白内障超声乳化术后OrbscanⅡ角膜参数与内皮细胞丢失率相关性的研究

The correlative study between corneal parameter measured by Orbscan Ⅱ and corneal endothelial cell loss rate after phacoemulsification cataract surgery

目的 探讨白内障超声乳化术后，OrbscanⅡ测得角膜后表面高度及角膜中央厚度改变与角膜内皮细胞丢失率的相关性。方法老年性白内障患者46人53眼，常规行白内障超声乳化及折叠式人工晶体植入术。记录术前、术后1d、1w、1m、3m的角膜后表面高度、角膜中央厚度及角膜内皮镜计数，采用SAS8．2统计软件对结果进行数据分析，指标前后比较使用配对t检验，简单直线相关计算术后3m角膜内皮细胞丢失率与术后第ld角膜后表面高度增加率的相关性，术后3m角膜内皮细胞丢失率与术后第ld角膜中央厚度增加率的相关性，并建立多元线性回归方程。结果①36人43眼完成该研究，术前角膜内皮细胞计数平均为2336±378cells／mm^2。②OrbscanⅡ显示术后第1d角膜后表面高度增加≤10％3眼，10．1％-20％4眼，〉20％36眼；角膜中央厚度增加≤5％13眼，5．1％-10％23眼，〉10％7眼。③角膜内皮镜计数显示：术后第1d 2324±382cells／mm2，1w2163±364cells／mm^2，1m2070±330cells／mm2，3m2038±332cells／mm^2，术后1w角膜内皮细胞的丢失率为7．4％，1月为11．4％，3月为12．7％。④简单直线相关分析：术后第1d角膜后表面高度增加与术后3m角膜内皮细胞选择率有相关性（R^2=0．14 p〈0．01），术后第1d角膜中央厚度的增加与术后3m角膜内皮细胞丢失率有相关性（R^2=0．66，P〈0．001）。结论 术后第1d角膜后表面高度增加、角膜中央厚度增加与术后3m内皮细胞丢失率有相关关系，提示术后第1d角膜后表面高度的增加及角膜中央厚度的增加可以预测角膜内皮细胞丢失率。

Objectiv To evaluate the correlation between the corneal parameter（corneal posterior surface height and thickness）measured by Orbscan Ⅱ and corneal endothelial cell loss rate after phacoemulsification. Methods The total of 53 eyes of 46 age related cataract patients.These involved patients were planned for phacoemulsification and intraocular lens implantation.Informed consent including Orbscan Ⅱ parameter and corneal endothelial cell count and so on. SAS8.2 software was used for statistical calculations. Student＇ paired t tests were used to test for preoperative and postoperative differences. Single linear correlation analysis was used to calculate affective factor relativity of corneal endothelial cell cell at 3 months and the corneal posterior surface height at day 1.The multiple linear regression analysis was performed to analyze the data acquired from single linear correlation analysis. Results （1）The data of 43eyes of 36 patients were analyzed. The preoperative average corneal endothelial cell count was 2336 ± 378cells/mm^2. （2）The increase in corneal posterior surface height at day 1 measured by Orbscan 1/was no more than 10% on 3 eyes, 10.1% to 20% on 4 eyes, more than 20% on 36 eyes. The increase in central corneal thickness was no more than 5% on 13 eyes, 5. 1% to 10% on 23 eyes, more than 10% on 7 eyes.（3）The corneal endothelial cell count measured by corneal endothelial specular microscope was 2324±382 cells/mm^2 at day 1. 2163 ± 364cells/mm^2 at 1 week. 2070 ± 330（2038 ±332 cells/mm^2） cells/mm^2 at 1 month, at 3 months. The corneal endothelial cell loss rate was ascending gradually. The corneal endothelial cell loss rate was 7.4% at 1 week, 11.4% at 1 month, 12.7% at 3 months.（4） Single linear correlation analysis was used for statistical calculation.The increase in corneal posterior surface height at day 1 was correlated with the corneal endothelial cell loss rate at 3 months （P〈0.01, R^2=14）. The increase in central corneal thickness at day 1 was strongly correlated with the corneal endothelial cell loss rate at 3 months（P〈0.001, R^2=0.66）. Conclusions The increase of corneal posterior surface height and corneal central thickness at postoperative day 1 were correlated with the corneal endothelial cell loss rate at 3 months. It suggested that the increase of corneal posterior surface height and corneal central thickness can predict the corneal endotheliai cell loss rate.