Ciliary muscle thickness in adults with Down syndrome

Area of Science:

• Ophthalmology
• Genetics
• Anatomy

Background:

• Down syndrome (DS) is associated with various ocular anomalies.
• Anterior ocular anatomy, including ciliary muscle thickness (CMT), may differ in individuals with DS.
• Understanding these differences is crucial for comprehensive eye care.

Purpose of the Study:

• To investigate the relationship between ciliary muscle thickness (CMT), age, and refractive error in adults with Down syndrome (DS).
• To determine if CMT in adults with DS differs from that reported in the general population.

Main Methods:

• Anterior segment optical coherence tomography (AS-OCT) was used to image the CMT in 33 adults with DS.
• CMT was measured at specific points (CMT1, CMT2, CMT3, CMTMAX) and apical thickness (AT) was calculated.
• Refractive error was determined, and multivariate regression analysis was performed to assess relationships with CMT and age.

Main Results:

• Mean CMT decreased posteriorly (CMT1: 804 μm, CMT2: 543 μm, CMT3: 312 μm).
• A significant negative correlation was found between CMT2/CMT3 and myopic refractive error, and a positive correlation between AT and hyperopic refractive error.
• CMT showed significant thinning with increasing age for CMT1 and CMT2.

Conclusions:

• Ciliary muscle thickness in adults with DS falls within a similar range to the general population.
• Refractive error trends in this DS cohort were comparable to previous reports, though influenced by moderate to high myopia.
• The findings suggest that CMT and its relationship with refractive error are broadly similar in adults with and without DS.