激光近视矫正原理与实现

小光斑准分子激光LASIK手术反应轻 ,视力恢复快 ,屈光回退少等优点成为目前矫治效果最好的角膜屈光手术方法。本文研究了LASIK术治疗近视的原理 ,定量地分析了近视度数以及术区直径和最大切削深度的关系 ,给出小光斑准分子激光治疗近视的软件硬件实现方法 ,经过临床表明本文给出的治疗模型的效果良好     

准分子激光角膜原位磨镶术治疗高度近视

本对８６例１６２只眼屈光度平均为－１１．２８±５．１１Ｄ（－６００－２７００Ｄ）高度近视行准分子激光角膜原位磨镶术（ＬＡＳＩＫ），术后半年视力、屈出度与术前比较，明术后视力、屈光度变化有规律性、分析影响疗效的因素，肯定ＬＡＳＩＫ术矫正高度近视有效、安全、预测性强、稳定性好，并发症少。     

Effects of interactions among wave aberrations on optical image quality after refractive surgery

Research on wave aberrations indicates that interactions and balances among aberrations can provide better visual quality for normal eyes. In this paper, we investigate the aberration compensatory mechanism for eyes after LASIK surgery. Data of Zernike coefficients of wave-front aberrations are collected from 60 post-operative eyes through a Hartmann-Shack wave-front sensor, and then a series of Monte Carlo simulations are performed by manipulating the value of each Zernike coefficient (second order through seventh order). The modulation transfer function (MTF) ratio as a function of spatial frequency is used to evaluate the aberrations’ characteristic of independence. Finally, in a control condition, “synthetic” model eyes are produced through Monte Carlo arithmetic and the aberration independence of the synthetic eyes is analyzed. The results suggest that, for 6 and 3 mm pupil size, aberrations of the eyes after LASIK surgery are still not independent and the adaptive mechanism still exists. However, the adaptive mechanism does not hold for the “synthetic” eyes.     

LASIK 治疗近视的临床分析

目的 :为了评价初学LASIK治疗近视可能出现的术中术后并发症及预防、处理。方法 :对 1 0 0例 ( 1 88眼 )屈光不正患者 ,采用LASIK进行治疗。结果 :术中并发症有薄角膜瓣、不完全角膜瓣、游离角膜瓣、角膜瓣偏离中心、层间异物残留和结膜下出血 ,术后短期并发症有眩光、欠矫或过矫、最佳矫正视力下降、角膜感染、角膜瓣异位、早期屈光回退。结论 :LASIK手术能有效地治疗近视 ,预测性和准确性较高 ,但是对于初学者要注意并发症的处理及经验的总结     

前弹力层下切削术与传统薄瓣准分子激光原位角膜磨镶术在矫正中高度近视时的疗效比较

目的：比较前弹力层下切削术与传统薄瓣准分子激光原位角膜磨镶术在矫正中高度近视中的疗效。方法：回顾性研究过去四个月在我院分别行前弹力层下切削术和传统薄瓣LASIK术治疗近视患者236例（470只眼）的术后情况;其中接受SBK近视矫正的患者118例（235只眼）,接受薄瓣LASIK近视矫正的患者118例（235只眼）。所有患者术前等效球镜值介于-3.0到-9.0度,以及等效柱镜值≤-3.0度。分别对术后1周,1个月和3个月裸眼视力进行比较并作统计学处理。结果：SBK组平均术前等效球镜值为-6.17±1.67D,LASIK组平均术前等效球镜值为-6.08±1.37（P=0.5）。术后1周裸眼视力（UCVA）,SBK组为1.07±0.19,LASIK组为1.12±0.17（P〈0.05）;术后1个月裸眼视力,SBK组1.07±0.19,LASIK组为1.154±0.18（P=0.000）;术后3个月裸眼视力,SBK组为1.0±0.20,其中裸眼视力〉1.0占77.3%,LASIK组为1.15±0.19,其中裸眼视力〉1.0占94.0%（P=0.001）。术后3个月疗效指数（术后裸眼视力/术前最佳矫正视力）比较,SBK组为0.88±0.16,LASIK组为0.93±0.19（P=0.14）。结论：本研究显示,与SBK术相比,传统薄瓣LASIK术在矫正中高度近视时能得到更好的视力效果,但两者的疗效指数没有差异。     

The aberration and the modulation transfer function in LASEK and LASIK: Pupil size dependence

The wave-front aberrations on the postoperative eyes with two different type of excimer laser surgery have been measured by a Hartmann-Shack wave-front sensor. We have calculated the aberrations for both 3 and 6 mm pupils, and with which to acquire the MTF of the eye. There are no significant differences in wave-front aberrations postoperatively (P>0.05) for 3 mm pupil size, but with 6 mm pupil, LASIK-treated eyes exhibit significant higher aberrations than LASEK-treated eyes for 4th and 5th-order aberrations. For individual Zernike terms, there are significant difference in , and . The MTF for 6 mm pupil is much lower than those for 3 mm pupil across all spatial frequencies. The LASEK curve shows higher than that with LASIK at spatial frequencies less than 60 c/d, which means that the optical quality in LASEK-treated eyes showed better than in LASIK-treated eyes.     

早期降眼压药物对高度近视术后屈光回退影响的研究

目的：探讨早期应用降眼压药物噻吗洛尔对高度近视术后屈光回退的影响。方法：将高度近视患者41例（81眼）LASIK手术后分为两组：常规组和噻吗洛尔组,分别于术前和术后1m、3m、6m、12m检查裸眼视力、屈光度、角膜前表面曲率等指标,比较分析并计算屈光回退率。结果：两组术后随着时间的推移,屈光回退率及角膜前表面曲率值均有增加,但用药组回退率及曲率增加值在术后1m、3m、6m、12m分别低于常规组,差异有统计学意义（P〈0.05）。结论：早期应用降眼压药物能够较好的降低高度近视术后屈光回退,稳定手术效果。     

LASIK手术对人眼波前像差的影响

采用主观光线追迹的像差仪测量人眼波前像差,比较3mm和6mm 瞳孔直径下,LASIK手术前与术后四个月的29只人眼波像差情况.数据比较分析表明,手术后人眼高阶像差一般会大于术前,且像差增大量随术前屈光度数的增大和瞳孔直径的增大而增加,如3 mm瞳孔直径下86%的人眼高阶像差的RMSH<0.12 μ,>0.4μ.比较人眼波像差的Zernik展开式中各项发现球差Z04无论在3 mm还是6 mm孔径下术后改变都最大;其中,当比较3阶,4阶和5至7阶时可看出对于3 mm孔径第三阶术后改变比例较大,为1.87,6 mm时第四阶改变较大,比例为2.21.     

准分子激光近视矫正系统的基本原理及实现

小光斑准分子激光辅助角膜磨镶术(LASIK)手术具有术后反应较轻、视力恢复快、屈光回退少等优点,成为目前近视矫治效果最好的角膜屈光手术方法.文中研究了LASIK术治疗近视的原理,定量地分析了近视度数以及手术区直径和最大切削深度的关系,给出某种小光斑准分子激光治疗近视的软件硬件的基本实现方法,经过临床表明,文中所给出治疗模型的效果良好.