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

Abstract

BackgroundImpairment of visual function is one of the major symptoms of people with multiple sclerosis (pwMS). A multitude of disease effects including inflammation and neurodegeneration lead to structural impairment in the visual system. However, the gold standard of disability quantification, the expanded disability status scale (EDSS), relies on visual assessment charts. A more comprehensive assessment of visual function is the full contrast sensitivity function (CSF), but most tools are time consuming and not feasible in clinical routine. The quantitative CSF (qCSF) test is a computerized test to assess the full CSF. We have already shown a better correlation with visual quality of life (QoL) than for classical high and low contrast charts in multiple sclerosis (MS).ObjectiveTo study the precision, test duration, and repeatability of the qCSF in pwMS. In order to evaluate the discrimination ability, we compared the data of pwMS to healthy controls.MethodsWe recruited two independent cohorts of MS patients. Within the precision cohort (n = 54), we analyzed the benefit of running 50 instead of 25 qCSF trials. The repeatability cohort (n = 44) was assessed by high contrast vision charts and qCSF assessments twice and we computed repeatability metrics. For the discrimination ability we used the data from all pwMS without any previous optic neuritis and compared the area under the log CSF (AULCSF) to an age-matched healthy control data set.ResultsWe identified 25 trials of the qCSF algorithm as a sufficient amount for a precise estimate of the CSF. The median test duration for one eye was 185 s (range 129–373 s). The AULCSF had better test–retest repeatability (Mean Average Precision, MAP) than visual acuity measured by standard high contrast visual acuity charts or CSF acuity measured with the qCSF (0.18 vs. 0.11 and 0.17, respectively). Even better repeatability (MAP = 0.19) was demonstrated by a CSF-derived feature that was inspired by low-contrast acuity charts, i.e., the highest spatial frequency at 25% contrast. When compared to healthy controls, the MS patients showed reduced CSF (average AULCSF 1.21 vs. 1.42, p < 0.01).ConclusionHigh precision, usability, repeatability, and discrimination support the qCSF as a tool to assess contrast vision in pwMS.

The Characteristics of Quick Contrast Sensitivity Function in Keratoconus and Its Correlation with Corneal Topography

“…Second, this study compared the qCSF characteristics of patients with different degrees of keratoconus but did not include a normal control group. Compared with previous studies in the normal population, qCSF seemed to decrease in keratoconus [ 10 , 36 ]. However, it cannot be compared directly as contrast sensitivity is correlated with age and refraction [ 13 , 37 ].…”

“…Traditional CS tests, such as the Pelli–Robson chart, use coarse quantization and sampling, and are limited to a fixed spatial frequency [ 8 ], while the qCSF test can identify and measure disproportionate reductions in CS at specific spatial frequencies through depicting a complete CSF curve. The qCSF has been applied to measure CSF in several clinical populations, including amblyopia [ 9 ], multiple sclerosis [ 10 ], glaucoma [ 11 ], early diabetic retinopathy [ 12 ], and aging [ 13 ] with great test–retest reliability and high sensitivity in detecting subtle changes in visual function [ 4 , 5 ]. The present study is the first to report on qCSF in keratoconus.…”

Reduced contrast sensitivity function correlated with superficial retinal capillary plexus impairment in early stage of dysthyroid optic neuropathy

“…The CSF was measured using the Manifold Contrast Vision Meter (AST Inc., San Diego, CA). The device incorporated the quick CSF (qCSF) method [26,27] to efficiently estimate the entire CSF curve, which has been applied in quantifying functional vision deficits in many clinical conditions [9][10][11][12].…”

“…CSF, on the other hand, provides a comprehensive evaluation of spatial vision at various spatial frequencies [7] and is better correlated with daily visual function in tasks such as reading, driving, and walking [8]. It is more sensitive in detecting subtle functional differences in early retinopathy and optic neuropathy [9][10][11][12]. Previous studies have shown that CSF is reduced in moderate to severe DON patients who experienced significant orbital apex crowding and significant vision loss [13][14][15][16].…”

Contrast Sensitivity Deficits and Its Structural Correlates in Fuchs Uveitis Syndrome

“…Previous studies have proven that this metric's reproducibility and accuracy are superior to those of conventional assays ( 21 ). The qCSF has been used to assess visual impairment in multiple sclerosis ( 22 ), age-related macular degeneration ( 23 ), retinal vein occlusion ( 24 ), and various other ophthalmic diseases. Therefore, the qCSF may provide a suitable tool for clinical functional assessment in patients with FUS.…”