Yucatan Miniature Swine Surgical Glaucoma Model Development and Response to Therapy
Renna, S., Moore, C., Liu, J., Burks, Z., Brown, L., Blair, E., White, D., Hanks, B.C., Horlen, K., Bouchard, G.F.
The purpose of this project was to develop a model of glaucoma via surgical induction of increased intraocular pressure (IOP) in Yucatan miniature swine. Three pigs (two female, one male) had bilateral IOP measurements performed prior to surgical intervention to establish a baseline IOP for each animal from which future changes in IOP could be identified. IOP measurements (mm Hg) were taken with a Tonopen Vet Tonometer. In order to reduce venous drainage from the eyes, episcleral veins were scarified by cauterization in each eye. IOPs were periodically measured for several weeks post-cauterization surgery. Pharmacologic intervention was then instituted with a commercially available synthetic prostamide analog with ocular hypotensive activity. Drops were applied once daily, and IOPs continued to be measured. After 7 weeks of daily treatment, eye drops were discontinued, and IOP measurements continued to be obtained. All animals presented with significant increases in IOP measurements post surgical intervention and significant decreases in IOP with pharmacological therapy. Statistical tests included sample mean comparison by 2-tail T-test, P-value (T≤t). Data by phase as follows-Mean±SD(N readings), P-value (comparison): Baseline:19±4 (65); Post-Surgery: 24±5 (124), ≤0.005 (Baseline vs. Post-Surg); Treatment: 18±4 (75), ≤0.0006 (Post-Surgvs Treatment) Recovery: 20±4 (80), ≤0.006 (Treatment vs Recovery). Therefore, the Yucatan miniature swine should be considered a viable model for surgically induced glaucoma. The miniature swine eye is also responsive to pharmacological therapy to reduce IOP and as such could be a potential model for future pharmacological research.