Ocular Microbiology and Immunology Group
Back to OMIG Main Page

< Previous | 2026 Agenda and Abstracts | Next

2026 OMIG Abstract

Evaluating Cytomegalovirus Anterior Uveitis Treatment: the STACCATO RCT

John A. Gonzales¹, Thanapong Somkijrungroj², Wipada Laovirojjanakul³, Fanxiu Xiong¹, Benjamin A. Pinsky⁴, Benjamin F. Arnold¹, Thuy Doan¹, Gerami D. Seitzman¹, and Thomas M. Lietman¹

¹Francis I. Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, San Francisco, California; ²Chulalongkorn University, Thailand; ³Khon Kaen University, Thailand; ⁴Stanford University School of Medicine, Stanford, California

Purpose: No comparative trial has defined optimal antiviral therapy for cytomegalovirus (CMV) anterior uveitis. We compared oral valganciclovir, topical ganciclovir 2%, and placebo using aqueous CMV viral load (a quantitative microbiologic endpoint not previously used as the primary outcome of a uveitis randomized trial).

Methods: Three-arm, double-masked, placebo-controlled trial at 3 tertiary centers (US, Thailand), 2020–2024. Adults with active anterior uveitis and CMV detected by PCR of aqueous obtained by anterior chamber (AC) paracentesis were randomized 1:1:1 to oral valganciclovir 900 mg BID, topical ganciclovir 2% six times daily, or placebo for 21 days; all received standard-of-care topical corticosteroids. A second AC paracentesis was performed at day 7. The primary outcome was log₁₀ CMV viral load at day 7 (ANCOVA adjusted for baseline viral load and site). Secondary outcomes included AC cell, intraocular pressure, and visual acuity at days 7 and 21.

Results: Of 51 enrolled, 47 had paired day-7 viral loads (retention 92%); enrollment stopped early due to COVID-19 delays/funding expiration. Oral valganciclovir produced the greatest fold-reduction in viral load (2.27-fold) versus topical ganciclovir (1.39-fold) and placebo (1.47-fold), and a 37% lower adjusted mean post-treatment viral load than topical ganciclovir (ratio 0.63, 95% CI 0.29-1.91), though no between-arm comparison reached significance. No clinical endpoint differed between arms, and repeat AC paracenteses were well tolerated.

Conclusions: Oral valganciclovir produced the greatest reduction in aqueous CMV viral load, though differences were not significant in this feasibility study. STACCATO demonstrates that a masked, multicenter uveitis trial anchored to a microbiologic endpoint and requiring serial AC paracentesis is feasible and safe. These data informed a now-funded NIH sequential trial (NCT07513623) evaluating acute treatment and extended antiviral suppression.