Visual function in congenital and childhood myotonic dystrophy type 1

Area of Science:

• Ophthalmology
• Genetics
• Neurology

Background:

• Myotonic dystrophy type 1 (DM1) is a multisystem disorder with potential ocular manifestations.
• Congenital and childhood DM1 present unique challenges in visual development.

Purpose of the Study:

• To assess visual function in children with DM1.
• To correlate visual outcomes with cytosine-thymine-guanine (CTG) repeat expansion size and disease onset.
• To compare visual function in DM1 patients with a control group.

Main Methods:

• Cross-sectional study involving 49 individuals with congenital/childhood DM1 and age/gender-matched controls.
• Ophthalmologic examinations included visual acuity, refraction, slit-lamp microscopy, indirect ophthalmoscopy, and flash visual evoked potentials (VEPs).
• Key outcome measures were visual acuity, refractive error, lens/fundus pathology, and VEP abnormalities.

Main Results:

• Individuals with DM1 showed higher rates of low visual acuity, hyperopia, and astigmatism compared to controls.
• Larger CTG repeat expansions were associated with lower best-corrected visual acuity (BCVA) across subgroups.
• In childhood DM1, greater CTG repeat expansion size correlated with high hyperopia and astigmatism.

Conclusions:

• Children and adolescents with DM1 exhibit diverse visual function pathologies.
• DM1 significantly impacts the developing visual system.
• Early and regular ophthalmologic assessment is crucial for managing visual complications in DM1.