目的 比较中高度散光患者配戴框架眼镜和透气性硬性接触镜（RGPCL）的主客观视觉质量。 方法 选取2008年6月－2011年5月中高度角膜散光20例共40只眼进行角膜地形图、综合验光仪验光等检查后，选择合适试戴片作配适评估并定制RGPCL。要求患者戴镜后1周、1个月、3个月和6个月复查，记录矫正视力、镜片配适、眼部情况，并在第4次复查时进行对比敏感度视力检查及主观问卷调查。 结果 RGPCL矫正视力优于框架眼镜，但两者对比敏感度视力在各空间频率均无明显差异。主观评分时，远视力两者无明显差别；中距离视力框架眼镜评分（3.825 ± 0.245）分，RGPCL评分（3.525 ± 0.302）分，差异有统计学意义（t=5.339，P=0.000）；近距离视力框架眼镜评分（3.795 ± 0.233）分，RGPCL评分（3.690 ± 0.194）分，差异有统计学意义（t=3.462，P=0.030）。有45%患者选择RGPCL为主要配戴方式；40%患者选择RGP CL和框架眼镜交替使用的方式；10%患者选择仅在有特殊社交需求时使用RGPCL；另5%患者放弃使用RGPCL。 结论 RGPCL和框架眼镜矫正中高度角膜散光均能取得较满意效果，在中近距离精细作业时框架眼镜矫正视力更为稳定清晰。但由于RGPCL在成像质量和外观上的优势，多数患者仍愿意坚持配戴RGPCL。
【摘要】 目的 探讨双眼散光轴向的关系。 方法 随机选取2010年1—12月预行准分子激光原位角膜磨镶术（laser in situ keratomileusis，LASIK）手术患者200例400只眼（散光gt;-0.50 D），收集全眼散光和角膜散光轴向，定性和定量分析双眼散光轴向的关系。 结果 ①定性分析：双眼全眼散光性质相同病例在电脑验光仪结果中占92.5%，在综合验光仪结果中占95.0%；双眼角膜散光性质相同病例在电脑验光仪结果中占95.5%，在角膜地形图结果中占97.5%。②定量分析：双眼全眼散光在电脑验光仪结果中对称者为36.5%，近似对称为25.0%，非对称为38.5%；在综合验光仪结果中对称者为50.5%，近似对称为19.5%，非对称为30.0%。双眼角膜散光在电脑验光仪结果中对称者为37.0%，近似对称为31.5%，非对称为31.5%；在角膜地形图结果中对称者为43.0%，近似对称为32.0%，非对称为25.0%。双眼散光轴向对称性指数的中位数在4种检查结果中分别为：8、6、8、6。 结论 双眼的全眼和角膜散光在轴向方面都具有同质性，并且具有对称或近似对称趋势。【Abstract】 Objective To analyze the relationship between binocular astigmatism axes. Methods This study included 400 eyes of 200 patients treated by laser in situ keratomileusis (LASIK) between January and December 2010, whose astigmatic degrees were greater than -0.5 D. We collected astigmatic axles coming from either whole eye or cornea. The relationship between binocular astigmatism axes was analyzed qualitatively and quantitatively. Results ① Qualitative analysis: cases of total astigmatism axis with similar quality in autorefraction took up 92.5%, and 95% in subjective refraction. Cases of cornea astigmatism axis with similar quality in autorefraction took up 95.5%, and 97.5% in cornea topography. ② Quantitative analysis: in autorefraction, cases of total astigmatism axes were symmetrical in 36.5%, approximately symmetrical in 25%, and dissymmetrical in 35% of the subjects. In subjective refraction, 50.5% showed symmetry, 19.5% approximate symmetry, and 30% dissymmetry. In autorefraction, cases of cornea astigmatism axis were symmetrical in about 37%, approximately symmetrical in 31.5%, and dissymmetrical in 31.5% of the patients. In cornea topography, 43% of the cases were symmetrical, about 32% were approximately symmetrical, and 25% were dissymmetrical. The middle numbers of the symmetrical index for the four kinds of examinations were respectively 8, 6, 8, and 6. Conclusion The total astigmatism axis and the binocular astigmatism axis of cornea have the characteristic of homogeneity, also the trend of symmetry.
目的:分析探讨单眼散光弱视患儿对比敏感度(CS)视功能的受损特点。方法:对正常儿童组36例、单眼散光弱视组34例、单眼非散光弱视组33例,共103例,用静态F.A.C.T图表和计算机Gabor斑CS检查程序分别检查患儿对侧眼、弱视眼及90°和180°两主子午线方向上的对比敏感度。结果:①单眼散光弱视组和单眼非散光弱视组的对侧眼、弱视眼的CS值在所有空间频率均较正常组的CS降低(Plt;0.05),表现为中、高空间频率区CS的明显受损(Plt;0.01)。②单眼散光弱视组的弱视眼在90°和180°两主子午线方向上的对比敏感度有显著差异(Plt;0.01)。结论:弱视儿童的对侧眼不正常。用计算机Gabor斑检查可以了解弱视散光儿童不同子午线上的CS存在的差异,明确定位弱子午线,并可以针对子午线性弱视,进一步开展知觉学习的治疗。
ObjectiveTo evaluate the effectiveness of using a six-dimensional eye-tracking system during femtosecond laser-assisted sub-Bowman keratomileusis (FS-SBK) surgery to correct myopia and astigmatism. MethodsA total of 23 patients (36 eyes) with ametropia undergoing FS-SBK were retrospectively analyzed and divided into the static cyclotorsion control (SCC) group (11 patients, 20 eyes) and the non-SCC group (12 patients, 16 eyes). According to the static eyeball rotation degrees, the SCC group was further divided into three subgroups: within ±2° group (5 patients, 9 eyes), ±2°-±5° group (4 patients, 7 eyes), and above ±5° group (2 patients, 4 eyes). The preoprative and postoperative one-month uncorrected visual acuity, best corrected visual acuity, diopter of spherical power, diopter of cylindrical power, corneal curvature, and the rotating degree in SCC were observed; the root-mean-square values of the total higher-order aberrations, spherical aberration, coma, Strehl ratio, etc. when the pupil diameter was 6.5 mm were extracted; and the therapeutic efficacy was observed. ResultsNo severe intraoperative or postoperative complications occurred in any subject. The effectiveness index of the SCC group was 0.947±0.145, and that of the non-SCC group was 1.005±0.141, with no statistically significant difference (P>0.05). Compared with the preoperative levels, in the two groups, the postoperative uncorrected visual acuity was significantly elevated; the postoperative diopter of spherical power, diopter of cylindrical power, and corneal curvature difference were reduced; the postoperative total higher-order aberrations, spherical aberration, and coma increased; all the differences mentioned above were statistically significant (P<0.05). In the SCC group, the difference between the preoperative and the postoperative Strehl ratio was statistically significant (P<0.05). There was no significant difference in postoperative indicators between the SCC group and the non-SCC group (P>0.05). The difference in postoperative increment of coma between the SCC group and the non-SCC group was statistically significant (P<0.05). In the SCC group, no statistically significant difference was found in postoperative increment of any indicator among the three subgroups (P<0.05). ConclusionsFS-SBK of six-dimensional eye-tracking system is effective in correcting myopia and astigmatism. FS-SBK can reduce lower-order aberrations while introducing higher-order aberrations, and whether SCC is performed intraoperatively is meaningless.
ObjectiveTo investigate whether the corneal shape recovered after discontinuation of long-term orthokeratology and whether orthokeratology increased the corneal astigmatism and ocular astigmatism.MethodsFrom December 2016 to April 2018, a retrospective study was conducted on 33 myopic patients who had undergone two times standard orthokeratology in the outpatient department of West China Hospital of Sichuan University, and had stopped wearing the first orthokeratology lens for one month before fitting the second orthokeratology lens. A total of 32 myopia frame glasses wearers were selected by simple random sampling as control. The changes of corneal flat meridian curvature (flat K), corneal steep meridian curvature (steep K), corneal astigmatism and ocular astigmatism before and after discontinuation of orthokeratology were analyzed.ResultsAmong the patients with baseline myopia diopter of −0.25～−2.75 D, the average annual change of corneal flat K was (−0.03±0.21) D in the frame glasses group and (−0.24±0.14) D in the orthokeratology group, the difference was statistically significant (t=5.555, P<0.001). Among the patients with baseline myopia diopter of −0.25～−2.75 D, the average annual change of corneal steep K was (0.20±0.42) D in the frame glasses group and (0.15±0.20) D in the orthokeratology group, the difference was not statistically significant (t=0.785, P=0.435). Among the patients with baseline myopia diopter of −3.00～−5.75 D, the average annual change of corneal steep K was (0.29±0.39) D in the frame glasses group and (−0.01±0.20) D in the orthokeratology group, the difference was statistically significant (t=2.758, P=0.014). The average changes of corneal astigmatism were analyzed according to the difference of eyes, gender, age and baseline corneal astigmatism, the difference was not statistically significant (P>0.05), respectively. For patients with baseline astigmatism absolute value less than or equal to 0.50 D, the astigmatism annual change of the frame glasses group was 0.00 (0.50) D, and that of orthokeratology group was −0.33 (0.48) D, the difference was statistically significant (Z=−2.301, P=0.021).ConclusionsThe flat K of the cornea becomes flatter and the steep K does not change after one month’s discontinuation of long-term orthokeratology. There was no difference in the increase of corneal astigmatism compared with those wearing frame glasses. When the baseline ocular astigmatism is less than or equal to 0.50 D, the increase of astigmatism may occur after discontinuation of orthokeratology.
The inverse problem of diffuse optical tomography (DOT) is ill-posed. Traditional method cannot achieve high imaging accuracy and the calculation process is time-consuming, which restricts the clinical application of DOT. Therefore, a method based on stacked auto-encoder (SAE) was proposed and used for the DOT inverse problem. Firstly, a traditional SAE method is used to solved the inverse problem. Then, the output structure of SAE neural network is improved to a single output SAE, which reduce the burden on the neural network. Finally, the improved SAE method is used to compare with traditional SAE method and traditional levenberg-marquardt (LM) iterative method. The result shows that the average time to solve the inverse problem of the method proposed in this paper is only 1.67% of the LM method. The mean square error (MSE) value is 46.21% lower than the traditional iterative method, 61.53% lower than the traditional SAE method, and the image correlation coefficient(ICC) value is 4.03% higher than the traditional iterative method, 18.7% higher than the traditional SAE method and has good noise immunity under 3% noise conditions. The research results in this article prove that the improved SAE method has higher image quality and noise resistance than the traditional SAE method, and at the same time has a faster calculation speed than the traditional iterative method, which is conducive to the application of neural networks in DOT inverse problem calculation.
ObjectiveTo compare the changes of corneal astigmatism after long-term spherical and toric orthokeratology wearing, and to investigate the effects of different orthokeratology design on corneal astigmatism.MethodsThe medical records of myopic adolescent patients who have been prescribed spherical and toric orthokeratology in the contact lens clinic of West China Hospital, Sichuan University between January 2019 and December 2021 were analyzed retrospectively.The differences of corneal astigmatism changes after wearing spherical and toric orthokeratology for a long time and one month discontinuation were compared. The influencing factors of corneal astigmatism changes were analyzed. ResultsA total of 156 patients were included. There were 76 cases (76 eyes) in spherical orthokeratology group and 80 cases (80 eyes) in toric orthokeratology group. There was no significant difference between the two groups in age, gender, baseline myopia diopter and total lens wearing time (P>0.05). There were statistically significant differences between the spherical orthokeratology group and the toric orthokeratology group in the baseline corneal flat K value [42.1 (41.3, 43.3) vs. 43.1 (42.0, 44.1) D], baseline corneal steep K value [(43.4±1.3) vs. (44.6±1.5) D], baseline corneal astigmatism [(1.1±0.5) vs. (1.6±0.6) D], and baseline total eye astigmatism [−0.6 (−1.2, 0.0) vs. −1.4 (−1.8, −1.0) D] before wearing the orthokeratology (P<0.05). Compared with the baseline value, 1 month after the two groups stopped wearing the orthokeratology, the corneal flat K values became flatter [spherical orthokeratology group: 42.09 (41.28, 43.34) vs. 41.73 (40.98, 43.16) D, toric orthokeratology group: 43.09 (41.95, 44.10) vs. 42.61 (41.52, 43.56) D; P<0.05], the changes of corneal steep K values were not statistically significant (P>0.05), but the corneal astigmatism values increased [spherical orthokeratology group: (1.05±0.49) vs. (1.37±0.56) D, toric orthokeratology group: (1.62±0.57) vs. (1.99±0.63) D; P<0.05]. There was no significant difference in the changes of corneal flat K value, corneal steep K value and corneal astigmatism between the two groups (P>0.05). Multivariate analysis showed that age (P=0.011) and the total duration of orthokeratology wearing (P=0.004) were the main factors affecting the changes of corneal astigmatism. ConclusionAfter 1 month of non-wearing, the flat K value of the cornea becomes flat, the steep K value remains unchanged, and the corneal astigmatism increases. There is no difference in the effect of the spherical and toric orthokeratology on corneal astigmatism. The change of corneal astigmatism is related to the patient’s age and the total duration of wearing the orthokeratology. The younger the age, the longer the duration of orthokeratology wearing, the more significant the increase of corneal astigmatism after stopping wearing the orthokeratology.