Purchase this article with an account.
G. Lafond, M.C. Boucher, P. Labelle, J. Dumas; The Effects of Laser Panretinal Photocoagulation on Cone, Rod and Oscillatory Potentials Responses in Proliferative Diabetic Retinopathy . Invest. Ophthalmol. Vis. Sci. 2003;44(13):3986.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To analyse the relationship between laser panretinal photocoagulation (PRP) and the A and B-wave of the cone and the rod responses as well as the oscillatory potentials of the electroretinogram (ERG). Methods: The study group consisted of 24 patients with proliferative diabetic retinopathy. The PRP treatment was done in two sessions. During each PRP session, 800 burns of 500 µm.diameter and 0.2 sec duration were administered starting from the posterior pole towards the periphery, such that the PRP1 lesions were produced on the inferior half of the retina, and PRP2 lesions on the upper half. Both amplitude and implicit time of each ERG responses were investigated before the PRP (T=0), 3 weeks after PRP1, then 1, 3, 6 and 12 months after PRP2 in photopic and scotopic conditions. Results: Results indicate that rod and cone B-wave amplitudes decreased respectively of 71% and 36% three weeks after PRP1 and of 87% and 51% one month after PRP2. At lower intensity of light stimulation, rod responses continue to decrease until extinction after 6 months. The cone responses decreased of 68% one year after PRP2 treatment. In both photopic and scotopic conditions, the amplitudes of the A-wave and the oscillatory potentials were decreased in the same proportion as the cone responses. Rod and cone implicit times were significantly shortened after PRP treatment. In contrast, the implicit times of the A-wave and the oscillatory potentials were not significantly modified after PRP. Conclusions: These results demonstrate that cone and rod amplitudes are differently reduced after PRP treatment while their implicit times were shortened. The implicit times analysis enhances the diagnosis utility of the ERG in proliferative DR after PRP treatment.
This PDF is available to Subscribers Only