Abstract
Purpose :
Insulin upregulates vascular endothelial growth factor (VEGF) gene expression and protein secretion in the retinal pigmented epithelium; therefore, we hypothesize that diabetes management with insulin may be correlated with less effective intraocular anti-VEGF treatment for diabetic macular edema (DME), compared to those taking non-insulin based medications.
Methods :
This is a retrospective cohort study of patients with treatment-naïve DME undergoing their first anti-VEGF injection between January 2008 and February 2019 in a tertiary care center. One eye per patient was included. The response to a single anti-VEGF injection was compared between patients on insulin-based and solely non-insulin based diabetic medications. Primary outcome measure was macular retinal volume as measured by spectral domain-optical coherence tomography (SD-OCT). Secondary outcome measure was visual acuity. Data was analyzed using two-tailed paired and independent T-tests in SPSS.
Results :
There was a total of 354 patients, where 243 were on insulin-based medications and 111 were on non-insulin based medications. There was no statistically significant change in retinal volume after the first anti-VEGF injection between the insulin-based and non-insulin based groups (p=0.607, 95% CI [-0.1802, 0.3081]). There was also no statistically significant improvement in best-available visual acuity (LogMAR) in the insulin-based compared to non-insulin based patients measured on that date of injection (p= 0.835, 95% CI [-0.1363, 0.1102]) and on one-month follow-up (p= 0.588, 95% CI [-0.1272, -0.0722]).
Conclusions :
There is no decreased anatomic effectiveness of a single anti-VEGF injection for DME in patients taking insulin compared with those not taking insulin for their systemic diabetes management. Our findings suggest that further work is needed to see if, after multiple anti-VEGF injections are administered, we will observe a change in the effectiveness of the injections between the two groups. This will help inform whether systemic diabetic management should be considered for intraocular treatments.
This is a 2020 ARVO Annual Meeting abstract.