Spectral domain optical coherence tomography findings in myotonic dystrophy

The purpose of the study is to evaluate retinal involvement in a cohort of patients affected by Myotonic Dystrophy type 1 (DM1). Both eyes of 30 patients and one eye of a 31st patient with genetically proven diagnosis of DM1 and both eyes of 20 healthy age- and gender-matched subjects were enrolled. All patients underwent complete ophthalmologic examination including best-corrected visual acuity, intraocular pressure measurement, fundoscopy, fundus autofluorescence, infrared imaging and spectral-domain optical coherence tomography with central macular thickness measurement. DM1 patients showed statistically significant higher central macular thickness values than controls. In the DM1 group, butterfly (14.8%) and reticular (13.1%) pigment abnormalities were found with corresponding drusenoid deposit and focal disruption of photoreceptor and retinal pigment epithelium layers. Compared with the controls, DM1 group had higher prevalence of epiretinal membrane. In the DM1 group, the prevalence of epiretinal membrane and retinal pigment epithelium alterations were directly correlated with age, whereas no correlation was found with disease duration, CTG expansion and MIRS score. In conclusion, in addition to the typical retinal pigment epithelium changes, DM1 is also associated with abnormalities of the vitreoretinal interface, particularly epiretinal membrane, resulting in central macular thickness increase. Both inner and outer retinal alterations were associated with increasing age, suggesting that DM1 may cause a premature aging of the retina.