Changes of the tear film lipid layer thickness after cataract surgery in patients with diabetes mellitus

Purpose To evaluate changes in the tear film lipid layer thickness (LLT) in cataract patients with diabetes mellitus (DM) after cataract surgery. Methods We recruited consecutive cataract patients and recorded data regarding DM condition. Lipid layer thickness (LLT) and partial blinks rates measured with the LipiView interferometer, tear break-up time (TBUT) and Schirmer's tests, and dry eye symptoms evaluated with the Ocular Surface Disease Index (OSDI) questionnaire were conducted before and one month after cataract surgery. Results Finally, 38 age-related cataract (ARC) and 31 diabetic cataract (DC) patients were available for analysis. No significant difference in preoperative LLT and partial blink rates was found between ARC and DC group. However, preoperative TBUT and Schirmer's test results were significantly lower in DC group compared to ARC group (both p < 0.001). DC group showed higher preoperative OSDI score with no significant difference than ARC group (p = 0.279). In DC group, LLT was significantly thinner in cases with longer duration of DM (over 10 years) than in those with shorter duration (p < 0.001). One month after surgery, LLT of DC group was significantly thinner than at baseline (pre: 65.7 +/- 23.3, post: 51.3 +/- 17.1, p = 0.002). While in ARC group, LLT had no significant difference before and after cataract surgery (pre: 67.1 +/- 23.4, post: 60.2 +/- 21.1, p = 0.078). Compared to baseline data, there was no statistically significant difference between two groups in the partial blink rates, TBUT and Schirmer's test results after cataract surgery (p > 0.05). Ocular Surface Disease Index (OSDI) scores were significantly higher after surgery than at baseline in both ARC (pre: 8.9 +/- 8.4, post: 12.4 +/- 8.5, p = 0.003) and DC group (pre: 11.4 +/- 10.3, post: 18.5 +/- 8.5, p = 0.001). Multivariate linear regression analysis showed OSDI scores were associated with LLT either before or after cataract surgery (beta = -0.862, p < 0.001 and beta = -0.592, p < 0.001, respectively). Conclusion The tear film LLT is correlated with duration of DM and becomes significantly thinner one month after cataract surgery, leading to the aggravation of dry eye symptoms.