The clinical features of albinism and their correlation with visual evoked potentials

• Published in: British journal of ophthalmology Vol. 87; no. 6; pp. 767 - 772
• Main Authors: Dorey, S E, Neveu, M M, Burton, L C, Sloper, J J, Holder, G E
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 01.06.2003; BMJ; BMJ Publishing Group LTD; Copyright 2003 British Journal of Ophthalmology
• Subjects: Adolescent; Adult; Albinism; Albinism, Ocular - physiopathology; Aminoacid disorders; binocular vision; Biological and medical sciences; Child; Child, Preschool; Clinical Science; Dermatology; Errors of metabolism; Evoked Potentials, Visual - physiology; Female; Humans; Male; Medical sciences; Metabolic diseases; nystagmus; Ophthalmology; Pigmentary diseases of the skin; Reaction Time; Visual Acuity - physiology; visual development; visual evoked potentials; United Kingdom; Human; Visual evoked potential; Electrodiagnosis; Correlation; Uvea disease; Albinism
• DOI: 10.1136/bjo.87.6.767
• ISSN: 0007-1161

Aim: To investigate the relation between the clinical and electrophysiological abnormalities of patients undergoing visual evoked potential investigation for albinism. Methods: 40 subjects with a probable or possible clinical diagnosis of albinism underwent pattern appearance and/or flash visual evoked potential (VEP) examination. The VEP findings are correlated with the clinical features of albinism determined by clinical examination and orthoptic assessment. Results: The majority of patients with clinical evidence of albinism showed a contralateral predominance in the VEPs. There was close correlation between the clinical signs of albinism and the degree of contralateral VEP predominance. This manifested as an interhemispheric latency asymmetry to monocular pattern appearance stimulation but amplitude asymmetry to flash stimulation. The strongest correlation for pattern appearance interhemispheric latency difference was with foveal hypoplasia (rho = 0.58; p = 0.0003) followed by nystagmus (rho = 0.48; p = 0.0027) and iris transillumination (rho = 0.33; p = 0.039). The VEP abnormalities were of greater magnitude in those patients with most features of albinism. Several patients with apparently mild disorders of ocular pigmentation had small but significantly abnormal VEP latency asymmetries. Conclusion: There is a strong association between the magnitude of the interhemispheric latency asymmetry of the pattern appearance VEP, and of amplitude asymmetry of the flash VEP, with the clinical signs of albinism. The data are consistent with a spectrum of abnormalities in albinism involving both clinical expression and electrophysiological misrouting, which is wider than previously recognised.