Eight-year Follow-up of Photorefractive Keratectomy for Myopia

Abstract

PURPOSE: We evaluated 8-year results of excimer laser photorefractive keratectomy (PRK) for myopia in terms of stability and late complications. METHODS: Ninety-two myopic eyes of 55 patients were treated with a single-step method using an Aesculap-Meditec MEL 60 excimer laser with a 5.0-mm ablation zone. Treated eyes were divided into three groups according to preoperative refraction: low myopes (≤-6.00 D), medium myopes (-6.10 to -10.00 D), and high myopes (>-10.00D). RESULTS: Change in myopic regression stabilized in all myopia groups within 12 months, although a small myopic shift occurred up to 8 years after PRK. Mean change in refraction between 2 and 8 years was -0.42 ± 0.48 D for low myopes, -0.37 ± 0.34 D for medium myopes, and -0.41 ± 0.50 D for high myopes. The percentage of eyes within ±1.00 D of emmetropia 8 years after PRK was 78.3% in the low myopia group, 68.8% in the medium myopia group, and 57.1% in the high myopia group. One eye lost 2 lines of best spectacle-corrected visual acuity due to irregular astigmatism. In 13.0% of eyes, a residual trace corneal haze was observed, which had no effect on visual acuity. Apart from the loss of 2 lines of BSCVA in one eye, there were no other late complications during the study period. CONCLUSIONS: The mean change in refraction between 2 and 8 years was less than -0.50 D, regardless of preoperative refraction, and may be attributed to natural age-related refractive change. The appearance of residual corneal haze after 8 years correlated with the amount of myopic correction. PRK was a safe and stable surgical procedure in this group of patients. [J Refract Surg 2004;20: 110-115]

Long-term Outcomes of Photorefractive Keratectomy for Low to High Myopia: 13 to 19 Years of Follow-Up

“…Our results seem comparable with other long-term prospective and retrospective results 8 to 16 years after PRK. [11][12][13][14][20][21][22][23] Concerning refractive predictability and stability, Alio et al 20,21 reported 75% of eyes (with less than -6 D) and 58% of eyes (with more than -6 D) being within ±1.0 D 10 years after PRK. Bricola et al 12 reported no late regression after 14 years, and Guerin et al 11 found a mean SE error of -0.69 ± 0.79 in 23 patients after 16 years.…”

Response of the Cornea for up to Four Years After Photorefractive Keratectomy for Myopia

“…Many authors have reported, as a common occurrence after PRK, a mean early postoperative refractive regression of Ϫ0.50 D during the fi rst year after treatment and a slow myopic regression for up to 8 years of follow-up. [14][15][16][17][18] However, aside from the role of the anterior 19 and posterior corneal curvatures, 20 the refraction of the eye optics may depend on more variables such as age-related changes of the lens and vitreous. [21][22][23] Because the laser ablation reshapes the corneal tissue that showed mechanical response to a change in its structure 24,25 and considering the expected longevity of patients undergoing refractive procedures, it is a main point of interest to investigate whether progressive remodeling of the cornea occurs in the years following refractive surgery.…”

Laser epithelial keratomileusis in 2010 – a review

“…Pietilä et al . in an 8‐year retrospective follow‐up study reported good stability and minimal haze and concluded the PRK was safe for patients with myopia up to and in excess of 10 D 20 . The 12‐year follow‐up study by Rajan et al 21 .…”