Abstract
Purpose: :
Ferrets are conventional experimental animal, and so far many electrophysiologic and molecular biological approaches are applied. Since ferrets have binocular vision unlike mice and rats, they are more suitable for analyzing the central visual pathway damage caused by glaucoma compared to mice and rats. Recent studies indicated that not only optic nerve but also lateral geniculate nucleus (LGN) and visual cortex were damaged by glaucoma. Thus, we tried to establish the ferret ocular hypertension model and to analyze the damage of the central visual pathway.
Methods: :
We excised conjunctiva from ferret eyes and cultivated conjunctival cells in Dulbecco's modified Eagle mediumwith 20% fetal bovine serum. Right eyes of 14 ferrets were injected with 1.65x105 obtained conjunctival fibroblast cells (OH eyes), and left eyes were used as control (control eyes). Intraocular pressure (IOP) was weekly measured using Tonolab® for 3 months. Three months after the cell injection, red and green fluorescence-labeled cholera toxin B (CTB) was injected to the vitreous space of the right OH eyes and left control eyes, respectively. Four days after CTB injection, eye balls, optic nerve and brain stem were removed from the skull of ferret. Diameter of eye balls were measured with electrical caliper. Eye balls and optic nerve were histologically analyzed and LGN and superior colliculus (SC) were analyzed with fluorescent microscope.
Results: :
IOP of right OH eyes elevated 1 week after the injection and sustained for 3 months. Average of IOP of right OH and left control eyes were 42.8±15.3 and 14.1±3.9mmHg, respectively. IOP of OH eyes were significantly higher than IOP of control eyes for 3 months. The diameters of OH eyes and control eyes were 7.76±0.33mm and 6.64±0.13mm. Glaucomatous disc cupping was histologically appeared in optic nerve disc of OH eyes. Fluorescence intensity of LGN and SC was apparently decreased in contralateral left side projected from right OH eye compared right side projected from left eye.
Conclusions: :
Experimental ferret ocular hypertension model is useful for analysis of the central visual pathway damage in glaucoma.
Keywords: intraocular pressure • pathology: experimental • optic nerve