Changes In The Higher Order Corneal Aberrations After Corneal Wavefront-Guided Phototherapeutic Keratectomy In The Treatment Of Granular Corneal Dystrophy

The objective was to assess the impact of corneal wavefront-guided phototherapeutic keratectomy (PTK) on corneal higher-order aberrations (HOAs), with particular emphasis on spherical aberration, in patients with granular corneal dystrophy.

We compared and analyzed the changes in HOAs before and after the PTK procedure.

Specialty Eye Hospital Svjetlost Sarajevo, Bosnia and Herzegovina

A 20-year-old male with a positive family history of granular dystrophy presented with progressive blurred vision since childhood in both eyes in February 2023. The best corrected visual acuity was 20/30 in the right eye and 20/25 in the left eye.  During the slit-lamp biomicroscope examination, the patient exhibited honeycomb opacities in both eyes, which were documented using photographic records. The corneal values were evaluated using a high-resolution corneal topography device equipped with an aberrometer (Peramis, Schwind) before and seven days after the treatment. The PTK procedure was performed using an Amaris 1050Hz excimer laser (Schwind) under topical anesthesia, and ablation was followed by a 30-second application of Mitomycin-C (0.02%). The laser beam was applied with an epithelial ablation diameter of 9.0 mm and a central ablation depth of 75 microns. The laser treatment profile used the aberrometric correction with an ablation of 8.0 mm for the optical zone.

The preoperative value of total corneal HOAS on the right eye was 1.42, and spherical aberration amounted to 0.38. Total corneal HOAs on the left eye amounted to 0.72, from what spherical aberration was 0.40. Postoperatively, opacities of both eyes were removed, and the vision improved to 20/25 on the right and 20/20 on the left. Total corneal HOAs on the right eye were reduced to 0.34 and spherical aberration to 0.01; on the left eye, the number of total HOAs was 0.36 and spherical aberration to 0.02.

Corneal wavefront-guided phototherapeutic keratectomy (PTK) has been found to significantly enhance the efficacy of PTK treatment for patients with irregular corneal surfaces and granular corneal dystrophy. This is primarily attributed to the reduction of corneal aberrations, particularly spherical aberration, which has been shown to be a predominant factor in these conditions.