Characteristics of patients with Retinitis Pigmentosa (RP) who have been to ERG examination at Ullevål University Hospital 2003-2006
BackgroundRP is a group of inherited retinal degenerative disorders in which abnormalities of the photoreceptors or the retinal pigment epithelium lead to progressive visual loss. Electroretinography (ERG) examination is an objective diagnostic method to identify this disorder. The purpose of our study was to identify characteristics of RP-patients examined at an ERG laboratory. Also, we wanted to examine the applicability of the ERG-method for the purpose of a more precise diagnosis of RP.Material and methodsWe carried out a retrospective study of patients who have been to ERG examination at UUS. Data from 77 patients who fulfilled the inclusion criteria were recorded in a database. ResultsWe found 41 patients with RP, who all had positive ERG. Among the RP patients 48,8 % had autosomal dominant (AD) mode of inheritance (n = 22), 22 % had autosomal recessive (AR) mode of inheritance (n = 9) and 22 % were isolated cases (n = 9). Ten patients who were members of AD-families did not have RP. One of these was a healthy carrier of an autosomal dominant RP gene.ConclusionsOur findings on RP heredity gave approximately the same distribution as larger retrospective studies. ERG examination has an essential differential diagnostic function, which plays an important role when RP is to be diagnosed objectively. Quality assurance of prospective registration is needed, and two questionnaires were developed for this purpose. This will hopefully help future research in this area and put more focus on this patient group.