Clinical study of pain sensation during phacoemulsification with and without cryoanalgesia

PURPOSE: To compare the analgesic efficacy of 2 types of anesthetic techniques-topical and topical associated with cryoanalgesia-during cataract surgery. SETTING: Department of Ophthalmology, University of Sao Paulo, Ribeirao Preto, Brazil. DESIGN: Prospective randomized study. METHODS: Patients with symmetrical bilateral cataract had phacoemulsification with the use of an intraocular irrigation solution at room temperature in 1 eye and a cold (4 degrees C) solution in the contralateral eye (Group 2). The pain related to the procedure was assessed using a visual analog scale ranging from 0 to 100, with 0 representing no pain and 100 the worst pain. In addition, endothelial cell loss, the change in corneal thickness, and visual acuity were evaluated 30 days +/- 2 (SD) after each surgery. The surgery duration, total irrigation volume, phacoemulsification time, and ultrasound power used were analyzed. RESULTS: The study enrolled 25 patients (50 eyes). There was no statistically significant difference in the mean pain score between Group 1 (26.0 +/- 3.7) and Group 2 (21.3 +/- 3.6) (P = .2016, paired t test). No significant difference was found in the mean corneal endothelial cell loss (Group 1: 10.0% +/- 0.4%; Group 2: 9.9% +/- 0.3%; P = .7576), corneal thickness increase (Group 1: 1.5 +/- 1.0 mu m; Group 2: 1.4 +/- 0.9 mu m; P = .9340), or visual acuity gain (Group 1: 0.54 +/- 0.06 logMAR; Group 2: 0.55 +/- 0.09 logMAR; P = .8208). CONCLUSION: There is no difference in the intensity of pain during phacoemulsification with the use of topical anesthesia or topical anesthesia associated with cryoanalgesia.