Intravitreal Ranibizumab in Exudative Age-related Macular Degeneration With Posterior Vitreomacular Adhesion

Primary Outcome Measures:

• Changes from baseline in visual acuity and central macular thickness at 12 months [ Time Frame: 12 months ]

  Efficacy of intravitreal administration of Ranibizumab combined with intravitreous injection of expansile gas and induction of posterior vitreous detachment on best-corrected visual acuity and ocular coherence tomography (OCT) macular thickness in subjects with exudative age-related macular degeneration (AMD) with posterior vitreomacular adhesion (VMA).

  Visual acuity measurement: logMAR visual acuity with early treatment of diabetic retinopathy study (ETDRS) chart, Macular thickness measurement: OCT

  
  

Secondary Outcome Measures:

• Number of participants with nonocular complications [ Time Frame: 12 months ]
  - Incidence of non ocular complications (thromboembolic events, non ocular hemorrhage, myocardiac infarct etc.)
  
  
• Number of participants with ocular complications [ Time Frame: 12 months ]
  Incidence of ocular complications (increased intraocular pressure, endophthalmitis, central retinal artery occlusion etc)
  
  

Age-related macular degeneration (AMD) is the leading cause of severe visual loss in industrialized countries. In recent years, the advent of anti-vascular endothelial growth factor (VEGF) therapies, such as ranibizumab and bevacizumab, has revolutionized neovascular AMD treatment and anti-VEGF has become the standard treatment for choroidal neovascularization (CNV) with a better visual outcome than previous therapies such as photodynamic therapy (PDT). However, one study reported that up to 45% of cases (20 out of 44 eyes) were non-responders showing resistance to anti-VEGF. In these cases, visual acuity did not improve and persistent subretinal fluid remained despite the usual monthly injection of anti-VEGF. A current focus of anti-VEGF treatment is how to determine which eyes will respond to treatment. To date, three genetic studies into the response to treatment for wet AMD have shown that specific genotypes for complement factor H and LOC genes are associated with treatment response. Previous studies have described the relationship between the posterior vitreous and the macula in AMD and have suggested that vitreomacular adhesion (VMA) plays an important role in the development of exudative AMD. In a recent paired eye study, we controlled confounding variables by selecting only patients with unilateral exudative AMD, and showed that eyes with exudative AMD had a significantly higher incidence of posterior VMA than paired normal eyes (P=0.0007). This result indicates that VMA is a possible risk factor for exudative AMD. In another recent study, Mojana and co-workers reported improvement in VA after 25-gauge trans pars plana vitrectomy (TPPV) with hyaloid removal in five patients who had a history of demonstrable VMA and poorly responsive CNV despite aggressive anti-VEGF therapy. We postulated that a subpopulation of exudative AMD cases do not respond to anti-VEGF therapy and that VMA may play a role in this resistance to therapy. The recent results of our study indicate that posterior VMA has a negative effect on visual outcome after intravitreal anti-VEGF treatment for exudative AMD. BCVA did not improve in eyes with posterior VMA despite anti-VEGF treatment. Posterior hyaloid removal by intravitreous injection of expansile gas and induction of posterior vitreous detachment may be considered as a treatment option in patients with VMA who are poor responders to anti-VEGF treatment.