Hydrogel ocular inserts for the treatment of infectious bovine keratoconjunctivitis

dc.contributor.advisor Raymond T. Greer
dc.contributor.author Ryoo, Je-Phil
dc.contributor.department Chemical and Biological Engineering
dc.date 2018-08-15T04:53:52.000
dc.date.accessioned 2020-07-02T06:11:10Z
dc.date.available 2020-07-02T06:11:10Z
dc.date.copyright Sun Jan 01 00:00:00 UTC 1989
dc.date.issued 1989
dc.description.abstract <p>Hydrogel coated ring shaped ocular inserts (containing the antibiotic, tylosin tartrate) were used in an evaluation of the effectiveness of polymeric ocular drug release devices for treating infectious bovine keratoconjunctivitis. Two major in vivo tests were done: a treatment test using infected cattle and a test to evaluate ring retention characteristics. The in vivo experiments represent the first experiments using hydrogel ocular inserts containing an antibiotic for treating infectious bovine keratoconjunctivitis;The bacterium, Moraxella bovis, was used to replicate the disease. In the infection tests, ten calves were challenged with 2.4 x 10[superscript]8 - 1.6 x 10[superscript]9 M. bovis colonies per eye following two ten minute ultraviolet radiation eye preconditioning exposures. Ninety five percent of the eyes (19 of 20 eyes) were successfully infected by this method. The first measurements were performed at day 3 of the tests. For 14 days, all infected eyes were monitored for the presence of the bacteria quantitatively. Clinical observations were also made. At day 7 after inoculation of both eyes of a calf with M. bovis, a medicated or a non-medicated ring-shaped device was inserted into each eye of a calf. The eye receiving the non-medicated ring was taken as a control for comparison with the eye that received a medicated ring. During the next 7 day period following a medicated ring insertion, the number of bacteria in the treated eye dropped dramatically to negligible levels (0 to 30 colony forming units/swab), while the control eye which received a non-medicated ring still exhibited a relatively high number of bacteria (10[superscript]3 to 10[superscript]6 colony forming units/swab). The number of bacteria was significantly reduced by the antibiotic released from the medicated ocular insert;In the retention test, the optimal size criterion of a ring was determined using a two-tailed t-test in order to select the proper size range for rings so that they would be retained for a week. By using the criterion, 1.18L < ring size < 1.23L, where L is the side-to-side dimension of the palpebral aperture of the eye, 56 of 70 eyes (for 38 cows) retained (non-medicated, hydrogel coated) rings for at least 7 days. Also, the success rate for the population (any large group of cattle) was estimated as approximately 70% to 90% (P < 0.05).</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/9080/
dc.identifier.articleid 10079
dc.identifier.contextkey 6348154
dc.identifier.doi https://doi.org/10.31274/rtd-180813-11323
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/9080
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/82140
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/9080/r_9003561.pdf|||Sat Jan 15 02:27:51 UTC 2022
dc.subject.disciplines Biomedical Engineering and Bioengineering
dc.subject.disciplines Veterinary Medicine
dc.subject.keywords Biomedical engineering
dc.title Hydrogel ocular inserts for the treatment of infectious bovine keratoconjunctivitis
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 86545861-382c-4c15-8c52-eb8e9afe6b75
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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