The aim was to report 4 cases of Fuchs endothelial corneal dystrophy (FECD) in patients with an established diagnosis of myotonic dystrophy (DM) and suggest a mechanism for their association based on the known molecular genetics and potential pathophysiological parallels of DM and FECD.
We reviewed all available medical records and pathology slides for the 4 reported cases from the Department of Ophthalmology at Oregon Health and Science University's Casey Eye Institute and Devers Eye Institute at the Legacy Good Samaritan Medical Center in Portland, OR.
Four patients were found to have DM and bilateral corneal guttae, consistent with the diagnosis of FECD. All the identified patients were female and were aged between 34 and 63, and 2 patients were related (mother and daughter). The corneal specimens from 2 of the 4 patients who had undergone a corneal transplant were pathologically confirmed to be consistent with the diagnosis of FECD.
To our knowledge, FECD has not been previously reported in association with DM. Because both diseases are somewhat prevalent in the United States, it is possible that their coexistence is merely a coincidence in these patients. However, recent studies into the pathogenesis of each disease have shown more parallels between FECD and DM, suggesting the possibility of a noncoincidental association. Potential mutual pathogenic mechanisms may involve altered protein expression causing the deregulation of ion homeostasis, an unstable intronic trinucleotide repeat expansion, or activation of the unfolded protein response and oxidative stress pathways.