gms | German Medical Science

Objective: To describe the use of 360° Scheimpflug imaging as a diagnostic tool for detection and documentation of subtle corneal changes preceding an upcoming allograft rejection after Descemet membrane endothelial keratoplasty (DMEK).

Method: 17 eyes (16 patients) were diagnosed with a clinically manifest allograft rejection 2 to 42 months after DMEK. 360° Scheimpflug images of consecutive follow-up examinations (from 3 until 60 months) of ‘asymptomatic’ eyes before, during and after rejection were retrospectively analyzed, to determine which abnormalities could be detected before rejection became clinically manifest. The images were compared to DMEK control eyes (without rejection).

Results: Scheimpflug images at the time of rejection showed keratic precipitates as distinct retrocorneal nodular elevations and/or a significant increase in pachymetry. Similar but more subtle changes could in retrospect be identified in 9/17 eyes (53%) on average 8 (±5) months before rejection became clinically manifest; in all eyes, these subtle changes were not recognized at routine slit-lamp exams by various ophthalmologists as inflammatory changes heralding an allograft rejection. 4/17 eyes (24%) developed secondary graft failure. None of the control eyes showed relevant corneal abnormalities with Scheimpflug imaging.

Conclusion: By screening the posterior corneal surface with 360° Scheimpflug imaging, subtle inflammatory retrocorneal deposits can be detected and recorded during consecutive follow-up visits. Hence, Scheimpflug imaging may have potential to become a diagnostic tool in the early detection of an upcoming allograft rejection in 'asymptomatic' DMEK eyes, i.e., before the immune response becomes clinically manifest with substantial endothelial cell damage.