Repeatability of the Glaucoma Hemifield Test in automated perimetry

Area of Science:

• Ophthalmology
• Visual field testing
• Glaucoma diagnostics

Background:

• Automated visual field testing is crucial for glaucoma detection.
• The Glaucoma Hemifield Test (GHT) is a common screening tool.
• Assessing test-retest variability is important for clinical trial design.

Purpose of the Study:

• To evaluate the concordance of the Glaucoma Hemifield Test and other visual field indices between two consecutive Humphrey Field Analyzer tests.
• To determine the impact of using two tests on specificity and sensitivity for clinical trial enrollment.

Main Methods:

• Two automated visual field tests were performed on normal subjects, ocular hypertensive subjects, and glaucoma patients.
• The Glaucoma Hemifield Test, mean deviation, and corrected pattern standard deviation were compared between consecutive tests.
• Test-retest intervals varied from 1 to 2 years for normal subjects and 1 year for others.

Main Results:

• The proportion of normal subjects meeting abnormality criteria on two tests was 2.4%, and 10.5% of glaucoma subjects had normal results on two tests.
• Requiring two abnormal tests increased specificity for glaucoma trials from 80.8% to 89.9%.
• Requiring two normal tests increased specificity for ocular hypertension trials from 84.2% to 89.5%.

Conclusions:

• While consecutive Glaucoma Hemifield Test results show concordance, some disagreement exists.
• Employing a second visual field test enhances specificity in clinical trial settings.
• This approach offers improved diagnostic accuracy for patient selection in trials.