人眼像差在自适应光学系统矫正后的稳定性变化

Changes of ocular aberration stability after correction with adaptive optics system

背景 自适应光学（AO）系统在眼科临床及基础研究中日渐重要,但人眼像差矫正后Zernike系数主要项的稳定性变化特点尚少见报道. 目的 观察AO测量人眼像差的重复性,并探讨不同像差矫正后Zernike系数稳定性的变化. 方法 纳入2014年2-4月在校硕士研究生及符合条件的志愿者41名.应用AO测量波前像差,分别研究并分析散光（Z2-2、Z22）、离焦（Z20）、彗差（Z3-1、Z31）、三叶草（Z3-3、Z33）和球差（Z40）的Zernike系数,第3～7阶像差、总高阶像差（HOA）及总像差（TOA）的均方根值（RMS）重复性及矫正像差后的稳定性变化.测量的重复性评估采用重复测量的方差分析、组内标准差（Sw）、重测度（r）及组内相关系数（ICC）综合分析.波前像差矫正后的稳定性变化采用非参数Friedman双向秩次方差分析. 结果 Z2-2、Z22、Z20及TOA RMS的测量显示良好的可重复性（ICC＞0.9）;Z1、Z3-3、Z33、Z40、3阶像差RMS、4阶像差RMS、HOARMS的测量均显示较好的可重复性（均ICC＞0.75）;其余参数的测量显示可重复性弱（均ICC＜0.75）.各波前像差中Z31的r最大,为0.163 μm;各Zernike单项系数及各阶像差RMS值总体比较,差异均无统计学意义（均P＞0.05）.低阶像差矫正前后不同时间点Z2-2、Z20、Z22、Z3-3、Z3-1、Z31、Z33、Z40和HOA RMS总体比较,差异均有统计学意义（均P＜0.05）;Z2-2、Z22在矫正后第4秒进入稳定状态,Z20在矫正后第6秒进入稳定状态;Z3-3、Z33分别在矫正后第4秒、第3秒进入稳定状态,Z3-11在矫正后第4秒进入稳定状态,Z3-1在矫正后第3秒至第9秒处于稳定状态,Z0、HOA RMS分别在矫正后第3秒、第5秒进入稳定状态.矫正5阶内像差前后不同时间点Z2-2、Z20、Z2-2、Z3-3、Z3-1、Z33、Z40和HOA RMS总体比较,差异均有统计学意义（均P＜0.05）,Z31总体比较差异无统计学意义（P＞0.05）;Z2-2、Z20、Z22分别在矫正后第4秒、第5秒、第3秒进入稳定状态;Z3-3、Z33分别在矫正后第2秒、第3秒进入稳定状态,Z3-1及Z40均在矫正后第2秒进入稳定状态;HOA RMS在矫正后第5秒进入稳定状态.结论 人眼像差矫正后,不同像差达到稳定的时间不同.5阶内像差矫正后Z20、Z22、Z3-3、Z3-1、Z40比仅矫正低阶像差更早进入稳定状态.

Background The use of adaptive optics （AO） system in ophthalmic clinic and basic studies has increased in recent years.However,there are few reports on the stability of ocular aberrations after correction.Objective This study was to analyze the stability of aberration after correction by observing the repeatability of ocular aberration measurements.Methods Forty-one postgraduate school students and volunteers who meet the conditions were included from February to April 2014.The Zernike aberration coefficients including astigmatism （Z2-2,Z22）,defocus （Z02）,trefoil （Z33,Z3-3）,coma （Z3-1,Z13）,spherical aberration （Z40） and the value of root mean square （RMS） including 3rd-order to 7th-order aberrations,total higher-order aberrations （HOAs） and total ocular aberrations （TOAs） were measured by using AO system.The repeatability and stability of these data after corrected with AO system were analyzed.The repeatability was evaluated by ANOVA,within-subject standard deviation （Sw）,repeatability （r） and intra-class correlation coefficients （ICC）.The stability was evaluated by the nonparametric Friedman＆#39;s rank test.Results AO system showed excellent repeatability on Z2-2,Z22,Z20 and TOA RMS （ICC〉 0.9）,good repeatability on Z13,Z33,Z3-3,Z40,3rd-order RMS,4th-order RMS,HOA RMS （ICC 〉 0.75）,poor repeatability on Z3-1,5th-order RMS,6th-order RMS,7th-order RMS （ICC 〈 0.75）.Repeatability （2.77 Sw） values ranged from 0.009 mm （7th-order RMS） to 0.163 mm （Z31）.After low-order ocular aberrations were corrected,It was founded that Z2-2,Z22 reached stable state at the 4th second;Z02 was stable at the 6th second;Z3-3 and Z33 reached stable state at the 4th second and third second,separately;Z13 was stable from 3rd-second to 9th-second,Z3-1 was stable at the 4th-second.Z40 and HOA RMS were stable at the third second and fifth second,respectively.The Z2-2,Z02,Z22,Z3-3,Z3-1,Z33,Z40 and HOA RMS were significantly different among different time points before and after low-order aberrations correction （all at P 〈 0.05）.Z2-2,Z22,Z20 reached stable state at the 4th-second,3rd-second and 5th-second,respectively;Z3-3,Z33 reached stable state at the 2nd-second and 3rd-second,respectively;Z3-1and Z40 reached stable state at the 2nd-second;HOA RMS reached stable state at the 5th-second.Conclusions After correcting the human ocular aberration,different aberrations can reach stable state at different time.The time of Z02,Z22,Z3-3,Z3-1,Z40reaching stable state after 2nd-order to 5th-order ocular aberrations correction was earlier than those of lower-order aberrations correction.