白内障手术相关的不等像及其对术后双眼视觉的影响

目的：探讨双眼白内障术后不等像的变化，并分析不等像对术后双眼视觉状态的影响。方法：前瞻性临床研究。2019年1—11月于萨鲁斯大学宾夕法尼亚视光学院和LewisLASIK眼科诊所招募拟接受双眼白内障手术的患者（≥50岁）73例。所有受检者在第1眼手术前接受不等像检查，第2眼手术后接受不等像检查和综合双眼视检查。综合双眼视检查方案包括立体视、眼位、融像性聚散、聚散灵活度及集合近点检查等。根据双眼视检查结果确定受检者的双眼视觉状态（正常双眼视或双眼视异常）。采用McNemar卡方检验比较手术前、后有临床意义的不等像比例（≥3%）；Spearman检验分析不等像与屈光参差、双眼人工晶状体（IOL）度数差值及立体视之间的相关性；Logistic回归分析不等像对术后双眼视觉状态的影响；受试者工作特征（ROC）曲线确定能预测术后是否存在双眼视异常的不等像临界值。结果：术后平均随访时间为2个月。最终纳入51例受检者，其中13例（25%）在术后被诊断为非斜视性双眼视异常，主要为集合不足11例（22%）。术后有临床意义的不等像比例较术前差异无统计学意义（χ2=1.14,P=0.286）。术前、术后及术源性不等像与屈光参差、双眼IOL度数差值及立体视均无相关性。Logistic回归分析显示，术后的双眼视异常与术前（OR=1.46,P=0.047）、术后（OR=1.67,P=0.031）及术源性（OR=1.48,P=0.021）不等像之间均存在相关性。ROC曲线分析显示，术源性不等像显示出最佳的曲线下面积（AUC），其AUC值为0.74，术源性不等像>2.4%时，其预测术后双眼视异常的敏感性和特异性最佳，分别为80.6%和65.0%。术前和术后的不等像AUC值分别为0.68、0.66，分别取临界值3.3%和2.9%时，预测的敏感性和特异性最佳。结论：双眼白内障手术并不明显改变不等像。然而，双眼白内障手术群体的不等像可作为预测因子，用来预测术后发生双眼视异常的风险。

Aniseikonia Associated with Cataract Surgery and Its Impact on Post-Surgical Binocular Vision

Objective: To investigate the change in the aniseikonia after cataract surgery and its effect on postsurgical binocular vision status. Methods: A prospective, clinical study of 73 patients ( ≥ 50 years) who elected to undergo bilateral cataract surgery at Pennsylvania College of Optometry at Salus University and LewisLASIK Eye Clinic from January 2019 to November 2019 was implemented. All subjects underwent aniseikonia test before surgery of the first eye. Aniseikonia and comprehensive binocular vision test battery were performed for all subjects after surgery of the second eye. A comprehensive binocular vision test battery including stereopsis, ocular alignment, fusional vergence, vergence facility and near point of convergence. A detailed diagnostic classification protocol was applied to identify the presence of binocular vision anormalies after surgery. McNemar Chi-square test was used to compare the proportion of significant aniseikonia before and after surgery. Spearman test was used to detect the correlations between aniseikonia and anisometropia, interocular difference in intraocular lens (IOL) power or stereopsis. Logistic regression was used to test the effects of aniseikonia on post-surgical binocular vision status.The receiver operating characteristic (ROC) curve was used to determine the cut-off values of aniseikonia that can predict the presence of post-surgical binocular vision anormalies. Results: The mean follow-up interval was 2 months. A total of 51 subjects were included, of which 13 cases (25%) were diagnosed with non-strabismic binocular vision anormalies after surgery, mainly with convergence insufficiency (11 cases, 22%). There were no statistically significant changes in the changes in proportions of clinically significant aniseikonia (≥3%) after surgery (x2 =1.14, P=0.286). There were no statistically significant correlations between aniseikonia and anisometropia, interocular difference in IOL power or stereopsis either at baseline or after surgery. Logistic regression results showed significant associations between the presence of post-surgical binocular vision anormalies and pre-surgical (OR=1.46, P=0.047), post-surgical (OR=1.67, P=0.031) aniseikonia, and surgically induced (OR=1.48, P=0.021) aniseikonia. ROC curve indicated that the best area under curve (AUC) was shown for surgically induced aniseikonia (AUC=0.74), and a cut-off value of 2.4% provides the optimal sensitivity and specificity for whether predicting a post-surgical binocular vision anormaly. Before and after surgical aniseikonia had similar AUC values (0.68 vs. 0.66), and the cutoff values of 3.3% and 2.9% showing the best combination of sensitivity and specificity. Conclusions: Bilateral cataract surgery does not appear to significantly change aniseikonia. However, this study found a significant predictive effect of aniseikonia for the occurrence of binocular vision disorders after surgery.