A case of myotonic dystrophy with pigmentary retinal changes

A 46-year-old man presented with visual disturbances in both eyes. His best corrected visual acuity was 0.7 (both eyes). Ptosis and limitation of ocular movement in every direction were observed. Slit lamp examination showed a bilateral iridescent cataract. Fundus examination showed peripheral depigmentation of the retinal pigment epithelium and pigmentary clumping in both eyes that agreed with blocked fluorescence and widow defects on fluorescein angiography. The amplitude of b-wave was decreased on electroretinography. Fourteen months later, the patient's best corrected visual acuity decreased to 0.3 due to increased lens opacity. Phacoemulsification and intraocular lens implantation were performed on both eyes. At the patient's final visit, retinal findings were stable with a best corrected visual acuity of 0.7 in both eyes. In conclusion, the visual disturbance could have been caused by both cataracts and retinal degeneration, meaning the fundus should be examined carefully in patients with myotonic dystrophy.