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Refractive and Topographical Analyses After Wavefront-Optimized Photorefractive Keratectomy With 75% Angle Kappa
Burak Tanriverdi1, Nurullah Cagil
1Department of Ophthalmology, Lokman Hekim University, Akay Hospital, Ankara, Turkey .
Eye & Contact Lens
|October 2, 2025
Summary
Photorefractive keratectomy (PRK) with 75% angle kappa compensation showed similar refractive and topographic outcomes for myopic eyes, regardless of kappa angle size. This approach may avoid inducing additional corneal changes in eyes with significant angle kappa.
Area of Science:
- Ophthalmology
- Refractive Surgery
- Corneal Optics
Background:
- Angle kappa, the distance between the pupil center and the visual axis, can influence refractive surgery outcomes.
- Wavefront-optimized photorefractive keratectomy (PRK) aims to optimize visual quality by considering aberrometric data.
- Compensating for angle kappa during PRK may improve refractive and topographic results in myopic patients.
Purpose of the Study:
- To evaluate the refractive and topographic outcomes of PRK with 75% angle kappa (P-Dist) compensation in myopic eyes.
- To compare outcomes between patients with small- and large-angle kappa.
- To determine if angle kappa compensation affects higher-order aberrations (HOAs) and point-spread function (PSF).
Main Methods:
- Retrospective study of 127 myopic eyes undergoing wavefront-optimized PRK with 75% P-Dist compensation.
- Eyes were grouped based on mean P-Dist: small-angle kappa (<232.13 μm) and large-angle kappa (>232.13 μm).
- Preoperative and 6-month postoperative measurements included visual acuity, refraction, topography, aberrometry, and PSF.
Main Results:
- Preoperative P-Dist correlated with higher-order aberrations and coma, with larger angles showing more preoperative coma.
- At 6 months postoperatively, refractive and topographic outcomes, visual acuity, HOAs, and PSF were similar between small- and large-angle kappa groups.
- No significant correlation was found between preoperative P-Dist and postoperative HOAs or PSF changes.
Conclusions:
- PRK with 75% angle kappa compensation provides comparable refractive and topographic outcomes in myopic eyes with varying angle kappa sizes.
- Aligning ablation with P-Dist compensation in eyes with significant angle kappa does not appear to induce additional refractive or topographical changes.
- Wavefront-optimized PRK with angle kappa compensation is a potentially effective strategy for managing myopia.
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