Abstract
Purpose:
Ischemia, due to improper blood circulation in the retinal region, is believed to be associated with number of optic neuropathies such as anterior ischemic optic neuropathy (AION), Glaucoma, retinal and choroidal vessel occlusions, retinopathy of prematurity (ROP), diabetic retinopathy, and traumatic optic neuropathy. Animal models present good substitutes to study the pathology of human diseases and thus various models have been established to study the retinal ischemia in animals. Pterygopalatine artery occlusion (PPA) model is a novel and reproducible model of ischemia. The PPA supplies blood to ophthalmic artery while ECA is known to contribute to the vascular network between PPA and ophthalmic artery.
Methods:
Swiss Albino mice were subjected to temporary PPA occlusion for 2 hours by ligation of external carotid artery (ECA) and pterygopalatine artery (PPA) using sutures. After 2 hours of ischemia sutures were removed and reperfusion was carried out for 5 days. To validate the establishment of the model fundus imaging and florescein angiography of retina was performed before and after the occlusion of arteries. Blood flow measurement before the initiation of experiment, after ligation of arteries and after reperfusion was measured using laser Doppler.
Results:
Animals subjected to PPA ligation showed the reduced flow of blood as indicated by blood flow measurement using laser Doppler. Fundus imaging revealed thinning of blood vessels supplying retinal tissue and florescein angiography further supported the constriction of blood vessels and reduced blood flow.
Conclusions:
The study indicated Pterygopalantine artery ligation (PPA) to be a good model to study mechanisms of retinal ischemia. This model can be used as a potential retinal degeneration model and various therapeutic targets can be evaluated using it.
Keywords: 695 retinal degenerations: cell biology •
688 retina •
554 immunohistochemistry