Precision and Normative Values of a New Computerized Chart for Contrast Sensitivity Testing

Giacomo Savini,Domenico Schiano-Lomoriello,Antonio Calossi,Piero Barboni

doi:10.1038/s41598-019-52987-9

Abstract

The purpose was to define a normative database for a grating test for contrast sensitivity, based on a chart monitor with high-definition liquid crystal display, and validate its measurements by assessing their repeatability and determining responsiveness to cataract surgery. Three samples were analyzed: (1) healthy volunteers to assess the repeatability of measurements, (2) healthy subjects to develop the normative database, (3) patients undergoing cataract surgery. All subjects were tested with the grating contrast sensitivity test (Vision Chart, CSO) at 1.5, 3, 6, 12 and 18 cycles per degree. The instrument software progressively reduces the contrast of the gratings according to the Quick Estimate by Sequential Testing (QUEST) procedure. In the subjects of the first sample, three consecutive measurements were taken and repeatability was assessed on the basis of the intra-session test-retest variability and the coefficient of variation. The test offered high repeatability, with test-retest variability ranging between 0.05 and 0.23 Log CS and the coefficient of variation between 0.61 and 4.21%. Normative data did not show a normal distribution. The highest median values were observed at 1.5, 3 and 6 cycles per degree frequencies. At these frequencies a ceiling effect was evident. In cataract patients, postoperative values showed an improvement at all spatial frequencies. In conclusion, the new contrast sensitivity test provides repeatable measurements that can be used for clinical purposes. In patients with healthy eyes and good vision, attention has to be paid to the ceiling effect.

Highlights

Over the last thirty years, measurement of contrast sensitivity (CS) has gained increasing relevance in ophthalmology, since it can provide useful information about a patient’s visual function that may not be revealed by visual acuity
Foundation and was used to assess the repeatability of measurements, the second included healthy subjects examined for minor refractive defects and was used to develop the normative database, and the third included a series of consecutive patients before and after cataract surgery
Healthy subjects were enrolled on condition that their corrected distance visual acuity was 20/20 or better, the spherical equivalent of their refraction was within 3 diopters (D), they had not received any kind of ocular surgery, they had not any ocular disease, and their lens was fully transparent

Summary

Introduction

Over the last thirty years, measurement of contrast sensitivity (CS) has gained increasing relevance in ophthalmology, since it can provide useful information about a patient’s visual function that may not be revealed by visual acuity. CS has been used to investigate the clinical outcomes of corneal refractive surgery and intraocular lens (IOL) implantation[1,2,3]; it has been found to be reduced in patients with glaucoma[4,5], age-related macular degeneration[6], neurological diseases[7,8], and other pathological conditions[9]

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