When a 31-year-old man arrived at an ophthalmology clinic in France with sudden vision loss, eye redness, and pain, the initial clinical picture pointed toward a common herpes virus infection. What followed — a diagnostic pivot, rapid disease progression to near-total vision loss, and an unconventional combination antiviral regimen — illustrates both the expanding clinical complexity of mpox and the glaring absence of evidence-based treatment standards for its most severe manifestations.
The case, published in Emerging Infectious Diseases by Dr. Brousse and colleagues at Bordeaux University Hospital, France, describes what appears to be one of the first documented uses of combined intravenous cidofovir and oral tecovirimat to treat mpox-associated disciform keratitis — a potentially blinding corneal condition. The case study arrives as global mpox case counts have exceeded 140,000 since 2022, driven largely by the clade IIb strain that fueled the multinational outbreak in Western Europe and the United States.
A Diagnostic Detour With Consequences
The patient’s case unfolded against a backdrop of confirmed monkeypox virus (MPXV) infection diagnosed one month prior, which had already produced cutaneous lesions requiring surgical intervention. One week after that surgery, he presented with disciform keratitis in his left eye and some vision impairment. Initial empirical treatment with oral valaciclovir, targeting presumed herpes simplex or varicella-zoster virus, produced no improvement.
A corneal swab obtained on day eight tested positive for MPXV, with a cycle threshold value of 29, confirming the viral etiology. Retrospective analysis revealed that the original conjunctival swab from day zero had also been MPXV-positive, underscoring how diagnostic delays can allow ocular disease to advance unchecked. Without effective intervention, the patient’s vision deteriorated to counting fingers only — effectively functional blindness in the affected eye.
Combination Approach Yields Rapid Recovery
The clinical team pursued an aggressive dual-drug strategy starting on day 15. They administered cidofovir—a broad-spectrum antiviral known to inhibit viral replication—paired with tecovirimat, which prevents newly formed virus from spreading. Probenecid was added to protect kidney function, a known concern with cidofovir. Topical steroids continued as before. The rationale was straightforward: by attacking the virus at two different points in its lifecycle, the combination could provide better control than either drug alone.
The results were compelling. Within a week of the cidofovir infusion, vision improved sharply and viral testing came back negative. By day 29, all visible eye inflammation had resolved. By day 56, the patient had regained near-normal sight—substantially faster than the typical recovery timeline of roughly a month reported in medical literature.
Public Health Implications
This case offers several practical lessons for frontline responders and policymakers:
Eye involvement is underrecognized. Mpox can affect the eyes in 1–10% of cases, yet many clinicians don’t routinely screen for it. The risk: permanent vision loss. Public health guidance should prompt doctors to check for ocular symptoms in mpox patients and refer to eye specialists when needed.
Treatment options are limited and inconsistent. Recent clinical trials showed that tecovirimat alone doesn’t reliably clear the virus in newer mpox variants. There’s no standard playbook yet for severe cases. This gap matters for biosecurity preparedness.
Older antivirals may deserve a second look. Cidofovir, developed decades ago for other viral eye infections, showed promise here. It’s generally safe in younger patients without serious underlying conditions—precisely the population most affected by mpox. As mpox spreads and new variants emerge, revisiting existing drugs could accelerate treatment options without waiting for new drug development.
Important caveats: This is a single patient case, so it cannot prove that the drug combination caused the improvement. Disease may have resolved partially on its own. The authors are appropriately cautious, noting that larger, controlled studies would be needed to establish whether this combination approach should become standard treatment.
Sources and further reading:
Brousse et al. Treatment of Severe Ocular Mpox with Cidofovir and Tecovirimat. Emerging Infectious Diseases, April 10, 2026