The Risk Factors for Myopia Undercorrection in Second-Generation (Visumax 800) Keratorefractive Lenticule Extraction...

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Myopia undercorrection after keratorefractive lenticule extraction (KLEx) can impact visual outcomes.
• Identifying risk factors is crucial for optimizing surgical planning and patient selection in second-generation KLEx procedures.

Purpose of the Study:

• To evaluate the risk factors associated with myopia undercorrection following second-generation KLEx surgery.
• To differentiate risk factors between the general, high-myopia, and low-myopia populations.

Main Methods:

• A retrospective case-control study involving patients who underwent second-generation KLEx surgery.
• Matching of myopia undercorrection cases (n=22) with control cases (n=88) based on age.
• Analysis of demographic, refractive, topographic, and surgical data using a generalized linear model.

Main Results:

• The undercorrection group exhibited significantly worse uncorrected distance visual acuity (UDVA) and higher residual myopia and spherical equivalent (SE) post-surgery.
• In the overall and high-myopia populations, higher manifest sphere power, steeper keratometry, increased topographic cylinder, lower central corneal thickness (CCT), greater CCT difference, and lower residual stromal thickness (RST) were associated with undercorrection.
• In the low-myopia group, higher myopia and lower RST were linked to undercorrection.

Conclusions:

• High sphere power and irregular corneal topography are significant predictors of myopia undercorrection after second-generation KLEx.
• These risk factors are particularly pronounced in patients with high myopia, necessitating careful consideration during surgical planning.