[Electrophysiology in the differential diagnosis between sex-linked ocular albinism and central nystagmus].
OBJECTIVE
More than 20% of nystagmus misdiagnosed as central idiopathic nystagmus are cases of recessive sex-linked ocular albinism (AOX). We have studied a family (3 generations) diagnosed as AOX in order to evaluate the diagnostic contribution of clinical data, histological data and VEP. Our purpose was to evaluate the most convenient protocol of VEP for these cases.


METHODS
Examinations included extensive clinical and ophthalmological evaluation of 36 members from 3 generations of a family, including transillumination iris photography, retinography, biopsies of skin and a special method to record VEP.


RESULTS
The results showed that iris and macula photography are significant, but macromelanosomae found in the biopsies are not pathognomonic. In our experience, flash VEP is the conclusive test, particularly with electrodes placed 3 and 6 cm off the median line, showing an interhemispheric asymmetry.


CONCLUSIONS
We conclude that clinical examination is insufficient and biopsy may be suggestive, but ocular electrophysiology (VEP) is the key to diagnosis, although the recording method remains controversial.
Aramendía Salvador E
Servicio de Oftalmología Policlínica Guipúzcoa, San Sebastián, España.
Zabaleta Arsuaga M
Munoa Roiz JL
D016117:Albinism, Ocular / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004594:Electrophysiology; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009759:Nystagmus, Pathologic / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology*; D010375:Pedigree; D014960:X Chromosome