Three-dimensional heads up display in anterior segment surgeries- Expanding frontiers in the COVID-19 era

Evolution of operating microscopes and development of 3D visualization systems for intraocular surgery

The recent development of high-resolution, heads-up, 3D visualization microscopy systems has provided new technical and visualization options for ophthalmic surgeons. In this review, we explore the evolution of microscope technologies, the science behind modern 3D visualization microscopy systems, and the practical benefits (as well as disadvantages) that these systems provide over conventional microscopes for intraocular surgical practice. Overall, modern 3D visualization systems reduce the requirements for artificial illumination and provide enhanced visualization and resolution of ocular structures, improving ergonomics, and facilitating a superior educational experience. Even when considering their disadvantages, such as those related to technical feasibility, 3D visualization systems have an overall positive benefit/risk ratio. It is hoped these systems will be adopted into routine clinical practice, pending further clinical evidence on the benefits they may provide on clinical outcomes.

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.

Impact of Heads-Up Display Use on Ophthalmologist Productivity, Wellness, and Musculoskeletal Symptoms: A Survey Study

Purpose

To explore how ophthalmologist productivity, wellness, and musculoskeletal (MSK) symptoms are affected by heads-up display (HUD) use.

Methods

A digital survey was emailed to the United States ophthalmologists. Questions covered topics including MSK health, surgical output, work hours, wellness hours, and factors related to HUD use.

Results

One hundred and forty-four ophthalmologists responded, and 99 completed all eligible questions. HUDs were utilized by 33 respondents, 29 of whom submitted complete surveys. HUD users worked 353 more hours annually (P = 0.01) and performed 673 more cases (P = 0.07) than nonusers. MSK symptom presence (P = 0.79), severity (P = 0.80), and frequency (P = 0.86) were independent of use. Over half (n = 16/29) of users identified symptomatic improvement attributable to the device, mostly in the cervical and lumbar regions. Mean job stress was moderate-severe for both users and nonusers (P = 0.10), and there was no significant difference in wellness hours (P = 0.44). Retina specialists (P = 0.02) and males (P = 0.03) were more likely to have operated with the technology. Nearly half of heads-up surgeons (n = 12/29) had obtained new equipment to target MSK symptoms, versus 1.4% of nonusers (n = 1/70; P = 0.0009). Most of those who operated with HUDs would recommend them to others (69.0%, n = 20/29), but 44.8% (n = 13/29) indicated ergonomic challenges. Primary concerns included awkward viewing angles, setup difficulties, and a lack of access.

Conclusions

HUD surgeons reported greater work output versus nonusers without significant compromises in wellness or MSK health. User feedback suggests that the technology may lessen neck and low back pains, but barriers including cost and system inconveniences may impede adoption.

Three-Dimensional Heads-Up vs. Standard Operating Microscope for Cataract Surgery: A Systematic Review and Meta-Analysis

Background: The surgical time duration, the postoperative best-corrected visual acuity (BCVA), and the incidence rate of intraoperative complications, alongside the vision and posturing parameters, were estimated by systematic review and meta-analysis to compare the three-dimensional (3D) heads-up visualization system (HUVS) and standard operating microscope (SOM) in cataract surgery. Methods: A literature search was conducted using PubMed, Embase, and Scopus on 26 June 2022. The weighted mean difference (WMD) was used to present postoperative BCVA and the mean surgical time duration, whereas the risk ratio (RR) was used to present the incidence rate of intraoperative complications. Publication bias was evaluated with Egger’s test. The Cochrane Collaboration’s Tool for randomized clinical trials, the methodological index for non-randomized, and the Newcastle-Ottawa Scale were used to assess the risk of bias. The research has been registered with the PROSPERO database (identifier, CRD42022339186). Results: In the meta-analysis of five studies with 1021 participants, the pooled weighted mean difference (WMD) of the postoperative BCVA showed no significant difference between patients who underwent HUVS versus SOM cataract surgery (WMD = −0.01, 95% confidence interval (CI): −0.01 −0.02). In the meta-analysis of nine studies with 5505 participants, the pooled WMD of mean surgical time duration revealed no significant difference between patients who underwent HUVS versus SOM cataract surgery (WMD = 0.17, 95% CI: −0.43–0.76). In the meta-analysis of nine studies with 8609 participants, the pooled risk RR associated with intraoperative complications was 1.00 (95% CI, 1.00–1.01). Conclusions: 3D HUVS and SOM provide comparable surgical time duration, postoperative BCVA, and incidence rate of intraoperative complications.

Optimization of surgeon ergonomics with three-dimensional heads-up display for ophthalmic surgeries

PURPOSE

To describe the variables that may be utilized in the optimization of three-dimensional heads-up surgeries (3D-HUS) for achieving better ergonomics among ophthalmic surgeons.

METHODS

A.

cross-sectional study was conducted at the operating room of a tertiary eye care center, equipped with an ARTEVO 800 3D surgical microscope and display monitor. The parameters noted were monitor height (MH), surgeon eye-to-floor distance (ETFD), surgeon eye-to-monitor distance (ETMD) and viewing tilt (VT) angle. The neck and eye strain of the surgeon and assistant were scored as per Borg's CR-10 scale, before and after surgeries.

RESULTS

Thirty (13 right, 17 left) eye surgeries were analyzed. The minimum ETMD was 51 inches (in) and the eye strain reduced with shorter ETMD (within the range 51 inches to 83 inches).The VT and ETFD were higher for right eye surgeries. The optimum MH was between 50 and 55 in. Overall, the neck strain and eye strain were in the range of 0-3 and 0-1, respectively.

CONCLUSION

The various parameters affecting the 3D image quality, neck and eye strain are chair height, VT angle, eye centration, monitor distance, laterality of the eye, and room illumination.

Initial experience with three-dimensional heads-up display system for cataract surgery - A comparative study

Purpose:

To compare the complication rates, surgical time and learning curve using the 3-D Heads up display system in comparison with the conventional microscope for routine cataract surgery.

Methods:

Consecutive consenting adults with uncomplicated cataract were offered phacoemulsification using the 3-D Heads up display system (ARTEVO 800 Carl Zeiss Meditec) or the conventional microscope (Zeiss Lumera 700) by two experienced surgeons. Surgical time, measured from start of corneal incision to removal of microscope from the surgical field and complication rates were compared between the groups.

Results:

Of the 343 eyes enrolled, 100 (29%) underwent surgery using the 3-D Heads up display system. The surgical time for 3-D Heads up display system was significantly higher in the 3-D group (8.4 ± 2.1 vs. 6.5 ± 1.8 minutes, P < 0.001). There were no group differences in surgical complications (2% in 3-D vs. 2.5% in conventional microscope, P = 0.28). Comparing across 4 quartiles within the 3-D group, the mean surgical time was slightly higher during the 1^st quartile (n = 25, 9.1 ± 1.9 minutes) compared to the last quartile (n = 25, 8.2 ± 1.9 minutes) (p = 0.17). Complications in the 3-D group occurred only in the initial 50% of cases. Seven (7%) cases in the 3-D group were converted to conventional binocular microscope of which 3 each were due to difficulty in depth perception and low illumination while one was due to intraoperative pupillary constriction.

Conclusion:

Phacoemulsification with the 3-D Heads up display system takes longer time but offers excellent visualization, ergonomics and safety compared to conventional microscopes. Experienced surgeons should be able to adapt easily after their first 50 surgeries.

Three-Dimensional Heads-up Cataract Surgery Using Femtosecond Laser: Efficiency, Efficacy, Safety, and Medical Education-A Randomized Clinical Trial

Purpose

To compare the efficiency, efficacy, and safety, as well as the educational value, of heads-up (three-dimensional visualization system–assisted) and traditional microscopic cataract surgery.

Methods

This randomized noninferiority trial enrolled 242 eyes of 201 patients who received femtosecond laser-assisted cataract surgery. The questionnaire study enrolled 26 medical interns and 39 medical students. Patients received surgery under either a three-dimensional visualization system (3D group, 117 eyes) or traditional microscope (TM group, 125 eyes) after random allocation. The primary outcome was surgical time. The noninferiority margin of surgical time was 60 seconds. Secondary outcomes included ultrasound power, phacoemulsification time, visual acuity, intraocular pressure, endothelial cell density, central corneal thickness, complications, and observer satisfaction scores for surgical procedures.

Results

Surgical time was 462.03 ± 80.36 seconds in the 3D group and 452.13 ± 76.63 seconds in the TM group (difference 9.90 seconds; 95% CI, –9.98 to 29.78; P = 0.365). Visual acuity and other perioperative parameters were comparable between the 3D group and the TM group (all P > 0.05). Incidences of both intraoperative and postoperative complications were low and not statistically different between groups (all P > 0.05). Across all observers, 3D surgery was superior to TM surgery for improving the degree of satisfaction (all P < 0.001).

Conclusions

The surgical efficiency of heads-up cataract surgery is not inferior to traditional microscopic surgery. Both methods achieved similar efficacy and safety outcomes. Moreover, heads-up cataract surgery showed a significant advantage in medical education.

Translational Relevance

Our findings show that heads-up cataract surgery has comparable efficiency, efficacy, and safety, as well as superior medical educational value, to TM surgery, which lays the foundation for promoting and popularizing this technology.

Virtual Reality and Augmented Reality in Ophthalmology: A Contemporary Prospective

PURPOSE

Most published systematic reviews have focused on the use of virtual reality (VR)/augmented reality (AR) technology in ophthalmology as it relates to surgical training. To date, this is the first review that investigates the current state of VR/AR technology applied more broadly to the entire field of ophthalmology.

METHODS

PubMed, Embase, and CINAHL databases were searched systematically from January 2014 through December 1, 2020. Studies that discussed VR and/or AR as it relates to the field of ophthalmology and provided information on the technology used were considered. Abstracts, non-peer-reviewed literature, review articles, studies that reported only qualitative data, and studies without English translations were excluded.

RESULTS

A total of 77 studies were included in this review. Of these, 28 evaluated the use of VR/AR in ophthalmic surgical training/assessment and guidance, 7 in clinical training, 23 in diagnosis/screening, and 19 in treatment/therapy. 15 studies used AR, 61 used VR, and 1 used both. Most studies focused on the validity and usability of novel technologies.

CONCLUSIONS

Ophthalmology is a field of medicine that is well suited for the use of VR/AR. However, further longitudinal studies examining the practical feasibility, efficacy, and safety of such novel technologies, the cost-effectiveness, and medical/legal considerations are still needed. We believe that time will indeed foster further technological advances and lead to widespread use of VR/AR in routine ophthalmic practice.