The Sheep Cornea: Structural and Clinical Characteristics.

Area of Science:

• Ophthalmology
• Veterinary Medicine
• Corneal Biology

Background:

• The sheep cornea is a potential model for human eye research.
• Comprehensive characterization of sheep corneal anatomy and physiology is lacking.

Purpose of the Study:

• To perform qualitative and quantitative analyses of young, healthy sheep corneas.
• To establish the suitability of sheep as a model for ophthalmic research.

Main Methods:

• Inclusion of eight healthy male sheep (10 months to 1 year old).
• Measurements included central corneal thickness (pachymetry), topography, and microstructural imaging (Heidelberg Retina Tomograph III Rostock Corneal Module in vivo corneal microscope).
• Quantitative data on intraocular pressure (IOP), corneal hysteresis (CH), and corneal resistance factor were obtained using the Ocular Response Analyzer (ORA). Histology and immunohistochemistry were also performed.

Main Results:

• Microscopy revealed a stratified epithelium, limbal crypts, thick basement membrane, thin Bowman's layer, dense keratocyte population in the stroma, and thick Descemet's membrane.
• In vivo corneal microscopy (IVCM) showed higher basal epithelial cell density and significantly higher keratocyte density in the anterior stroma (P=0.0223).
• Mean central corneal pachymetry was approximately 620 μm. Mean IOPcc was ~15 mm Hg and mean CH was ~3.6 mm Hg.

Conclusions:

• The detailed anatomical and clinical characteristics confirm the sheep cornea's suitability as a model for ophthalmic studies.
• This research provides valuable data for researchers utilizing sheep models in ophthalmology.