Combination of iris vessel area density and surgery interval as the predictor of perceived pain during consecutive second-eye cataract surgery.

PURPOSE: To explore clinical indicators to predict perceived pain during second-eye phacoemulsification surgery in patients with bilateral cataracts. SETTING: Shanghai General Hospital, China. DESIGN: A case‒control study and a prospective cohort study. METHODS: Patients with age-related cataract who underwent first-eye or second-eye uneventful phacoemulsification surgery were enrolled. Before surgery, ocular examination results, including vessel area density (VAD) and vessel skeleton density (VSD), obtained by optical coherence tomography angiography examination of the iris were performed. Patients completed a visual analog scale pain survey 3 times postoperatively: 1 hour, 3 hours, and 24 hours postoperatively. RESULTS: 70 patients were enrolled in the case‒control study, and the pain scores of the second-eye surgery group under local anesthesia were significantly greater than those of the first-eye surgery group ( P = .0005). Preoperative iris VAD in the second-eye group affected perioperative pain scores ( P = .0047). The optimal cutoff value of VAD was 0.2167 with a specificity of 76% and a sensitivity of 62%. In the prospective cohort study, 124 patients were included in the second-eye group. Preoperative iris VAD ( P = .0361) and the time interval ( P = .0221) were independent factors for second-eye surgery pain. Combined with preoperative iris VAD and surgical interval, the negative predictive value and positive predictive value were 0.95 and 0.29 for predicting moderate pain or above, the sensitivity and specificity were 0.97 and 0.23, respectively. CONCLUSIONS: The combination of iris VAD and the time interval between both eye surgeries can be an effective method to predict the timing of the second-eye cataract surgery and to avoid intraoperative pain.