Introduction: Anti-inflammatory, topical therapy of severe keratitis in dry eye disease (DED) and ocular graft-versus-host disease (oGvHD) includes steroids, cyclosporine (Cs), and others. In Germany, a commercial product containing 0.1% Cs in a cationic formulation is available since 2015. Objective: The aim of this study was to present real-life data using cationic 0.1% Cs in oGvHD patients. Methods: This was a retrospective study of 26 oGvHD and 41 DED patients with corneal staining of at least Oxford grade III. Parameters analyzed were Ocular Surface Disease Index, corneal staining, intraocular pressure, tear film break-up time, Schirmer, and visual acuity. In addition, it was evaluated how different Cs formulations were tolerated. Results: Corneal staining improved significantly in 1 eye in DED but not in oGvHD. In DED, cationic 0.1% Cs was not tolerated by 32% of the patients, in contrast to 0.05% Cs in castor oil not tolerated by 47% and liposomal 0.05% Cs by 63%. In oGvHD patients, cationic 0.1% Cs was not tolerated by 62%, 0.05% Cs in castor oil by 33%, and liposomal 0.05% Cs by 39% of the patients. Conclusions: This study demonstrates differences between the tolerance of different Cs formulations depending on the underlying cause of severe keratitis. Cationic 0.1% Cs is considerably less tolerated in oGvHD, and its use should be considered with care
