Rao S K, Mukesh B N, Bakshi H, Sitalakshmi G, Padmanabhan P
Sankara Nethralaya, Medical & Vision Research Foundation, Madras, India.
Ophthalmic Surg Lasers. 1996 May;27(5 Suppl):S444-53.
Excimer laser photorefractive keratectomy (PRK) is quickly establishing itself as a dependable treatment modality for the correction of myopia. We review in this report our experience with the Summit OmniMed UV200 excimer laser (Summit Technology, Inc., Waltham, MA) in the treatment of low to high degrees of myopia.
We retrospectively analyzed the results of excimer laser PRK in 139 eyes of 127 patients treated between November 1993 and August 1994.
The study population was comprised of 75 males and 52 females with a mean ago of 26.9 +/- 6.21 years (range, 19 to 52 years). All patients were followed for at least six months and the mean follow-up was 11.7 +/- 3.63 months (range, 6 to 22 months). Mean pre-operative myopia was -8.23 +/- 3.32 diopters (D) (-2.63 to -19.50 D). Of 139 eyes, 101 (72.7%) had a pre-operative myopia greater than -6.00 D; and 32 (23.0%) had a pre-operative myopia greater than -10.00 D. At last follow-up, 73 (52.5%) eyes were within +/-1.00 D of emmetropia, 92 (66.2%) eyes had an uncorrected visual acuity of > or = 6/12, and 12 (8.6%) eyes lost 2 or more lines of spectacle corrected visual acuity. Severe corneal haze (grade 3 to 4) was seen in 20 (14.4%) eyes at last follow-up. Complications encountered in this series included steroid response in 15 (10.8%) eyes, and reactivation of herpes simplex keratitis in one (0.7%) eye. Statistical analysis reveals that the only risk factor independently associated with regression > or = 2.00 D following PRK is the occurrence of severe corneal haze (grade 3 and 4).
Excimer laser PRK appears to be a safe and predictable method for the treatment of myopia < 6.00 D. With higher degrees of myopia the results appeared to be more guarded, mainly due to the healing pattern of the cornea following single zone myopic ablations.
准分子激光屈光性角膜切削术（PRK）正迅速成为一种可靠的近视矫正治疗方式。在本报告中，我们回顾了使用Summit OmniMed UV200准分子激光（Summit Technology公司，马萨诸塞州沃尔瑟姆）治疗低度至高度近视的经验。
我们回顾性分析了1993年11月至1994年8月期间接受准分子激光PRK治疗的127例患者139只眼的结果。
研究人群包括75名男性和52名女性，平均年龄为26.9±6.21岁（范围19至52岁）。所有患者至少随访6个月，平均随访时间为11.7±3.63个月（范围6至22个月）。术前平均近视度数为-8.23±3.32屈光度（D）（-2.63至-19.50 D）。在139只眼中，101只（72.7%）术前近视度数大于-6.00 D；32只（23.0%）术前近视度数大于-10.00 D。在最后一次随访时，73只（52.5%）眼的屈光不正度数在正视眼±1.00 D范围内，92只（66.2%）眼的裸眼视力≥6/12，12只（8.6%）眼的矫正视力下降了2行或更多。在最后一次随访时，20只（14.4%）眼出现了严重角膜混浊（3至4级）。本系列中遇到的并发症包括15只（10.8%）眼出现类固醇反应，1只（0.7%）眼单纯疱疹性角膜炎复发。统计分析显示，PRK术后屈光回退≥2.00 D的唯一独立危险因素是严重角膜混浊（3级和4级）的发生。
准分子激光PRK似乎是治疗<6.00 D近视的一种安全且可预测的方法。对于更高度数的近视，结果似乎更不乐观，主要是由于单区近视性切削后角膜的愈合模式。
