First intraoperative experience with three-dimensional (3D) high-definition (HD) nasal endoscopy for lacrimal surgeries

Computational microscopy for fast widefield deep-tissue fluorescence imaging using a commercial dual-cannula probe

A solid-glass cannula serves as a micro-endoscope that can deliver excitation light deep inside tissue while also collecting emitted fluorescence. Then, we utilize deep neural networks to reconstruct images from the collected intensity distributions. By using a commercially available dual-cannula probe, and training a separate deep neural network for each cannula, we effectively double the field of view compared to prior work. We demonstrated ex vivo imaging of fluorescent beads and brain slices and in vivo imaging from whole brains. We clearly resolved 4 μm beads, with FOV from each cannula of 0.2 mm (diameter), and produced images from a depth of ~1.2 mm in the whole brain, currently limited primarily by the labeling. Since no scanning is required, fast widefield fluorescence imaging limited primarily by the brightness of the fluorophores, collection efficiency of our system, and the frame rate of the camera becomes possible.

Clinical Experiences of 3-Dimensional Biportal Endoscopic Spine Surgery for Lumbar Degenerative Disease

BACKGROUND

The lack of stereoscopic vision in endoscopic spine surgery may lead to a risk of neural or vascular injury during endoscopic surgery. Three-dimensional (3D) endoscopy has not yet been attempted in the field of spinal endoscopic surgery.

OBJECTIVE

To present the technique, clinical efficacy, and safety of the 3D biportal endoscopic approach for the treatment of lumbar degenerative disease.

METHODS

We attempted 3D biportal endoscopic surgery for lumbar degenerative disease in a series of patients. Clinical outcomes and complications were evaluated postoperatively using a short questionnaire about 3D biportal endoscopic spine surgery that solicited respondents' opinions on the advantages and disadvantages of 3D biportal endoscopic surgery compared to the conventional 2D biportal endoscopic approach.

RESULTS

We performed 3D biportal endoscopic spine surgery in 38 patients with lumbar degenerative disease. Optimal neural decompression was revealed by postoperative magnetic resonance imaging in all enrolled patients. The 3D endoscopic vision clearly demonstrated the surgical anatomy starting with the exposure of ligamentum flavum, dura, and nerve root, and 3D endoscopy precisely depicted pathologic lesions such as bony osteophytes and ruptured disc herniation. There were no major complications including neural injury or durotomy.

CONCLUSION

The 3D endoscope may be able to distinguish between normal structures and lesions. The stereognosis and depth sensation of 3D biportal endoscopic spinal surgery might have a favorable impact on the safety of patients during endoscopic spine surgery.

Three-dimensional light-field microendoscopy with a GRIN lens array

Optical endoscopy has emerged as an indispensable clinical tool for modern minimally invasive surgery. Most systems primarily capture a 2D projection of the 3D surgical field. Currently available 3D endoscopes can restore stereoscopic vision directly by projecting laterally shifted views of the operating field to each eye through 3D glasses. These tools provide surgeons with informative 3D visualizations, but they do not enable quantitative volumetric rendering of tissue. Therefore, advanced tools are desired to quantify tissue tomography for high precision microsurgery or medical robotics. Light-field imaging suggests itself as a promising solution to the challenge. The approach can capture both the spatial and angular information of optical signals, permitting the computational synthesis of the 3D volume of an object. In this work, we present GRIN lens array microendoscopy (GLAM), a single-shot, full-color, and quantitative 3D microendoscopy system. GLAM contains integrated fiber optics for illumination and a GRIN lens array to capture the reflected light field. The system exhibits a 3D resolution of ∼100 µm over an imaging depth of ∼22 mm and field of view up to 1 cm². GLAM maintains a small form factor consistent with the clinically desirable design, making the system readily translatable to a clinical prototype.

Applications of Extended Reality in Ophthalmology: Systematic Review

BACKGROUND

Virtual reality, augmented reality, and mixed reality make use of a variety of different software and hardware, but they share three main characteristics: immersion, presence, and interaction. The umbrella term for technologies with these characteristics is extended reality. The ability of extended reality to create environments that are otherwise impossible in the real world has practical implications in the medical discipline. In ophthalmology, virtual reality simulators have become increasingly popular as tools for surgical education. Recent developments have also explored diagnostic and therapeutic uses in ophthalmology.

OBJECTIVE

This systematic review aims to identify and investigate the utility of extended reality in ophthalmic education, diagnostics, and therapeutics.

METHODS

A literature search was conducted using PubMed, Embase, and Cochrane Register of Controlled Trials. Publications from January 1, 1956 to April 15, 2020 were included. Inclusion criteria were studies evaluating the use of extended reality in ophthalmic education, diagnostics, and therapeutics. Eligible studies were evaluated using the Oxford Centre for Evidence-Based Medicine levels of evidence. Relevant studies were also evaluated using a validity framework. Findings and relevant data from the studies were extracted, evaluated, and compared to determine the utility of extended reality in ophthalmology.

RESULTS

We identified 12,490 unique records in our literature search; 87 met final eligibility criteria, comprising studies that evaluated the use of extended reality in education (n=54), diagnostics (n=5), and therapeutics (n=28). Of these, 79 studies (91%) achieved evidence levels in the range 2b to 4, indicating poor quality. Only 2 (9%) out of 22 relevant studies addressed all 5 sources of validity evidence. In education, we found that ophthalmic surgical simulators demonstrated efficacy and validity in improving surgical performance and reducing complication rates. Ophthalmoscopy simulators demonstrated efficacy and validity evidence in improving ophthalmoscopy skills in the clinical setting. In diagnostics, studies demonstrated proof-of-concept in presenting ocular imaging data on extended reality platforms and validity in assessing the function of patients with ophthalmic diseases. In therapeutics, heads-up surgical systems had similar complication rates, procedural success rates, and outcomes in comparison with conventional ophthalmic surgery.

CONCLUSIONS

Extended reality has promising areas of application in ophthalmology, but additional high-quality comparative studies are needed to assess their roles among incumbent methods of ophthalmic education, diagnostics, and therapeutics.

COVID-19 pandemic and lacrimal practice: Multipronged resumption strategies and getting back on our feet

The aim of this review was to propose multi-pronged resumption strategies for lacrimal practice in an effort to plan a sustainable recommencement of elective surgeries after we emerge from the peak of COVID-19 pandemic. The strategies for lacrimal practice were classified into 7 subtypes, and each of the blueprints were reassessed based on existing information on resumption strategies of elective surgeries from other specialties in COVID-19 era. The specific needs of lacrimal practice were then added to construct algorithms summarizing the resumption strategies. The basic principle of 'primum non nocere' needs to be followed. The overall proposed plan advocates the transition to a more sustainable health care reality in a world where we would still co-exist with COVID-19. A comprehensive effort involving screening, laboratory testing, appropriate triage, effective personal protection and specific precautionary measures for lacrimal clinics and operating room are needed to be able to safely resume elective surgery when the pandemic peak declines. To predict the timing of the resumption of elective surgeries is quite complex and influenced by several geographic, political and economic factors. It is equally important to remember that COVID-19 crisis is a dynamic situation and constantly evolving, hence the strategies provided are subject to change. Strict adherence to standard COVID-19 guidelines combined with effective testing and personal protection strategies can ensure slow yet smooth and safe return to full lacrimal practice after the COVID-19 pandemic calms down. The local government directives, individual and institutional discretion are advised.

3D video-assisted trans-oral removal of deep hilo-parenchymal sub-mandibular stones

The aim of this paper is to describe the intra-operative findings and surgical results of the first application of 3D high-definition (HD) endoscopic support to the trans-oral surgical treatment of five patients with deep hilo-parenchymal sub-mandibular stones who underwent clinical and ultrasonographic (US) follow-up examinations at one month after the procedure. Five patients undergoing 2D-HD video-assisted transoral surgery for the same condition were used as controls. The results were classified as successful (US - demonstrated complete clearance) or unsuccessful (US - demonstrated total or partial persistence). Visual analogue scales (VAS) were used post-surgically to evaluate the sharpness and brightness of the 2D and 3D images on the screen and stereoscopic depth perception (SDP) of the 3D-HD endoscope. Successful stone removal and significant subjective improvement (lack of obstructive symptoms) was obtained in all but one of the patients in the 3D group, in whom the one-month US evaluation revealed a residual 3 mm asymptomatic hilo-parenchymal stone that was successfully treated by sialendoscopy-assisted intra-corporeal laser lithotripsy. Wharton’s duct and the lingual nerve were identified and preserved in all cases. The mean 3D-HD VAS results were brightness 7 (range 6-8), sharpness 7.8 (range 7-9) and SDP 8.2 (range 8-9); the mean 2D-HD results were brightness 7.8 (range 7-9) and sharpness 7 (range 7-8). Our findings confirm the safety and efficacy of conservative transoral surgical treatment of hilo-parenchymal sub-mandibular stones. From a surgeon’s perspective, 3D-HD guided exploration of the oral floor seems to provide a better view of Wharton’s duct and the lingual nerve, especially near the sub-mandibular parenchyma. The 3D-HD video-assisted transoral removal of deep hilo-parenchymal sub-mandibular stones can therefore be considered a useful new means of preserving the function of an obstructed salivary gland.

Endoscopic Endonasal Surgery for Removal of Pituitary Adenomas: A Surgical Case Series of Treatment Results Using Different 2- and 3-Dimensional Visualization Systems

BACKGROUND

Endoscopic endonasal transsphenoidal surgery (EETS) is a common treatment for patients with pituitary adenomas (PAs). A disadvantage of endoscopic surgery has been the lack of stereoscopic vision and depth perception. Recent developments offer high-definition 3-dimensional (3D-HD) visualization with a higher resolution and better image quality compared with 3D standard endoscopy (3D-SD). In this study, we compared treatment results of surgically treated patients with PAs using 3 different visualization systems: 2-dimensional (2D)-HD, 3D-SD, and 3D-HD.

METHODS

Data from patients with primary PAs that were surgically treated between December 2008 and December 2017 were analyzed. Preoperative and postoperative tumor size and location, perioperative complications, and ophthalmologic, endocrine, and clinical outcomes were compared.

RESULTS

A total of 170 patients underwent endoscopic resection of a primary PA (54 patients with 2D-HD, 75 with 3D-SD, and 41 with 3D-HD). Preoperatively, no statistical differences were found for tumor size, extension, and endocrine and ophthalmologic status. Tumor resection was not statistically different among the 3 groups. Complete resection was performed in 33 patients (80%) in the 3D-HD group, 54 patients (72%) in the 3D-SD group, and 39 patients (72%) in the 2D-HD group. The number of complications was not different across the groups (P = 0.436). Ophthalmologic outcomes did not differ based on EETS technique. The rate of new pituitary insufficiency was slightly lower in the 3D-HD group compared with 2D-HD and 3D-SD groups (4.8%, 16.6%, and 12%, respectively; P = 0.290).

CONCLUSIONS

Although the resection rate was higher in the 3D-HD group, and subjective advantages of the 3D-HD endoscopes were noted, there were no significant differences in terms of gross total resection or new hormonal deficits among the 3 groups.