Comparison between corrected intraocular pressure using contact versus noncontact methods in glaucoma patients

Abstract

Background To determine the difference between corrected intraocular pressure (IOP), based on the central corneal thickness (CCT), measured by the noncontact anterior segment anterior segment optical coherence tomography (AS-OCT), versus contact ultrasound pachymetry (USP) in the management of glaucoma patients. Patients and methods Ophthalmology Department, Ain Shams University, Cairo, Egypt. The study is a prospective, nonrandomized case series. Fifty patients were diagnosed with open-angle glaucoma and controlled with medical treatment with prostaglandin analogs and β-blockers fixed combination, controlled under medical treatment. CCT is measured by two methods, the AS-OCT and by the USP of ocular response analyzer. IOP was measured by applanation tonometry. Corrected IOP was calculated adjustment factor using Ehler’s correction nomogram, statistical analysis of the adjusted IOP with the contact and noncontact methods was done in relation to the CCT measurements. Results The mean age was 60.5±5.24 years, 54% of the studied patients were men while 46% were women. The mean CCT using AS-OCT for the right eye was 529.86±43.52 μm and for the left eye was 530.28±43.57 μm, while CCT using USP for the right eye was 534.88±43.59 μm and for the left eye was 533.34±44.33 μm. Highly significant correlation between CCT was measured by AS-OCT and ultrasound; 0.94 (P Conclusion Although USP has slightly higher measurements of CCT in comparison with measurements with anterior segment OCT, it has no significance on the adjusted IOP in controlled glaucoma patients, making the two methods equally accurate in the management and follow-up of these patients.