Association of ocular hypotensive medication types with dynamic contour tonometry and Goldmann applanation tonometry measurements in a glaucoma and ocular hypertensive population.

PURPOSE: The aim of this study was to evaluate the association between different intraocular pressure (IOP)-lowering medications and IOP measurements by dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in a glaucoma and ocular hypertensive population.

METHODS: In a prospective, observational case series study, 410 eyes from 410 consecutive patients with open-angle glaucoma (OAG) or ocular hypertension (OHT), were enrolled. All eyes included in the study received unaltered ocular hypotensive medication for at least 6 months before IOP measurement. All eyes underwent 2 GAT and 3 DCT measurements, and their means were used for the analysis.

RESULTS: DCT-GAT IOP difference (ΔIOP) did not differ statistically significantly (P=0.49) between OAG and OHT group yielding a mean±SD of 4.26±2.02 mmHg and 4.41±2.25 mmHg, respectively. The number of IOP-lowering agents did not have any statistically significant influence on ΔIOP (p=0.177), DCT (P=0.28) and GAT (P=0.13) measurements. A statistically higher ΔIOP was revealed in monotherapy patients receiving Carbonic Anhydrase Inhibitors (CAIs) (ΔIOP=5.75 mmHg) in comparison to patients receiving Prostaglandin Analogs (ΔIOP=4.09 mm Hg) or beta Blockers (ΔIOP=3.78 mmHg) as single topical therapy (F=4.373, P=0.005). Eyes treated with CAIs as a part of the ocular hypotensive therapy yielded a significantly greater ΔIOP (P=0.0035) than those without CAIs in the therapeutic schema.

CONCLUSIONS: The difference between DCT and GAT IOP measurements is found to be statistically significantly higher in patients receiving CAIs either as monotherapy or as a part of a combined ocular hypotensive treatment, while DCT and GAT readings remain unaffected. The type of diagnosis and the number of ocular hypotensive medications had no statistically significant influence on ΔIOP.