角膜后表面曲率变化和 6 个月夜间角膜塑形治疗后的恢复。

Posterior corneal curvature change and recovery after 6 months of overnight orthokeratology treatment.

机构信息

School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.

出版信息

Ophthalmic Physiol Opt. 2010 May;30(3):274-80. doi: 10.1111/j.1475-1313.2010.00710.x.

DOI:10.1111/j.1475-1313.2010.00710.x

PMID:20444134

Abstract

PURPOSE

To investigate the changes in, and recovery of, posterior corneal curvature after 6 months of overnight orthokeratology (ortho-k).

METHODS

Twenty-eight healthy young adults were recruited for a 6-month period of ortho-k treatment and data from their right eyes were analyzed. The mean +/- standard deviation spherical equivalent refraction (SER) at baseline was -2.95 +/- 0.88 D. Posterior simulated keratometry (Sim K) readings were measured with a corneal topographer based on rotating Scheimpflug imaging. The three phases in the study were the 6-month treatment period (Phase I); diurnal changes over a period of 8 h immediately after lens removal at the completion of the treatment period (Phase II); and a 2-month recovery period after cessation of treatment (Phase III). Measurements were taken after lens wear overnight, and after 1 week, and 1, 2, 3 and 6 months of lens wear in Phase I. In Phase II, measurements were taken immediately, and then 2, 4 and 8 h after lens removal. In Phase III, corneal parameters were monitored 1 week, 2 weeks, 1 month and 2 months after cessation of ortho-k treatment.

RESULTS

In Phase I, the posterior Sim K readings were significantly steepened after the first overnight lens wear. These significant changes were not found at other visits. In Phase II, the posterior Sim K readings were the steepest immediately after lens removal and significantly flattened 2 h after lens removal. In Phase III, all the posterior Sim K readings were similar to the baseline results.

CONCLUSIONS

Steepening of the posterior cornea was only observed immediately after lens removal. It returns to its original shape within 2 h after cessation of lens wear. These changes appear to be in line with recent reports of the diurnal variation in the posterior corneal shape in non-contact lens wearers. The reduction in myopia from ortho-k treatment is therefore mainly due to a flattening of the anterior cornea.

摘要

目的

研究夜间角膜塑形术（ortho-k）治疗 6 个月后，后角膜曲率的变化和恢复情况。

方法

招募 28 名健康的年轻成年人进行 6 个月的 ortho-k 治疗，并分析他们右眼的数据。基线时平均（+/-标准偏差）球镜等效屈光度（SER）为-2.95 +/- 0.88 D。使用基于旋转 Scheimpflug 成像的角膜地形图仪测量后模拟角膜曲率（Sim K）读数。研究的三个阶段是：6 个月的治疗期（第 I 阶段）；治疗结束后立即在镜片去除后 8 小时内的日间变化（第 II 阶段）；治疗停止后的 2 个月恢复期（第 III 阶段）。第 I 阶段在夜间戴镜后、戴镜 1 周后、1 个月、2 个月和 3 个月以及 6 个月时进行测量。在第 II 阶段，立即进行测量，然后在镜片去除后 2、4 和 8 小时进行测量。在第 III 阶段，在停止 ortho-k 治疗后 1 周、2 周、1 个月和 2 个月监测角膜参数。