Rod photoreceptor temporal properties in retinal degenerative diseases

Abstract

Using paired-flash electroretinogram (ERG), our goal was to determine whether the inactivation of rod phototransduction is altered in patients with Retinal Degenerative Diseases (RDDs). The rod photoresponses were derived from 18 patients with autosomal dominant retinitis pigmentosa (adRP) (n = 18), 5 patients with cone-rod dystrophy (CRD), and 4 patients with Stargardt disease. Thirteen subjects with normal eye exams served as controls. T sat, the parameter describing phototransduction inactivation, was derived using the paired-flash ERG protocol. Rod a-wave recovery initiates at 544 ± 92 ms (mean ± SD) after a just-saturating test flash in subjects with normal vision. For patients with RDDs, the rod a-wave recovery initiates at 331 ± 99 ms (autosomal dominant RP, P < 0.001, t-test), 473 ± 113 ms (CRD, P = 0.26, t-test), and 491 ± 98 ms (Stargardt disease, P = 0.38, t-test). Thus patients with adRP show earlier-than-normal photoresponse recovery, while patients with CRD or Stargardt disease typically have T sat values within the normal range. © 2012 Springer Science+Business Media, LLC.