Effects of adjuvant omega-3 fatty acid supplementation on dry eye syndrome following cataract surgery: A randomized clinical trial

PURPOSE: To investigate the effect of omega-3 polyunsaturated fatty acid supplement on qualitative and quantitative subjective (ocular surface disease index [OSDI]) and objective (Schirmer's test, tear break up time [TBUT], and tear osmolarity) dry eye indices after cataract surgery. METHODS: In this randomized clinical study, 61 eyes of 48 patients complaining of new onset dry eye symptoms after phacoemulsification were enrolled. Subjects were randomly allocated into two groups using urn randomization. Controls received conventional treatment. The treatment group received omega-3 dietary supplement in addition to conventional therapy. RESULTS: There was no significant difference between the control and treatment groups in pre-treatment indices of Schirmer (3.50 ± 3.13 and 2.96 ± 3.39, respectively, P = 0.582), TBUT (6.67 ± 1.36 and 4.87 ± 2.22, respectively, P = 0.687), osmolarity (316.66 ± 8.50 and 315.4 ± 17.06, respectively, P = 0.906), and OSDI (32.99 ± 19.03 and 35.32 ± 18.99, respectively, P = 0.635). Mean pre-treatment OSDI in the control group was 32.99 ± 19.03, which improved significantly after treatment to 25.43 ± 14.49 (P = 0.003). The mean pre-treatment OSDI in the treatment group was 35.32 ± 18.99 (range: 7.5–77.77), which improved significantly after treatment to 16.31 ± 13.72 (range: 2.77–47.22) (P < 0.001). OSDI improvement was significantly higher in the treatment group than the control group (P = 0.026). TBUT improved in both the control and treatment groups after treatment (P < 0.001). However, TBUT was affected significantly more in the treatment group compared with the control group (P = 0.038). Mean tear film osmolarity in the control group was 316.67 ± 8.50 (range: 308–325), which improved insignificantly after treatment to 311.33 ± 6.35 (range: 304–315) (P = 0.157). Mean pre-treatment tear film osmolarity in the treatment group was 315.40 ± 17.06 (range: 279–340), which improved significantly after treatment to 296.90 ± 14.39 (range: 260–310) (P < 0.001). Also, post-treatment Schirmer results between the two groups were not statistically significant (P = 0.155). CONCLUSION: Omega-3 dietary supplements have an additive effect on tear film indices of patients with dry eye syndrome after phacoemulsification.