Intraocular Pressure Measurement Using iCare 200 and Goldmann Applanation Tonometer in Eyes with Normal Central Corneal Thickness
DOI:
https://doi.org/10.51253/pafmj.v76i5.11464Keywords:
Goldmann Applanation Tonometry; Intraocular Pressure; Icare 200; Rebound TonometryAbstract
Objective: To compare intraocular pressure measurements by iCare 200 and Goldmann applanation tonometer in patients having central corneal thickness within normal limits.
Study Design: Cross-sectional study.
Place and Duration of Study: Corneal Transplant and Refractive Surgery Department, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan, from Nov to Dec 2022.
Methodology: Intraocular pressure measurement by iCare 200 was taken before Goldmann applanation tonometry to avoid artificially lowering the pressure. TOPCON® SP 3000 specular microscope was used to measure central corneal thickness, and a minimum of three readings were documented.
Results: Among 75 patients, 40(53.3%) were males and 35(46.7%) were females. The mean age was 43.02±11.3 years. Mean central corneal thickness was 529 ± 10.83 μm. Mean pressure measured by Goldmann applanation tonometry was 15.14±3.03 mmHg, while that measured by iCare 200 was 13.90 ± 3.18 mmHg. iCare 200 readings were relatively lower. The mean difference in intraocular pressure between the two methods was 1.21±0.77 mmHg, with a minimum difference of -2.50 mmHg and maximum difference of 3.50 mmHg (p<0.01). Correlation between central corneal thickness and intraocular pressure measured by both methods was statistically significant (p<0.05).
Conclusion: iCare 200 rebound tonometer provides comparable intraocular pressure readings to Goldmann applanation tonometry in patients with central corneal thickness within the normal range; however, it slightly underestimates intraocular pressure compared with Goldmann applanation tonometry.
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Copyright (c) 2026 Taimoor Ashraf Khan, Teyyeb Azeem, Asfandyar Khan, Abdul Qadir, Saad Hassan Bhatti, Omer Ishtiaq
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