Flattening of central corneal curvature with intrastromal corneal rings of increasing thickness: An eye-bank eye study. - Burris,T.E.; Baker,P.C.; Ayer,C.T.; Loomas,B.E.; Matihis,M.L.; Silvestrin,T.A. (J Cataract Refract Surg Suppl, 1993)