Coats disease is unilateral in more than 90%
of cases and most frequently occurs in otherwise healthy patients. Bilateral
occurrence is so rare that some researchers recommend questioning the
diagnosis in these patients. The disease manifests as a deterioration in
either central or peripheral vision. Rarely, Coats disease is associated
with pathologic findings of the head and neck (microcephaly, intracranial
calcifications, ataxia, depressed premaxillary region), the skin (absent
scalp hair, syndactyly of fingers, dysplastic, grooved nails), and other
ocular manifestations (paresis of ocular muscles, glaucoma). Renal
impairment has been reported in some patients.