Laser in situ keratomileusis for hyperopia and hyperopic astigmatism

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Hyperopic LASIK presents challenges due to post-operative regression and loss of effect.
• Excimer laser in situ keratomileusis (LASIK) is being evaluated for hyperopia correction.
• A modified nomogram and NIDEK scanning slit excimer laser were utilized.

Purpose of the Study:

• To evaluate the safety and efficacy of LASIK for correcting hyperopia and hyperopic astigmatism.
• To assess the predictability and stability of hyperopic LASIK outcomes.
• To identify areas for improvement in excimer laser algorithms for hyperopic correction.

Main Methods:

• A consecutive series of 58 eyes with hyperopia and hyperopic astigmatism were treated by a single surgeon.
• Nidek excimer laser and Chiron automated corneal shaper were used for the procedures.
• A two-step ablation process was employed: myopic ablation for astigmatism followed by hyperopic ablation.

Main Results:

• A mean reduction in hyperopic spherical equivalent refraction was observed, from +3.75 D preoperatively to +2.25 D at 6 months.
• Mean preoperative astigmatism of 2.75 D decreased to 1.25 D postoperatively.
• Four eyes experienced reduced visual quality due to ablation decentration or small ablation zones; no vision-threatening complications occurred.

Conclusions:

• LASIK is a safe, effective, and repeatable procedure for hyperopia and hyperopic astigmatism.
• Predictability and long-term refractive stability require enhancement.
• Excimer laser manufacturers should provide improved ablation profiles and modified algorithms.