Comparison of VEGF level in tears post phacoemulsification between non-proliferative diabetic retinopathy and non-diabetic patients.

BACKGROUND: Progression of diabetic retinopathy post cataract surgery is related to the increased level of vascular endothelial growth factor (VEGF) in ocular fluid post operatively. The aim of this study was to compare the VEGF level in tears post phacoemulsification between non-proliferative diabetic retinopathy (NPDR) and non-diabetic patients. 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 < 0.001) and control (p < 0.001). There was also significant reduction of tear VEGF level from D7 to D30 post phacoemulsification in both groups (p < 0.001 in NPDR and p = 0.027 in control). The tear VEGF level was significantly higher in NPDR group compared to control at D7 post phacoemulsification (149.4 SD 55.2 pg/mL vs 109.7 SD 48.7 pg/mL, p = 0.003). CONCLUSION: VEGF level in tears showed significant elevation post early cataract surgery in NPDR compared to non-diabetic patient. Therefore, tears VEGF level may provide as a non-invasive method to predict progression of diabetic retinopathy post operation among diabetic patients.