Stromal microsporidial keratitis successfully treated with medical therapy

Role of Topical Fumagillin 0.007% in the Management of Microsporidial Stromal Keratitis: Interventional Pilot Study with Literature Review

PURPOSE

The standard management of Microsporidial Stromal Keratitis (MSK) traditionally involves therapeutic penetrating keratoplasty, often accompanied by complications. This pilot study investigated medical management, evaluating outcomes using topical fumagillin alone or in combination with topical voriconazole and oral albendazole.

METHODS

Mild to moderate MSK cases (January 2019-2024) with informed consent were included. The diagnosis was confirmed by microsporidial spores on smear (potassium hydroxide with calcofluor white, Gram, or modified Ziehl-Neelsen stain). Patients received 0.007% topical fumagillin (Sigma-Aldrich, F6771) alone or with topical voriconazole and oral albendazole.

RESULTS

Five patients (six eyes, 17.2%) of 29 MSK cases were enrolled, all males, with a mean age of 52.4 ± 12.3 years (37-74). Symptoms lasted 5.2 ± 3.8 months (1-12) before presentation. The mean IOP was 27.6 ± 7.6 mmHg; two were on anti-glaucoma medications. Corneal infiltrates measured 3.4 ± 0.8 mm (horizontal) and 3.4 ± 1.4 mm (vertical). Three patients received additional topical voriconazole 1% (Vozole) and oral albendazole 400 mg daily for 1 month. Clinical resolution occurred in all cases after 9.4 ± 5.2 months of treatment, with no recurrence over a 12.6 ± 3.4-month follow-up.

CONCLUSION

The findings of this study support the potential of medical management for MSK, suggesting that topical fumagillin 0.007% may offer a viable treatment option for mild to moderate cases.

Microbial keratitis in lattice corneal dystrophy: microsporidia as a new cause

A patient in his sixth decade presented to us with redness, pain and a deterioration of vision in his left eye. He had previously been diagnosed with lattice corneal dystrophy (LCD). He was diagnosed with microbial keratitis, and mixed infection was confirmed on culture (bacteria and fungus) with a protracted healing period before resolution of keratitis. He presented 2 years later with similar issues in the same eye and was noted to have a second episode of microbial keratitis, with microsporidia spores noted on gram, potassium hydroxide and calcofluor white stains. He was diagnosed with microsporidial stromal keratitis and underwent therapeutic penetrating keratoplasty. Unfortunately, he suffered a recurrence of microsporidial keratitis following surgery with eventual transplant failure. Microsporidia as an infection in LCD has, to our knowledge, not been previously reported. We aim to discuss microsporidial infection and recurrent microbial keratitis in the setting of LCD.