Transcorneal Freezing in Aged Rabbits as a Platform for Evaluating Corneal Endothelial Cell Therapeutics

Area of Science:

• Ophthalmology
• Regenerative Medicine
• Animal Models

Background:

• Transcorneal freezing is a standard method for inducing corneal endothelium damage in rabbits.
• Previous research has explored various freezing parameters and rabbit ages.

Purpose of the Study:

• To characterize the aged rabbit corneal endothelium response to transcorneal freezing.
• To establish the innate corneal endothelial cell regrowth rate in aged rabbits.
• To propose this model for evaluating therapeutic efficacy.

Main Methods:

• Aged New Zealand White rabbits (18-24 months) underwent transcorneal freezing using nitrous oxide cooled probes for 30 seconds.
• Corneal assessments included in vivo confocal microscopy, specular microscopy, OCT, tonometry, and histology.
• Contralateral eyes served as controls, with imaging at multiple time points post-injury.

Main Results:

• A 95% decrease in corneal endothelium density was observed immediately post-injury, with 38% reduction by day 14, indicating linear recovery.
• Corneal thickness temporarily increased but normalized by day 14.
• Increased endothelial pleomorphism was noted throughout the study period; intraocular pressure remained unaffected.

Conclusions:

• The transcorneal freezing model in aged rabbits is suitable for corneal endothelium injury and therapeutic research.
• The model demonstrates rapid injury induction with minimal impact on corneal thickness and intraocular pressure.
• Understanding the innate corneal endothelial cell regrowth rate is essential for accurate therapeutic efficacy assessment in this model.