The effect of intravitreal antiangiogenic diabetic macular edema treatment on the corneal endothelium cell count

BACKGROUND: Antiangiogenic treatment of diabetic macular edema is a first-line therapy in modern ophthalmology. Novel antiangiogenic drugs are increasingly being developed to improve treatment results and solve certain issues. However, owing to the advent of new drugs, more questions arise about their effect on the patient’s retina and other structures of the eye, such as the cornea.

AIM: The study aimed to investigate the effect of intravitreal administration of the anti-VEGF drug brolucizumab on the corneal endothelium in patients with diabetic macular edema.

METHODS: 106 patients (106 eyes) were included in the prospective study: 31 men and 75 women. The main group consisted of 56 patients (56 eyes) were included in the prospective study: 14 men and 42 women with different stages of diabetic retinopathy with diabetic macular edema, the average age of patients was 62.2±8.4 years. The average number of endothelial cells per 1 mm² in these patients before the loading dose of brolucizumab was 2378.9±393.3 cl/mm². The control group included 50 patients (50 eyes) without diabetes who did not receive intravitreal injections or any other surgical interventions on the examined eye for 1 year. All patients underwent endothelial microscopy using the Tomey EM-4000 endothelial microscope (REN 2017/6294), estimated: CD (the number of endothelial cells per 1 mm²); CCT (the central thickness of the cornea, microns); CV (the coefficient of variation, %); 6A (the proportion of hexagonal cells, %). All study participants received intravitreal injections of brolucizumab in a volume of 0.05 ml (5 injections with an interval of 6 weeks).

RESULTS: In the main group before intravitreal injections, the indices of the central corneal thickness and the number of endothelial cells per 1 mm² were 549.7±30.1 microns and 2378.9±393.3 cells/mm², respectively. After a course of antiangiogenic diabetic macular edema therapy, the central thickness of the cornea was 548.2±30.6 microns, and the number of endothelial cells per 1 mm² was 2382.3±424.9 cells/mm². The indicators CV (coefficient of variability, %) and 6A (proportion of hexagonal cells, %) before the start of intravitreal injections were 36.9±5% and 46.8±6.3%, respectively, after the introduction of the loading dose drugs, the average values were 37.9±4.3% and 45.8±6.3%. Changes in all indicators were not static significant.

CONCLUSION: The use of brolucizumab as therapy in patients with diabetic macular edema did not cause a negative effect on the cornea, there were no statistically significant changes in the central thickness of the cornea, the number of endothelial cells per 1 mm², the coefficient of variation and the proportion of hexagonal cells.