Dual corneal involvement by endothelial and epithelial corneal dystrophies in Steinert's disease: A case of triple dystrophy.

INTRODUCTION: A case of dual corneal involvement due to Fuchs endothelial corneal dystrophy and epithelial basement membrane corneal dystrophy in a patient with Steinert's myotonic dystrophy type 1 is described, and a literature review on the triple association is made. CASE DESCRIPTION: A 52-year-old male diagnosed with myotonic dystrophy type 1 presented due to progressive bilateral vision loss during the past year. A full ophthalmological evaluation was made, with biomicroscopy, funduscopy, anterior segment optical coherence tomography, and endothelial cell count using specular microscopy. Exploration revealed bilateral superior palpebral ptosis, visual acuity 0.5 in the right eye and 0.3 in the left eye, and with an intraocular pressure of 11 and 10 mmHg, respectively. Biomicroscopy revealed map-dot-fingerprint lesions characteristic of epithelial basement membrane corneal dystrophy in both eyes, as well as abundant endothelial guttae due to Fuchs endothelial corneal dystrophy (stage II) and bilateral nuclear and posterior subcapsular cataracts. Specular microscopy in turn showed cell loss and a destructured endothelial map. Finally, anterior segment optical coherence tomography revealed the accumulation of epithelial basement membrane and hyperreflective endothelial excrescences corresponding to guttae. CONCLUSION: The association of Fuchs endothelial corneal dystrophy with myotonic dystrophy has been described and explained by a common genetic basis in the expansion of a CTG trinucleotide repeat, though this is the first reported case of the triple association of Fuchs endothelial corneal dystrophy, epithelial basement membrane corneal dystrophy, and myotonic dystrophy type 1. New mutations or still unknown genetic alterations could possibly explain the triple association reported in our case.