[The influence of VEGF inhibitors on corneal endothelium after injection into the anterior chamber in a porcine eye model]

Effect of Repeated Intravitreal Ranibizumab and Aflibercept Injections on the Cornea in Patients with Age-Related Macular Degeneration

Purpose

To assess the effect of repeated intravitreal ranibizumab injections (RI) and aflibercept injections (AI) on the corneal endothelium and central corneal thickness (CCT) in patients with age-related macular degeneration (AMD).

Materials and Methods

In the retrospective study, 110 eyes of 106 patients, aged 52 to 93 years, were analyzed. Fifty eyes were treated only with RI (I group), and 60 eyes were treated only with AI (II group). Every patient received one intravitreal injection of 0.5 mg of ranibizumab once a month or 2 mg of aflibercept for 3 subsequent months. Each patient received only 3 injections during the whole observation period. Corneal analysis was obtained with the specular microscope. Examinations were performed before initial treatment, after each injection, and 6 months after the first injection. Analysis included corneal endothelial cell density (ECD), hexagonal cell percentage (% Hex), coefficient of variation (CoV), and CCT.

Results

There was a statistically significant ECD loss, regardless of the type of the anti-VEGF agent. The mean ECD value in the I group was 2397 ± 459 cells/mm² before RI, 2389 ± 459 cells/mm² after the first RI, 2386 ± 467 cells/mm² after the second RI, 2378 ± 475 cells/mm² after the third RI, and 2357 ± 460 cells/mm² 6 months after the first RI. The mean ECD value in the II group was 2448 ± 493 cells/mm² before treatment, 2456 ± 498 cells/mm² after the first AI, 2426 ± 496 cells/mm² after the second AI, 2402 ± 488 cells/mm² after the third AI, and 2348 ± 473 cells/mm² 6 months after the first AI. In comparison with the group treated with RI, the group treated with AI presented a greater ECD loss at each measuring point. The percentage of hexagonal cells was decreased in both groups. There was a slight increase in polymegathism in both treated groups. Ranibizumab proved to cause a small increase in CCT, while CCT remained unchanged in the aflibercept group.

Conclusions

Repeated intravitreal injections of 0.5 mg of ranibizumab or 2 mg of aflibercept can influence the morphology of the corneal endothelium but not CCT.

The era of anti-vascular endothelial growth factor (VEGF) drugs in ophthalmology, VEGF and anti-VEGF therapy

Angiogenesis is a clue process for tissue development and function, both in normal and pathological conditions. This process is regulated by multiple molecular systems. One of the most potent is vascular endothelial growth factor (VEGF) and its receptor (VEGFR) system. Members of this family are involved in new vessel formation in embryogenesis and maturation, as well as in reparative or pathological reactions in later stages. They play a substantial role in regeneration, inflammation, wound healing, as well as in cancer pathology. Nowadays it is possible to modulate VEGF-VEGFR interactions in many pathological conditions using anti-VEGF therapy. This therapy has already achieved a grounded position in the management of rheumatological disorders, tumour progression, and metastasis. Such drugs as bevacizumab, ranibizumab, aflibercept, and pegaptanib have also proven to be very effective in the treatment of several ocular diseases, such as age-related macular degeneration (AMD), macular oedema, or proliferative retinopathies and iris neovascularisation. The indications for the application of this therapy in ophthalmology are becoming wider and wider. It may also be used for corneal pathologies and in anti-glaucoma procedures.