Dr. John Miller delivered a presentation at the 2024 Annual Meeting of the American Society of Retina Specialists, titled “Quantitative Contrast Sensitivity Longitudinal Changes Correlate Better Than Visual Acuity With Geographic Atrophy Progression”. His talk centered on the need for alternative functional endpoints, other than visual acuity (VA), that are more reflective of the progression of geographic atrophy (GA) and its size.
Typically, fundus autofluorescence (FAF) is the recognized gold standard for GA diagnosis. However, the functional outcomes of GA are less well-defined. Clinical studies have revealed that VA and a few other functional tests have a weak correlation with GA size and progression. In recent times, there has been a shift towards optical coherence tomography (OCT) biomarkers, which are more sensitive to early GA alterations, as stated by Dr. Miller. Despite the early appearance of changes in contrast sensitivity (CS) in age-related macular degeneration (AMD), these changes are not routinely tested in clinical practice.
Dr. Miller then highlighted the results of a study held at Mass Eye and Ear, which aimed to explore the correlations between GA size and the quantitative contrast sensitivity function (qCSF) test. This test utilized spectral-domain (SD)-OCT for GA diagnosis and FAF for GA size measurement. The study included eyes with GA and fovea involvement: 83 eyes were tested cross-sectionally and 30 longitudinally. The minimum follow-up period was between 6 months and 1 year.
On the same day as qCSF testing, SD-OCT and FAF were carried out. Total GA size was assessed by two masked graders on FAF using the semiautomatic Heidelberg RegionFinder tool. Primary endpoints included total GA size, VA, and qCSF outcomes.
Regression models revealed that total GA was associated with multiple qCSF outcomes but not with VA. Pearson correlations also showed a correlation between total GA size and qCSF outcomes, but not VA. The qCSF test results also correlated with the visual field quality of life (VFQ) scores but not VA in AMD. Strong test–retest reliability was observed in 121 eyes.
Dr. Miller touted the benefits of the qCSF test, noting that it tests a wide range of contrast and spatial frequencies, allows for personalization through an active learning-based algorithm, and is more time-efficient. Additionally, it can generate a contrast curve in 2–5 minutes per eye.
As per Dr. Miller, around 50% of his clinical practice gets tested with this device every day. He concluded his presentation by emphasizing that contrast sensitivity seems to be a more effective functional endpoint to track GA progression and measure treatment effects in AMD routine practice and clinical trials.
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