Purchase this article with an account.
D Olzi, V Parisi, D Canu, G Iarossi, B Falsini; Altered Recovery of Macular Function After Bleaching in Stargardt Disease/Fundus Flavimaculatus: Pattern VEP Evidence . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1159.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To evaluate recovery of macular function after bleaching in patients with Stargardt Dystrophy/Fundus Flavimaculatus (STD/FF). Methods: Recovery of pattern visual evoked potentials (VEPs) after macular bleaching was evaluated in sixteen patients with a diagnosis of STD/FF [age: 26-52, visual acuity: 0.2-1.0; phenotype I (n = 6), phenotype II (n = 8) or phenotype III (n = 2)] and 15 age-matched controls. VEPs were recorded in response to counterphased (2 reversals/s) checkerboards (mean luminance: 80 cd/m2; contrast: 80%; field size: 18°) in baseline condition and at 20, 40 and 60 s following 30 s exposure to a bleaching light (3.58 log photopic Trolands), presented to the central (6° field) retina. In all patients, macular focal electroretinograms (FERGs) to a 18° uniform field, flickering at 41 Hz, were also recorded in separate sessions. Results: At every post-bleach time, VEPs were delayed and suppressed in amplitude, with respect to pre-bleach values, in both patients and controls. However, the amount of delay and suppression was, on average, more pronounced (p < 0.001) in STD/FF patients than in controls. This difference was not accounted for by eccentric fixation in patients (n = 8) with central scotoma, and was still substantial when only patients (n = 8) with normal visual field and acuity were considered. In individual patients, baseline FERG amplitudes were correlated (r = - 0.6, p < 0.01) with the amount of VEP amplitude suppression at 40 s post-bleach. Conclusion: The results indicate an altered recovery of pattern VEPs after macular bleaching in STD/FF patients, and suggest adaptation abnormalities in macular cone photoreceptors occurring at disease stages with relatively preserved central visual field and acuity.
This PDF is available to Subscribers Only