Changes of Functional Optical Zone After LASIK for Hyperopia and Hyperopic Astigmatism.

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Hyperopic LASIK aims to correct farsightedness using laser vision correction.
• The functional optical zone (FOZ) is critical for visual quality after LASIK.
• Understanding factors influencing FOZ size is essential for optimizing outcomes in hyperopic LASIK.

Purpose of the Study:

• To identify factors affecting the postoperative functional optical zone size after hyperopic LASIK.
• To analyze the impact of hyperopia severity on FOZ reduction.

Main Methods:

• Thirty-three eyes with hyperopia underwent LASIK.
• Refraction, corneal power, and visual acuity were assessed postoperatively.
• Eyes were categorized into low and high hyperopia groups based on spherical equivalent.

Main Results:

• One year post-LASIK, 82% of eyes achieved uncorrected distance visual acuity of 0.5 or better.
• The functional optical zone decreased by 32% overall, with a more pronounced reduction in high hyperopia.
• Preoperative spherical equivalent and corneal refractive power were additive predictors of postoperative FOZ size.

Conclusions:

• A smaller FOZ in high hyperopia LASIK is expected but can cause glare and halos.
• Preoperative refractive error and corneal power are key determinants of FOZ size.
• While not an absolute exclusion criterion, the potential for reduced FOZ in high hyperopia should be considered.