双通道视觉质量分析系统评价翼状胬肉手术前后患者的视觉质量

Assessment of optical quality of patients with pterygium by a double pass visual optical quality analysis system

目的利用视觉质量分析系统对翼状胬肉切除前后患者的客观光学质量变化进行分析。方法选取我院2016年9月至2017年5月在武汉大学人民医院眼科中心确诊为单眼翼状胬肉并且进行翼状胬肉切除伴自体结膜瓣移植手术患者20例20眼,根据翼状胬肉尺寸大小分为小胬肉组10例10眼和大胬肉组10例10眼,采用双通道视觉质量分析系统Ⅱ进行视觉质量检测,记录健康眼及患眼术前、术后1个月、3个月的调制传递函数截止频率(modulation transfer function cut off,MTF_(cutoff))、斯特列尔比(Strehl ratio,SR)、基础客观散射指数及总客观散射指数值,通过计算得出泪膜客观散射指数(tear film objective scatter index,TF-OSI)。结果与术前相比,两组中患眼术后3个月MTF_(cutoff)、SR均升高,TF-OSI降低,差异均有统计学意义(均为P<0.05),而术前与术后1个月相比两组三项视觉质量参数无明显统计学差异(均为P>0.05)。两组之间的视觉质量参数相比,只有术后3个月的MTF_(cutoff)、SR、TF-OSI比较差异具有统计学意义(均为P<0.05),术前与术后1个月的视觉质量参数均无统计学意义(均为P>0.05)。两组中健康眼与患眼术前相比MTF_(cutoff)、SR、TF-OSI均有统计学意义(均为P<0.05)。结论翼状胬肉会影响视觉质量及泪膜功能,早期手术切除能够带来改善,但这种改善可能出现在术后较长的一段时间内。利用视觉质量分析系统Ⅱ可以对手术前后的结果进行客观分析,MTF_(cutoff)、SR、TF-OSI可作为综合指标来评价临床上翼状胬肉患者的视觉质量。

Objective To analyze the objective optical quality changes before and after the pterygium excision using the optical quality analysis system.Methods Twenty patients who were diagnosed with monocular pterygium were selected in this study and treated with the pterygium excision(with autologous conjunctival flap transplantation)between September 2016 and May 2017 in the eye center of Renmin Hospital of Wuhan University.According to the sizes of the pterygium,the twenty patients were divided into group A(smaller pterygium group)with 10 patients(10 eyes)and group B(larger pterygium group)with 10 patients(10 eyes).The visual quality was checked using the double-pass OQAS II(optical quality analysis system II)to take a record of the MTFcutoff(modulation trasnsfer function cut-off frequency),SR(Strehl ratio),the basic objective of scattering index,as well as the total objective scattering index value of three different phases,namely the healthy eye,one month before and after the treatment,and three months before and after the treatment of the pterygium affected eye.Finally,TF-OSI(the tear film objective scatter index)is calculated.Results According to the calculation,both the MTFcutoff and SR of three months before treatment in group A showed an increase comparing respectively to the figures of three months after treatment while the TF-OSI was reduced with a statistical significance(all P<0.05).However,the three optical quality figures of one month before and after the treatment showed no statistically significant difference(all P>0.05).Such same result was also obtained in group B.If we compared the optical quality figures between group A and group B,it could be found that comparison of MTFcutoff,SR and TF-OSI showed statistical significance only for the figures of three months after the treatment(all P<0.05),while all the figures had no statistical significance for one month before and after the treatment(all P<0.05).In group A,if we compared the healthy eye with the pterygium affected eye,we could find that the MTFcutoff,SR and TF-OSI all showed the statistical significance(all P<0.05).The same results are obtained in group B.Conclusion Pterygium may affect visual quality and tear film function,and early pterygium excision treatment helps to relieve the symptom.However,such relief may not visible until a long period of time after surgical treatment.Using the optical quality analysis system will help to perform an objective analysis on the results before and after the treatment.MTFcutoff,SR,TF-OSI may be used as a comprehensive index to evaluate the optical quality of the clinical pterygium patients.