Dr. Alberto Bellone recently observed an interesting clinical case of keratoconus in two 22-year-old homozygous twin brothers. One of the brothers came to Dr. Bellone's attention after he was denied access to a military career because of a diagnosed keratoconus in his left eye. This generally healthy patient does not wear glasses or contact lenses. One notable anamnestic finding is his habit of frequent eye rubbing.

Corneal topography of the patient revealed keratoconus in the “snowman” phenotype, according to the Fernandez-Vega/Alfonso classification, in the left eye. Interestingly, the right eye showed normal condition with no signs of estasia, but further analysis revealed a mild deformation similar to that in the left eye, although at a much earlier stage.

The twin brother, who had no symptoms, underwent corneal topography. Surprisingly, the examination showed similar abnormalities in both eyes, comparable to those in the first brother's better eye. This case suggests that the habit of eye rubbing may have revealed a genetic predisposition to keratoconus.

TWIN 1

Aberrometry, right eye

Keratoconus indices, right eye

Right eye

Aberrometry, left eye

Keratoconus indices, left eye

Left eye

TWIN 2 

Left eye

Keratoconus indices, left eye

Aberrometry, left eye

Left eye

Keratoconus indices, right eye

Aberrometry, right eye

Source: https://albertobellone.it/cheratocono-in-fratelli-gemelli-omozigoti/

Thanks to Dr. Alberto Bellone