Only a small number of cases have been reported so far of the characteristic opacity of the cornea first described by Coats.1 To the 42 cases collected by Bietti,2 including 4 of his own, 2 cases of MacRae3 and 5 of Waldman4 may now be added.
In 46 of the 50 cases available, only one eye was affected and only one ring was present. One of Ballantyne's5 patients had two rings in one cornea ; 1 of Kuan's6 had one ring in each cornea ; 1 of MacRae's7 had one ring in one cornea and several rings in the other cornea, and 1 of Coats's8 had multiple rings in both eyes.
The rings occur in any part of the corneal field. By slit lamp examination the white deposit is seen in or adjacent to Bowman's membrane.
The rings cause no symptoms. As a matter