Influence of the difference between corneal and refractive astigmatism on LASIK outcomes using solid-state technology

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Optics

Background:

• Laser in situ keratomileusis (LASIK) is a common procedure for correcting myopic astigmatism.
• Understanding factors influencing refractive outcomes is crucial for patient satisfaction.
• Ocular residual astigmatism (ORA), the difference between corneal and refractive astigmatism, is a complex optical phenomenon.

Purpose of the Study:

• To investigate the impact of preoperative ocular residual astigmatism (ORA) on LASIK outcomes.
• To evaluate the efficacy and safety of solid-state laser technology for myopic astigmatism correction in relation to ORA.
• To analyze changes in ORA, anterior corneal astigmatism, and posterior corneal astigmatism (PCA) post-LASIK.

Main Methods:

• A prospective study included 101 eyes of 55 patients undergoing LASIK for myopia or myopic astigmatism.
• The Pulzar Z1 solid-state laser system was used for the procedures.
• Visual and refractive outcomes, ORA, anterior corneal astigmatism, and PCA were assessed at 6 months postoperatively.

Main Results:

• Significant improvements in uncorrected distance visual acuity and reductions in refractive cylinder and spherical equivalent were observed post-LASIK.
• No significant changes in ORA or anterior corneal astigmatism were detected.
• Postoperative ORA correlated significantly with PCA and manifest refraction, but not preoperatively.
• Efficacy and safety indices did not correlate with preoperative ORA.

Conclusions:

• Preoperative ORA magnitude is not a reliable predictor of LASIK efficacy or safety with solid-state laser platforms.
• Postoperative changes in PCA may contribute to unexpected residual refractive errors.
• Further research into the role of PCA in refractive outcomes is warranted.