Clinical applications of tacrolimus in the treatment of ocular diseases: a narrative literature review

PURPOSE: To narratively review clinical use of topical and periocular tacrolimus in ophthalmology, with emphasis on allergic keratoconjunctivitis (VKC/AKC), ocular GVHD, post‑keratoplasty prophylaxis, and selected keratitis/uveitis indications. METHODS: Narrative search of PubMed/Scopus through October 2025 focusing on prospective, randomized, and comparative studies of topical/periocular tacrolimus; recent formulation advances (nanoemulsions, in‑situ gels, cyclodextrin complexes) were included. RESULTS: Across VKC/AKC, tacrolimus (0.03-0.1% ointment; 0.05-0.1% solutions/suspensions) improves signs/symptoms and reduces steroid burden; comparative data suggest faster epithelial healing than topical corticosteroid in shield ulcers. In ocular GVHD, pilot randomized data demonstrate symptom relief with acceptable safety. Observational studies suggest benefit as post‑keratoplasty adjunct in high‑risk grafts. Emerging delivery systems address solubility, residence time, and tolerability and show promising preclinical pharmacokinetics. CONCLUSION: Tacrolimus is a practical steroid‑sparing therapy for severe ocular surface inflammation. Priority trials should be formulation‑specific with standardized outcomes and pharmacokinetic endpoints, alongside pediatric safety registries and head‑to‑head comparisons versus cyclosporine 2% and soft steroids.