Goldmann applanation tonometry after myopic photorefractive keratectomy.
OBJECTIVE
To determine the accuracy of applanation tonometry in patients with corneas thinned by photorefractive keratectomy, and to correlate corneal changes with tonometric readings.


METHODS
The intraocular pressure was measured with Goldmann applanation tonometry in 87 patients who underwent photorefractive keratectomy before and 1, 6 and 12 months after treatment. The treatments ranged from -1.5 to -14 diopters (mean=-7.6+/-4.1 diopters) and the fellow eyes were used as controls.


RESULTS
In the treated eyes the intraocular pressure before surgery ranged from 11 to 26 mmHg (mean=17.7+/-2.8 mmHg). One month after surgery it ranged from 5 to 22 mmHg (mean=11.9+/-2.7 mmHg) with a significant underestimation (P=1x10(-33)). Six months after surgery it ranged from 6 to 22 mmHg (mean=12+/-3 mmHg) with a significant underestimation (P=5x10(-30)). Twelve months after surgery it ranged from 8 to 22 mmHg (mean=12.7+/-2.7 mmHg) with a significant underestimation (P=5x10(-31)).


CONCLUSIONS
A correcting factor should be applied when using applanation tonometry to measure intraocular pressure in patients who have undergone PRK.
Rosa
N
N
Eye Department, University Federico II, Naples, Italy.
Cennamo
G
G
Breve
M A
MA
La Rana
A
A
D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D012029:Refraction, Ocular; D012189:Retrospective Studies; D014065:Tonometry, Ocular