Assessment of retinal sensitivity using a time-saving strategy in normal individuals

Area of Science:

• Ophthalmology
• Visual field testing
• Retinal sensitivity measurement

Background:

• Visual field testing is crucial for diagnosing and monitoring ophthalmic conditions.
• Standardized algorithms are essential for reliable and comparable visual field data.
• Comparing different visual field testing strategies is important for clinical practice.

Purpose of the Study:

• To compare retinal sensitivities in normal individuals using the Swedish Interactive Threshold Algorithm Standard (SITA-S) on the Humphrey field analyzer versus the Dynamic strategy on the Octopus perimeter.
• To evaluate potential differences in sensitivity measurements between these two common visual field testing algorithms.

Main Methods:

• Standardized background luminance, stimulus size, and exposure time were used for both devices.
• 67 normal individuals (age > 20) underwent visual field examinations using SITA-S (central 30-2 program) followed by Dynamic (32 program).
• Eyes with corrected visual acuity ≥ 0.8, refractive error ≤ -6.0 diopters, and reliable fields were selected for analysis.

Main Results:

• Mean retinal sensitivity was significantly higher with SITA-S (29.0 ± 2.4 dB) compared to Dynamic (26.8 ± 2.1 dB) (P < 0.0001).
• Age-related decline in retinal sensitivity was significantly greater with Dynamic (-0.09 dB/year) than SITA-S (-0.07 dB/year) (P = 0.0003).
• SITA-S showed significantly higher retinal sensitivities across central, mid-peripheral, and peripheral visual field areas (P < 0.0001).

Conclusions:

• The Swedish Interactive Threshold Algorithm Standard (SITA-S) and Dynamic strategies yield different retinal sensitivity values in normal individuals.
• These observed differences in visual field testing may stem from inherent variations in the algorithms' methodologies.
• Understanding these discrepancies is vital for accurate interpretation of visual field test results in clinical settings.