摘要
目的探讨机械法准分子激光上皮下角膜磨镶术（epipolis laser in keratomileusis，Epi-LASIK）后视觉质量变化及高阶像差对其影响。方法前瞻性研究。行角膜屈光手术的患者102例，其中52例行Epi—LASIK手术，另50例行LASIK手术作为对照组。分别于术前和术后4—6个月应用Wavescan波阵面像差仪测量波阵面像差，并对100％、25％、10％和5％对比度下的视力和眩光视力进行测量。其中病历完整者Epi—LASIK术后35例，LASIK术后33例，均取单眼进行分析。应用配对t检验和独立样本t检验分析Epi—LASIK术后视觉质量的变化及与LASIK术后的比较，应用多重线性回归分析高阶像差与对比度视力的关系，Pearson相关分析影响各对比度下视力的主要像差因素。结果有无眩光状态下Epi-LASIK术后5％及10％对比度视力分别为0．46±0．18、0．47±0．15、0．30±0．17、0．33±0．16，均较术前明显降低（眩光：t=-1．949，-2．283；P=0．047，0．029；无眩光：t=-4．863，3．950；P=0．000，0．000）。25％和100％对比度时，有无眩光状态下手术前后比较差异均无统计学意义（P〉0．05）。各高阶RMS值与对比度视力逐步回归分析，S4与5％对比度视力呈正相关（r2=0．282；P=0．025）；S。与10％对比度视力呈正相关，S5与其呈负相关（r2=0．192；P=0．033）；各高阶RMS对25％和100％对比度视力均无明显影响。各Zernike项回归分析，a和c与5％对比度视力呈正相关（r2=0．233；P=0．024）；C4^-4与10％对比度视力呈负相关，a和c5^-5与其呈正相关（r2=0．289；P=0．013）；各高阶像差Zernike项对25％和100％对比度视力的影响无统计学意义。S4和C4^0与各对比度视力的相关系数随着对比度的降低而增加，与5％对比度视力相关具有统计学意义（r=0．378，0．390；P=0．025，0．021）。与LASIK组对比，术后视力在100％对比度无眩光下略低于LASIK组，其他各对比度视力及术后屈光度两组间均无差别。结论Epi-LASIK手术后早期，无眩光下100％对比度视力略低于LASIK组；有无眩光状态时，低对比度下的视力均受到不同程度影响。球差和球样像差（S4）可能是降低低对比度视力的主要因素。
Objective To investigate changes of visual performance and effects of higher order aberration on visual performance after Epi-LASIK for myopia Method In this prospective study, 102 patients were included. The trial group had 52 patients with Epi-LASIK, and 50 cases with LASIK as the control group. Ocular higher order aberrations were measured with the Hartman-shack wavefront analyzer, and high （ 100% ）, moderate （25 % ）, low contrast （ 10% ） and very low contrast （ 5 % ） visual acuity with and without glare were measured with Multi-Function Visual Acuity Tester under mesopic condition preoperatively and 4 - 6 months after surgery. 35 subjects in Epi-LASIK and 33 cases in LASIK were followed up 4 -6 months later. Paired t test were used to analyze different contrast visual acuity before and after Epi-LASIK. Multiple linear regression analysis was performed to find the explanatory aberrations which contributed to the visual acuity. The Pearson correlation was used to explore the correlation between high- and low -contrast visual acuity and the explanatory higher order aberrations. The independent t test was used to analyze the difference of refraction power and visual acuity between Epi-LASIK and LASIK. Results There were significantly statistical differences at 5% and 10% contrast level compared to preoperation with glare and with no glare. With no glare, the mean logMAR visual acuity at 5% and 10% contrast level were 0. 32 -0. 14 and 0. 21 ± 0. 12 preoperatively, and 0. 47 ± 0. 15 and 0. 33 ± 0. 16 postoperatively （ t = -4. 863,3. 950 ;P = 0. 000,0.000 ）. With glare, the mean logMAR visual acuity were 0. 37 ± 0.20 and 0. 22 ± 0. 13 preoperatively, and 0. 46 ± 0. 18 and 0. 30 ± 0. 17 postoperatively（ t = - 1. 949, -2. 283; P = 0. 047,0. 029）. Using stepwise multiple linear regressions to evaluate which higher order aberration was significantly associated with each contrast VA. For each order RMS, S4 was positive correlated with 5% contrast visual acuity （ r2 = 0. 282 ; P = 0. 025 ） ; S4 was positive and S5 was negative correlated with 10% contrast visual acuity （ r2 = 0. 192 ; P = 0. 033 ）. None of the higher order RMS can significantly affect the 25% and 100% contrast visual acuity. For each Zernike coefficients, C4^4 and were positive correlated with 5% contrast visual acuity （ r2 = 0. 233 ; P = 0. 024 ） ; C44 was negative, C^4 and C5-5 were positive correlated with 10% contrast visual acuity （ r2 = 0. 289 ; P = 0. 013 ） ; None of Zernike coefficients had a significant correlation with 25% and 100% contrast visual acuity. The Pearson correlated coefficients between S4, Rand each contrast visual acuity increased as the contrast level decreased. S4 and C4^0 were associated significantly with 5% contrast visual acuity, the correlation coefficients were 0. 378 and 0. 390 （P = 0. 025 and 0. 021 ）. The visual acuity under 100% contrast with no glare was a little poorer than in LASIK. Conclusions At the early stage after Epi-LASIK, the visual acuity for lower contrast level was worse compared to preoperative with glare and with no glare. Spherical aberration and the spherical-like aberration may contribute to this.
出处
《中华眼科杂志》
CAS
CSCD
北大核心
2010年第3期197-202,共6页
Chinese Journal of Ophthalmology
基金
天津市自然科学基金资助项目（07JCYBJC09500）
关键词
角膜切削术
上皮下
激光
像差
视敏度
近视
Keratectomy, subepithelial, laser-assisted
Aberration
Visual acuity
Myopia
