Role of Tear Osmolarity in Dry Eye Symptoms After Cataract Surgery

PURPOSE: To analyze changes in tear osmolarity and the Ocular Surface Disease Index (OSDI) in patients after cataract surgery. DESIGN: Prospective, observational cohort study. METHODS: SETTING: Institutional. PATIENT POPULATION: Fifty-two patients with a unilateral cataract (study eye) scheduled for surgery and good visual function in the fellow (control eye). Patients were excluded who were receiving chronic topical therapy, such as glaucoma medications, or had a history of previous ocular surgery. INTERVENTION: Examinations were performed preoperatively and 1 and 3 months postoperatively. At each visit, complete anterior and posterior segment examinations were performed. MAIN OUTCOME MEASURES: Best corrected and uncorrected visual acuities, tear osmolarity, and OSDI scores. RESULTS: The mean tear osmolarity values were, respectively, 305.63 +/- 15.07, 305.70 +/- 16.48, and 303.88 +/- 11.75 mOsm/L at baseline and 1 and 3 months postoperatively (P = .067), compared with 309.74 +/- 15.92, 306.74 +/- 13.22, and 303.19 +/- 11.02 mOsm/L at the same times in the unoperated control eyes (P = .064). Patients with normal osmolarity (< 312 mOsm/L) and hyperosmolarity values (312 mOsm/L) had respective OSDI scores of 22.77 +/- 15.73 and 36.02 +/- 12.20 at baseline (P = .01), 12.44 +/- 12.44 and 14.45 +/- 13.45 at 1 month (P = .7), and 10.37 +/- 11.11 and 16.48 +/- 8.08 at 3 months postoperatively (P = .01). CONCLUSIONS: We did not find differences in tear film osmolarity between the operated eyes and the fellow unoperated control eyes at any time period during the study. Patients with tear osmolarity values of 312 mOsm/L or higher are more likely to have more ocular discomfort postoperatively. Ophthalmologists should consider evaluating tear " osmolarity preoperatively, especially in highly demanding patients. (C) 2016 Elsevier Inc. All rights reserved.