BACKGROUNDFor patients who experience dry eye after phacoemulsification, vision and quality of life can significantly deteriorate. In this study, the efficacy and safety of carboxymethylcellulose sodium (CMC) 1% ophthalmic solution combined with conventional therapy in treating dry eye signs and symptoms after phacoemulsification were evaluated.METHODSIn this prospective, multicenter, open-label, controlled study, 180 patients with age-related cataract were randomized to treatment with conventional therapy plus CMC 1% (n = 90) or to conventional therapy only (control group, n = 90) after phacoemulsification and intraocular lens implantation. Tear breakup time (TBUT), the Schirmer test with anesthesia, and fluorescein and lissamine green staining were performed. The Ocular Surface Disease Index (OSDI) questionnaire and a patient subjective symptom evaluation were administered preoperatively (baseline) and postoperatively at 7 and 30 days.RESULTSTBUT was significantly longer in the treatment group compared with the control group at day 7 (8.5 ± 5.5 versus 6.6 ± 3.8 s; P = 0.0475) and day 30 (9.0 ± 5.9 versus 6.7 ± 4.8 s; P = 0.0258) after surgery. Compared with baseline, TBUT significantly increased in patients in the treatment group (P < 0.001 at both day 7 and day 30) with a presurgical diagnosis of dry eye, but significantly decreased in patients in the control group (P < 0.02 at both day 7 and day 30) with no prior diagnosis of dry eye. Fluorescein and lissamine staining, OSDI questionnaire and subjective symptom scores all improved from baseline, with no significant differences between the two groups. No significant differences in tolerability and safety were observed between the group receiving CMC and conventional therapy, and those receiving conventional therapy only.CONCLUSIONTreatment with CMC 1% can provide significant improvement in tear film stability after phacoemulsification for age-related cataract.TRIAL REGISTRATIONClinicalTrials.gov identifier NCT02028754 (Date of registration: Jan. 6, 2014).