Correlation between automated and subjective refraction before and after photorefractive keratectomy

J Refract Surg. 2002 Jul-Aug;18(4):449-53. doi: 10.3928/1081-597X-20020701-06.

Abstract

Purpose: To ascertain whether autorefractometry after photorefractive keratectomy (PRK) provides results that are comparable with subjective refractometry.

Methods: The refractions of 159 eyes before and 1 month after PRK were determined with both automated and subjective refractometry, and the results of the two methods were compared.

Results: Before PRK, subjective spherical equivalent refraction ranged from -15.25 to +0.25 D (mean -5.30 +/- 2.64 D) and automated spherical equivalent refraction ranged from -16.13 to -0.50 D (mean -6.10 +/- 2.74 D), with good correlation (r2 = 0.965) between the two methods. One month after PRK, subjective spherical equivalent refraction ranged from -1.63 to +3.50 D (mean +0.98 +/- 0.78 D) and automated spherical equivalent refraction ranged from -2.50 to +3.00 D (mean +0.36 +/- 0.96 D) with poor correlation (r2 = 0.401).

Conclusion: Autorefractometry is less reliable in eyes after PRK, and consequently software changes are recommended for overcoming this problem.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Cornea / surgery*
  • Humans
  • Lasers, Excimer
  • Middle Aged
  • Photorefractive Keratectomy*
  • Postoperative Period
  • Preoperative Care
  • Refraction, Ocular*
  • Refractive Surgical Procedures*
  • Vision Tests / methods*