Depth perception in patients with congenital color vision deficiency

Abstract

To assess the effect of type and severity of congenital color vision deficiency (CCVD) on depth perception. Thirty-one male patients with a known diagnosis of CCVD were included in the study group and 31 age-matched healthy subjects in the control group. After standard ophthalmological examination including best corrected visual acuity (BCVA) testing with Snellen chart, slit-lamp examination, non-contact tonometry, and fundus examination, all patients underwent color perception testing with Hardy–Rand–Rittler (HRR) 4th edition pseudoisochromatic test plates and stereoacuity testing with Titmus stereo test plates. Of the 31 patients with CCVD, 7 were protanope and 24 were deuteranope. Mean stereoacuity was 46.77 ± 11.3, 105.7 ± 69.0, and 134.1 ± 115.2 in the control, protanope, and deuteranope groups, respectively. Stereoacuity was significantly better in the control group than in the protanope and deuteranope groups ( p  = 0.039, p  < 0.001 respectively). No significant difference was observed between protanopes and deuteranopes regarding stereoacuity ( p  = 0.73). Mean BCVA was −0.01 ± 0.03, −0.02 ± 0.07, and −0.10 ± 0.11 in the control, protanope, and deuteranope groups, respectively. Mean BCVA in deuteranopes was significantly better than the control group ( p  = 0.004), while mean BCVA in deuteranopes and protanopes did not differ significantly ( p  = 0.056). No significant difference was observed between the control group and protanopes regarding visual acuity ( p  = 0.921). Our study showed that color vision had an important effect on depth perception and CCVD may cause decreased stereoacuity.