AbstractsBiology & Animal Science

Evaluation of efficacy and biocompatibility of indirect intraocular pressure monitoring using a telemetric scleral sensor

by Christa Lee Robinson




Institution: The Ohio State University
Department: Veterinary Clinical Sciences
Degree: MS
Year: 2010
Keywords: Ophthalmology; Veterinary Services; Intraocular pressure; Glaucoma; Rabbit; Tono-Vet; Telemetric
Record ID: 1887883
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=osu1274142444


Abstract

Purpose. To evaluate efficacy, biocompatibility and stability of a surgically implanted telemetric scleral sensor (TSS). To obtain an intraocular pressure (IOP) measurement without the need for topical anesthesia, patient compliance or corneal contact as is necessary with conventional applanation or rebound tonometry. Methods. A TSS was surgically implanted subconjunctivally and sutured to the sclera of the right eye of 10 juvenile female NZW rabbits. IOP was monitored using the TSS and a Tono-Vet twice daily for two weeks, then twice weekly until sacrifice. Ophthalmic examination was performed weekly and the eyes were graded according to the modified Hackett-MacDonald scheme. Two rabbits were sacrificed at 2, 4, 8, 12 and 16 weeks. Manometric IOP values were also recorded in 5mmHg intervals up to 70mmHg and compared to TSS. Eyes were submitted for histopathology. Results. Fibrosis and inflammation between the sclera and implant were graded on a scale of 0-4 for extent and severity, respectively. The grade of fibrosis and inflammatory response ranged from 1-4 (mean 2.5) and 0-2.3 (mean 1.2), respectively and was not associated with time. The predominant cell types recorded were the granulocyte and lymphocyte. Scleral thinning was observed at the site of TSS contact. Initial readings showed good correlation between the TSS and Tono-Vet, but premature dislocation of the TSS in 6 rabbits limited collection of manometric data. Conclusions. Although initial readings showed good correlation between the TSS and Tono-Vet, the overall size and design of the TSS contributed to fibrosis and premature dislocation of the sensor.