Retinal dystrophies in childhood: Retrospective analysis

Abstract

Purpose: To describe the clinical features and the results of diagnostic methods in all patients with diagnosis of one of the following retinal dystrophies: Leber congenital amaurosis (LCA), achromatopsia, cone distrophy or cone-rod distrophy, examined at the Low Vision Department of the Federal University of Minas Gerais, in the period of 1992 to 2003. Methods: Retrospective analysis of charts of 40 patients. Ten had LCA, 17 had achromatopsia, 6 had cone distrophy and 7 had conerod distrophy. Results: Visual acuity was extremely low in patients with LCA, ranging from 20/710 to light perception. The mean value for achromatopsia was 20/200, 20/280 for cone distrophy and 20/260 for cone-rod distrophy. High hyperopia was the most common refractional error in LCA patients. Hyperopia was more frequent in cases of achromatopsia and cone distrophy, while in cone-rod distrophy myopia predominated. Fundoscopy was altered in most cases of LCA, cone distrophy and rod-cone distrophy, and normal in most cases of achromatopsia. Oculodigital sign and enophtalmus were found only in LCA patients while photofobia and color vision defects prevailed in other groups. Nistagmus and strabismus were frequent findings in all groups. There was a high incidence of delayed neuro-psycho-motor development in LCA patients. Two of them had also associated genetic syndromes. Patients presented symptoms very early in life in LCA and achromatopsia, while in cone and cone-rod distrophies symptoms appeared later, but never after the age of 10. Consanguinity and positive familial history were strongly associated in all groups. The ERG was extinct in LCA, showed reduced photopic response in achromatopsia and diffuse reduction in cone-rod distrophy. Color vision tests were altered mainly in achromatopsia and in cone distrophy. Conclusions: Retinal distrophies in childhood are a heterogeneous group of diseases with unspecific symptoms. A careful analysis of clinical features and diagnostic tests, specially color vision tests, ERG and visual field may be useful in their diagnosis.