Ophthalmic findings in Alström syndrome

Abstract

Importance: Alström syndrome is a rare genetic disorder characterized by retinopathy and has life-threatening complications. Alström syndrome is frequently misdiagnosed or confused with other early childhood disorders with retinopathy. Understanding the spectrum of ocular manifestations of Alström syndrome is essential for ophthalmologists to recognize the cause and institute-appropriate care for this disorder that requires multidisciplinary attention.

Objective: To quantify and summarize the common ocular findings of Alström syndrome.

Design: Case series, clinical exam data obtained from 2015 to 2023.

Setting: Semiannual multidisciplinary Alström syndrome clinics (2015-2023) at the Greater Baltimore Medical Center (GBMC), organized by Alström Syndrome International (ASI).

Participants: Forty-eight patients (38 children, 10 adults) with a known diagnosis of Alström syndrome participated in the semiannual multidisciplinary Alström syndrome clinics. Patients apply to be seen and are accepted based on need and capacity.

Intervention(s) or exposure(s): Not applicable.

Main outcome(s) and measure(s): Clinical ocular findings.

Results: Participants in this study had a median age of 8 years (15 months to 42 years). Visual acuity and progression of vision loss varied. The youngest patient who was legally blind was 2 years old. The oldest patient who maintained useful vision was 7 years old. All patients 8 years old or older were legally blind. Nystagmus (94%, 45 of 48) and photophobia (73%, 35 of 48) were the most common first presenting ocular symptoms in childhood. Retinal vascular attenuation (91%, 40 of 44) and retinal internal limiting membrane changes (68%, 30 of 44) were the most commonly documented retinal findings in both children and adults followed by optic nerve (ON) pallor and retinal pigment epithelium (RPE) mottling. Less than half of the children had ON pallor (38%, 14 of 37) and RPEmottling (38%, 14 of 37), while all adults had these two findings (100%, 7 of 7). Retinal pigment clumps were not common in children (11%, 4 of 37), while common in adults (86%, 6 of 7).

Conclusions and relevance: Knowledge of these ocular findings is key to promptly recognize Alström syndrome. The ocular phenotype of Alström syndrome is largely dependent on age, suggesting that low vision interventions and potential gene-based therapeutics should target children with this disorder.

Keywords: Alström syndrome; Inherited Retinal Disease (IRD); childhood retinopathy.