Summary

The present report describes the clinical findings in a rare case of a child with trisomy 21 and hyperthyroidism, who developed severe acute hydrops with corneal perforation secondary to underlying keratoconus. There is a known association between trisomy 21 and keratoconus (a conic protrusion of the cornea),1 and children with trisomy 21 are also at increased risk of developing thyroid disease, including thyrotoxicosis with exophthalmos.2^,3 However, a paediatric case with dual underlying diagnoses of trisomy 21 and hyperthyroidism, who subsequently developed severe hydrops, has not to our knowledge been previously described.