Correlation between automated and subjective refraction before and after photorefractive keratectomy.
OBJECTIVE
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).


CONCLUSIONS
Autorefractometry is less reliable in eyes after PRK, and consequently software changes are recommended for overcoming this problem.
Rosa
Nicola
N
Eye Department, 2nd University of Naples, Italy. nicrosa@tin.it
Iura
Attilio
A
Romano
Mary
M
Verolino
Gianluca
G
Romano
Antonio
A
D000328:Adult; D003315:Cornea / Q000601:surgery*; D006801:Humans; D054018:Lasers, Excimer; D008875:Middle Aged; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D011300:Preoperative Care; D012029:Refraction, Ocular; D054140:Refractive Surgical Procedures; D014787:Vision Tests / Q000379:methods*