近视及近视散光眼高阶像差与对比度视力间的关系

摘要

Objective It has been shown that visual performance and aberration are related to pupil diameter. This study investigated the correlation between visual performance and higher-order aberration for corresponding pupil sizes under bright and dark backgrounds in patients with myopia and myopic astigmatism. Methods This was a prospective clinical study. One hundred and twenty-three right eyes of 123 subjects with a spherical equivalent refraction (SE) from-0.5 D to-10.00 D were enrolled in this study. An iTrace wavefront aberrometer was used to measure the aberration. MFVA-100 was used to measure contrast visual acuities. 100%, 25%, 10% and 5% contrast visual acuities under bright and dark backgrounds, and the pupil size for corresponding conditions were recorded with a Pupillometer. The root mean square (RMS) values of the wavefront aberrations under the corresponding pupil sizes were calculated. The relationship between higher-order aberrations and contrast visual acuity under bright and dark backgrounds were analyzed. A paired t test and multiple linear regression analysis was performed. Results Under a bright background, contrast visual acuities of 100%, 25%, 10%, 5% were 5.155, 4.989, 4.759, 4.665; Under a dark background, the corresponding contrast visual acuities were 5.068, 4.875, 4.665, 4.439, the differences between the two backgrouds were significant of the same contrast (t=20.095, 18.241, 12.422, 28.538, P＜ 0.01). Under the same background, visual acuities among different contrast were significant (F= 500.564, 842.708, P＜0.01). Under a bright background, the RMS of coma (both the horizontal and vertical coma) was significantly associated with four different contrast visual acuities (r2=0.072, 0.124, 0.104, 0.119, P＜0.01 for all). Under a dark background, RMS of the fourth-order Zernike coefficients was significantly associated with contrast visual acuity (r2=0.045, 0.123, 0.161, 0.067, P＜0.05 for all). Conclusion The link between visual performance and aberration depends on the variation in pupil size. Under a bright background, coma is the main factor affecting visual performance. Under a dark background, fourth-order Zernike coefficients contributes to the degradation of the contrast visual acuity because of the larger pupil size.%目的 探讨明、暗环境下近视及近视散光眼高阶像差与对比度视力之间的关系.方法 前瞻性临床研究.对123例近视患者的单眼进行研究.采用iTracy波前像差仪测量像差;分别在明、暗环境下测量100%、25%、10%、5%四种对比度视力,同时用Pupillometer测量相应瞳孔大小.分析所有受试者相应瞳孔大小下的高阶像差的均方根与不同对比度视力间的关系,数据分别采用配对t检验、多元线性回归进行分析.结果 在明环境下,100%、25%、10%、5%的对比度视力平均值分别为5.155、4.989、4.759、4.665;而在暗环境下,相应的对比度视力平均值分别为5.068、4.875、4.665、4.439.两种环境同一对比度下,对比度视力间差异有统计学意义(t=20.095、18.241、12.422、28.538,P均＜0.01);同一环境下,各个对比度视力间差异有统计学意义(F=500.564、842.708,P均＜0.01).在明环境下,100%、25%、10%、5%对比度视力均与彗差相关(r2=0.072、0.124、0.104、0.119,P均＜0.01).在暗环境下,100%、25%、10%、5%对比度视力均与四阶像差相关(r2=0.045、0.123、0.161、0.067,P均＜0.05).结论 对比度视力与像差的相关性随着瞳孔大小变化而变化.在明环境下,影响对比度视力的主要是彗差.在暗环境下,随着瞳孔增大,影响对比度视力的主要是四阶像差.