Unilateral childhood-onset glaucoma associated with Phelan-McDermid syndrome.

Purpose: Phelan-McDermid Syndrome (PHMDS) is a rare neurogenetic, highly heterogenous, disorder with hallmark signs of neonatal hypotonia, dysmorphic facial features, and developmental delay. We report a case of unilateral ocular hypertension with glaucomatous concern in a child with PHMDS. Observations/interventions: A 7-year-old female with genetically confirmed chromosome 22q13.3 deletion was referred for unilateral ocular hypertension and signs of elevated episcleral venous pressure (EVP). Given a complex genetic profile and past medical history, minimal topical medication was tolerated leaving a persistently elevated intraocular pressure (IOP) of 20 mmHg in the right eye compared to 12 mmHg in the left eye with concerns for glaucomatous cupping. Magnetic resonance imaging with angiography of the brain and orbits was unrevealing for a cause of her suspected unilateral elevated EVP. Transscleral diode cyclophotocoagulation was performed and achieved successful IOP control with limited topical therapy. Conclusions/importance: This case highlights the challenges of evaluating and managing ocular hypertension with glaucomatous concern in a medically complex child, as early recognition and individualized intervention can effectively manage glaucoma in the context of complex systemic comorbidities.