Safety and efficacy of 0.05% tacrolimus eye drops for refractory ulcerative keratitis

Abstract

Background Local medical treatment of refractory immunologic keratitis is unsuccessful, and systemic steroids and immunosuppressive agents could cause severe side-effects. Tacrolimus is a potent immunosuppressive drug, it has been proved that topical application of tacrolimus could reduce immunologic inflammation. The safety and efficacy of 0. 05% tacrolimus eye drops for refractory immunologic keratitis has not been described. Objective This study was to evaluate efficacy and safety of 0. 05% tacrolimus eye drops for refractory ulcerative keratitis. Methods A retrospective study was performed. Twenty-one eyes of 17 patients with refractory immunologic keratitis, which had uncontrolled inflammation despite initially treatment including topical steroids and 1% cyclosporine A, were enrolled, including 11 males and 6 females, with the mean ages of 52 years. Infectious ulcer was excluded by laboratory tests. No systemic disease was found in 11 patients, and Wegener's granulomatosis, rheumatoid arthritis and ulcerative colitis were seen in 1 patient, 4 patients and 1 patient respectively before presentation and they were all in remission under conventional systemic therapy. Four patients got binocularly involved and thirteen patients were monocularly involved. Of the 21 eyes, 2 eyes with ulcer were ≥3 quarters of the limbus, and 19 eyes with ulcer were ≤2 quarters. All patients were treated with 0. 05% tacrolimus eyedrops after discontinuing cyclosporine A. The dosage was adjusted according to the severity of inflammation and was gradually tapered when improvement occurred. The corneal lesions were examined under the slit lamp microscope and Heidelberg HRT3 Rostock Cornea Module regularly, and inflammatory cell infiltrations were analyzed with Cell Count® software (Heidelberg Engineering GmbH). The safety variables were monitored regularly, including adverse response of eye, tacrolimus blood concentrations measured by chemiluminescent microparticle immunoassay (CMIA) and laboratory examinations of blood routine, blood glucose level, liver and kidney function. Results The patients were treated and followed-up for a mean duration of 18. 1 months (range, 8-24 months). Corneal ulcer area was obviously reduced 1 month after treatment in 19 eyes, and 2 eyes of 2 cases received anterior lamellar keratoplasty due to progressive corneal destruction despite of tacrolimus therapy. Corneal ulcer was cured 3 months after treatment, and stromal edema and infiltration disappeared 6 months after treatment under the slit lamp microscope. The inflammatory cell densities at lesion zone were (958±329), (858±339), (459±261), (192±124), (98±52), (44±24) and (3±2)/mm2 before treatment and 1 week, 1 month as well as 3, 6, 12, 24 months following treatment, respectively, showing a gradually decline as time lapse (F=125. 439, P=0. 000), and the inflammatory cells were significantly decreased in 1, 3, 6, 12 and 24 months following the administration of 0. 05% tacrolimus eye drops in comparison with that before treatment (all at P=0. 000). The therapy duration was 12 months in 9 eyes and 24 months in 12 eyes. Transient irritation sensation occurred in 4 eyes during the treating period. Blood concentrations of tacrolimus were below 1. 0 ng/ml in all of the patients. No abnormality was found in laboratory tests. Conclusions The use of 0. 05% tacrolimus eye drops is a safe and effective approach to refractory immunologic keratitis. Key words: Corneal ulcer/drug therapy; Ophthalmic solutions; Tacrolimus/therapeutic use; Tacrolimus/adverse effects; Microscopy, confocal; Treatment outcome