Corneal Diameter as a Factor Influencing Corneal Astigmatism After XXXX Surgery.

@entity940 @entity2270 @entity86 @entity231
PURPOSE: To evaluate the corneal horizontal diameter [white-to-white (WTW) distance] as a factor influencing surgically induced @entity940 (SIA) and postoperative @entity940 . METHODS: A total of 330 eyes with corneal @entity940  <=1.5 D underwent @entity231 surgery with phacoemulsification. A 3-step, superotemporal for the right eye and superonasal for the left eye, clear corneal incision of 3.0 mm was made. Four groups were created according to WTW distance: group A  <=11.6 mm, group B 11.7 to 11.9 mm, group C 12.0 to 12.2 mm, and group D >= 12.3 mm. SIA was calculated by vector analysis using the Alpins method. We noted all cases, in which a change greater than 0.5 diopters (D) in @entity940 took place and a change greater than 20 degrees in @entity2270 torque, despite @entity2270 direction, on the first and sixth postoperative months. RESULTS: SIA was found in group A 0.98 D    0.6 (SD), B 0.79 D    0.43 (SD), C 0.68 D    0.45 (SD), and D 0.53 D    0.32 (SD) at the first @entity86 . At the sixth @entity86 , SIA was 0.77 D    0.43 (SD), 0.69 D    0.34 (SD), 0.62    0.36 (SD), and 0.49 D    0.27 (SD), respectively. A change greater than 0.5 D in corneal astigmatic power at the first and sixth months postoperatively was significantly lower in eyes with WTW distance 12.0 to 12.2 mm and >= 12.3 mm in comparison with eyes with WTW distance  <=11.6 mm and 11.7 to 11.9 mm (P < 0.05). Changes greater than 20 degrees in @entity940 at the first and sixth postoperative months were not significantly different according to the horizontal corneal diameter. CONCLUSIONS: WTW distance should always be measured preoperatively when planning @entity231 surgery and should be accounted for in cases of large and small corneas.
