This study investigates the effects of 0.05% topical tacrolimus as an adjunct therapy for patients with non-necrotizing herpetic stromal keratitis (HSK).

In this clinical trial, patients with non-necrotizing HSK, referred to the Cornea Clinic at Amiralmomenin Hospital in Rasht, Iran, between September 2016 and February 2018, were randomly assigned into two groups. The control group (N = 25) received conventional treatment with systemic acyclovir and topical prednisolone, and the case group (N = 25), in addition to the above, received 0.05% tacrolimus eye drops four times a day for one month. Complete ocular examinations, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp exam, and photo slit lamp imaging were performed before treatment, and three, seven, 14, 21, and 28 days after the intervention. The primary outcome measures were the changes in corneal haziness and edema scores and the secondary outcome measures were the changes in corneal vascularization and epitheliopathy scores.

The mean age of the patients was 46.2 ± 12.9 years, and 70% of the patients were male; there was no difference between the groups in terms of age, sex and baseline ocular measurements (P > 0.05). The case group had a lower mean logarithm of the minimum angle of resolution (LogMAR) for BCVA, lower grading scores and steeper decreasing trends for corneal haziness, edema, neovascularization, and epitheliopathy compared to the control group after the second week (P < 0.05), while IOP remained unchanged between groups (P > 0.05).

The addition of 0.05% topical tacrolimus enhances visual acuity and reduces corneal inflammation, neovascularization, and scarring; thus, it can be suggested and used as an appropriate adjunct treatment for patients with HSK.