Computer-assisted videokeratography to measure changes in astigmatism induced by sutureless cataract surgery

Abstract

Purpose: To compare the visual outcome, change in surgically induced astigmatism, and corneal thickness after sutureless cataract surgery through either a scleral tunnel or clear corneal incision. Setting: Department of Ophthalmology, Kangnam St. Mary's Hospital, Catholic University Medical College, Seoul, Korea. Methods: This retrospective study evaluated 79 eyes of 64 patients who had cataract surgery using a 6.0 mm scleral tunnel incision (Group 1, n = 20 eyes), 3.1 mm clear corneal incision at the 12 o'clock position (Group 2, n = 35 eyes), or 3.1 mm clear corneal incision at the 10 o'clock position (Group 3, n = 24 eyes). Changes in surgically induced astigmatism were analyzed using computer-assisted videokeratography (CVK) 1 day, 8 weeks, and 6 months postoperatively. Results: Eleven eyes (55.0%) in Group 1, 15 (42.8%) in Group 2, and 11 (48.5%) in Group 3 had an uncorrected visual acuity of 20/40 or better 1 day postoperatively. The CVK measurements showed significantly more flattening at radial distances of 0.75, 1.50, and 2.50 mm along the 90 degree semimeridian in Group 2 than in Group 1 (P < .05) 1 day after surgery; in Group 3, flattening along the incisional semimeridian fell between the amounts in Groups 1 and 2. At 8 weeks, the amount of flattening decreased in all groups, and the differences between groups were not statistically significantly different (P > .05). In the CVK pattern, corneal flattening along the incisional meridian was narrower and longer in Groups 2 and 3 than in Group 1. Conclusion: Localized flattening along the incisional meridian was prominent temporally after clear corneal incision surgery. However, there was no difference in early visual rehabilitation between the clear corneal and scleral tunnel incision groups.