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 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.

CONCLUSION

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.

中文翻译：

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上、水平透明角膜切口白内障术后远期角膜散光变化的比较

目的

比较接受上透明角膜切口 (CCI) 或水平 CCI 的眼睛在超声乳化术后手术诱导散光 (SIA) 稳定后的长期角膜散光变化。

设计

回顾性比较案例系列。

方法

我们在 SIA 稳定的术后当天（基线）检查了术前接受 2.4 mm 上 CCI（上 CCI 组，n = 43）或水平 CCI（水平 CCI 组，n = 43）的眼睛的前角膜散光，并且在基线后 ≥7 年使用自动角膜曲率计。从基线到基线后≥ 7 年的角膜散光变化（上 CCI 组的平均持续时间为 8.74 年，水平 CCI 组的平均持续时间为 9.05 年）被分解为垂直/水平（Rx）和倾斜散光变化分量（Ry），和2组之间进行比较。

结果

在术后 6 个月内，平均角膜散光成分在上 CCI 组和水平 CCI 组的规则散光中显着改变为逆规则（ATR）散光。在 SIA 稳定后，两组均显示平均 Rx 显着增加，平均 Ry 在大约 9 年内没有显着变化，表明长期 ATR 偏移。Rx 和 Ry 的平均变化在上级和水平 CCI 组之间没有显着差异。双角图显示了 9 年来两组之间的 ATR 变化程度相似。

结论

在 SIA 稳定后，在大约 9 年的时间里，在上 CCI 和水平 CCI 之后发生了类似程度的 ATR 变化，这表明 CCI 方向不会影响长期散光变化。