The Short-Term Effect of Limbal Relaxing Incision and Compression Suture on Post-Penetrating Keratoplasty Astigmatism

ABSTRACT

PURPOSE: To investigate the short-term effect of limbal relaxing incisions accompanied by compression sutures on postoperative astigmatism in penetrating keratoplasty. METHODS: The medical records of patients who underwent penetrating keratoplasty, were followed-up for at least 18 months and had residual astigmatism greater than 4.0 diopters (D), were retrospectively analyzed. The patients had paired limbal relaxing incisions on the steep axis and compression sutures on the flat axis. The paired limbal relaxing incision was done for 2 clock hours each with a depth of 85% of the corneal thickness, and the compression sutures with an average of 3.2 bites were added with a Troutman operating keratometer guide. The visual acuities, corneal astigmatism and complications were evaluated at 1 month and 6 months. RESULTS: At 1 month after the surgery, the best corrected visual acuities (log MAR) improved from 0.840 to 0.674 (p = 0.037) except for 1 patient with immediate postoperative rejection and another patient with a pre-existing cataract. The mean corneal astigmatism was reduced from 9.118 +/- 3.158 D to 4.982 +/- 3.063 D (p = 0.021). At 6 months after the surgery, the mean corneal astigmatism increased to 5.489 +/- 2.670 D (p = 0.008), and the effect of surgery became statistically insignificant (p = 0.477). CONCLUSIONS: Paired limbal relaxing incisions and compression sutures were effective short-term on reducing residual corneal astigmatism and improving visual acuities in keratoplasty patients with high astigmatism, but became less effective on corneal astigmatism at 6 months.