Anti-inflammatory treatments in microbial keratitis

Infectious keratitis remains a leading cause of corneal blindness worldwide. The role of topical anti-inflammatory agents such as corticosteroids, calcineurin inhibitors, and other steroid-sparing therapies in the management of infectious keratitis has not been clearly defined and remains controversial. The benefit of corticosteroids in the treatment of infectious keratitis varies depending on the causal organism. While one large randomized-controlled trial supports their use in some cases of bacterial keratitis, high-quality evidence for their use in fungal or amoebic keratitis is not well-established. There are few case reports and no randomized control trials evaluating the safety and efficacy of steroids in the treatment of fungal or amoebic keratitis, although generally steroids are avoided in fungal keratitis and used judiciously in amoebic keratitis. Topical steroid-sparing anti-inflammatory treatments such as calcineurin inhibitors may especially have a role in the treatment of fungal keratitis, where topical corticosteroid use is generally avoided. Emerging adjunctive therapies, including amniotic membrane transplantation, photoactivated chromophore cross-linking, and experimental immunomodulators, show preclinical or early clinical promise but lack robust human data. Large, multicenter trials are needed to establish evidence-based protocols for infectious keratitis treatment that balance infection eradication with control of host inflammation. While judicious anti-inflammatory use appears beneficial in many cases, optimal timing, dosing, and combination strategies remain uncertain. This review summarizes current evidence on topical anti-inflammatory therapy for infectious keratitis, focusing on bacterial, fungal and amoebic infections, and highlights key gaps in knowledge.