The objective of this study is to compare the safety and efficacy of topical tacrolimus 0.05% drops compared with topical methylprednisolone sodium succinate 0.5% drops in patients with ocular GVHD. 40 patients with ocular GVHD who meet the inclusion criteria of the study as determined by a screening visit will be divided into two equal groups. In addition to their current medication, one group will receive the topical tacrolimus 0.05% drops and the other group will receive the topical methylprednisolone sodium succinate 0.5% drops. The participants will then have two follow-up visits at the week 5 and week 10 markers after their screening visit.