Abstract
Purpose :
To measure the aqueous levels of vascular endothelial growth factor (VEGF) in patients with diabetic macular edema (DME) undergoing treatment with anti-VEGF agents and correlate it with central macular thickness (CMT) by OCT.
Methods :
Patients with DME undergoing treatment with intravitreal injections of anti-VEGF agents were included in the study. At each injection, paracentesis was done to equalize the intraocular pressure and the aqueous sample thus obtained was used for analyses. For controls, aqueous was collected from patients undergoing cataract extraction, who did not have any other retinal pathology. Samples, after collection, were immediately stored in -800 C freezer. At the time of analysis, aqueous samples were thawed at room temperature. VEGF levels (pg/ml) were measured using human premixed multi-analyte kit on Luminex MAGPIX analyzer (Austin, TX, USA). Spectral-domain OCT was obtained at each visit before the injection and CMT was measured.
For analysis, only those samples were considered for analyses where it was continuous and not more than 2 months break in between the collection of samples. The VEGF levels and the CMT measurements obtained at the time of the most recent injection were compared to the baseline levels, respectively. The VEGF levels in all samples were also compared with CMT.
Results :
343 samples from 50 patients and 70 eyes were analyzed, who received a minimum of 2 injections. The mean number of injections for an eye was 5 and range 2 - 15 injections. The average VEGF level at baseline was 59.7 pg/ml and at the most recent injection, 13.5 pg/ml (p value <0.0001). For controls (n=97), the mean VEGF level was 31.7 pg/ml. The average CMT at baseline was 434µm and at last visit 354µm (p value 0.0004). OCT data were available for 270 samples obtained from 42 patients and 60 eyes and there was a positive correlation between VEGF levels and CMT.
Conclusions :
Aqueous levels of VEGF can be easily measured at every injection in patients with diabetic macular edema. Aqueous levels of VEGF were significantly reduced after treatment with anti-VEGF agents. With the ease of obtaining the aqueous sample and measuring the VEGF levels, this may be a useful parameter in the future, in addition to visual acuity and retinal thickness, to personalize the treatment of patients with diabetic macular edema.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.