Systematic Underestimation of Visual Sensitivity Loss on Microperimetry: Implications for Testing Protocols in...

Area of Science:

• Ophthalmology
• Visual Science

Background:

• Microperimetry is crucial for assessing visual function in retinal diseases.
• Standardized testing protocols are essential for reliable clinical trial data.

Purpose of the Study:

• To determine if visual sensitivity measurements change systematically within a single microperimetry session.
• To investigate if these changes correlate with the degree of visual sensitivity loss.

Main Methods:

• Eighty participants with glaucoma or AMD underwent three microperimetry tests.
• The 4-2 staircase strategy was employed, measuring mean sensitivity (MS) and pointwise sensitivity (PWS).
• Changes in MS and PWS between tests were analyzed, along with the coefficient of repeatability (CoR).

Main Results:

• A significant decline in MS was observed between the first and second tests (P=0.001).
• This decline was most pronounced in areas with greater visual sensitivity loss (<18 dB).
• The CoR for MS was significantly lower in the second test pair (1.4 dB) compared to the first (2.5 dB).

Conclusions:

• The 4-2 staircase strategy underestimates visual sensitivity during the initial microperimetry test.
• Excluding the first test and using its results to seed subsequent tests can enhance measurement consistency and accuracy in clinical trials.