Keratoconus comorbidity with early-onset Fuchs’ endothelial dystrophy in identical twins

To report a case of keratoconus with early-onset Fuchs’ endothelial corneal dystrophy (FECD) changes in identical twins. A case report. A 22-year-old female had ocular findings of corneal protrusion, Fleischer’s ring, and corneal endothelium pigment dusting in both eyes. Corneal tomography showed increased corneal power and reduced thickness, and specular microscopy revealed loss of endothelial cells, the presence of a few non-confluent guttata, pleomorphism, and polymegathism in both eyes. Based on these findings, she was diagnosed as keratoconus with early grade FECD changes. Her family history revealed that she has an identical twin sister. Examination of her twin sister showed similar findings suggesting keratoconus with early grade FECD. This case report provides further evidence for the role of genetics in the development of keratoconus. Furthermore, it shows the diagnostic, monitoring, and treatment challenges due to the combination of two different diseases.