Abstract
Purpose: :
Exudative age-related macular degeneration (AMD) is characterized by the growth of abnormal blood vessels under the retina, known as choroidal neovascularization (CNV). These studies were designed to determine whether the anti-angiogenic effect of topical OC-10X is dose-dependent in a rat CNV model. In this model laser photocoagulation stimulates growth of aberrant blood vessels, mimicking AMD. Tolerability of OC-10X was also assessed.
Methods: :
OC-10X (0.1%, 1.0%, 2.0%) or vehicle (n=6/group) was administered as topical eye drops 3 times a day in a Brown Norway rat laser CNV model. OC-10X topical treatment was initiated 4 days prior to laser photocoagulation and continued for up to 4 weeks after laser. Development of CNV was monitored biweekly with systemic injection of fluorescein dye and digitally recorded fundus angiograms were analyzed to quantitate the area of CNV. General well being and ocular tolerability were observed by daily visual assessments and by monitoring body weight biweekly. Multifocal electroretinograms (mfERG) were performed at baseline and week 4 to assess retinal status.
Results: :
After four weeks of treatment, the mean CNV area was 1.90 ± 0.68, 2.02 ± 0.73, 1.36 ± 0.31 and 0.88 ± 0.35 mm2, for the vehicle, 0.1%, 1.0% and 2.0% OC-10X groups, respectively. In the 1.0% and 2.0% treatment groups areas were significantly less than vehicle (p=0.024; 0.001, respectively), whereas 0.1% was not (p=0.69). No sign of toxicity was noted by visual assessment. All groups had normal weight gain. mfERG showed no deterioration of retinal status.
Conclusions: :
Topical treatment with OC-10X decreases CNV in a dose dependent manner. Four weeks after laser photocoagulation, CNV, measured by fluorescein angiography, was significantly decreased by 28% with 1.0% and by 54% with 2.0% OC-10X, when compared to the vehicle. However, there was no difference in CNV area between the vehicle and 0.1% treated groups. No signs of ocular toxicity were noted by visual assessment, weight gain or mfERG.
Keywords: age-related macular degeneration