Eighteen-year follow-up of hyperopic photorefractive keratectomy.

PURPOSE: To investigate the long-term efficacy of hyperopic photorefractive keratectomy (PRK). SETTING: University Hospital, London, United Kingdom. DESIGN: Prospective case series. METHODS: Patients with a follow-up of 18 years ± 0.7 (SD) attended for examination. All had spherical corrections with a 6.5 mm optical zone and 1.5 mm blend zone. RESULTS: Twenty-five patients (45 eyes) were included. The mean preoperative spherical equivalent (SE) refractive error was +4.11 ± 1.8 diopters (D) (range +1.125 to +7.25 D). Between 1 year and 18 years, in eyes that had no cataract surgery (n = 34), there was a +1.14 ± 1.48 D increase in the mean SE (P < .0002). The increase between 7.5 years and 18.0 years did not reach clinical significance (P = .1). Uncorrected distance visual acuity improved at 18 years (P < .02). Corrected distance visual acuity (CDVA) was reduced (P < .001). The efficacy index was 0.47, and the safety index was 0.83. Six eyes (18%) lost 2 lines of CDVA, of which 4 eyes had preexisting cataract. Keratometry remained stable between 1 year and 18 years (P = .2). Forty percent still had traces of peripheral haze, and 4 (9%) had Salzmann-like changes. Eleven eyes (24%) had cataract surgery and 4 (9%) had laser iridotomy. There was no evidence of ectasia. CONCLUSIONS: Hyperopic PRK showed an increase in hyperopic SE between 1.0 year and 7.5 years but was generally stable thereafter. The efficacy was limited. Peripheral haze was evident in 40% of cases with Salzmann-like changes in some. Ocular comorbidity in relationship to cataract was common and reduced CDVA. FINANCIAL DISCLOSURE: Dr. Marshall was a consultant to Summit Technology, Inc. No author has a financial or proprietary interest in any material or method mentioned.

Corneal Cross-linking to Halt the Progression of Keratoconus and Corneal Ectasia: Seven-Year Follow-up.

PURPOSE: To determine long-term efficacy and safety of riboflavin/ultraviolet A corneal cross-linking (CXL). DESIGN: Prospective cohort study. METHODS: Thirty-six patients (36 eyes) who underwent epithelium-off CXL at a University Hospital (Guy's and St Thomas' National Health Service Foundation Trust) 6-8 years previously were examined. The main outcome measures were refractive error, visual acuity, corneal topographic keratometry, ultrasonic pachymetry, and topography-derived corneal wavefront. RESULTS: At 7 years compared to preoperative values, mean spherical equivalent refractive error (SEQ) increased by +0.78 diopter (D) (P < .005) and mean simulated topographic keratometry (SimK) and mean maximum keratometry (Kmax) reduced by -0.74 D (P < .0001) and -0.91 D (P < .0001), respectively. Uncorrected distance acuity (UCDA) (P < .0005) and corrected distance acuity (CDVA) (P < .0001) had improved and root mean square (RMS) (P < .0005), coma (P < .0005), and secondary astigmatism (P < .005) lessened. At 7 years compared to 1 year, CDVA improved (P < .05); mean SimK (P < .0005) and mean Kmax (P < .005) reduced by -0.45 D and -0.56 D, respectively; and RMS (P < .0005) and coma (P < .0005) decreased. At 7 years compared to 5 years, CDVA improved (P < .05) and trefoil reduced (P < .05). No treated eyes progressed. In 29 initially untreated fellow eyes mean SimK increased by +0.54 D (P < .02), mean Kmax by +0.87 D (P < .05), and refractive astigmatism increased (P < .0005). CONCLUSIONS: Following corneal cross-linking, improvements in topographic and wavefront parameters evident at 1 year were seen to continue to improve at 5 years and were maintained at 7 years. No treated eyes progressed over the 7-year follow-up period.