Single flash electroretinograms of mature cataractous and fellow eyes

BACKGROUND: It is generally stated that opacities of the ocular media, including senile cataract, have little effect on the electrical responses of the retina. However, lower amplitudes and longer implicit times are sometimes observed in electroretinograms (ERGs) of patients with mature cataract. METHODS: Single flash ERGs of mature cataractous eyes with decimal visual acuity less than 0.1 were compared with those of the fellow eyes with decimal visual acuity better than 0.5, in 105 senile cataract patients. RESULTS: The mean amplitudes and implicit times of ERG a-waves were, respectively, 323.6±95.8 μV and 14.7±3.5 ms in the cataractous eyes and 352.3±96.6 μV and 12.0±1.5 ms in the fellow eyes. The mean amplitudes and implicit times of ERG b-waves were, respectively, 390.1±108.7 μV and 63.4±27.9 ms in the cataractous eyes and 415.3±119.1 μV and 59.0±9.3 ms in the fellow eyes. The mean amplitudes of the a- and b-waves were significantly lower and the mean implicit times of the a- and b-wave were significantly longer in the cataractous eyes as compared to those of the fellow eyes. Postoperative visual acuity was similar in cataractous and fellow eyes. CONCLUSION: Even though single flash ERG was influenced due to mature cataract, eyes revealed good postoperative visual acuity. Single flash ERG does not always reflect the foveal function and the visual pathway; nevertheless, it remains a reliable guide to evaluate visual prognosis before cataract surgery.