Abstract
Purpose: :
Penetrating ocular injury (POI; dry-needle puncture of the globe at the temporal ora) inhibits neovascularization in a rodent model of oxygen-induced retinopathy (OIR) (Penn JS et al, Invest. Ophthalmol. Vis. Sci. 2006 47: 405-414). Evidence suggests that this effect is produced by release of endogenous antiangiogenic factors from the wound site. We sought to determine the influence of POI in a model of choroidal neovascularizaton (CNV) in order to determine if the degree of efficacy and the spatial distribution of the effect were consistent with previous findings in OIR models.
Methods: :
Laser-induced rupture of Bruch’s membrane was performed to produce CNV in 4- to 6-week-old, male Brown Norway rats. Using a hand-held cover slip as a contact lens, an argon laser photocoagulator (532nm) mounted on a slit-lamp (Coherent Novus Omni, Lumenis Inc.; Santa Clara, CA) was employed to create two lesions in both the temporal and nasal quadrants of the mid-peripheral retina (50 µm spot size, 0.1 sec duration, 360 mW). The animals’ eyes were then divided into two treatment groups: left eyes received a POI in the far periphery of the temporal quadrant at 1 and 7 days following laser treatment and right eyes received no injury. Fourteen days after laser application, rats were sacrificed to measure the extent of CNV at the Bruch’s membrane rupture sites.
Results: :
Needle puncture caused a 15.2% reduction in pan-retinal CNV area when POI eyes were compared to the non-POI control eyes. Comparisons between temporal and nasal laser lesions showed a 41.5% reduction in CNV area in the temporal (POI) region compared to the nasal (no POI) region (p < 0.05). No regional difference was observed in non-injured eyes.
Conclusions: :
CNV area is decreased in POI verses non-POI eyes, and the distribution of the effect is related to proximity of the CNV lesion to the needle-injury. This is consistent with the angiostatic effect of POI seen in OIR models. These observations suggest that POI causes the release of angiostatic factors, which may be an important consideration for intravitreal treatments of ocular diseases.
Keywords: choroid: neovascularization • injection • wound healing