Abstract
Purpose: :
To determine whether the intravitreal injection of anti–VEGF drugs (Kenalog, Macugen, Avastin) exerts any biological effect in the fellow eyes of patients with bilateral exudative AMD.
Methods: :
Pre– and post–injection (<6 weeks) OCTs of 29 patients (37 injections) with bilateral AMD were analyzed to determine the thickness change in nine OCT zones. Fellow eyes of patients treated with PDT were used as controls. Normograms prepared from normal individuals and untreated AMD patients were used to determine the significance of thickness changes for each zone. A "Standardized Volumetric Change Index" derived using the thickness and relative area of each sector was used to compare the efficacy of each treatment and the concordance of changes in the fellow eye.
Results: :
In parallel to the injected eye, comparable decreases in the macular thickness were observed in fellow AMD eyes after intravitreal injection of Kenalog, Macugen or Avastin (p>0.05). Paradoxically, the biologic effect of Macugen in the fellow eye was more prominent than in the injected eye (p=0.04). Avastin resulted in the greatest thickness reduction both in the injected and fellow eyes (p=0.02).
Conclusions: :
Intravitreal injections of anti–VEGF drugs exert a biologic effect in the fellow eye, possibly via systemic absorption. Intravitreal use of these drugs merits extreme caution due to their possible interference with physiological angiogenesis, such as coronary collateral formation and wound healing. The higher biologic efficacy of Macugen in the fellow eye suggests that doses lower than the conventional intravitreal doses may be efficacious for clinical use.
Keywords: age-related macular degeneration • choroid: neovascularization • pharmacology