Establishment and characterization of an acute model of ocular hypertension by laser-induced occlusion of episcleral veins

TitleEstablishment and characterization of an acute model of ocular hypertension by laser-induced occlusion of episcleral veins
Publication TypeJournal Article
Year of Publication2017
AuthorsZhang, L., G. Li, M. Shi, H. - H. Liu, S. Ge, Y. Ou, J. G. Flanagan, and L. Chen
JournalInvestigative Ophthalmology and Visual Science
Keywordsacute disease, adverse effects, animal, animal experiment, animal model, animal tissue, Animals, anterior eye chamber angle, anterior eye segment, antibiotic agent, Article, CD31 antigen, cell density, controlled study, cornea limbus, cornea thickness, disease model, Disease Models, epifluorescence microscopy, episcleral vein, Glaucoma, immunohistochemistry, inflammatory cell, intraocular hypertension, intraocular pressure, laser coagulation, Laser photocoagulation, Light Coagulation, Limbus Corneae, male, mouse, nonhuman, ocular blood vessel, Ocular Hypertension, optic disk, optic nerve lesion, Optical Coherence, Optical coherence tomography, pathology, pathophysiology, peripheral anterior synechiae, priority journal, radiation response, retina, retina ganglion cell, retina vein occlusion, Retinal Ganglion Cells, retinal nerve fiber layer thickness, Retinal Vein Occlusion, sclera, Tomography, tonometer, transcription factor POU4F1, tropicamide, vascularization, vein, Veins
AbstractPurpose. This study was designed to develop and characterize a laser-induced model of acute intraocular hypertension that permits the study of the anterior segment of the eye. METHODS. CD1 mice aged 5 and 8 weeks were examined for elevation of IOP induced by laser photocoagulation. We compared between occlusion of episcleral veins alone and when combined with 270° limbal vessel occlusion. Anterior chamber angle, corneal thickness, and retinal nerve fiber layer (RNFL) thickness were evaluated by anterior- and posterior-segment optical coherence tomography (OCT). Additionally, at day 7 post-procedure, the anterior segment was evaluated for inflammatory cellular presentation by histologic analysis and OCT, and limbal vessels and whole-mount retina were immunostained for CD31 and Brn3a, respectively. Brn3a-positive retinal ganglion cells (RGCs) were quantified with ImageJ software. RESULTS. After single or combined laser treatment in mice aged 5 or 8 weeks, IOP was significantly elevated for 5 to 6 days before returning to the baseline by day 7 post-procedure. Anterior segment assessment indicated less synechiae in the anterior chamber angle and better preserved limbal vessels with single versus combined laser treatment. Corneal thickness was significantly increased after single or combined treatment. No inflammatory cells were detected in the anterior chamber. The thickness of the RNFL and the density of RGCs were both significantly reduced after single or combined treatment. CONCLUSIONS. Laser photocoagulation of episcleral veins alone in CD1 mice aged 5 to 8 weeks may be used to induce ocular hypertension resulting in RNFL thinning and ganglion cell loss. This model permits the study of the anterior as well as the posterior segment of the eye. © 2017 The Authors.