Oldenburg CE, Sy A, Srinivasan M, Toutain-Kidd CM, Mascarenhas J, Ravindran M, Rajaraman R, Esterberg EJ, Chidambaram JD, Acharya NR, Lietman TM, Zegans ME. Pre-existing blindness in a cohort of patients with bacterial keratitis. Br J Ophthalmol. 2011 Dec;95(11):1612-3. doi: 10.1136/bjophthalmol-2011-300270.