Surgical Management Of Refractory Fungal And Mixed Infectious Keratitis: Therapeutic Outcomes

Advanced fungal and mixed infectious keratitis unresponsive to topical and systemic therapy represents a sight-threatening condition. These cases often require urgent surgical intervention due to progressive stromal necrosis, deep fungal penetration, and risk of perforation or scleral extension. The purpose of this study was to determine the therapeutic success rate of surgical management in advanced fungal keratitis. Therapeutic success was defined as complete eradication of infection and preservation of the globe following surgery combined with topical and or systemic therapy.

Retrospective case series conducted at specialized Cornea & Refractive surgery Service 

A retrospective chart review was performed including patients diagnosed with advanced fungal or mixed fungal keratitis between January 2023 and January 2026, who required surgical intervention after failure of maximal medical therapy. Demographic characteristics, infiltrate size and stromal depth (slit-lamp evaluation and AS-OCT), microbiologic diagnosis (culture and/or in vivo confocal microscopy), type of surgical procedure and therapeutic outcomes were analyzed. Surgical procedures included therapeutic penetrating keratoplasty (PK) or lamellar keratectomy with conjunctival flap Therapeutic success was defined as infection eradication with globe preservation. 

Seventeen eyes (10 females, 6 males; mean age 56.4 years, range 9–92) were included. Infiltrate size ranged from 1–8 mm, with mid-deep stromal involvement in most cases. Most patients underwent therapeutic penetrating keratoplasty; one required two sequential grafts for persistent infection. Lamellar keratectomy with conjunctival flap was performed in two cases with complete resolution. Globe preservation was achieved in 16/17 eyes (94.1%); one required evisceration due to endophthalmitis. Filamentous fungi predominated and yeast infections were identified in three cases. Mixed infections were observed in selected cases, including bacterial co-infection, herpetic keratitis and one case with concomitant Acanthamoeba infection.

Refractory fungal and mixed infectious keratitis remains a major therapeutic challenge due to limited antifungal penetration and the ability of filamentous fungi to invade deep stromal layers and into the anterior chamber. When medical therapy fails, early surgical intervention, particularly therapeutic penetrating keratoplasty plays a critical role in eradicating infection and preserving the globe. Prompt diagnosis and timely surgical management are essential to reduce irreversible and devastating outcomes.