Nystagmus in Trisomy 21 (Downs Syndrome)
Dilys L. Oladiwura, MBBS, MSc, FRCOphth; Yusrah Shweikh, FRCOphth; Maria Theodorou, PhD, FRCOphth
Moorfields Eye Hospital
City Road; London, EC1; United Kingdom
Introduction: Nystagmus has been reported in about 30% of people with Downs syndrome(DS). Despite being a well reported, it remains a poorly characterised entity. Our study describes the clinical features of patients with DS and nystagmus
Methods: Retrospective medical-records review of all patients with a documented diagnosis of DS and nystagmus seen at Moorfields Eye Hospital (London) between January 2005 and June 2015.
Results: 51 subjects were identified over the 10-year study period with complete data in 48. The mean age of presentation was 5.1years(range 0-26years), with mean reported age of nystagmus onset of 6.1 months(95% CI 2.2-10.0 months). A clinical diagnosis of Fusion Maldevelopment Nystagmus(FMN) was made in 3/48, Infantile Nystagmus(IN) 4/48, Internuclear Ophthalmoplegia in 1/48, and manifest horizontal nystagmus in 40/48. Electrodiagnostic tests were requested in 16/48 with diagnoses of Optic nerve dysfunction (2); achromatopsia (2) albinism (1) in 4/16.
Discussion: The findings of this small study suggest that children/adults with DS may be more heterogenous than previously thought, i.e. not associated with DS(and associated cerebellar findings) alone. It is therefore prudent to consider the full context in which a child or adult with DS presents, as is the case with non-DS patients presenting to the ophthalmologist with nystagmus.
Conclusion: In accordance with previous work, the most frequent reported type of clinical nystagmus in our cohort was manifest horizontal nystagmus (presumed IN), However, this small study highlights the importance of differentiating the nystagmus subtypes (IN, FMN, neurological nystagmus), to guide further investigations and management.
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3 da Cunha RP, Moreira JB. Ocular findings in Down’s syndrome. American Journal of Ophthalmology 1996;122(2):236-244.