ERG and EOG abnormalities in carriers of X-linked retinitis pigmentosa.
The diagnosis of X-linked retinitis pigmentosa (XL-RP) relies on the identification of the female carriers, in whom fundal abnormalities are often minimal and variable. The electroretinogram (ERG) has been reported as abnormal in 54-96% of heterozygote females. This study examines the combined use of electro-oculogram (EOG) and standardised ERG in 31 obligate and 33 non-obligate carriers of XL-RP. In the obligate carrier group, the EOG was abnormal in 13 carriers (41%), the ERG abnormal in 21 carriers (68%) and a combined EOG and ERG abnormality occurred in 24 carriers (77%). An EOG abnormality alone occurred in 2 carriers (6.5%). Fourteen obligate carriers (45%) showed a peak to peak delay of the ERG scotopic b wave, this being a previously unreported phenomenon. Similarly, in the non-obligate carrier group, the EOG was abnormal in 11 carriers (44%) and the ERG abnormal in 19 carriers (73%). The results of this study suggest that the use of both tests, including measurement of the scotopic b wave latency, may increase the carrier detection rate.
Stavrou
P
P
Birmingham and Midland Eye Centre, UK.
Good
P A
PA
Broadhurst
E J
EJ
Bundey
S
S
Fielder
A R
AR
Crews
S J
SJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004585:Electrooculography; D004596:Electroretinography; D005260:Female; D005654:Fundus Oculi; D006580:Genetic Carrier Screening; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008875:Middle Aged; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000503:physiopathology; D014960:X Chromosome