Effect of a Dexamethasone Implant on Rheological Blood Parameters in Patients Treated for Retinal Vein Thrombosis

To assess the effect of the prolonged-release dexamethasone implant (Ozurdex) in patients with retinal venous thrombosis on blood rheological parameters and evaluate the impact on morphological and functional parameters.

Prospective cross-sectional study involved 35 subjects treated with central retinal vein and vein branch occlusion with intravitreal dexamethasone implant and 35 healthy subjects in control group. Hematocrit, blood and plasma viscosity, erythrocyte aggregation amplitude (EAA), index (EAI), aggregation half-life time (EAT1/2), and erythrocyte deformability (ED) were evaluated. The best-corrected visual acuity (BCVA), central retinal thickness (CRT) and visual field (VF) were examined. All the parameters were examined at the baseline, 7 and 30 days after the treatment. The results were analyzed with correlation and regression and compared to the baseline values.

In the studied group, three hemorheological parameters improved as early as on the 7th day after the drug administration, and this improvement remained at a similar level on the 30th day. The EAA increased by 21.26% on day 7 and by 19.78% on day 30, the EAI decreased by 10.55% on day 7 and by 9.14% on day 30 and the EAT1/2 time increased by 38.50% on day 7 and by 31.02% on day 30. On day 7, the BCVA was improved by 1 row, CRT was reduced by 170.77 µm (24.49%), and the VF was improved by 9.8 dB (49.92%) compared to baseline parameters. On day 30, the BCVA was improved by three rows, CRT reduced by 244.68 µm (35.09%), and VF improved by 12.09 dB (61.59%).

The intravitreal dexamethasone implant used in treating macular oedema in patients with RVO has a statistically significant effect on some rheological parameters of blood, reduction of CRT and clinical improvement in BCVA and VF.