One-year visual and astigmatic outcomes of keratoconus patients following sequential crosslinking and topography-guided surface ablation: the TOPOLINK study

Abstract

PURPOSE: To evaluate long-term visual and astigmatic outcomes of sequential corneal crosslinking (CXL) followed by topography-guided photorefractive keratectomy (PRK). SETTING: Single-practice outpatient setting. DESIGN: Retrospective case review. METHODS: This is a single-surgeon retrospective case review of eyes with keratoconus undergoing sequential CXL and then topography-guided PRK. Change in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), topographic, refractive, and keratometric astigmatism was analyzed using power vector analyses at baseline, 6 months, and 12 months after topography-guided PRK. Changes in higher-order aberrations (HOAs), posterior astigmatism, spherical equivalent (SE), and central corneal thickness (CCT) were also analyzed. Correlations between age, time between CXL and PRK, sex, manifest SE, CCT, maximum and average keratometric values, and HOAs were evaluated for significance. RESULTS: Of the 62 eyes studied, regardless of refractive treatment, topography-guided PRK following CXL in patients with keratoconus improved CDVA (mean 20/30; 2-line improvement) and UDVA (mean 20/50; 4-line improvement). Over 12 months, visual acuity continued to improve across all eyes treated (P < .001). Overall, there were significant improvements in corneal astigmatism, maximum keratometry, mean keratometry, SE, posterior astigmatism, and total HOAs. No significant correlations were found between age, sex, time elapsed between CXL and PRK, and age at the time of either procedure on final visual acuity. CONCLUSIONS: Results of this study reinforced previous findings that topography-guided PRK in previously cross-linked keratoconus eyes proves to be an efficacious and safe method for improving visual acuity and reducing irregular corneal astigmatism, with continued improvement.

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