Sequential Custom Therapeutic Keratectomy for the Treatment of Granular Corneal Dystrophy Type 1: A Long-term Study

Abstract

Purpose: To evaluate the effectiveness of sequential custom phototherapeutic keratectomy (SCTK) for granular corneal dystrophy type 1 (GCD1). Methods: Thirty-seven eyes of 21 patients with GCD1 were treated with SCTK to remove superficial opacifications, regularize the corneal surface, and decrease optical aberrations. SCTK is a sequence of custom therapeutic excimer laser keratectomies with step-by-step intraoperative corneal topography monitoring of results. Six eyes of 5 patients previously treated with penetrating keratoplasty received SCTK for disease recurrence. Pre-operative and postoperative corrected distance visual acuity (CDVA), refractive values, mean pupillary keratometry, and pachymetry were retrospectively analyzed. The mean follow-up period was 41.3 months. Results: SCTK provided significant decimal CDVA improvement, from 0.33 ± 0.22 to 0.63 ± 0.24 ( P < .0001) at the last available follow-up visit. One eye, initially treated with penetrating keratoplasty, showed visually significant disease 8 years after the first SCTK and was re-treated. Mean corneal pachymetry difference between preoperative and final follow-up values was 78.42 ± 62.26 µm. Mean corneal curvature and the spherical component did not show a statistically significant change or hyperopic shift. Astigmatism and higher order aberration reduction were statistically significant. Conclusions: SCTK is a powerful tool for the treatment of anterior corneal pathologies hindering vision and quality of life, such as GCD1. SCTK is less invasive and fosters more rapid visual recovery than penetrating keratoplasty or deep anterior lamellar keratoplasty. Providing significant visual improvement, SCTK can be the preferred initial treatment in eyes with GCD1. [ J Refract Surg . 2023;39(6):422–429.]