Three year results of the Prospective Evaluation of Radial Keratotomy (PERK) study.
Indian J Ophthalmol
;
1990 Jul-Sep; 38(3): 107-13
Article
in English
| IMSEAR
| ID: sea-70586
ABSTRACT
The Prospective Evaluation of Radial Keratotomy (PERK) study is a nine-center clinical trial of a standardized technique of radial keratotomy in 435 patients who had simple myopia with a preoperative refractive error between -2.00 and -8.00 diopters (D). We report results for one eye of each patient. The surgical technique consisted of eight incisions using a diamond micrometer knife with the blade length determined by intraoperative ultrasonic pachymetry and the diameter of the central clear zone determined by the preoperative refractive error. At three years after surgery, 58% of eyes had refractive error within one diopter of emmetropia; 26% were undercorrected, and 16% were overcorrected by more than one diopter. Uncorrected visual acuity was 20/40 or better in 76% of eyes. The operation was more effective in eyes with a preoperative refractive error between -2.00 and -4.37 diopters. Between one and three years after surgery, the refractive error changed by 1.00 diopter or more in 12% of eyes, indicating a lack of stability in some eyes.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Prognosis
/
Astigmatism
/
Keratotomy, Radial
/
Humans
/
Visual Acuity
/
Prospective Studies
/
Regression Analysis
/
Follow-Up Studies
/
Evaluation Studies as Topic
/
Refractive Surgical Procedures
Type of study:
Controlled clinical trial
/
Diagnostic study
/
Evaluation studies
/
Observational study
/
Prognostic study
Language:
English
Journal:
Indian J Ophthalmol
Year:
1990
Type:
Article
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