A New Method For Testing Letter Contrast Sensitivity In A Clinical Setting: Comparing M&S Smart System II Letter Contrast Test With Pelli-robson Chart

Abstract

Purpose: : The M&S smart system II (MSSSII; M&S Technologies Inc, Illinois) is a novel computer-based contrast sensitivity assessment tool. The purpose of this study was to compare the utility of the MSSSII to the Pelli-Robson chart as a clinical test for contrast sensitivity.

Methods: : 105 participants aged 5 to 59 (25 visually normal subjects and 80 patients) were recruited. They were tested during monocular viewing using MSSSII and the Pelli-Robson chart in random order. Agreement between the two methods was assessed using the Bland-Altman test.

Results: : Bland-Altman tests demonstrated that these two methods gave similar results. For visually normal subjects, the mean contrast sensitivity (± standard deviation) was 1.70±0.11 with MSSSII and 1.64±0.04 with the Pelli-Robson chart. For patients, the mean contrast sensitivity (± standard deviation) was 1.48±0.25 with MSSSII and 1.52±0.23 with the Pelli-Robson chart. A minor difference in the values was noted due to a slight variation in the log step progression between the two methods.

Conclusions: : The MSSSII and Pelli-Robson test shows comparable contrast sensitivity values for both patients and visually normal subjects, indicating that the MSSSII is a valid tool for measuring contrast sensitivity as an alternative to the Pelli-Robson chart. Initial configuration and calibration of the MSSSII is simple. Once calibrated, the MSSSII provides reproducible, consistent, simple and easy assessment of contrast sensitivity in a wide variety of ophthalmic conditions in both adults and children as young as 5 years of age.

Keywords: contrast sensitivity • visual acuity • visual impairment: neuro-ophthalmological disease