Dégénérescence maculaire liée à l’âge exsudative : efficacité et limites des différents traitements

Pharmacogenetics of antiangiogenic and antineovascular therapies of age-related macular degeneration

Age-related macular degeneration (AMD), the most common age-related disease causing irreversible visual loss in industrialized countries, is a complex and multifactorial illness. Researchers have found components of the complement alternative pathway inside drusen and Bruch's membrane of AMD patients, underlying a possible important role of complement factor H in the pathogenesis of AMD. The neovascular (wet) AMD is the most destructive form and it is characterized by invasion of new blood vessels into subretinal spaces with subsequent exudation and bleeding, resulting in scarring of the macular region and loss of the central vision. The hallmark of the neovascular form is the choroidal neovascularization, where VEGF-A has an important role in the pathogenesis of the disease. SNPs of these genes have recently been investigated as potential pharmacogenetic markers of the antiangiogenic and antineovascular therapy of AMD, which includes verteporfin photodynamic therapy and anti-VEGF-A drugs, such as pegaptanib, bevacizumab and ranibizumab. The CFH rs1061170 CT and TT genotypes have been associated with an improvement of visual acuity in bevacizumab or ranibizumab treated patients, whereas patients harboring VEGF-A rs699946 G allele responded better to bevacizumab-based therapy if compared with patients carrying the A allele. In conclusion, the discovery of pharmacogenetic markers for the personalization of the antiangiogenic and/or antineovascular therapy could be, in the future, a key issue in ophthalmology to obtain a personalization of the therapy and to avoid unnecessary costs and adverse drug reactions.

[Subconjunctival bevacizumab for corneal neovascularization]

PURPOSE

To assess efficacy and safety of subconjunctival bevacizumab in corneal neovascularization treatment.

METHODS

The study was a prospective case series that included patients treated with subconjunctival bevacizumab injections for corneal neovascularization over a period of four months. A dose of 2.5 mg (0.1 mL) of bevacizumab (25 mg/mL) was injected into the subconjunctival area 1-2mm behind the limbus near the corneal neovascularization. The main outcome measures were visual acuity, corneal neovascularization, as well as local and general side effects.

RESULTS

Thirteen eyes of 12 patients were included. The mean patient age was 44.2 years (range, 18-87 years). Patients received from two to four bevacizumab injections. The mean corneal neovascularization area decreased from 41.1 to 33.7 % at day 45 (p=0.0003) and to 33.9 % at day 120 (p=0.0013). Median visual acuity changed from 1.32 to 1.28 LogMAR on day 45 and to 1.25 LogMAR on day 120. Subconjunctival bevacizumab was well tolerated without general side effects. There was no significant change in intraocular pressure. An epithelial defect was described in three patients after initiation of bevacizumab therapy.

CONCLUSIONS

Subconjunctival bevacizumab injections were effective and safe in reducing corneal neovascularization within the first four months. Meanwhile, improving vision may provide additional strategies.