Rod electroretinograms in an elevated cyclic guanosine monophosphate-type human retinal degeneration. Comparison with retinitis pigmentosa.
Unusual rod electroretinogram (ERG) intensity-response functions were recorded from three female patients with retinal degeneration who had visual acuities of 20/200, retinal arteriolar narrowing, and diffuse granularity of the retinal pigment epithelium. All three patients had rod b-waves that were profoundly subnormal in amplitude and markedly delayed in implicit time to bright stimuli. Rod a-wave slopes were reduced 50% below normal, indicating photoreceptor involvement. These unusual rod ERG intensity-response functions are similar to those previously reported for the isolated cat eye with elevated retinal cyclic guanosine monophosphate (cGMP) after perfusion with isobutylmethylxanthine. This finding supports the idea that these three patients may have an elevation of retinal cGMP. Their rod ERG intensity-response functions are contrasted with those recorded from some patients with retinitis pigmentosa.
Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114.
M A
MA
Sandberg
S
S
Miller
E L
EL
Berson
D015056:1-Methyl-3-isobutylxanthine / Q000008:administration & dosage; D000293:Adolescent; D000328:Adult; D000818:Animals; D002415:Cats; D002648:Child; D006152:Cyclic GMP / Q000378:metabolism*; D004596:Electroretinography; D005260:Female; D006801:Humans; D008875:Middle Aged; D010786:Photoreceptor Cells / Q000503:physiopathology*; D012160:Retina / Q000187:drug effects; D012162:Retinal Degeneration / Q000378:metabolism / Q000503:physiopathology*; D012174:Retinitis Pigmentosa / Q000503:physiopathology; D014792:Visual Acuity
D006152:Cyclic GMP; D015056:1-Methyl-3-isobutylxanthine