Abstract
Purpose: :
Propose novel illumination technique to maximize and enhance contrast. Explore ‘Tinting’ where white and colored light combine at unique intensities to produce novel lighting with enhanced contrast visualization of tissues
Methods: :
Evaluated endo-illumination with white (control), color and tinted light from a 20ga light pipe. Colored light was created by broadband (80nm) and narrowband (20nm) interference filters (Edmund Optics Inc.,NJ). Tinted light by combining two light paths (colored and white) with fiber optic 2x1 coupler (Mitsubishi Corporation, NY) from metal halide light source (Welch Allyn Lighting Products,NY). Luminous intensity, color temperature, chromaticity and spectrum were quantified with FOIS Integrated Sphere (OceanOptics,FL). Clinical feedback was provided by 5 vitreo-retinal specialists using OPMI 6-SFC surgical microscope (Carl Zeiss,NY), visualizing vitreous, retina, vessels, optic disc and macula structures in fresh porcine eyes. Clinicians evaluated structures through a) control illumination with colored visualization (broadband filter fitted in the microscope) and b) normal visualization with colored and tinted illumination. Structures were ranked by comparing to control (0: same; -1: worst, +1 improved). Photographs recorded by EOS-10D SLRdigital camera (Canon, NY); and video by HV-F22 Camera (Hitachi,CA)
Results: :
Clinicians completely rejected narrow bandwidth illumination, including tinted blue and red. There was 50% acceptance rate for tinted green for vitreous visualization; 70% for tinted cyan for optic disc; 60% for yellow tint for blood vessels and retina. YELLOW illumination was overall preferred followed by CYAN TINT. The spectral range (420-710 nm) with maximum intensity of white light 8 lumens with CIE (0.33,0.31,0.31) and tint utilizing entire chromaticity curve.
Conclusions: :
Tinted illumination is potential alternative to white light. It provides improved contrast visualization of specific fundus structures at low intensity (<5 lumens), allowing for reduction in patient photo-toxicity risks. Also it would allow clinician’s tunable illumination with the potential to visualize critical structure without dyes Additionally lay the foundation for the development of tunable illumination surgical system with surgeon based handheld control.
Keywords: vitreoretinal surgery • brightness and lightness • retina