Comparison of Long-Term Corneal Astigmatic Changes After Cataract Surgery in Eyes With Superior or Horizontal Clear Corneal Incisions

PURPOSE: To compare long-term corneal astigmatic changes after stabilization of surgically induced astigmatism (SIA) subsequent to phacoemulsification between eyes that underwent superior clear corneal incision (CCI) or horizontal CCI. DESIGN: Retrospective, comparative case series. METHODS: We examined the anterior corneal astigmatism of eyes that underwent a 2.4-mm superior CCI (superior CCI group, n = 43) or horizontal CCI (horizontal CCI group, n = 43) preoperatively, on the postoperative day that SIA stabilized (baseline), and at ≥7 years post-baseline using an autokeratometer. Corneal astigmatic changes from baseline to ≥7 years post-baseline (mean duration 8.74 years in the superior CCI group and 9.05 years in the horizontal CCI group) were decomposed to vertical/horizontal (Rx) and oblique astigmatic change components (Ry) and were compared between the 2 groups. RESULTS: The mean corneal astigmatism components changed significantly toward against-the-rule (ATR) astigmatism in the superior CCI group and with-the-rule astigmatism in the horizontal CCI group within 6 months postoperatively. After stabilization of the SIA, both groups showed a significant increase in the mean Rx and no significant change in the mean Ry over approximately 9 years, indicating a long-term ATR shift. The mean changes in the Rx and Ry did not differ significantly between the superior and horizontal CCI groups. Double-angle plots revealed a similar degree of ATR shift between the 2 groups over the 9 years. CONCLUSIONS: After stabilization of the SIA, a similar degree of ATR change occurred subsequent to superior and horizontal CCIs over approximately 9 years, suggesting that CCI direction does not affect long-term astigmatic changes.