Introducing a new method to assess vision: Computer-adaptive contrast-sensitivity testing predicts visual functioning better than charts in multiple sclerosis patients

Abstract

BackgroundImpaired low-contrast visual acuity (LCVA) is common in multiple sclerosis (MS) and other neurological diseases. Its assessment is often limited to selected contrasts, for example, 2.5% or 1.25%. Computerized adaptive testing with the quick contrast-sensitivity function (qCSF) method allows assessment across expanded contrast and spatial frequency ranges.ObjectiveThe objective of this article is to compare qCSF with high- and low-contrast charts and patient-reported visual function.MethodsWe enrolled 131 consecutive MS patients (mean age 39.6 years) to assess high-contrast visual acuity (HCVA) at 30 cm and 5 m, low-contrast vision with Sloan charts at 2.5% and 1.25%, qCSF and the National Eye Institute Visual Functioning Questionnaire (NEIVFQ). Associations between the different measures were estimated with linear regression models corrected for age, gender and multiple testing.ResultsThe association between qCSF and Sloan charts (R2 = 0.68) was higher than with HCVA (5 m: R2 = 0.5; 30 cm: R2 = 0.41). The highest association with NEIVFQ subscales was observed for qCSF (R2 0.20–0.57), while Sloan charts were not associated with any NEIVFQ subscale after correction for multiple testing.ConclusionThe qCSF is a promising new outcome for low-contrast vision in MS and other neurological diseases. Here we show a closer link to patient-reported visual function than standard low- and high-contrast charts.

Validation of Computer-Adaptive Contrast Sensitivity as a Tool to Assess Visual Impairment in Multiple Sclerosis Patients

“…In MS patients, however, low-contrast visual acuity (LCVA) seems to better correlate with the alterations of retinal morphology ( Schinzel et al, 2014 ) and cognitive function ( Wieder et al, 2013 ). LCVA is usually assessed by the low-contrast Sloan letter charts, but the evidence supporting this method is controversial as association with vision-related QoL in MS patients is inconsistent ( Mowry et al, 2009 ; Stellmann et al, 2015b ; Sabadia et al, 2016 ). Sloan LCVA charts usually measure at selected contrast levels [for example 1.25% or 2.5% ( Balcer et al, 2012 , 2017 )] whereas the affected contrast sensitivity changes on an individual basis for different letter sizes.…”

“…We recently showed that qCSF could be a useful tool for the assessment of visual function in MS patients as it correlated best with vision-related QoL measured by the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ) ( Stellmann et al, 2015b ), whereas VA with Sloan charts was not significantly associated with the NEI-VFQ administered to MS patients. However, to establish the qCSF as a diagnostic tool in routine clinical care and research, further validation is necessary in the intended patient population.…”

Measuring the Contrast Sensitivity Function Using the qCSF Method With 10 Digits

“…The contrast sensitivity function (CSF) provides a comprehensive assessment of spatial vision at a variety of spatial frequencies, 1 and is used to evaluate and screen a variety of visual disorders. 2 – 8 The conventional CSF measurement in the laboratory is very time-consuming, 9 while the clinically available chart for CSF assessment, such as the Vistech chart or Functional Acuity Contrast Test (FACT) exhibited very poor test–retest reliability. 10 , 11 Recently, Lesmes et al 12 developed the Bayesian adaptive quick CSF (qCSF) method to efficiently measure the CSF with high precision and accuracy.…”

“…In addition to its efficiency and precision, the qCSF has shown great test–retest reliability as well as sensitivity in detecting changes of visual functions. 14 The qCSF has been used to measure the CSF in several clinical populations, including subjects with amblyopia, 15 , 16 multiple sclerosis, 6 dry age-related macular degeneration, 17 central serous chorioretinopathy (Marmalidou, et al IOVS , 2018;59:ARVO E-Abstract 3126), glaucoma, 18 early diabetic retinopathy, 19 and aging. 20 It also has been used to investigate dynamic effects of visual adaptation, 21 the time course of postoperative recovery of the CSF of patients who experienced extended periods of early-onset blindness, 22 visual performance change after blur adaptation, 23 and the impact of emotional arousal on the CSF, 24 as well as CSF in peripheral vision.…”

New Precision Metrics for Contrast Sensitivity Testing

“…The contrast sensitivity function (CSF) thus provides a more fundamental and comprehensive assessment of visual performance than acuity by relating spatial frequency, or size, to the minimum contrast required to discern patterns of that size. Contrast sensitivity is better correlated with visual quality of life [16], [17] and notably may be impaired in neurodegenerative ocular pathologies even when acuity is unaffected [18], [19]. Despite its clinical value, contrast sensitivity testing has not found its way into routine clinical care because of practical constraints.…”