HFA 24

Jul 31, 2023

Behera G, et al. Optom Vis Sci. 2023;doi:10.1097/OPX.0000000000002020.

Behera G, et al. Optom Vis Sci. 2023;doi:10.1097/OPX.0000000000002020.

The Humphrey Field Analyzer 24-2C Faster may help initial visual field evaluation with the advantage of shorter testing time in patients with glaucoma, according to data published in Optometry and Vision Science.

“While the 10-2 remains useful for further characterizing the detected field defect in the central 10 degrees, the 24-2C Faster may be a good screening tool,” Geeta Behera, MD, associate professor of ophthalmology at Jawaharlal Institute of Postgraduate Medical Education and Research in India, and colleagues wrote.

In a cross-sectional, clinical quantitative study of 60 eyes of 60 adult patients with glaucoma, participants underwent the Humphrey Field Analyzer (HFA) 24-2C Faster, 24-2 SITA Standard and 10-2 field tests to determine the speed and effectiveness of the HFA 24-2C Faster in detecting defective central points and assess its clinical value as a screening tool.

The researchers found that on average the HFA 24-2C Faster test detected more than five defective points on the total deviation plot (17.5 vs. 12) and two more defective points on the pattern deviation plot (6 vs. 4) than the 24-2 SITA Standard test in the central 10 degrees. However, the 10-2 algorithm detected 2.5 times more points on the total deviation plot than HFA 24-2C Faster.

The HFA 24-2C Faster had a significantly lower testing time than both the 24-2 SITA Standard and 10-2 tests.

“Our study demonstrates that the HFA 24-2C Faster may be used for the initial evaluation of the visual field in glaucoma with the added advantage of a shorter testing time compared with the 24-2 SITA Standard program,” Behera and colleagues wrote.

Lisa M. Young, OD, FAAO

Automated static perimetry has seen very few changes in testing algorithms in the past few decades. The majority of practitioners use 24-2 sequencing for routine glaucoma testing and 10-2 as indicated for more central defects. One of the pitfalls of the 24-2 is a potential underestimation of central defects due to limited test points in the central 8 degrees to 10 degrees. The Humphrey 24-2C visual field test attempts to alleviate this 24-2 “pitfall” by offering a modified 24-2 test that incorporates 10 additional test points in the central 10 degrees of vision with a faster testing time than the SITA standard algorithm.

Behera and colleagues found the 24-2C detected 5.5 more points on the total deviation plot and 2 more points on the pattern deviation plot in the central 10 degrees, as compared to the 24-2. Additionally, there was not a significant difference between these two tests beyond the central 10 degrees.

Ultimately, 24-2C testing may be the best algorithm for initial or screening-based evaluations, potentially providing a better representation of central visual field defects, aid in diagnosis and help identify functional issues in our patients.