# The influence of color vision deficiency on vessel visibility during colorectal endoscopic submucosal dissection and the potential advantage of red dichromatic imaging to achieve color vision barrier‐free

## TL;DR

This study explores how color vision deficiency affects the ability to see blood vessels during colorectal endoscopic procedures and finds that red dichromatic imaging improves visibility for all color vision types.

## Contribution

The study introduces red dichromatic imaging as a potential solution to overcome visibility challenges caused by color vision deficiency in endoscopic procedures.

## Key findings

- Red dichromatic imaging increases color contrast between blood vessels and submucosa compared to white light imaging.
- The improvement in visibility is more significant for individuals with protanopia or deuteranopia.
- Red dichromatic imaging brings visibility for color-deficient individuals closer to that of people with normal color vision.

## Abstract

Although color information is important in gastrointestinal endoscopy, there are limited studies on how endoscopic images are viewed by people with color vision deficiency. We aimed to investigate the differences in the visibility of blood vessels during endoscopic submucosal dissection (ESD) among people with different color vision characteristics and to examine the effect of red dichromatic imaging (RDI) on blood vessel visibility.

Seventy‐seven pairs of endoscopic images of white light imaging (WLI) and RDI of the same site were obtained during colorectal ESD. The original images were set as type C (WLI‐C and RDI‐C), a common color vision. These images were computationally converted to simulate images perceived by people with color vision deficiency protanope (Type P) or deutanope (Type D) and denoted as WLI‐P and RDI‐P or WLI‐D and RDI‐D. Blood vessels and background submucosa that needed to be identified during ESD were selected in each image, and the color differences between these two objects were measured using the color difference (ΔE
00) to assess the visibility of blood vessels.

ΔE
00 between a blood vessel and the submucosa was greater under RDI (RDI‐C/P/D: 24.05 ± 0.64/22.85 ± 0.66/22.61 ± 0.64) than under WLI (WLI‐C/P/D: 22.26 ± 0.60/5.19 ± 0.30/8.62 ± 0.42), regardless of color vision characteristics. This improvement was more pronounced in Type P and Type D and approached Type C in RDI.

Color vision characteristics affect the visibility of blood vessels during ESD, and RDI improves blood vessel visibility regardless of color vision characteristics.