Evaluation of two Humphrey perimetry programs: full threshold and SITA standard testing strategy for learning effect

Area of Science:

• Ophthalmology
• Visual Neuroscience
• Medical Technology

Background:

• Visual field testing is crucial for diagnosing and monitoring glaucoma and other optic nerve disorders.
• Learning effect, or test-retest variability, can influence the interpretation of visual field results.
• Comparing different visual field testing strategies is essential for optimizing diagnostic accuracy and patient management.

Purpose of the Study:

• To compare the learning effect of the Swedish interactive threshold algorithm (SITA) standard strategy with full threshold (FT) testing.
• To quantify differences in test-retest variability between SITA standard and FT visual field testing.

Main Methods:

• Thirty-nine novice medical students underwent both FT and SITA standard visual field testing on different eyes within the same week.
• A within-subject design was employed to minimize inter-individual variability.
• Visual field parameters, including Mean Deviation (MD) and Pattern Standard Deviation (PSD), were analyzed for changes between initial and repeat testing.

Main Results:

• Both FT and SITA standard strategies demonstrated statistically significant learning effects, indicated by improvements in MD and PSD between the first and second tests (p<0.05).
• The percentage change in MD and PSD was significantly lower for the SITA standard strategy compared to FT (p=0.02 for MD, p=0.01 for PSD).
• These findings suggest that SITA standard testing is less susceptible to learning effects.

Conclusions:

• A learning effect is present in both full threshold and SITA standard visual field testing strategies.
• The SITA standard strategy appears to have a reduced learning effect compared to the full threshold testing.
• This implies SITA standard may offer more reliable results in novice testers or when minimizing learning effects is critical.