Epitropoulos Alice T, Matossian Cynthia, Berdy Gregg J, Malhotra Ranjan P, Potvin Richard
From the Eye Center of Columbus (Epitropoulos), Columbus, Ohio, Matossian Eye Associates (Matossian), Pennington, New Jersey, Ophthalmology Associates (Berdy, Malhotra), Saint Louis, Missouri, and Science in Vision (Potvin), Akron, New York, USA.
From the Eye Center of Columbus (Epitropoulos), Columbus, Ohio, Matossian Eye Associates (Matossian), Pennington, New Jersey, Ophthalmology Associates (Berdy, Malhotra), Saint Louis, Missouri, and Science in Vision (Potvin), Akron, New York, USA.
J Cataract Refract Surg. 2015 Aug;41(8):1672-7. doi: 10.1016/j.jcrs.2015.01.016.
To evaluate the effects of tear osmolarity on the repeatability of keratometry (K) measurements in patients presenting for cataract surgery.
Three clinical practices.
Observational prospective nonrandomized study.
Subjects were prospectively recruited based on tear osmolarity (Tearlab Osmolarity System); that is, osmolarity more than 316 mOsm/L in at least 1 eye (hyperosmolar) and osmolarity less than 308 mOsm/L in both eyes (normal). The baseline K value was measured, and a second measurement was taken on the same instrument (IOLMaster) within 3 weeks of the first. Variability in average K, calculated corneal astigmatism using vector analysis, and intraocular lens (IOL) sphere power calculations were compared between groups.
The hyperosmolar group (50 subjects) had a statistically significantly higher variability in the average K reading (P = .05) than the normal group (25 subjects) and a statistically significantly higher percentage of eyes with a 1.0 diopter (D) or greater difference in the measured corneal astigmatism (P = .02). A statistically significantly higher percentage of eyes in the hyperosmolar group had an IOL power difference of more than 0.5 D (P = .02). No statistically significant differences were present when the subjects were grouped by self-reported dry eye.
Significantly more variability in average K and anterior corneal astigmatism was observed in the hyperosmolar group, with significant resultant differences in IOL power calculations. Variability was not significantly different when subjects were grouped by self-reported dry eye. Measurement of tear osmolarity at the time of cataract surgery planning can effectively identify patients with a higher likelihood of high unexpected refractive error resulting from inaccurate keratometry.
Drs. Epitropoulos, Matossian, Berdy, and Malhotra received compensation from Tearlab for participating in the study. No author has a financial or proprietary interest in any material or method mentioned.
评估泪液渗透压对白内障手术患者角膜曲率计（K）测量重复性的影响。
三个临床机构。
观察性前瞻性非随机研究。
根据泪液渗透压（Tearlab渗透压系统）前瞻性招募受试者；即至少一只眼睛的渗透压超过316 mOsm/L（高渗）且双眼渗透压均低于308 mOsm/L（正常）。测量基线K值，并在第一次测量后的3周内在同一仪器（IOLMaster）上进行第二次测量。比较两组之间平均K值的变异性、使用矢量分析计算的角膜散光以及人工晶状体（IOL）球镜度数计算。
高渗组（50名受试者）平均K读数的变异性在统计学上显著高于正常组（25名受试者）（P = 0.05），且测量的角膜散光差异为1.0屈光度（D）或更大的眼睛百分比在统计学上显著更高（P = 0.02）。高渗组中IOL度数差异超过0.5 D的眼睛百分比在统计学上显著更高（P = 0.02）。当根据自我报告的干眼情况对受试者进行分组时，未发现统计学上的显著差异。
在高渗组中观察到平均K值和角膜前散光的变异性明显更大，导致IOL度数计算存在显著差异。当根据自我报告的干眼情况对受试者进行分组时，变异性没有显著差异。在白内障手术规划时测量泪液渗透压可以有效识别因角膜曲率计测量不准确而导致意外高屈光不正可能性较高的患者。
Epitropoulos医生、Matossian医生、Berdy医生和Malhotra医生因参与该研究而从Tearlab获得报酬。没有作者对文中提及的任何材料或方法拥有财务或专利权益。
