Biomaterial Database

Experimental glaucoma: perimetric field defects and intraocular pressure. 1997

R S Harwerth, and E L Smith, and L DeSantis

College of Optometry, University of Houston, TX 77204-6052, USA.

OBJECTIVE To investigate the relationship between intraocular pressure (IOP) and the progression of visual field defects caused by experimental glaucoma in Macaca mulatta monkeys. METHODS Perimetric fields were measured by behavioral methods in 18 rhesus monkeys during the course of unilateral glaucoma produced by argon laser treatment of the trabecular meshwork. The monkeys' IOPs were measured by applanation tonometry. Visual field defects were quantified by the mean deviation perimetric index from Humphrey Field Analyzer C24-2, model 630 (Humphrey Allergan, San Leandro, CA, U.S.A.), full-threshold data. RESULTS The monkeys' eyes demonstrated considerable variability in their susceptibility to pressure-induced neural damage. For 10 of the monkeys, significant field defects were correlated with the increases in their IOPs and the defects progressed monotonically to end-state glaucoma. For the other monkeys, the mean deviation index was not well correlated with IOP; some eyes withstood pressures in excess of 35 mm Hg for several months before significant reduction in visual sensitivity. However, once they began, the rate of progression of field defects was similar across subjects. CONCLUSIONS Laser ablation of the trabecular meshwork in monkeys provides a model for investigations of the effects of IOP that are not confounded by other ocular or visual disorders. Behavioral perimetry showed the same intersubject variability in the effects of elevated IOP on visual field sensitivities of monkeys that are common with high-tension glaucoma or ocular hypertension in patients. Thus, these investigations provide additional support for the use of the model for a wide variety of clinical investigations on glaucoma.

UI	MeSH Term	Description	Entries
D007429	Intraocular Pressure	The pressure of the fluids in the eye.	Ocular Tension,Intraocular Pressures,Ocular Tensions,Pressure, Intraocular,Pressures, Intraocular,Tension, Ocular,Tensions, Ocular
D008253	Macaca mulatta	A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.	Chinese Rhesus Macaques,Macaca mulatta lasiota,Monkey, Rhesus,Rhesus Monkey,Rhesus Macaque,Chinese Rhesus Macaque,Macaca mulatta lasiotas,Macaque, Rhesus,Rhesus Macaque, Chinese,Rhesus Macaques,Rhesus Macaques, Chinese,Rhesus Monkeys
D008297	Male		Males
D009900	Optic Nerve	The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.	Cranial Nerve II,Second Cranial Nerve,Nervus Opticus,Cranial Nerve, Second,Cranial Nerves, Second,Nerve, Optic,Nerve, Second Cranial,Nerves, Optic,Nerves, Second Cranial,Optic Nerves,Second Cranial Nerves
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D005260	Female		Females
D005500	Follow-Up Studies	Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.	Followup Studies,Follow Up Studies,Follow-Up Study,Followup Study,Studies, Follow-Up,Studies, Followup,Study, Follow-Up,Study, Followup
D005901	Glaucoma	An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)	Glaucomas
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity