Use of Digital Methods to Optimize Visualization during Surgical Gonioscopy

Abstract

Purpose: The aim of this study was to evaluate the efficacy of digital visualization for enhancing the visualization of iridocorneal structures during surgical gonioscopy. Methods: This was a prospective, single-center study on a series of 26 cases of trabecular stent implantation performed by the same surgeon. Images were recorded during surgical gonioscopy, and before stent implantation, with standard colors and with the optimization of various settings, principally color saturation and temperature and the use of the cyan color filter. Subjective analyses were performed by two glaucoma surgeons, and objective contrast measurements were made on iridocorneal structure images. Results: The surgeons evaluating the images considered the optimized digital settings to produce enhanced tissue visibility for both trabecular meshwork pigmentation and Schlemm’s canal in more than 65% of cases. The mean difference in the standard deviation of the pixel intensity values was 37.87 (±4.61) for the optimized filter images and 32.37 (±3.51) for the standard-color images (p < 0.001). The use of a cyan filter provided a good level of contrast for the visualization of trabecular meshwork pigmentation. Increasing the color temperature highlighted the red appearance of Schlemm’s canal. Conclusions: We report here the utility of optimized digital settings including the cyan filter and a warmer color for enhancing the visualization of iridocorneal structures during surgical gonioscopy. These settings could be used in surgical practice to enhance the visualization of the trabecular meshwork and Schlemm’s canal during minimally invasive glaucoma surgery.

Red-Free (Green) Filter-Enhanced Gonioscopy with Smartphone: A Pilot Study

“…Using digital technology makes it possible to apply color filters during surgical procedures, resulting in improved contrast and enabling more accurate imaging of anatomical structures. According to Sandali et al, optimal digital settings improve tissue perception of Schlemm's canal and the color of the trabecular meshwork in almost 65% of instances [3]. Enhanced visibility during cataract surgery and epiretinal membrane staining has been seen by surgeons due to the utilization of digital imaging, as reported in many publications [8][9][10][11].…”

“…However, the image turned orange if we used the warm color filter on the slit-lamp. According to the findings of Sandali et al, modifying the temperature colors can enhance the visibility of Schlemm's canal, which is typically difficult to discern using conventional color settings [3]. This modification results in a reddish look to the canal, facilitates its identification, and has the potential to enhance the precision and safety of stent placement through MIGS.…”

“…Good visualization of the ICA structures, especially trabecular meshwork (TM), is, therefore, essential to ensuring the proper grading of the ICA. Iridocorneal structures are more challenging to discern in patients with a minimum or lack of pigmentation, which may compromise the accuracy of the ICA grading [3].…”