Methods: This was a prospective cohort study and was conducted from June 2017 to May 2019. Patients with underlying NPDR who were planned for phacoemulsification were recruited in this study. Non-diabetic patients who were planned for phacoemulsification were included as control group. Tears samples were collected using Schirmer strip two weeks prior to operation, at day (D) 7 and D30 post phacoemulsification. Tears samples were analyzed for VEGF level.
Results: A total of 65 patients were recruited in this study (NPDR: 32 and control: 33). There was significant increase of VEGF levels in tears from pre operation to D7 post phacoemulsification in NPDR (p
METHODS: A comparative cross-sectional study was conducted between August 2016 and May 2018 involving type 2 DM patients with no DR, non-proliferative DR (NPDR), and proliferative DR (PDR). Tear samples were collected using no.41 Whatman filter paper (Schirmer strips) and 5 mL blood samples were drawn by venous puncture. VEGF levels in tears and serum were measured by enzyme-linked immunosorbent assay.
RESULTS: A total of 88 type 2 DM patients (no DR: 30 patients, NPDR: 28 patients, PDR: 30 patients) were included in the study. Mean tear VEGF levels were significantly higher in the NPDR and PDR groups (114.4 SD 52.5 pg/mL and 150.8 SD 49.7 pg/mL, respectively) compared to the no DR group (40.4 SD 26.5 pg/mL, p < 0.001). There was no significant difference in the mean serum VEGF levels between the three groups. There was a fair correlation between serum and tear VEGF levels (p = 0.015, r = 0.263).
CONCLUSION: VEGF levels in tears were significantly higher amongst diabetic patients with DR compared to those without DR and were significantly associated with the severity of DR. There was a fair correlation between serum and tear VEGF levels. Detection of VEGF in tears is a good non-invasive predictor test for the severity of DR. A large cohort study is needed for further evaluation.