弱视眼波前像差的研究

Study of wavefront aberrations in amblyopia

目的研究弱视眼波前像差特点,分析像差在弱视形成中的作用机制,为弱视治疗提供依据。设计病例系列研究。研究对象弱视患者112例,正视眼30例。方法利用主观波前像差仪比较弱视眼与正视眼的像差,对可能参与弱视形成的球镜、柱镜和年龄等因素进行协方差分析,明确主要影响因素。主要指标整体像差、高阶波前像差、各阶及各项波前像差。结果弱视组整体像差(0.90±0.72)大于正视眼组(0.35±0.17),在像差第5项(45°和135°斜散光),正视眼组、弱视组、弱视治愈组、难治性弱视组间表现出特征性差异,其中弱视组(0.32±0.64)明显高于正视眼组(0.06±0.21);难治性弱视组最佳矫正视力虽已达到0.7～0.8,但第5项像差(0.33±0.36)仍明显高于正视眼组;而弱视治愈组(0.11±0.25)与正视眼组无显著差异,弱视治愈组斜散光趋于正常。结论视网膜成像质量下降与弱视形成有关。人眼正视化过程中难以矫正的斜散光使视觉信息质量下降,最终导致弱视。斜散光不仅是导致弱视的重要原因之一,也是治疗弱视的关键。

Objective To investigate the characteristics of wavefront aberrations in amblyopia, and then to explore the practicability of aberration correction therapy in amblyopia by discussing the possible mechanism that the aberration effect amblyopia. Design Case series. Participants Amblyopic 112 cases, 30 cases as control. Methods A subjective wavefront aberrations instrument was used in measuring the both eyes of the subjects. In addition to t test and multiple comparison among experimental groups, analysis of covariance was used to compare the contribution of each possible influence factor on wavefront aberration and retinal quanlity. Main Outcome Measures The mean RMS value of overall wavefront aberrations, high order aberration, and aberration of individual orders were calculated, moreover, Zernike aberrations were also included in statistic analysis. Results Comparing with emmetropia, amblyopic groups showed a greater value for overall wavefront aberration, amblyopia group vs emmetropia group was 0.90±0.72 vs 0.35±0.17. Further more, common amblyopic group and stable amblyopic group presented higher oblique astigmatism （Z5 aberration）, 0.32±0.64 and 0.33±0.36 respectively, although the vision acuity of stable amblyopic group ranged around 0.7-0.8. In contrast to this, both emmetropic group and recovered amblyopic group hold low oblique astigmatism. Conclusions The increased total wavefront aberration confirm the close relationship between low quality of retinal image and amblyopia. During the emmetropization process in amblyopia, the axes shift of astigmatism stopped at oblique astigmatism for some reason, which extremely decreased the retinal quality and consequently led to amblyopia. Oblique astigmatism might be a clinic marker of both the recovery of amblyopia and the restart of emmetropization.