Abstract
Purpose :
To evaluate the clinical validity of the Rabin cone contrast test (RCCT; Innova Systems, Inc.) in patients with congenital color vision deficiency (CVD).
Methods :
L, M and S-CCT scores (range,0-100) in the RCCT and the RCCT sensitivity and specificity were evaluated in 161 men with congenital CVD ( 22 with protanopia, 23 with protanomaly, 61 with deuteranopia and 55 with deuteranomaly; mean age±SD,14.9±5.5 years) and 10 controls ( mean age±SD,11.0±1.8 years). They were diagnosed by examination with an anomaloscope (Model１, Schmidt and Haensch, Berlin, Germany). All participants had Snellen best corrected visual acuity (BCVA) of 20/20 or better Snellen best corrected visual acuity (BCVA).
Results :
Mean L, M and S-CCT scores were 24.5±13.5, 93.0±8.9 and 99.8±1.0 in protanope; 56.3±22.9, 95.4±4.6 and 100±0 in protanomal; 95.0±11.5, 55.6±17.9 and 98.4±4.1 in deuteranope; 94.7±7.5, 59.5±16.6 and 99.3±2.2 in deuteranomaly; 97.0±4.0, 97.5±3.4 and 99.0±2.0 in controls. Score of 75 or less is defined as abnormal based on Rabin Cone Contrast Test recommendation, when we use the normal score on the CCT( 75≧), the sensitivity was 88.8% and the specificity was 100% for diagnosing the CVD types using the RCCT. To compare the standard Ishihara test with the RCCT, 95.6% of protan and 97.4% of deutan were matched the type of CVD in the RCCT, 44.4% of protan and 97.4% of deutan were matched the type of CVD in the Ishihara test. The standard Ishihara test has 98.8% sensitivity and 100% specificity for diagnosing the CVD. Among 45 patients of protan, 43 patients were determined as P type in the RCCT, while 18 protan were determined as P type in the Ishihara test. Among 116 patients of deutan, 113 deutan were determined as D type both in the RCCT and the Ishihara test.
Conclusions :
The RCCT is useful for CVD screening and typing. Compared with the Ishihara test, the RCCT is particularly useful the detection of protan.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.