Vijay K Wagh1, Reena Dave1, David P S O'Brart2, Wei S Lim1, Parul Patel1, Connan Tam1, Jennifer Lee1, John Marshall1. 1. From the Keratoconus Research Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. 2. From the Keratoconus Research Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. Electronic address: davidobrart@aol.com.
Abstract
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.
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.