When Immune System and Herpes Virus Infection Collide: A Case of Severe Stromal Herpetic Keratitis in a Patient with Rheumatoid Arthritis Under Methotrexate

Claudia Corda,1,* Filippo Lixi,1,2,* Antonio Budroni,1 Mara-Ioana Tomi,3 Alina-Gabriela Gheorghe,3 Giuseppe Giannaccare11Ophthalmology Unit, Department of Surgical Sciences, University of Cagliari, Cagliari, 09124, Italy; 2Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, 09124, Italy; 3Department of Ophthalmology, Clinical Institute of Ophthalmological Emergencies, Bucharest, 010464, Romania*These authors contributed equally to this workCorrespondence: Giuseppe Giannaccare, Full Professor of Ophthalmology and Chairman of Eye Clinic, Director of Ophthalmology Residency Program, Ophthalmology Unit, Department of Surgical Sciences, University of Cagliari, Cagliari, 09124, Italy, Tel +0039 3317186201, Email giuseppe.giannaccare@gmail.comPurpose: To report a case of refractory herpes simplex virus keratitis (HSVK) complicated by keratolysis and severe stromal thinning in a patient with rheumatoid arthritis (RA) under treatment with methotrexate (MTX).Observations: A 79‑year‑old patient with a history of HSVK and RA, treated with weekly MTX, presented with pain and photophobia in the right eye. Best‑corrected visual acuity (BCVA) was limited to counting fingers. Slit‑lamp examination revealed a supero-nasal corneal ulcer (area of 2.98 mm2) with deep stromal involvement and keratolysis. A recurrent episode of HSVK was diagnosed, and treatment with 3 times daily oral acyclovir, 4 times daily 0.15% ganciclovir ophthalmic gel, and 3 times daily 0.15% topical dexamethasone was started. After one week, the picture worsened with corneal thinning (corneal thinnest point [CTP] 82 μm) and anterior chamber fibrin. Cycloplegic therapy 3 times daily was added. Considering the refractory course, the history of recurrent HSVK, and the concomitant systemic immunomodulation, the MTX injection scheduled for the subsequent weeks was interrupted. After 2 weeks, conjunctival hyperemia improved (Efron grade II) and a progressive increase of corneal thickness (CTP 199 μm) was documented. Two months later, complete healing was achieved with no signs of active inflammation or recurrence; BCVA improved to 0.4 LogMAR, with mild residual stromal thinning and opacity (CTP 231 μm).Conclusion and Importance: This case underscores how systemic immunomodulatory treatment may play a clinically relevant role in patients with recurrent HSVK. In selected cases, a conservative, surgery‑sparing approach through the optimization of systemic therapy can help promoting viral load control and corneal healing.Keywords: herpes simplex virus keratitis, herpes virus, stromal herpetic keratitis, rheumatoid arthritis, corneal ulcer, methotrexate