Photorefractive Keratectomy in Keratoconus: Long-Term Outcomes from a Pre-Cross-Linking Era Cohort

Vollständiger Abstract

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Purpose: To describe long-term visual, refractive, and topographic outcomes after photorefractive keratectomy (PRK) in keratoconus patients treated before corneal cross-linking (CXL) became available. Setting: Single private ophthalmic center in Bogotá, Colombia. Design: Retrospective observational study. Methods: 1,532 archived paper charts from all patients at the practice between 1996 and 2004 were screened. Patients with keratoconus who underwent PRK using multiple excimer laser techniques, with adequate preoperative documentation and available for re-evaluation after ≥20 years, were included. Outcomes included uncorrected (UDVA) and corrected distance visual acuity (CDVA), refractive spherical equivalent, astigmatism, and keratometry. Results: Sixty-eight keratoconus patients treated with PRK were identified; 16 patients (29 eyes) with available long-term follow-up were included, (mean follow-up of 22 years). UDVA improved from 0.81 ± 0.50 to 0.46 ± 0.36 logMAR (P = .005) and CDVA from 0.14 ± 0.17 to 0.08 ± 0.11 logMAR (P = .02), although not significant after excluding eyes that later required keratoplasty. Spherical equivalent decreased by 1.51 D (P = .001), and astigmatism by 0.82 D (P = .03). Maximum keratometry showed no significant change (P = .19). Four eyes (13.8%) required keratoplasty, including 3 of 7 (43%) with advanced disease. The remaining 25 eyes (86.2%) did not require keratoplasty, although some required additional interventions. Conclusion: In this small pre-CXL cohort, mild-to-moderate keratoconus eyes had visual and refractive improvement, while keratoplasty was required mainly in advanced cases. These findings offer historical observational context rather than evidence of safety or efficacy.