Leber’s Congenital Amaurosis
Purpose: Clinical evaluation of 42 patients with primarily suspected diagnosis of Leber's congenital amaurosis (LCA).
Methods: We used the electroretinogram (ERG), visual acuity, fundus ap- pearance, age of onset, and systemic findings to confirm or revise the diagnosis of LCA.
Results: Twenty-four patients had a non-recordable ERG, and 3 showed small, residual, mainly cone-driven b-waves. Profound visual loss ranged from no light perception to 20/200. Visual acuity of light perception was frequent at <1 year of age. Three patients never had light perception. Most patients had a stable visual acuity despite progressive retinal pigmentary changes. A normal fundus was seen predominantly in patients younger than 1 year of age, but could also be found in patients of all age groups. The first, and frequently the only pigmentary changes were vascular attenuation and rarefaction, later in life heterogeneous retinal findings appeared. None of the 9 reexamined patients showed a normal fundus. Nystagmus and strabismus were principal presenting symptoms. Eleven patients presented with the oculodigital sign, three of them were enophthalmic, and 12 patients showed roving eye movements. Patients with additional (nonocular) findings such as mental retardation (n = 12), renal (n = 3) and skeletal (n = 4) abnormalities revealed no different ERG- or ophthalmoscopic findings than the remaining patients. Twelve patients revealed abnormal psychomotor development.
From the initial cohort of 42 patients with suspected LCA, the diagnosis had to be revised in 15 cases as follows: juvenile RP (n = 8), infantile Refsum syndrome (n = 1), and 6 patients could not yet be classified with certainty.
Conclusion: Bilateral visual impairment in infants should be assessed clinically and electroretinographically within the first year. Later in life, the diagnosis of LCA can be a challenge due to its phenotypical heterogeneity. Systemic disorders are inde pendent of ocular findings. In patients older than two years with non-recordable ERG, visual acuity better than 201200, progressive visual loss, normal pupillary responses, absent oculodigital sign and absence of systemic abnormalities, juvenile retinitis pigmentosa should be considered.
KeywordsVisual Acuity Retinal Pigment Epithelium Retinitis Pigmentosa Retinal Vessel Light Perception
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