Consistency of Ocular Palpation Tonometry with Goldman Applanation Tonometry and Its Reproducibility by Separate Examiners

INTRODUCTION: Elevated intraocular pressure (IOP) remains to be the best known modifiable risk factor for glaucoma. Ocular palpation tonometry (OPT) is an old, fast and simple method for IOP measurement. Our aim is to investigate accuracy, reproducibility of ocular palpation tonometry and its suitability to be used for screening purposes.
METHODS: Consecutive patients without corneal pathology and glaucoma diagnosis history were included in the study. After routine ophthalmologic examination the IOP was measured by an ophthalmology specialist with Goldmann applanation tonomety (GAT). Later a blinded other ophthalmology specialist and a resident evaluated the same patients’ IOP with ocular palpation tonometry. Agreement between GAT and OPT, reproducibility of OPT were evaluated using Cohen Kappa Analysis.
RESULTS: 214 eyes of 107 patients were included in the study with a mean IOP of 16.4±3.6 (min: 8, max: 27) mmHg with GAT. OPT measurements by the resident ophthalmologist and the ophthalmology specialist were in concordance with GAT for 44.4% and 50.5% of the evaluations, respectively. We couldn’t detect a significant kappa value for the agreement between GAT and OPT measurements by the resident ophthalmologist (p=0.333). Whereas a slight agreement was found between GAT and OPT measurements by the ophthalmology specialist (K=0.176, p=0.001). OPT measurements showed slight reproducibility (K=0.153, p=0.009).
DISCUSSION AND CONCLUSION: Ocular palpation tonometry has low reliability, reproducibility and is not suitable to be used as a screening test. Except obligatory states, it should not be used as a primary and only test, and must be verified by other methods.