The Feasibility and Utility of Anterior Segment Optical Coherence Tomography Quantification of Anterior Chamber Inflammation as a Predictor of Corneal Graft Health

Abstract

Purpose : To assess the feasibility and utility of using quantified anterior chamber (AC) inflammation measured by anterior segment optical coherence tomography (AS-OCT) as a predictor of graft rejection and to evaluate its impact on central corneal (CCT) and graft (GT) thickness in cornea transplant patients.

Methods : This is a consecutive case series of patients who underwent corneal keratoplasty including Penetrating Keratoplasty (PK), Descemet Stripped Automated Endothelial Keratoplasty (DSAEK), Descemet Membrane Endothelial Keratoplasty (DMEK) and/or Deep Anterior Lamellar Keratoplasty (DALK). AS-OCT images were obtained on the Optovue XR Avanti. CCT pachymetry in all eyes, and central and peripheral GT in DSAEK eyes only were measured. AC inflammation was quantified from AS-OCT scans using an automated, proprietary algorithm that detected the inflammatory cell count over the measured AC volume (cell density).

Results : 86 eyes of 51 patients were included with a mean age of 62 years (range: 21-86 years), a mean follow-up time of 31 months (range: 0.25-268 months), and 49 (57%) were females. The cohort consisted of 24 (28%) DMEK, 43 (50%) DSAEK, 17 (20%) PK, and 2 (2%) DALK. Average cell density was measured by surgery subtype: DMEK (0.62±1.18 cells/mm³), DSAEK (3.77±11.75 cells/mm³), and PK (1.03±1.61 cells/mm³). By Kruskal-Wallis, there was no difference in cell density between groups (p=0.49). Trends were noted for GT vs. cell density (r=0.22, p=0.27) and CCT vs. cell density (r=0.20, p=0.07). Patients with concurrent glaucoma had significantly higher (p=0.0025) average cell density (7.66±17.60 cells/mm³, n=12) compared to patients who did not have glaucoma (1.66±5.46 cells/mm³, n=74).

Two patients developed graft rejection after obtaining AS-OCT images and both had quantifiable AC cell. The first patient was a 27-year old female with a DSAEK and a history of prior transplants. Her imaging revealed posterior endothelial protrusions. The second patient was a 49-year old male with chorioretinitis who underwent DSAEK and whose imaging showed an edematous cornea with varied corneal hyperreflectance.

Conclusions : Quantifying AC inflammation is feasible in corneal transplant patients and may have a potential relationship to CCT and GT. The utility of AS-OCT imaging as a predictor for graft rejection requires further investigation.

This is a 2020 ARVO Annual Meeting abstract.