Corneal topographic changes and induced astigmatism resulting from superior and temporal scleral pocket incisions

BACKGROUND AND OBJECTIVE: To determine the corneal topographic changes that are induced by superior and temporal 5-mm scleral pocket incisions. PATIENTS AND METHODS: The authors retrospectively reviewed the records of 43 patients who underwent phacoemulsification with posterior chamber lens implantation through unsutured 5-mm scleral pocket incisions, 24 superiorly and 19 temporally. Corneal curvature was measured using computerized videokeratography, and the induced astigmatism was calculated with the Holladay-Cravy-Koch formula. RESULTS: At 4 to 6 weeks postoperatively, there was mild flattening along the meridian of the incision in both groups. The change was greater with the superior incisions, but the differences between the groups were not statistically significant. Surgically induced astigmatism was 0.7 D (+/- 0.1 D) in the eyes that received superior incisions, and 0.3 D (+/- 0.1 D) in the eyes that received temporal incisions; this difference was statistically significant (P<.03). CONCLUSIONS: At 4 to 6 weeks postoperatively, temporal 5.0-mm scleral pocket incisions provide more stable postoperative topography than do superior scleral pocket incisions.