Manual keratometry and videokeratography after photorefractive keratectomy.
OBJECTIVE
To examine the relative accuracy of manual keratometry and videokeratography in eyes treated by photorefractive keratectomy (PRK).


METHODS
Eye Clinic, Cantonal Hospital, Lucerne, Switzerland.


METHODS
Results of manual keratometry and videokeratography were compared with those of subjective refraction in 128 eyes before and 6 months after PRK.


RESULTS
Six months after PRK, the mean subjective refraction of all eyes decreased more than the mean corneal dioptric power measured with videokeratography (P <.0001). The change in the mean subjective refraction compared with the corresponding difference in the mean manual keratometry of all eyes was also significant (P <.0001).


CONCLUSIONS
This study confirmed an earlier observation that there is a disparity between the change in refraction and the reduction in corneal power measured by videokeratography and with the manual keratometer. Topographical changes from PRK and the subsequent wound-healing processes are likely to falsify objective measurements. The keratometric value in the center of the cornea, since it is not measured by manual keratometry and videokeratography, may actually be lower.
Peter
R
R
Lucerne Eye Clinic, Cantonal Hospital, Lucerne, Switzerland.
Hazeghi
M
M
Job
O
O
Wienecke
L
L
Schipper
I
I
D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000150:complications / Q000601:surgery; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000150:complications / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D012029:Refraction, Ocular; D015203:Reproducibility of Results