Customized Color Settings of Digitally Assisted Vitreoretinal Surgery to Enable Use of Lower Dye Concentrations During Macular Surgery

Relationship between Image Quality and Reproducibility of Surgical Images in 3D Digital Surgery

Objectives: Ophthalmic three-dimensional (3D) digital surgery can reproduce high-definition surgical images; however, 3D digital surgery is limited by recording capacities. We examined the relationship between the minimum image quality required to reproduce surgical images and recording capacity. Methods: Patients who underwent simultaneous vitrectomy and cataract surgery by the same surgeon using a 3D digital surgery system at Juntendo University Urayasu Hospital between February and October 2021 were evaluated. Various quality (Q) and frame rate (FR) settings were used for each case. Four vitreous surgeons evaluated the reproducibility of recorded images of macular manipulation for epiretinal membrane (ERM) and macular hole (MH) cases and those of peripheral retinal manipulation for rhegmatogenous retinal detachment (RRD) cases. The video bitrate and minimum settings required to reproduce surgical images and factors affecting surgical image reproducibility were examined. Results: A total of 129 eyes of 129 patients were observed. The minimum image quality required to reproduce surgical images was 11.67 Mbps. The Q and FR for periretinal processing and Q for macular manipulation affected surgical image reproducibility (p = 0.025, p = 0.019, and p = 0.07, respectively). The minimum recording settings required to obtain highly reproducible images were Q = 3 and FR = 40. The total file size for vitrectomy video recordings with these settings was as compact as 3.17 GB for 28 min. Conclusions: During 3D digital surgery, highly reproducible surgical images can be obtained with a small storage capacity using settings of at least Q = 3 and FR = 40.

Color enhancement and achromatization to increase the visibility of indocyanine green-stained internal limiting membrane during digitally assisted vitreoretinal surgery

PURPOSE

To investigate the impact of using digital assisted vitrectomy (DAV) for color enhancement in color channel and achromatization in color profile on the visibility of indocyanine green (ICG)-stained internal limiting membrane (ILM).

STUDY DESIGN

Retrospective observational study.

METHODS

Twenty eyes from 20 patients (7 men, 13 women) who underwent 27-gauge pars plana vitrectomy for epiretinal membrane removal were included. The presettings of five different imaging modes of the NGENUITY® 3D visualization system (Alcon laboratories, Inc.), were adjusted, and intraoperative images of ILM removal were captured under each presetting. The color contrast ratios (CCR) between the ICG-stained ILM area and peeled ILM area were compared across presettings objectively. Subjective visibility of ILM in each patient for different presettings was ranked using a Likert scale and evaluated by five examiners. Data on sex, age, preoperative and postoperative best-corrected visual acuity (BCVA), preoperative and postoperative intraocular pressure (IOP), and postoperative complications were analyzed.

RESULTS

Compared to other presettings the best CCR was achieved by adjusting the color channel to enhance red and by modifying the color profile to create a monochrome image (P<0.01). The same presetting resulted in a highest subjective visibility (P<0.01). Mean preoperative BCVA and 6-month postoperative BCVA (logMAR) were 0.11±0.18 and 0.05±0.19, respectively (p=0.24). Mean preoperative IOP and 6-month postoperative IOP were 13.8±2.8 mmHg and 13.3±3.4 mmHg, respectively (p=0.51). No apparent intra- and post-operative complications were observed.

CONCLUSION

Color enhancement and achromatization using DAV may offer potential advantages to enhance the visibility of ICG-stained ILM.

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

AIM

This pilot study aimed to demonstrate the usefulness of the red-free (green) filter as a novel modification for better iridocorneal angle visibility during routine gonioscopy.

METHODS

As a pilot project, we observed 20 eyes of 10 patients aged 22 to 60 who attended the glaucoma department of a tertiary eye hospital in Bangladesh. All patients underwent a thorough ocular examination, from best-corrected visual acuity to the dilated fundus evaluation. Images and videos were obtained with a smartphone during gonioscopy with standard halogen light and the red-free (green) filter, subjectively analyzed by two glaucoma specialists.

RESULTS

The mean age of the patients was 37 ± 13.42 years, of whom 70% were men. In this study, 40% of the patients had open-angle glaucoma, and 60% had open-angle without glaucoma. Without impairing the ability to see the iridocorneal angle structures in detail, the gonioscopy picture contrast was enhanced objectively for red-free filter images compared to standard light photos. The built-in warm filter of the slit-lamp also provided better visualization of the iridocorneal angle structures.

CONCLUSION

Using the red-free (green) filter and a warm filter instead of the traditionally used standard light of the slit-lamp may significantly enhance the diagnostic capability during routine gonioscopy.

Heads-Up Three-Dimensional Viewing Systems in Vitreoretinal Surgery: An Updated Perspective

Three-Dimensional (3D) heads-up visualization systems have significantly advanced vitreoretinal surgery, providing enhanced detail and improved ergonomics. This review discusses the application of 3D systems in vitreoretinal surgery, their use in various procedures, their combination with other imaging modalities, and the role of this technology in medical education and telementoring. Furthermore, the review highlights the benefits of 3D systems, such as improved ergonomics, reduced phototoxicity, enhanced depth of field, and the use of color filters. Potential challenges, including the learning curve and additional costs, are also addressed. The review concludes by exploring promising future applications, including teleophthalmology for remote assistance and specialist availability expansion, virtual reality integration for global clinical education, and the combination of remotely robotic-guided surgery with artificial intelligence for precise, efficient surgical procedures. This comprehensive review offers insights into the current state and future potential of 3D heads-up visualization systems in vitreoretinal surgery, underscoring the transformative impact of this technology on ophthalmology.

Use of Digital Methods to Optimize Visualization during Surgical Gonioscopy

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.

Image sharpening algorithms improve clarity of surgical field during 3D heads-up surgery

BACKGROUND

Image-sharpening algorithms with color adjustments enable real-time processing of the surgical field with a delay of 4 msec for heads-up surgery using digital three-dimensional displays. The aim of this study was to investigate the usefulness of the algorithms with the Artevo 800^® digital microscope.

METHODS

Seven vitreoretinal surgeons evaluated the effects of image-sharpening processing on the clarity of the surgical field with the Artevo 800^® system that is used for cataract and vitreous surgeries. The scorings were made on a 10-point scale for anterior capsulotomy, phacoemulsification, cortex aspiration, core vitrectomy, and peeling of an epiretinal membrane or an internal limiting membrane. In addition, the images during the internal limiting membrane peeling were processed with or without color adjustments. We also evaluated the skewness (asymmetry in the distribution of the pixels) and kurtosis (sharpness in the distribution of the pixel) of the images to evaluate the contrast with each intensity of image-sharpening.

RESULTS

Our results showed that the mean visibility score increased significantly from 4.9 ± 0.5 at 0% (original image) to 6.6 ± 0.5 at 25% intensity of the image-sharpening algorithm (P < 0.01). The visibility scores of the internal limiting membrane increased significantly from 0% (6.8 ± 0.3, no color adjustments) to 50% after the color adjustments (7.4 ± 0.4, P = 0.012). The mean skewness decreased significantly from 0.83 ± 2.02 at 0% (original source) to 0.55 ± 1.36 at 25% intensity of the image-sharpening algorithm (P = 0.01). The mean kurtosis decreased significantly from 0.93 ± 2.14 at 0% (original image) to 0.60 ± 1.44 at 25% intensity of the image-sharpening algorithm (P = 0.02).

CONCLUSIONS

We conclude that the image-sharpening algorithms can improve the clarity of the surgical field during 3D heads-up surgery by decreasing the skewness and kurtosis.

TRIAL REGISTRATION

This was a prospective clinical study performed at a single academic institution, and the procedures used were approved by the Institutional Review Committee of the Kyorin University School of Medicine (reference number, 1904). The procedures also conformed to the tenets of the Declaration of Helsinki.

Use of Black-and-White Digital Filters to Optimize Visualization in Cataract Surgery

PURPOSE

To evaluate the effect of a black-and-white (BW) filter on the optimization of visualization at each stage of cataract surgery.

METHODS

Prospective, single-center, single-surgeon, consecutive case series of 40 patients undergoing cataract surgery with BW filter. Surgical images and videos were recorded with and without the BW filter at each stage of cataract surgery. Contrast measurements of surgical images and subjective analysis of video sequences were performed.

RESULTS

The surgeons assessed the BW filter to optimize the tissue visibility of capsulorhexis contours, hydrodissection fluid wave perception, the contrast of instruments through a nucleus during phaco-chop, and subincisional cortex contrast through the corneal edema. Despite the higher contrasts' value obtained with BW filter images during nucleus removal, posterior capsular polishing and viscous removal, the surgeons subjectively reported no significant advantage of using a BW filter. Standard color images were found to be better for localizing the limbal area during incision and for nucleus sculpture to assess groove depth.

CONCLUSIONS

In conclusion, we describe here the potential indications for BW filter use at particular stages in cataract surgery. A BW filter could be used, with caution, in cases of poor visualization.

Comparison of Surgeon Muscular Properties between Standard Operating Microscope and Digitally Assisted Vitreoretinal Surgery Systems

PURPOSE

To quantitatively analyze surgical ergonomics between standard operating microscope (SOM) and digitally assisted vitreoretinal surgery (DAVS) systems.

METHODS

The surgeon conducted procedures on 110 patients; 52 patients underwent a combined phacoemulsification and pars plana vitrectomy (Phaco-PPV group, 24 using SOM and 28 using DAVS), and 58 patients underwent phacoemulsification (Phaco group, 30 using SOM and 28 using DAVS). The surgeon's muscle tone and stiffness in the sternocleidomastoid (SCM) and the two positions of the upper trapezius (UT), which are 2 cm intervals along the UT muscle fibers, UT1 and UT2, were measured at preoperative, intraoperative, and postoperative time points.

RESULTS

In the Phaco-PPV group using the SOM, intraoperative muscle tone and stiffness were higher than pre- and postoperative values in the SCM (P<0.001, respectively), UT1 (P<0.001, respectively), and UT2 (P<0.001 and P<0.01, respectively). In the Phaco group using the SOM, intraoperative muscle tone and stiffness were higher than pre- and postoperative values in the SCM (P<0.001, respectively) and UT1 (P<0.001 and P<0.01, respectively). By contrast, when the surgeon used the DAVS, there were no differences in muscle properties at any measurement site or during any time point in the Phaco-PPV and Phaco groups (P>0.05).

CONCLUSIONS

This study provides quantitative measurement of retina surgeon ergonomics, suggesting that compared with a SOM, the DAVS can reduce intraoperative muscle fatigue.