Keratoconus In Siblings With Congenital Distichiasis

Eye rubbing is an important predisposing factor in the pathogenesis of keratoconus. There are various ocular associations with keratoconus like vernal kerato-conjunctivitis, blepharoptosis, floppy eyelid syndrome, retinitis pigmentosa and syndromes like Down’s syndrome, Leber’s congenital amaurosis. Distichiasis can lead recurrent symptoms of discomfort, tearing, photophobia, eye rubbing. Congenital distichiasis can be associated with various systemic abnormalities like lymphedema-distichiasis syndrome, congenital heart defects, renal abnormalities, scoliosis. The association between distichiasis and keratoconus has not been reported. This case report describes a previously unreported association of keratoconus in congenital distichiasis.

Cataract and Refractive Surgery Services and Oculoplasty Services, LV Prasad Eye Institute, Hyderabad, India.

A 17-year-old male presented with tearing and photophobia in both eyes. There was a history of photophobia in both eyes since birth and some lid surgery in both eyes. Clinical examination revealed a central corneal scar with descemet membrane tear suggestive of healed hydrops in the right eye. Both eyes showed topographic features of keratoconus. The younger sibling , a 14-year-old female, also had similar symptoms of photophobia and tearing since birth. There is history of electrolysis performed in both eyes. Topography revealed subclinical keratoconus in both eyes. Father of the patients was also diagnosed with distichiasis and keratoconus in the second decade of life.

The association of  keratoconus and congenital distichiasis has not been reported earlier. Both the patients had symptoms of photophobia and tearing since birth, suggesting that eye rubbing associated with the condition could have been the predisposing risk factor for keratoconus in both the siblings. Congenital distichiasis can produce symptoms from birth and lead to excessive eye rubbing in early adolescence, which is the age when keratoconus manifests. Hence, aggressive, and definitive management of the condition should be pursued at an early age to prevent complications as was seen in the first patient who had hydrops. The parents should be educated and affected children should be advised to avoid rubbing their eyes from an early age.