Intraoperative Wave Front Analyzer Guided Peripheral Corneal Relaxing Incisions During Cataract Surgery

To evaluate the validity of intraoperative astigmatism correction through peripheral corneal relaxing incision with reference to astigmatism measurements by wavefront analyzer (ORA system, Alcon) during cataract surgery

Single center study at Otani Eye Clinic, Wakayama, Japan

This retrospective study included the patients who underwent corneal relaxing incision during cataract surgery. All the corneal relaxing incisions were made with 3 mm width slit knife (MANI, Japan) along the steepest axis measured by ORA just before intraocular lens insertion. We performed ORA measurements before and after the corneal relaxing incision to confirm the reduction of astigmatism in each case.

Residual astigmatism and uncorrected visual acuity were evaluated at 1, 3, and 12 months after surgery. Astigmatism was evaluated by best corrected visual acuity, auto refracto-keratometer, and wavefront aberration analyzer (Topcon, Japan) at each timepoint

89 eyes of 79 patients were included in this study. The mean (±SD) corneal astigmatism was 1.16±0.41D preoperatively. The mean residual astigmatism was -0.36±0.47D at 1 month, -0.44±0.60D at 3 month, and -0.40±0.55D at 12 month. The centroid of whole eye astigmatism measured by ORA during surgery before corneal relaxing incision was 0.90D at 6 degrees ± 0.91D and that of immediate after corneal relaxing incision was 0.30D at 7 degrees ± 0.62D. The centroid of preoperative corneal astigmatism was 0.81D at 8 degrees ± 0.93D and that of residual astigmatism at 3 months was 0.22D at 4 degrees ± 0.71D. Uncorrected visual acuity (log MAR) at 1, 3, and 12 months after surgery were 0.00±0.10, -0.01±0.11, and 0.02±0.13, respectively

The need for astigmatism correction in cataract surgery is increasing. The use of toric intraocular lenses is highly effective, but due to the complexity of the procedure, the accuracy of predictions, and problems such as postoperative intraocular lens rotation, stable effects cannot be obtained in not a small number of cases. In this study we have shown that the WPCRI using intraoperative residual astigmatism as an index can easily obtain a stable effect without using a toric lens. Although there is a limit to the extent of astigmatism correction, it might be a very useful method for fine-tuning residual astigmatism, which affects postoperative uncorrectedvisual acuity