Ocular findings in a Spanish cohort of myotonic dystrophy type 1

Myotonic dystrophy type 1 is the most common muscular dystrophy in adulthood, caused by a triplet repeat in chromosome 19q13.3. The present study investigates the frequency of the different ocular alterations in Spanish patients with DM1 and its relationship with the severity of the genetic alteration.

Cross-sectional and multicenter study was conducted on patients with genetically confirmed DM1. Ophthalmologic examinations included visual acuity assessment, manifest refraction, slit-lamp biomicroscopy, tonometry, ocular motility, corneal tomography, and macular and optic nerve optical coherence tomography.

A total of 42 patients (84 eyes) were included. Mean age was 46.9 ± 13.4 (SD) years, and 57.1% were women. Fifteen patients had undergone cataract surgery in at least one eye (35.7%), and 13 (30.9%) had significant cataract. Mean intraocular pressure (IOP) was 10.5 ± 2.9 mmHg, and mean central corneal thickness (CCT) was 580.04 ± 48.61 μm. Half of the patients had significant ptosis, and 8 patients (9.75%) had undergone eyelid surgery. Macular abnormalities included retinal pigment epithelium alterations in 8 eyes of 6 patients, epiretinal membrane in 3 eyes, and lamellar hole in 2 eyes. A moderate correlation was found between IOP and ptosis with the number of triplet repeats.

Early cataract onset, low IOP, thicker CCT, and ptosis were the most significant manifestations of DM in our sample. Correlation found between IOP and ptosis with CTG repeat could be interesting in order to improve diagnosis and medical care of these patients but should be confirmed in further studies.