A Study of Prediction of Postoperative Visual Acuity using Simple Electroretinogram Before Cataract Extraction

Kim, So Young; Park, Tae Kwan; Ohn, Young Hoon

Abstract

PURPOSE
To evaluate the usefulness of the electroretinogram using EMS (Electrophysiology Modular System; TMS, Luneberg, Germany), a simpler method compared with standard ERG as a preoperative evaluation of cataract. METHOD: Forty-six eyes of 25 patients who had undergone cataract surgery were included. Scotopic, photopic and 30 Hz flicker response were examined with EMS. On the basis of fundus finding, the subjects were classified into two groups: Group 1 (cataract with normal fundus) and group 2 (cataract with abnormal fundus). On the basis of lens opacity, group 1 was subclassified into the following three sub-groups: mild, moderate, and severe opacity. We analyzed the differences of the ERG values of these three sub-groups. And also we analyzed the difference of the ERG values of two groups and postoperative visual acuity. RESULTS: In group 1, the ERG responses were generally reduced as the lens opacity increased and the photopic a wave amplitude was significantly reduced especially when the opacity was severe. But there was no significant difference between the lens opacity and the prognosis of postoperative visual acuity. In group 2, scotopic b wave and photopic a, b wave amplitude were significantly reduced and the prognosis of postoperative visual acuity was poor (P>0.05).
Conclusion
Our results show that the ERG would be a clinically significant test in evaluating the function of the retina and detecting the retinal lesions, and it can be used in the prediction of the prognosis of postoperative visual acuity. And the EMS shows similar results comparable to the previous reports, so it can be used clinically in more simple manners.