Acuity recovery and cone pigment regeneration after a bleach in patients with retinitis pigmentosa and rhodopsin mutations.
OBJECTIVE
To assess visual acuity recovery times and cone photopigment regeneration kinetics after a bleach in the fovea of patients with dominant retinitis pigmentosa due to rhodopsin mutations.


METHODS
The authors measured acuity recovery times by computerized photostress testing in 13 patients with dominant retinitis pigmentosa and one of eight rhodopsin mutations. The authors also measured their time constants of cone photopigment regeneration with a video imaging fundus reflectometer to determine whether acuity recovery time depended on pigment regeneration kinetics. These values were compared with those of normal subjects, by the Mann-Whitney U test. The relationship between acuity recovery time and the time constant of cone photopigment regeneration among the patients was quantified by the Spearman rank correlation.


RESULTS
The visual acuity recovery times, which averaged 22.0 seconds for the patients with retinitis pigmentosa and 11.2 seconds for the normal subjects, were significantly slower for the patient group (P < 0.001). The time constants of cone pigment regeneration, which averaged 172 seconds for the patients with retinitis pigmentosa and 118 seconds for the normal subjects, also were significantly slower for the patient group (P = 0.043). The authors also found a significant, positive correlation between the visual acuity recovery time and the time constant of pigment regeneration for the patients with retinitis pigmentosa (r = 0.65, P = 0.017).


CONCLUSIONS
A slowing of foveal visual acuity recovery and cone pigment regeneration, which are related to each other, can occur in patients with retinitis pigmentosa, due to a rod-specific gene defect.
Sandberg
M A
MA
Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114, USA. masandberg@aol.com
Pawlyk
B S
BS
Berson
E L
EL
D000328:Adult; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D017354:Point Mutation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology* / Q000528:radiation effects; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000503:physiopathology; D012243:Rhodopsin / Q000235:genetics*; D017299:Rod Opsins / Q000502:physiology* / Q000528:radiation effects; D014792:Visual Acuity / Q000502:physiology*
D017299:Rod Opsins; D012243:Rhodopsin