Sensitivity and Stability of Functional Vision Tests in Detecting Subtle Changes Under Multiple Simulated Conditions

PURPOSE: To explore whether subtle changes in visual quality can be detected using different measures of visual function against the quick contrast sensitivity function test (quick CSF). METHODS: Sixty participants, aged 17 to 34 years, were enrolled. Participants’ vision was degraded by 0.25 D undercorrection (0.25 D), 60% neutral density filter brightness reduction (60% ND), and 0.8 Bangerter foil optical diffusion (0.8BAN). Visual function tests including visual acuity and contrast sensitivity (CSV-1000E and quick CSF) were measured with participant's best-corrected vision and under simulated visual degradation conditions. Test sensitivities in detecting differences were compared. RESULTS: Statistically significant visual acuity degradation was observed in the 0.8BAN condition only (P(corrected) < 0.001). With CSV-1000E and outliers removed, significant CS degradation was observed in all spatial frequencies, area under log CSF (AULCSF) in the 0.8BAN condition (P(corrected) < 0.001 for all), medium and high spatial frequencies and AULCSF in the 60%ND condition (P(corrected)(,6cpd) = 0.002, P(corrected)(,12cpd) = 0.005, P(corrected)(,18cpd) = 0.001, P(corrected)(,AULCSF) < 0.001) and the 0.25 D condition (P(corrected)(,6cpd) = 0.011, P(corrected)(,12cpd) = 0.013, P(corrected)(,18cpd) = 0.015, P(corrected)(,AULCSF) < 0.001). With the quick CSF, significant CS degradation was observed in all simulated visual conditions in all spatial frequencies, cutoff frequency and AULCSF (P(corrected) < 0.001 for all). Test-retest reliability of the quick CSF method was high; coefficient of repeatability ranged from 0.14 to 0.18 logCS. CONCLUSIONS: Compared with visual acuity and chart-based CS tests, the quick CSF method provided more reliable and sensitive measures to detect small visual changes. TRANSLATIONAL RELEVANCE: The quick CSF method can provide sensitive and reliable measures to monitor disease progression and assess treatment outcomes.