Effect of hyperopic photorefractive keratectomy on corneal sensitivity: a longitudinal study.
OBJECTIVE
To investigate corneal sensitivity after photorefractive keratectomy (PRK) for low hyperopia, as measured with a non-invasive stimulus.


METHODS
Two experimental groups were recruited: a control group of 17 patients (mean age 61.65 years) who underwent no treatment, and a PRK group of 11 patients (mean age 58.64 years) who underwent one of three attempted hyperopic corrections: +2.00 D (two patients), +3.00 D (four patients), +4.00 D (five patients). Corneal sensitivity was assessed centrally and peripherally, at temporal, medial, and inferior locations, approximately 1 mm from the limbus, using the Non-Contact Corneal Aesthesiometer (NCCA). Measurements were taken at each location for the control group and at preoperative, and postoperative weeks 1 and 2, 1, 3, and 6 months for the PRK group.


RESULTS
Comparison of control and PRK groups (preoperative sensation threshold) (t-test): central P=.715, temporal P=.719, medial P=.943, inferior P= .920. Comparison of longitudinal changes in PRK group (one-way ANOVA): central P=.612, temporal P=.997, medial P=.981, inferior P=.993.


CONCLUSIONS
Using the Non-Contact Corneal Aesthesiometer, no significant difference was found between the control and PRK groups for preoperative sensation thresholds, and no significant change in corneal sensitivity was found between any of the test time periods at any of the four corneal test locations for the PRK group.
Murphy
Paul J
PJ
Department of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom. MurphyPJ@cardiff.ac.uk
O'Brart
David P S
DP
Stephenson
Christopher G
CG
Oliver
Katherine M
KM
Patel
Sudi
S
Marshall
John
J
D000328:Adult; D000368:Aged; D003315:Cornea / Q000502:physiology* / Q000601:surgery; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D054018:Lasers, Excimer; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy; D012677:Sensation / Q000502:physiology*; D012684:Sensory Thresholds