Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study One Year After Surgery

Repeated Excimer Laser Treatment After Photorefractive Keratectomy

“…The re-treatment group was divided into three subgroups: (1) repeated photoablation due to scarring , no undercorrection; (2) Figure 3 compares the best corrected visual acuities before and after initial PRK and after re-treatment (6-month follow-up). The …”

Reported Satisfaction, Fluctuation of Vision, and Glare Among Patients One Year After Surgery in the Prospective Evaluation of Radial Keratotomy (PERK) Study

“…To reduce the chance that patients would memorize the letters, three different specially designed Snellen charts were used.12 Visual acuity was recorded as the number of letters correctly read on each line and was converted into Snellen notation. 13 Cycloplegic refractions were performed without records of previous refraction results by the clinical technician/ coordinator and verified by an ophthalmologist/examiner who did not perform the surgery.12…”

“…13 Nevertheless, approximately 17% of the patients complained of a lot of trouble with glare, and, for some individuals, surgery increased glare to the point that it dimin¬ ished their postoperative satisfaction with the surgi¬ cal outcome.…”

Etiology and Clinical Presentation of Astigmatism

“…The effect can be unpredictable. In the report of the PERK (prospective evaluation of radial keratotomy) study (Waring et al 1985), ten percent of patients increased astigmatism by more than 1.00 diopter. In a large scale survey of radial keratotomy complications (Marmer, 1987), irregular astigmatism was one of the reported complications.…”