Electro-Ophthalmology in Senile Macular Degenerations

The Success of Cataract Surgery and the Preoperative Measurement of Retinal Function by Electrophysiological Techniques

Purpose. To study the effect of different electrophysiological methods to evaluate retinal function prior to cataract surgery. Methods. Cataract patients who had no significant other eye disease were chosen. VA, pattern visual evoked potential (PVEP), electroretinogram (ERG), and multifocal electroretinogram (mfERG) responses were measured from 150 cataract patients and 20 control subjects. Results. When the preoperative VA was more than 0.3 in cataract patients, the amplitude of PVEP was not significantly different between cataract and control subjects. The amplitude of central point mfERG was significantly lower in cataract patients compared with control group from HM to 0.8 of preoperative VA. The 95% confidence intervals (CIs) of the amplitudes of center point mfERG were calculated for a range of preoperative VA values. Most of the patients within 95% CI of the center point mfERG had a postoperative VA more than 0.5. Conclusions. The amplitude of central point mfERG in cataract patients was the most relevant parameter to the preoperative VA compared with PVEP and ERG. The 95% CI of the amplitude of central point mfERG for each level of VA could help to evaluate preoperative macular function which is used to predict the outcome of cataract surgery.

Pattern electroretinography in senile macular degeneration

The value of pattern electroretinography (PERG) for the detection and differentiation of senile macular degeneration (SMD) was assessed. A group of patients with atrophic SMD and a group with exudative SMD were compared with an age-matched reference group. Differences were only found in visual acuity and in the amplitude of the negative peak N95. No statistical differences between the atrophic and exudative groups were found. Conclusions may be drawn from these results with regard to the use of PERG in senile macular degeneration.

The clinical utility of the foveal electroretinogram: a review

The historical development of the foveal electroretinogram is reviewed. The factors required to obtain a local cone electroretinogram with a small focal source of illumination against a lighted background are discussed. From these considerations and various studies of macular degeneration, the optimal size of the foveal source is found to be 5 degrees diameter or less. Applications of the foveal electroretinogram in various diseases are summarized. The foveal electroretinogram is abnormal with reduced acuity in age-related macular degeneration, juvenile macular degeneration (Stargardt's disease), retinitis pigmentosa, and diabetic retinopathy. Normal foveal electroretinograms are found in optic atrophy, amblyopia, and optic neuritis. Foveal electroretinograms are normal or abnormal in Best's disease, central serous retinopathy, and several other diseases discussed.

The value of preoperative electro-ophthalmological examination before cataract extraction

In 203 senile cataractous eyes preoperative results of photopic flash ERGs and VERs were compared with the optimum visual acuity after cataract extraction. Because preoperatively for some reason a good function of the retina or the conductive system was questionable, patients were referred to the electro-ophthalmological department. This encompassed approximately 10% of patients with a senile cataract. The relationships found indicated that the photopic flash ERGs and VERs are a good support for estimating post-operative visual function.