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dc.contributor.authorWeigt, Anne Kelleyen_US
dc.date.accessioned2014-03-14T20:40:02Z
dc.date.available2014-03-14T20:40:02Z
dc.date.issued2001-06-04en_US
dc.identifier.otheretd-06152001-152749en_US
dc.identifier.urihttp://hdl.handle.net/10919/33583
dc.description.abstractABSTRACT: Corneal ulceration with prolonged healing following Nd:YAG laser cyclophotocoagulation in dogs is a frequent complication. It is hypothesized that these corneal ulcerations may be a form of neurotrophic keratitis due to laser-induced damage to corneal innervation. Fifteen clinically normal dogs had the neodymium:yttrium aluminum garnet(Nd:YAG) laser cyclophotocoagulation performed on the left eye. Each treated eye received 100 Joules of laser energy. Corneal touch threshold (CTT) and Schirmer I tear tests (STT) were performed before the surgery and on days 1,3,5,7,9,11, and 13 post-laser treatment. Applanation tonometry was performed before surgery and twice daily for 14 days post-laser treatment. Eyes were enucleated after 14 days and corneal nerves were stained using a gold chloride technique. Major nerve bundles entering the cornea were quantitated by quadrant, using camera lucida reproductions. Nerve bundle diameters were measured using NIH image computer software on computer-scanned images. Statistical methods included repeated values for analysis of variance for CTT, STT and IOP, and a paired t-test for nerve diameters and bundles. All laser treated eyes had significantly higher CTTs (P<0.05) compared to control eyes for all measurements. Six out of fifteen dogs had evidence of ulcerative keratitis. Intraocular pressure was significantly lower in laser treated eyes compared to control eyes in the a.m. on days 2-9,and 14, and in the p.m. on days 2-11 using a Bonferroni-corrected alpha level (P<0.0039). A significant decrease of one nerve bundle per corneal quadrant was found between the laser treated and control eyes. There was no significant difference in STT or nerve bundle diameters between laser treated and control eyes. Nd:YAG laser cyclophotocoagulation effectively reduces IOP while increasing CTT. The procedure also causes a significant decrease in the number of major nerve bundles entering the cornea, but has no effect on the diameter of those bundles. These findings support the hypothesis that nerve damage and corneal hypoesthesia are etiologic factors in ulcerative keratitis following Nd:YAG laser cyclophotocoagulation.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartmasters.-ed.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectcorneal sensitivityen_US
dc.subjectaqueous tear productionen_US
dc.subjectintraocular pressureen_US
dc.subjectcorneal touch thresholden_US
dc.subjectcorneal nerve morphologyen_US
dc.subjectdogen_US
dc.subjectcyclophotocoagulationen_US
dc.titleThe effects of Nd:YAG laser cyclophotocoagulation on corneal sensitivity, intraocular pressure, aqueous tear production and corneal nerve morphology in the canine eyeen_US
dc.typeThesisen_US
dc.contributor.departmentVeterinary Medical Sciencesen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineVeterinary Medical Sciencesen_US
dc.contributor.committeechairHerring, Ian P.en_US
dc.contributor.committeememberPickett, J. Phillipen_US
dc.contributor.committeememberMarfurt, Carl F.en_US
dc.contributor.committeememberDuncan, Robert B. Jr.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06152001-152749/en_US
dc.date.sdate2001-06-15en_US
dc.date.rdate2002-06-26
dc.date.adate2001-06-26en_US


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