Applanation intraocular pressure (IOP) decreases only slightly after a reduction in central corneal thickness (CCT) with myopic photorefractive keratektom (PRK)

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Purpose: Increase in IOP has been positive correlated with increasing CCT in normal eyes Eyes undergoing f'Rk offer a unique nppi riumi to study the effect of decreasing CCT on IOP.
Methods: A desiripme study of paiiaiHs undergoing excimer laser myopic PRK was performed. Eles were excluded from PF K if lhe> had glaucoma, corneal, or intraocular pathology IOP u a; measured In GoHmann applanation, and CCT by an ultrasonic pachymeter centered on the pupil We elan ined correlalion between IOP and CCT pre and postop as well as indidu;il poslop changes n IOP vs changes in CCT.
Results: Results are staled as mean ± SU Pieup liiere u ere 4 eles. 50 7% female and 49 3% male, mean age 38 4 ± 104 Diopters The mean preop IOP was 14 43 ± 2.99 mm l Ig and CCT 544 ± d (m A significant correlation between IOP and CCT was seen both preop (0 41 ~ u 1 7 n,in Hg drop m IOP per 50m decrease in CCT, p=0.015) and at 6 months postop (0 :S2o + o 1'J mm Hg per 50m, p=0 007). There was a significant correlation between drop in IOP and change in CCT at both 6 (N=220) and 12 (N=167) months (p=u 015, n uii9) '1 he mum change in IOP was -1 04 ± 3 50 at 6 months, and -I 31 ± 3 8d mm Hg at 12 moiilhs CCT changes were -60 7 ± 39 7/m and -56.2 ± 39 Om. respeclixeK No signilicant correl mon was noted between CCT and age, or preop refracthe error Coiiflusioii. Paiienls u idergomg myopic PRK at our institution have a significant decrease in IOP and CCT pos op However. the magnitude of this IOP drop appears small enough .Hal clinical correcii in does not seem warranted in most cases.


This work was published before the author joined Aga Khan University.


Investigative Ophthalmology and Visual Science