Effects of intraocular treatments for Epstein-Barr virus (EBV) retinitis: A case report

Rationale: Intraocular infection of Epstein–Barr virus (EBV) may cause severe visual loss. However, it is relatively rare, and there is no consensus on its treatment. Patient concerns: A 44-year-old woman complained of a right-eye floater and exhibited a unilateral exudative change along the retinal veins at the Department of Ophthalmology, St. Luke’s International Hospital. Diagnosis: EBV retinitis was diagnosed based on EBV-positive (9.09 X 10³ copies/ml) and cytomegalovirus-negative results in the aqueous humor. Interventions: Oral prescription of valaciclovir hydrochloride, and an intravitreal injection of foscarnet sodium hydrate was administered. However, the retinal infiltration progressed, and vitreous opacity with cellular infiltration appeared. Intravitreal methotrexate (MTX) injection effectively suppressed retinal and vitreous infiltration. However, she developed optic-nerve papillitis, and central retinal vein occlusion related to the severe swelling of the optic-nerve, and began steroid pulse therapy. Considering the increase in intraocular EBV levels to 6.4 X 10⁴ copies/ml, we restarted intravitreal foscarnet injections replacing MTX. This in turn rapidly reduced the EBV levels to 3.27 X 10⁴ copies/ml, followed by papillitis alleviation. Outcomes: The intraocular MTX administration reduced the inflammatory vitreous and retinal infiltration, but not the EBV load, while foscarnet reduced the EBV load and papillitis, but not vitreous infiltration. Lessons: The retinal infiltration may have involved EBV infection to the retinal neurons but also EBV-free reactive inflammatory cells. EBV infection to the neurons may have been, at least partially, treated by intravitreal foscarnet treatment, and the reactive inflammatory cells by intravitreal MTX. Further observations are warranted to reach a consensus on treating intraocular EBV infection.