material. The basic structure of the vitreous matrix is a scaffold of cross-linked collagen fibrils with hyaluronic acid molecules within the scaffold. Hyaluronic acid is very hydrophilic, and water molecules are attracted to the scaffold providing turgor and rigidity to the matrix. The vitreous is primarily a solid gel in children’s eyes but becomes progressively more liquid with aging. Liquefaction of the vitreous occurs when the hyaluronic acid depolymerizes, freeing the bound water and allowing the collagen scaffold to collapse. The collagen filaments then coalesce to form collagen fibers, causing the “floaters“ seen by patients with aging of the vitreous.

Retinal vascular disorders in children, unlike those in adults, rarely represent the sequelae of chronic systemic insults such as hyperglycemia or hypertension. Children are more likely to suffer from developmental, infectious, neoplastic, or traumatic retinal vascular disorders. As with any other cause of visual loss in childhood, prompt treatment of retinal vascular disorders can be essential to the avoidance of amblyopia. Table 7-1 lists the usual age of presentation for the entities discussed in this chapter.

This chapter discusses some of the nonvascular hamartomas and choristomas of the retina, retinal pigment epithelium (RPE),and choroid that may be seen in the pediatric population. Although many of the lesions discussed in this chapter are present in childhood, they are frequently discovered later in life during routine examination or when late visual symptoms develop.

Much of the vision loss that we as pediatric ophthalmologists accept as normal with retinoblastoma can be prevented or reversed with aggressive screening, early diagnosis, and treat- ment. In fact, we are convinced that in the coming decades detecting early disease by lowering the average age at initial diagnosis will prove to be a much more efficient and cost- effective way to manage retinoblastoma than developing exotic new drugs or gene therapy for advanced disease. For retinopathy of prematurity (ROP), we readily accept that early detection and treatment can prevent vision loss. The problem there, however, seems a bit more manageable; the children at risk for ROP all belong to a small and easily identifiable group based on low birth weight.

Retinopathy of prematurity (ROP)is a disease that occurs in premature infants and affects the blood vessels of the devel- oping retina. It results in the development of vascular shunts, neovascularization, and, in its more severe forms, traction retinal detachment. The development of retinal vascular shunts and neovascularization in ROP is believed to be related to local ischemia, which is a predominant feature of other proliferative retinopathies such as sickle cell and diabetic retinopathy. The unique feature of ROP relates to its occurrence only in prema- ture infants with immature and incompletely vascularized retina. ROP is mild and undergoes spontaneous regression with no visual sequelae in the majority of affected infants. However, progression to advanced ROP does occur in a significant number of infants and can lead to severe visual impairment and even complete unilateral or bilateral blindness in some cases. Recent technological advances in neonatology have increased the sur- vival rate of very low birth weight infants, which has led to a correspondingly increased incidence of ROP. This, in turn, has provided a major challenge to all physicians treating the prema- ture infant and has created renewed interest in the pathogene- sis, prevention, and treatment of ROP.