Histopathological and statistical study of corneal repair in rabbits. A new way to understand corneal recovery.

The study aims to evaluate corneal healing post amniotic membrane transplantation in controlled corneal defects, justifying its application in routine ophthalmology practice. The objective is to establish a reliable method for assessing the repair process. In three groups of six adult New Zealand rabbits, keratectomy and a monolayer transplant of dehydrated human amniotic membrane (AM) were conducted in the left eye (OS) with the right eye (OD) serving as the control eye. Clinical signs were assessed, and both eyes were enucleated at 1, 2, and 4 weeks for optical coherence tomography (OCT) measurements and histological analysis, collecting data from different epithelium, stroma, and limbus regions. This study was conducted using a formula that combines histologic data categorizing their presence and/or type as beneficial for corneal repair. No statistically significant differences were found between the experimental and control eyes regarding all clinical signs and OCT measurements. However, a linear model using histopathological results showed a period-implant mode interaction with statistical significance (<i>p</i>=0.010). The use of the single-layer amniotic membrane resulted in improved corneal recovery with the stromal side showing better performance in the first week and the epithelial side proving to be more effective than the stromal side in the long term. For the first time, a statistical formula employing histopathological data is introduced to determine corneal recovery, potentially offering a more accurate and reliable method compared with the observation of clinical signs and corneal measurements with OCT.