Scheimpflug images and graft rejection

1 December 2016 | Magdalena Popiela | EYE - Cornea, EYE - General

This study aimed to assess corneal changes using 360-degree Scheimpflug images and pachymetry readings to outline screening parameters, which define graft rejection. Seventeen eyes of 16 patients developed clinically manifest allograft rejection two to 42 months after surgery – those were compared to a cohort of asymptomatic 34 patients with similar follow-up. Retrocorneal spots varying in size and density and / or an increase in central corneal thickess (CCT) of more than 7% could be identified on Scheimpflug images before clinical manifestation of the allograft rejection in 9/17 eyes (53%) on average eight months before the clinical manifestation of graft rejection. At the time of graft rejection Scheimpflug images were made on 11 patients. In five eyes CCT increased more than 7% compared with the previous follow-ups. Ten eyes had retrocorneal elevated spots across the endothelium. In the control group the average increase in CCT ranged from 0.0% to 6.6%, and did not exceed 7% between consecutive postoperative follow-ups and no keratic precipitates were observed. This study suggests Scheimpflug images could aid in postoperative screening of patients who underwent descemet membrane endothelial keratoplasty (DMEK) but is limited by small numbers. The predictive value of Scheimpflug imaging in the detection of upcoming allograft rejection would require at least two images with a sufficient time interval in between. Interestingly, changes on Scheimpflug were detected on average eight months before clinical diagnosis of graft rejection, giving scope for increasing steroid therapy earlier to prevent clinically manifest rejection. Further studies are needed to determine if such an approach would work.