management of unpredictable post-prk corneal ectasia with intacs implantation

purpose : to present the clinical features, biomechanical properties and management of a patient who developed unilateral corneal ectasia after photorefractive keratectomy (prk) case report : the patient was a 24-year-old man without any obvious preoperative risk factor for ectasia who underwent bilateral prk. four years after keratorefractive surgery, the patient presented with loss of visual acuity (va) in his right eye. pentacam findings were persistent with corneal ectasia and ocular response analyzer measurements showed differences in signal shape between two eyes. a single piece intrastromal segment ring was implanted and ceased the progression of ectasia until now. conclusion : corneal ectasia after prk is extremely rare and can occur without tangible risk factors. differences between signal shapes in ocular response analyzer and abnormal measurements may be useful in detecting high risk patients. intacs implantation appeared to improve ecstatic progressive changes and patient's symptoms.    iranian journal of ophthalmology 200921(3):63-70 © 2009 by the iranian society of ophthalmology