REDUCTION IN INTRAOCULAR-PRESSURE AFTER EXCIMER-LASER PHOTOREFRACTIVEKERATECTOMY - CORRELATION WITH PRETREATMENT MYOPIA

Purpose: The authors relate the observed reduction in intraocular pres sure (IOP) after excimer laser treatment to the degree of myopia treat ed, Background: Intraocular pressure, measured by both Goldmann applan ation and noncontact tonometry, has been reported to decrease after ex cimer laser photorefractive keratectomy (PRK). However, IOP readings a fter excimer laser PRK might be inaccurate as a consequence of changes in both the thickness and curvature of the cornea. Methods: Baseline IOP readings were measured by noncontact tonometry in each eye of a gr oup of 1320 patients at the time of their initial consultation. These were compared to readings obtained before treatment of the second eye, which took place a minimum of 4 months later, The untreated eyes serv ed as controls. The paired Student's t test was used for statistical a nalysis, Results: After PRK, a decrease was observed in the IOP of tre ated eyes that was related to the, degree of myopia treated, A signifi cant difference was observed between treated and untreated eyes (P < 0 .0000). Conclusions: The IOP measured after PRK for myopia-may be redu ced because of changes in corneal thickness (absence of Bowman's membr ane and central thinning) and topography. This is of particular releva nce when monitoring the IOP of those patients who are given steroid dr ops to prevent regression, It also may be of importance in the managem ent of any future glaucoma.