Interobserver agreement using Goldmann applanation tonometry and dynamic contour tonometry: comparing...

Area of Science:

• Ophthalmology
• Medical Devices
• Clinical Measurement

Background:

• Intraocular pressure (IOP) measurement is crucial for glaucoma diagnosis and management.
• Goldmann applanation tonometry (GAT) is the established standard, but requires skilled personnel.
• Emerging tonometers like Pascal dynamic contour tonometry (DCT) offer potential for improved accuracy and ease of use.

Purpose of the Study:

• To compare the agreement of intraocular pressure (IOP) measurements between ophthalmologists and non-ophthalmologists (nurses, ophthalmic technicians).
• To evaluate agreement using two different tonometry methods: Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry (DCT).

Main Methods:

• A study involving patients attending routine glaucoma outpatient appointments.
• Intraocular pressure (IOP) was measured by pairs of ophthalmologists, non-ophthalmologists, or one of each.
• Agreement was assessed using Bland-Altman analysis, calculating mean differences and 95% limits of agreement (LoA) for each observer group and tonometer.

Main Results:

• The DCT consistently showed higher IOP readings compared to the GAT across all observer groups.
• Ophthalmologists demonstrated good agreement with each other using GAT (mean difference -0.20, 95% LoA 4.9 mmHg).
• Non-ophthalmologists showed better agreement using DCT (mean difference 0.3, 95% LoA 4.2 mmHg) compared to GAT (mean difference 0.6, 95% LoA 5.4 mmHg).

Conclusions:

• Non-ophthalmologists achieve higher measurement agreement with the Pascal dynamic contour tonometry (DCT) than with the Goldmann applanation tonometry (GAT).
• The DCT may be suitable for delegation of IOP measurements to nursing staff or technicians.
• Measurements obtained by DCT and GAT are not interchangeable and require distinct interpretation protocols.