A New Contrast Sensitivity Test for Pediatric Patients: Feasibility and Inter-Examiner Reliability in Ocular Disorders and Cerebral Visual Impairment

Abstract

Purpose: Assess feasibility and interexaminer reliability of a new test of contrast sensitivity (CS) for pediatric populations.

Methods: The Double Happy (DH) measures CS using a method similar to the Teller Acuity Cards. The schematic DH face is 16 degrees in diameter with features of 0.3 c/d and a channel frequency of 0.8 c/d. DH log₁₀ CS is in 0.15 log unit steps, 0.05 to 2.1. Participants were 43 unselected patients, ages 2 to 18 years: 23 were diagnosed with ocular disorders only; 20 were diagnosed with cerebral visual impairment (CVI). Two examiners measured DH log₁₀ CS. Visual acuity (VA) was also measured.

Results: All 43 participants were tested for binocular DH log₁₀CS. Cohen's kappa values for interexaminer reliability were fair. The between examiner ICC was +0.92 (P < 0.001). The mean difference between examiners was near zero, and the 95% CI was -0.44 to 0.45 log₁₀CS. DH log₁₀CS was near normal in the ocular disorder group and reduced in the CVI group. VA was reduced in both groups. DH log₁₀ CS and VA were correlated (r = -0.65). DH log₁₀ CS was a marginally better predictor of diagnosis than VA.

Conclusions: DH log₁₀CS test was successful in a diverse pediatric population diagnosed with ocular disorders or CVI. Interexaminer reliability was comparable to that of adults tested previously using the same stimuli and methods. Both CS and VA are reduced in CVI.

Translational relevance: CS and VA both should be tested in pediatric clinical populations, especially in those at risk of CVI.

Keywords: contrast sensitivity; inter-examiner reliability; pediatrics; preferential looking; psychophysics.