Excimer Laser in different ablation model for moderate and high compound myopic astigmatism

Abstract

Objective To determine the safety and efficacy of laser in situ keratomileusis (LASIK) in standard sphere/cylindrical or ellipsoidal ablation model to treat moderate and high compound myopic astigmatism. Methods The LaserSight SLX laser (5.3 software) was used in LASIK. In standard sphere/cylindrical ablation model group (23 eyes), the preoperative mean uncorrected visual acuity (UCVA) was 0.155: 0.09,sphere -4.40± 2.07D, cylinder -2.42± 0.47D, the final follow-up 6.04± 3.74 months. In ellipsoidal ablation model group (33 eyes), the UCVA was 0.13± 0.05, sphere -5.43±2.26D, cylinder-2.71± 0.76D, the final follow-up 6.91± 5.10 months. Results In two groups, the UCVA was 1.11± 0.17 and 1.05± 0.10, sphere -0.17± 0.77D and-0.18± 0.89, cylinder-0.62± 0.39D and-0.64± 0.68, respectively. No statistical different was found (P > 0.05 ). However, the postoperatively mean corneal asphericity (Q-value) was 0.60± 0.35 in sphere/cylindrical group and 0.29± 0.5928.1% (9/32) in ellipsoidai group with statistical difference. Conclusions LASIK using the LaserSight SLX excimer laser (5.3 software) in standard sphere/cylindrical or custom ellipsoidal ablation model is effective and stable for moderate and high compound myopic astigmatism. The postoperative Q-value in ellipsoidal ablation model is easier to maintain preoperatively negative characteristic. Key words: Compound myopic astigmatism; Laser in Situ Keratomileusis (LASIK); Q-value