Is Accurate Assessment of the Intraocular Pressure after Refraction OperationsPossible?

Overview

Objective:
To evaluate how the change of thickness or curving of the cornea afterrefraction operations (PRK or LASIK) influences the intraocular pressure (IOP)during assessment with a noncontact tonometer.Place of investigation: Ophthalmological Clinic SPAM and Ophthalmological ambulanceEXCIMER.Material and methods: With regard to the performed refraction operation thepatientswere dividedintotwogroups.Thefirstgroupcomprised87patientswherePRK was performed to correct myopia. The mean myopia in this group was -5.27D ± 2.32. The second group comprised 62 patients where LASIK surgery wasperformed to correct myopia. The mean myopia in this group was -10.18 ± 4.36.IOP was assessed by means of a noncontact tonometer before and 6 months aftersurgery.Results. In the first group a mean reduction of IOP by 4.8±2.1 mm Hg occurred.The central thickness of the cornea declined on average by 55.69 ±28.9 micros andthe curving of the cornea diminished on average by 3.72 D ± 1.76 D.In the second group of patients the IOP declined on average by 7.97 ± 2.04 mmHg.The central thickness of the cornea diminished by 78.75 microns ± 42.26 and thecurving of the cornea by 4.65D ± 2.07In both groups a significant correlation was found between the reduction of IOP and the central thickness and curving of thecornea.Conclusion: Diminution of the thickness of the central cornea and diminution ofthe curving lead to lower values of the IOP. There is a direct correlation betweenthinning of the cornea and the decline of IOP.

Key words:
intraocular pressure, refraction operation, accuracy of assessment