PURPOSE: To evaluate the effects of tear osmolarity on the repeatability of keratometry (K) measurements in @entity1 presenting for @entity231 surgery. SETTING: Three clinical practices. DESIGN: Observational prospective nonrandomized study. METHODS: Subjects were prospectively recruited based on tear osmolarity (Tearlab Osmolarity System); that is, osmolarity more than 316 mOsm/L in at least 1 eye ( @entity1602 ) 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 @entity940 using vector analysis, and intraocular lens (IOL) sphere power calculations were compared between groups. RESULTS: The @entity1602 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 @entity940 (P = .02). A statistically significantly higher percentage of eyes in the @entity1602 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 @entity936 . CONCLUSIONS: Significantly more variability in average K and anterior corneal @entity940 was observed in the @entity1602 group, with significant resultant differences in IOL power calculations. Variability was not significantly different when subjects were grouped by self-reported @entity936 . Measurement of tear osmolarity at the time of @entity231 surgery planning can effectively identify @entity1 with a higher likelihood of high unexpected @entity2516 resulting from inaccurate keratometry. FINANCIAL DISCLOSURE: 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.

Effect of tear osmolarity on repeatability of  keratometry for XXXX surgery planning.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity940 :: ('MESH:D001251', 'Disease') :: ['astigmatism'] @entity231 :: ('MESH:D002386', 'Disease') :: ['cataract'] @entity2516 :: ('MESH:D012030', 'Disease') :: ['refractive error'] @entity936 :: ('MESH:D015352', 'Disease') :: ['dry eye'] @entity1602 :: ('MESH:D006944', 'Disease') :: ['hyperosmolar']
@entity231 :: (MESH:D002386,Disease) :: ['cataract']
