Temporal versus superior clear corneal incision for eyes with oblique astigmatism: a randomized comparative study

To compare the amount of total cornea astigmatism and corneal astigmatic change between eyes with near against-the-rule (ATR) and near with-the-rule (WTR) oblique astigmatism that underwent a temporal (TCI) or superior clear corneal incisions (SCI).

Randomized comparative study.

Two-hundred forty eyes with near ATR (46°-59° and 121°-135°; n=120) or near WTR (31°-45° and 136°-149°; n=120) oblique corneal astigmatism of ≥ 0.5 diopters were randomly assigned to undergo a 2.4-mm TCI or SCI. The vertical/horizontal (Rx) and oblique astigmatism components (Ry) were evaluated preoperatively and at 2 months postoperatively. Bivariate analysis was performed to compare between the two time points and the TCI and SCI groups.

All 240 eyes were included in the analysis. In eyes with near ATR or near WTR oblique astigmatism, the mean Rx and Ry did not change significantly in the TCI group but were significantly increased from preoperatively to 2 months postoperatively in the SCI group (P≤0.002). The mean Rx and Ry did not differ significantly between the TCI and SCI groups preoperatively, but these values were significantly lower in the TCI group than in the SCI group at 2 months postoperatively (P<0.001).

TCI did not significantly change the corneal astigmatism, while SCI increased the astigmatism from preoperatively to 2 months postoperatively in eyes with near ATR or WTR oblique astigmatism. Residual corneal astigmatism at 2 months postoperatively was significantly lower after TCI than after SCI, suggesting that TCI is a more favorable surgical approach for eyes with oblique astigmatism.