Intraocular Pressure After Corneal Refractive Surgery

Laser in situ keratomileusis (LASIK), a refractive surgery procedure is being performed in a large number among people with refractive errors. In all the people undergoing the procedure, there is a potential risk to misdiagnose the glaucoma disease due to changes in central corneal thickness (CCT). In subjects who have undergone laser refractive interventions, intraocular tension may be lower and underestimated, and this can lead to later detection of glaucoma.

The objective of this study was to analyze the intraocular pressure (IOP) after LASIK in patients with myopia.

Thirty-seven patients underwent LASIK intervention to treat myopia. In total, 74 eyes were treated. Before the intervention, all patients underwent complete ophthalmologic examination, including the measurement of central corneal thickness (CCT) and measurement of IOP with non-contact tonometer. The IOP was also measured on days 1, 3 and 30 after the surgery. The mean IOP was taken for statistical analysis.

Seventy-four eyes of 37 patients (mean age 31.6) underwent LASIK intervention to treat myopia. Mean CCT before the intervention was 551.9 ±31.9µm, while mean postoperative CCT was 469.8 ±45.3µm (p<0.0001). Mean preoperative IOP was 16.4mmHg while mean postoperative IOP was 11.0mmHg (p<0.0001). The average spherical equivalent was -5.9 diopters.

The reduction of IOP after LASIK refractive surgery is significant. This reduction is about 1mmHg per 1 diopter. This should be taken into account in the future in these patients because, due to the underestimation of the IOP, the glaucoma disease may be overlooked.