The U.S. Air Force Photorefractive Keratectomy (PRK) Study: Evaluation of Residual Refractive Error and High- and Low-Contrast Visual Acuity
Final rept. Jun 1998-Jul 2006
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX AEROSPACE OPTHALMOLOGY BRANCH
Pagination or Media Count:
While corneal refractive surgery offers the potential to reduce dependence on optical appliances and widen the potential candidate pool, residual optical effects from such elective surgery can impact quality of vision and visual performance not identified using the traditional 2020 standard derived from a high contrast Snellen-type letter chart. The major area of postoperative concern following photorefractive keratectomy PRK found in this study was the potential for residual refractive errors, including undercorrection, overcorrection, induced astigmatism, and anisometropia. Low to moderate residual refractive error after refractive surgery may be operationally significant in aviators, especially if not optimally corrected. The prevalence in this study for PRK-treated eyes to have low to moderate residual refractive errors, defined as equal to or more than -0.50 D of myopia spherical equivalent on cycloplegic refraction, was relatively high. Yet, very few of these subjects wore corrective lenses to meet current standards. The fundamental question is whether most individuals, particularly aviators, will wear relatively minor optical corrections in spectacles after refractive surgery, especially if they meet the current 2020 requirement uncorrected and are therefore not required to wear corrective lenses. Failure to do so, however, may mean that certain visual performance parameters would be compromised and could potentially result in operational limitations of significance in addition to reduced contrast sensitivity and degraded performance under impoverished environmental conditions.
- Anatomy and Physiology
- Medicine and Medical Research
- Military Forces and Organizations