Screening tonometry by technicians

Area of Science:

• Ophthalmology
• Biomedical Engineering

Background:

• Accurate intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
• Various tonometry devices exist, each with potential advantages and limitations for clinical use.

Purpose of the Study:

• To comparatively evaluate the accuracy and usability of the Pneumatonograph, GlaucoTest, Halberg, and Schiotz tonometers against Goldmann applanation tonometry.
• To assess the suitability of these instruments for screening and routine IOP measurements.

Main Methods:

• Comparative study involving 200 eyes.
• Goldmann applanation tonometry served as the reference standard.
• Measurements were performed by a trained technician using Pneumatonograph, GlaucoTest, Halberg, and Schiotz tonometers.

Main Results:

• Pneumatonograph demonstrated good agreement with Goldmann readings for seated patients.
• GlaucoTest proved effective as a screening tool for ocular hypertensives with minimal training.
• Halberg tonometer yielded imprecise IOP readings and was difficult to use.
• Schiotz tonometer had limited value in screening tonometry.

Conclusions:

• The Pneumatonograph and GlaucoTest are valuable tools for IOP measurement and screening, respectively.
• The Halberg and Schiotz tonometers showed limitations in accuracy and usability for clinical application.
• Further investigation into the influence of body position on IOP measurements across different tonometric methods is warranted.