Abstract
Purpose: :
Pegaptanib sodium (PS) is a vascular endothelial growth factor (VEGF) antagonist, clinically in use to treat choroidal neovascularization (CNV) caused by age–related macular degeneration. No published reports currently describe the performance of PS in a CNV animal model. This study evaluated the prophylactic effect of intravitreal PS on CNVM development and compared it to the corticosteroid triamcinolone acetonide (TA).
Methods: :
After induction of laser trauma sites (75µm diameter), 10 rats in each of 6 designated groups (∼80 sites/group) received either an intravitreal injection (5µL) of: 1) PS 100% (17µg), 2) PS 50% (9µg), 3) PS vehicle (control), 4) TA (200µg), or 5) TA vehicle (control), or received 6) laser only (LO: no injection control). On day 21, fluorescein angiography (FA) was performed at designated times from 1 to 300 sec and late phase (90/180 sec) staining was scored on a 0 low to 3 high scale. CNVM diameters were measured for each site.
Results: :
FA revealed no significant differences in mean scores for staining between the PS 100% (x=1.7) and the PS vehicle (1.7), TA vehicle (1.6), or LO (2.0) groups. The PS 50% group score (1.5) also was not significantly different from either PS vehicle or TA vehicle groups, but was significantly (P< .01) lower in comparison to the LO group. The TA score (0.6) was significantly lower compared to all other groups. The CNVM mean diameter for the PS 100% group (176µm) was not significantly different as compared to the PS vehicle (192µm) or TA vehicle (189µm) groups, but was significant (10% reduction; P< .05) to the LO (196µm) group. Comparing the PS 50% group (170µm) to the LO group did represent a small (14%) but statistically significant (P< .01) reduction in mean CNVM diameter, while the TA group (112µm) demonstrated a 43% reduction in CNVM diameter as compared to the LO group and significant differences (P< .01) as compared to all groups.
Conclusions: :
Intravitreal PS at the 50% dosage concentration elicited a significant but marginal reduction both in mean CNVM dye–staining and diameter as compared to the LO group only, whereas intravitreal TA resulted in significant and pronounced inhibition of CNVM development as compared to all groups.
Keywords: choroid: neovascularization • growth factors/growth factor receptors • age-related macular degeneration