An Unusual Manifestation of HSV-1 Uveitis Transforming into an Acute Iris Transilluminationlike Syndrome with Pigmentary Glaucoma: A Reminder of Treatment Pitfalls in Herpetic Uveitis

We report an unusual case of herpes simplex virus type 1 (HSV-1) anterior uveitis evolving into an acute iris transillumination-like syndrome with secondary pigmentary glaucoma, highlighting diagnostic challenges and treatment considerations. A 61-year-old immunocompetent woman presented with unilateral anterior uveitis characterized by keratic precipitates and mild inflammation. She was initially treated with topical and subconjunctival corticosteroids, but without antiviral therapy. After an initial resolution of symptoms, upon cessation of treatment, the patient developed features resembling unilateral acute iris transillumination (UAIT) with elevated intraocular pressure, diffuse pigment dispersion, and iris transillumination defects. Polymerase chain reaction (PCR) testing confirmed HSV-1 infection. Despite the initiation of antiviral therapy, her condition progressed to severe pigmentary glaucoma, with intraocular pressure measurements fluctuating due to prior LASIK surgery affecting tonometry accuracy, necessitating cataract extraction, vitrectomy, and Ahmed valve implantation. The eye eventually stabilized with partial recovery of visual acuity. This case illustrates that HSV-1 anterior uveitis can mimic or transition into a UAIT-like syndrome, possibly due to steroid use without concurrent antiviral treatment, which may exacerbate viral replication and tissue damage to the iris pigment epithelium. Aqueous PCR testing aids in differential diagnosis, but indicative medical history and clinical findings should remain instrumental. Clinicians should maintain a high index of suspicion for viral etiology and initiate prompt treatment with antiviral therapy to prevent potentially sight-threatening complications such as UAIT-like exacerbation and pigmentary glaucoma.