Anthony Kriss

Follow-up and Diagnostic Reappraisal of 75 Patients with Leber's Congenital Amaurosis

We reexamined 75 children in whom Lebers congenital amaurosis had been previously diagnosed. On review, 30 of these patients had an ocular or systemic disorder other than Lebers congenital amaurosis. The most common of these revised diagnoses were congenital stationary night blindness, achromatopsia, infantile-onset retinitis pigmentosa, Jouberts syndrome, Zellweger syndrome, and infantile Refsums disease. Of the 45 patients with Lebers congenital amaurosis, mental retardation occurred in six patients, and visual deterioration in six patients. Lebers congenital amaurosis should only be diagnosed if other known ocular and systemic disorders have been carefully excluded.

Neonatal cataract: Aetiology, pathogenesis and management

We review the epidemiology, aetiology, pathogenetic mechanisms and clinical management of neonatal cataract. Visual development and the effects of visual deprivation in the infant with congenital cataract are discussed and related to the timing of surgery. Surgical techniques and the important operative and post-operative complications are discussed. We review post-operative management and compare the different techniques available for aphakic correction, and describe the VEP changes found in patients with monocular cataract.

Modulation of amblyopia therapy following early surgery for unilateral congenital cataracts.

BACKGROUND--Stimulus deprivation amblyopia is the principal cause of visual impairment in infants with unilateral congenital cataract. Even if lensectomy is undertaken at an early age, intensive postoperative occlusion of the phakic eye is essential for the development of useful vision in the aphakic eye. Despite this, the optimum method of regulating occlusion therapy is uncertain. METHODS--Interocular acuity differences identified using clinical preferential looking techniques (Keeler cards) were used to regulate target levels of phakic eye occlusion in a prospective evaluation of 10 systemically, metabolically, and neurologically normal infants in whom dense unilateral cataract was diagnosed before 8 weeks of age, and operated upon by 10 weeks. Actual occlusion levels were recorded each day by parents in a diary. The development of preferential looking acuity in the phakic and aphakic eye were compared with prediction intervals derived from observations on 43 normal children. RESULTS--Aphakic eye preferential looking acuities were within the normal range at last review in all but one infant. Interocular acuity differences were < or = 0.5 octave in all children older than 1 year of age at last review, and > or = 1 octave in three of four children less than 1 year old at last review (Fisher exact p = 0.033). Phakic eye acuities were within the normal range in all infants at all visits. CONCLUSION--Within the first 2 years of life, normal preferential looking acuity may be achieved in both eyes of infants undergoing early surgery for unilateral congenital cataract if occlusion therapy is modulated according to interocular acuity differences quantified by clinical preferential looking techniques.

The infant with nystagmus, normal appearing fundi, but an abnormal ERG

Many retinal disorders present during infancy with nystagmus, decreased vision, and normal-appearing fundi, but an abnormal ERG. The most common of these disorders are Lebers congenital amaurosis, achromatopsia, and congenital stationary night-blindness. Other disorders with similar ocular manifestations may be associated with a variety of life-threatening systemic abnormalities. This review describes the clinical, electrophysiological, and laboratory findings that can be used to distinguish among these conditions.

Delayed visual maturation: a longitudinal clinical and electrophysiological assessment

Delayed visual maturation is an idiopathic condition characterized by visual inattention during infancy. The authors followed longitudinally nine children with an initial diagnosis of delayed visual maturation and compared their electroretinograms (ERGs) and visual evoked potentials with those of age-matched controls. Eight of the nine patients consistently had normal visual evoked potentials to flash and to pattern stimulation. All of the children had normal ERGs. Visually mediated behavior gradually developed in all of these children when they were between 3 and 8 months of age (mean, 5.5 months). Five patients also were delayed in other spheres of development. Visual evoked potentials are helpful in formulating a visual prognosis for children with delayed visual maturation.

Albinism in childhood: a flash VEP and ERG study.

Flash visual evoked potentials (F. VEPs) and electroretinograms (ERGs) were recorded in a total of 20 young children with albinism (age range 5 months to 11 years, mean 4 years). All recordings were made without sedation. There were 13 oculocutaneous cases (one with Hermansky-Pudlak syndrome) and seven ocular albinos. Monocular flash stimulation commonly elicited an asymmetrical occipital VEP distribution with a well lateralised component at around 80 ms which was of opposite polarity in a comparison of VEPs from each eye. None of the normally pigmented matched controls or obligate female carriers showed this anomalous distribution. The albino electroretinogram, compared with controls, recorded under fully darkened conditions had a significantly larger a wave and significantly shorter latencies for both a and b waves. The accentuated ERG and asymmetrical VEP recorded in infants and young children with albinism permits distinction of these patients from those with congenital cone dysfunction and idiopathic nystagmus, with whom they may be confused by a clinical examination only.

The electroretinogram in infants and young children.

Electroretinography (ERG), especially when combined with visual evoked potential recording, can provide valuable information to the pediatric clinician assessing a young child with nystagmus who appears not to see. ERG changes are described in clinical conditions affecting rod and/or cone function, vitreoretinal disease, maculopathies, and disorders involving the retina and central nervous system. The role of ERG in monitoring treatment, and in excluding retinal disease prior to eye surgery, is also covered.

Ophthalmologic Assessment of Young Patients with Alport Syndrome

BACKGROUND Alport syndrome is an X-linked disease affecting basement membrane collagen. It is characterized by nephritis associated with high-tone sensorineural hearing impairment and ophthalmic signs. Although ocular changes have been described in adults, few data exist regarding the incidence of abnormal ocular features in adolescence and childhood. METHODS Fifteen male and five female patients with Alport syndrome underwent ophthalmologic, audiologic, and nephrologic assessments. All patients studied had hematuria and a positive family history of Alport syndrome. Thirteen patients had a renal biopsy that showed characteristic electron microscopic changes of the disease. Eleven patients had high-tone sensorineural impairment. Electrophysiologic investigations performed included electroretinography, visual-evoked potentials, and electro-oculography. RESULTS Two patients had early signs of anterior lenticonus, three had flecks in the retina, and two patients also had posterior subcapsular cataracts. None of the patients had significant electrophysiologic abnormalities. CONCLUSION These findings indicate that ocular changes are uncommon and subtle in young patients with Alport syndrome, and suggest that the signs increase in frequency and severity with age.

Aspects of Albinism

Genetic, clinical and electrophysiological aspects of albinism are described. Emphasis is placed on electrophysiological features which help to distinguish albinism from other clinical conditions, and on stimulating and recording factors which can affect the clarity of VEP results.

Leber's congenital amaurosis--a new syndrome with a cardiomyopathy.

Seven members of four families had nystagmus noted by 4 months of age, poor vision, photophobia, and a markedly reduced or absent electroretinogram. Six of these patients had a life threatening episode of cardiac failure in infancy. There were also two neonatal deaths, and one of the affected children died at 2 years and one at 19 years. The five surviving children are well, remain with nystagmus, and have visual acuities of less than 6/60, with the eldest two having lost perception of light. They have a short obese habitus distinct from that of their unaffected siblings and parents.