Correlation of Murine Anterior Segment Spectral Domain Optical Coherence Tomography Analysis With Corneal Allograft Rejection

Abstract

Purpose: : To determine if Spectral Domain Optical Coherence Tomography (SD-OCT) imaging of the anterior segment of mice can be used to detect early corneal allograft rejection.

Methods: : An ultrahigh-resolution SD-OCT with dedicated optical delivery systems for imaging anterior segment of small animals in vivo was used. Corneal transplants were performed in isogeneic (Balb/c to Balb/c) and allogeneic (C57BL6 to Balb/c) recipients and clinical scoring for clarity and vasularization was monitored at specific time points. Simultaneously, the anterior segment was imaged with SD-OCT, all images were processed and central corneal graft thickness was measured. Clinical scores and SD-OCT measurements were compared.

Results: : Average corneal thickness correlates with standardized clinical scoring system used for evaluating corneal graft rejection. Rejected corneal allografts, defined by a clinical score of 3, is equivalent to a SD-OCT corneal thickness of more than 300 um. Isogeneic and non-rejected corneal allografts with a clinical score of 1 have an average SD-OCT central thickness of 200um. Furthermore, corneal allograft rejection can be detected by SD-OCT as early as day 21 after surgery.

Conclusions: : Small animal anterior segment SD-OCT is a novel, efficient and objective method of monitoring corneal graft rejection in vivo and could represent a unique tool to assess early signs of corneal allograft rejection.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • transplantation • cornea: basic science