Direct Visual Field Research Articles

Augmented Reality ASL for 11:11 at Theatre Passe Muraille

In November 2020, Theatre Passe Muraille produced a workshop as a part of their Accessibility Labs (funded through the Toronto Arts Council’s Open Door Project). This workshop connected the development of Samson Bonkeabantu Brown’s play 11:11, directed by Tsholo Visions Khalema and choreographed by Mafa Makhubalo, with a collaboration between technology collectives Toasterlab and Cohort to experiment with the use of augmented reality to support the American Sign Language interpretation and live captioning in consultation with Courage Bacchus, Marcia Adolphe, and Carmelle Cachero, Jenelle Rouse, and Gaitrie Persaud. The collaborators spent a week building an interpretation distribution system that used affordable technology to create a proof-of-concept experiment to see what it would look like to move both text and sign interpretation from just offstage into the visual field of the performance. Using Cohort’s media distribution app developed for the synchronous delivery of media to mobile devices, this project explored live and pre-recorded versions of performance interpretation for a Deaf audience. These were displayed on the audience’s phone screens and in simple augmented reality headsets. The goal was to explore expanding the opportunities for an audience to access interpretation, making the experience more customizable through different forms of engagement, and seeking to provide more universal access across all performances by making a recorded alternative available. The workshop also explored the dramaturgical and scenographic implications of adding this information into the direct visual field of an audience member. This article, in the form of a compiled oral history of the workshop, documents the process, the findings, and the follow-up questions that the team identified over our short time together to provide a baseline for further exploration into the use of mixed-reality technologies in support of accessible performance spaces. It considers situated identity and Deaf culture in relationship to translating interpreted performance to a technological solution as it both outlines the practical steps that allowed this to happen and explores artist, interpreter, and technologist perspectives on what was learned.

Comparison of Preauricular Versus Retromandibular Approach in the Management of Mandibular Condyle Fractures

Objective: To compare the rate of complications encountered on using different incision to access the fracture site for the open reduction and internal fixation of condylar fractures.
 Setting: Department of Oral & Maxillofacial Surgery, Institute of Dentistry, LUMHS
 Subject and Methods: A total 64 patients with unilateral condyle fractures were randomly treated into two groups. Thirty two patients in group A were treated with preauricular incision and 32 were treated with Retro mandibular incision. Patients were followed for period of upto six months for assessment of complications of facial nerve injury such as: salivary fistula and hypertrophic scar formation.
 Results: The average age of the patients was 31.66±9.40 years. Rate of facial nerve palsy was significantly high in group A than group B (18.75% vs. 6.25%; p=0.021) similarly, the rate of salivary fistula and scar formation were also significantly high in group A as compare to groups B (12.5% vs. 1.56% p=0.026) and (14.06% vs. 1.56%;p=0.013) respectively. 
 Conclusion: The retromandibular approach is more suitable for the lower level condylar neck fractures, providing a direct visual field and wide, straight-line access for implant fixation at this region.

Aerosol Exposure During Surgical Tracheotomy in SARS-CoV-2 Positive Patients.

Since December 2019, the novel coronavirus SARS-CoV-2 has been spreading worldwide. Since the main route of infection with SARS-CoV-2 is probably via contact with virus-containing droplets of the exhaled air, any method of securing the airway is of extremely high risk for the health care professionals involved. We evaluated the aerosol exposure to the interventional team during a tracheotomy in a semiquantitative fashion. In addition, we present novel protective measures. To visualize the air movements occurring during a tracheotomy, we used a breathing simulator filled with artificial fog. Normal breathing and coughing were simulated under surgery. The speed of aerosol propagation and particle density in the direct visual field of the surgeon were evaluated. Laminar air flow (LAF) in the OR reduced significantly the aerosol exposure during tracheostomy. Only 4.8 ± 3.4% of the aerosol was in contact with the surgeon. Without LAF, however, the aerosol density in the inspiratory area of the surgeon is 10 times higher (47.9 ± 10.8%, P < 0.01). Coughing through the opened trachea exposed the surgeon within 400 ms with 76.0 ± 8.0% of the aerosol-independent of the function of the LAF. Only when a blocked tube was inserted into the airway, no aerosol leakage could be detected. Coughing and expiration during a surgical tracheotomy expose the surgical team considerably to airway aerosols. This is potentially associated with an increased risk for employees being infected by airborne-transmitted pathogens. Laminar airflow in an operating room leads to a significant reduction in the aerosol exposure of the surgeon and is therefore preferable to a bedside tracheotomy in terms of infection prevention. Ideal protection of medical staff is achieved when the procedure is performed under endotracheal intubation and muscle relaxation.

Effectiveness of ‘Preauricular-Retroparotid' and ‘Retromandibular-Transparotid' approaches in the management of displaced and dislocated condylar head and neck fractures.

Introduction: Management of fractures of the condylar head, neck and base regions can be quite tricky, owing to differences in the morphology and location of the fracture, degree & direction of displacement, extent of comminution, and position of condylar head in relation to glenoid fossa. Hence, choosing an ideal surgical approach for each individual case, is both difficult as well as important. Aim: To assess the effectiveness of two major surgical approaches, the ‘Preauricular-Retroparotid’ and ‘Retromandibular-Transparotid’ approaches in the management of different types of displaced and dislocated condylar head and neck fractures. Patients and Methods: This retrospective study includes 56 patients operated over a period of four years from Jan 2016 to Dec 2019, of whom 14 had bilateral and 42 had unilateral displaced condylar head or neck fractures. 22 surgeries were for condylar head or high condylar neck fractures, treated using the Preauricular-Retroparotid approach. 48 surgeries were for low condylar neck fractures, managed using the Retromandibular-Transparotid approach. Intraoperative and postoperative complications, and detailed objective, subjective and functional treatment outcome assessments, were recorded over a postoperative follow up period ranging from one to three years. Results & Conclusion: Both surgical approaches were found effective in achieving good esthetic and functional results with no major complications, other than occasional transient neurological deficits and few instances of salivary fistulas and sialocoeles. Depending upon the level of the condylar fractures, a preauricular approach is ideal for the condylar head and high condylar neck fractures, providing direct and easy visualization to the region, for retrieval and repositioning of the medially displaced and dislocated proximal fracture fragment. The retromandibular approach is more suited for the lower level condylar neck fractures, providing a direct visual field and a wide, straight line access for implant fixation at this region.

Treatment of Spontaneous Pneumothorax by using the Video Assisted Thoracoscopic Surgery and Mini Invasive Thoracoscopic Surgery

Background and Aim: The temporizing treatment for spontaneous pneumothorax had been established methodically, but thoracoscopic surgical methods has been not yet. The objective of the study is to show the treatment effect of intra- and post-operation by using rational thoracoscopic surgery for the patients with spontaneous pneumothorax. Methods: We had performed Video Assisted Thoracoscopic Surgery (VATS) and Mini Invasive Thoracoscopic Surgery (MITS) for 322 patients with spontaneous pneumothorax and established rational surgery approach between January 2011 and December 2017. And then we evaluated the outcome of surgery compared to common thoracotomy. Results: Compared to common thoracotomy, VATS was an operation with large economic efficacy because of light operation associated injury, fast recovery and the ability to decrease temporary disability rate. And also it saved different drugs and provided Quality of life (QOL) because of low operative cicatrix. Conclusion: VATS not only gave light operative burden to patients but also decreased surgeons’ mental and physical fatigue. In the MITS automatic suture tool with expensive cost and limited indications was not used and the range of indications were wide and operating time was shortened because of procedure under direct visual field associated with thoracoscopy.

A novel method for automatic retinal detachment detection and estimation using ocular ultrasound image

This paper presents a novel method for automated detection of retinal detachment from ocular ultrasound image using digital image processing and computational techniques. Retinal detachment (RD) is an ocular emergency in which retina gets detached from the tissues lying underneath it and often requires immediate intervention to prevent rapid, irreversible vision loss. Direct fundoscopy and visual field testing are most common methods for the detection of RD. These methods are difficult to perform and they do not completely rule out retinal detachment. Generally, Ophthalmologists use ocular ultrasound to enhance their clinical acumen in detecting RD. Sometimes it is difficult to extract diagnostic features from ultrasound (USG) images due to its poor quality. Also, noise present in the image would cause misinterpretation during visual inspection;this demands development of intelligent and automated techniques for detection of retinal detachment. Further, the paper proposes a novel frame work for accurate and automatic retinal detachment using image processing techniques and mathematical analysis of detached area contour detected within the ocular globe. Furthermore, the estimation of diagnostic parameters, indicative of retinal detachment is also computed. Based on the mathematical analysis, three such parameters, percentage area of detached retina (PADR) compared to the ocular globe, angular width of detachment (α) and maximum radial distance of detachment to choroid layer beneath it (β), are calculated. These estimated parameters are very useful in determining the exact location and extent of retinal detachment. Results obtained through the proposed retinal detachment detection scheme are validated by the radiologist.

Modified minimally invasive video-assisted lateral neck dissection for papillary thyroid carcinoma: a series of 130 cases

Objective: To discuss the feasibility, safety and oncologic completeness of modified minimally invasive video-assisted lateral neck dissection (MIVALND) for papillary thyroid carcinoma. Methods: Data of 130 patients from Department of Head and Neck Surgery, Sir Run Run Shaw Hospital, Medical School, Zhejiang University undergoing MIVALND from January 2013 to September 2015 were reviewed retrospectively. There were 31 male and 99 female patients with the mean age of (39±11) years. The thyroidectomy and central compartment dissection were performed under a direct visual field or video-assisted (VA) approach, lateral neck dissection was performed via the VA approach. Serum thyroglobulin and thyroglobulin antibody levels were measured every 6 months after surgery. Ulrasonography was performed to assess the thyroid bed and lateral neck compartment every 6 months after surgery. The mean operation time for MIVALND, mean postoperative hospital stay, size of primary tumor, number of retrieved lymph nodes, complication rates, and postoperative serum thyroglobulin levels were analyzed retrospectively. The patients were followed up by outpatient review and until March 2016. Results: Beside 1 case was converted to open procedure, 129 (99.2%) patients successfully underwent MIVALND. The mean operative time was (74±17) min (ranging from 40 to 120 min) for MIVALND. The mean postoperative hospital stay was (4.9±2.1) days (range 2 to 14 days). The mean size of primary tumor was (1.3±0.7) cm (range 0.3 to 4.0 cm). The mean number of lymph nodes removed was 42±13 (range 15 to 79) in lateral compartment. Postoperative complications included 19 transient hypoparathyroidism, 7 transient recurrent laryngeal nerve (RLN) palsy and 3 permanent RLN palsy (tumor invasion and the RLN was resected en bloc with the tumor in 2 cases), 2 (1.5%) transient palsy of spinal accessory nerve, 1 (0.8%) transient palsy of marginal mandibular branch of the facial nerve, 1 (0.8%) seroma, and 4 (3.1%) minor chyle leak. The mean follow-up period was (19±10) months (ranged 6 to 36 months). The mean serum thyroglobulin level was 0.10 μg/L during follow-up. No evidence of local residual or recurrent disease was observed at postoperative follow-up. Conclusion: The modified MIVALND is a safe and feasible approach in selected papillary thyroid carcinoma patients.

Computer-assisted bone tumour ablation using sparse radiographs

Percutaneous radiofrequency ablation (RFA) is a minimally invasive technique increasingly employed in the treatment of unresectable bone tumours due to its safety, less invasiveness, reduced complications, effectiveness, and predictability. This paper investigates a new pipeline of computer-assisted interventional system with navigation and planning functions for percutaneous RFA as an useful tool to improve clinicians’ performance. Unlike traditional open procedures, percutaneous RFA requires image guidance because a direct visual field of surgical targets is unavailable. Radiographic imaging can be used intra-operatively for navigation, but it generates radiation exposure to patients and clinicians. To reduce the risk of radiation exposure and enhance the performance in computer-assisted bone tumor RFA, this paper addressed two key problems: (1) statistical atlas is employed to construct a global navigation map by deformable registration using a minimal number of intra-operative fluoroscopic images to localize the tumor and (2) a multiple-objective optimization for treatment planning of large tumor RFA is proposed to obtain optimal trajectories and ablation coverage by considering clinical constraints. The proposed system was validated by experiments, showing that the construction error of patient-specific model was 0.84 mm in terms of surface-to-surface distance measure and the optimal planning achieved 100% tumor coverage under multiple clinical constraints.

Comparison of Approaches for the Rigid Fixation of Sub-Condylar Fractures

The objective of this study was to compare the rate of complications encountered on using different incisions to access the fracture site for the open reduction and internal fixation of isolated subcondylar fractures. The parameters evaluated are: the occurrence of salivary fistula, infection, and injuries to the seventh facial nerve. An assessment of the surgical scar was also undertaken. 20 patients who met the previous criteria and were willing to participate in the study were placed (five each) into the pre-auricular, submandibular, retromandibular transparotid or retromandibular transmassetric group based on the incision scar they selected after a description of the operation and being explained about the possible complications. Comparison of the complications could not ascertain the superiority of any approach over the other since the outcomes were not statistically significant. However, judging by operator and assistants' subjective assessment, the retromandibular approaches seem to provide a more direct visual field and an almost straight line access for the fixation of the fracture. The transmassetric approach seems to be a safer approach since the nerves encountered can be visualized and avoided.

Causes of visual impairment among commercial motor vehicle drivers in Uyo metropolis, Akwa Ibom State, Nigeria

Background: Commercial motor vehicles are a very important means oftransport in Nigeria where most people do not own personal vehicles and the railway system is not functioning.Aims and Objectives: The aim of the study is to assess the ocular health status of commercial motor vehicle drivers in Uyo metropolis and to determine the causes of visual impairment amongst them.Materials and Methods: Uyo is the capital city of Akwa Ibom State in theSouth-South geo-political zone of Nigeria with a population of 305,961according to 2006 National population census. This is a cross sectional survey of commercial motor vehicle drivers in all the eleven functional motor parks in Uyo as at the time of the study. A total of two hundred and ninety-one (291) drivers who consented to the study were recruited, interviewed with a standardized questionnaire and examined. Examination included distant visual acuity with Snellen’s Chart and near visual acuity with near chart, tonometry using Schiotz’s tonometer; penlight and magnifying loupe were used to examine the anterior segment, color vision test was with Ishihara chart, funduscopy with direct ophthalmoscope and visual field assessment by confrontation amongst other tests. Data were analysed with SPSS10 soft ware package.Results: Mean age of drivers was found to be ±41.5 years. Prevalence of road traffic accident (RTA) in the study was 24.7%. Human factor contributed 27.7% to the cause of accidents. Causes of visual impairment included refractive error, glaucoma and cataract.Conclusion: There was no statistically significant association between RTA and visual impairment but there was statistically significant association between RTA and visual field defect (P=0.037).Recommendation: Visual field assessment at least by confrontation should be made a requirement before issuance of motor vehicle driving licence and proper visual field assessment of suspected drivers be done by an ophthalmologist before issuance of license. A State-wide survey of visual status of commercial motor vehicle drivers is recommended.Keywords: Cataract, drivers, refractive error, road, transportation.

Use of Ocular Ultrasound for the Evaluation of Retinal Detachment

Retinal detachment is an ocular emergency posing diagnostic difficulty for the emergency practitioner. Direct fundoscopy and visual field testing are difficult to perform and do not completely rule out retinal detachment. Ophthalmologists use ocular ultrasound to enhance their clinical acumen in detecting retinal detachments (RD), and bedside ultrasound capability is readily available to many emergency practitioners (EP). Our study sought to assess whether ocular ultrasound would be a helpful adjunct for the diagnosis of RD for the practicing EP. This was a prospective observational study with a convenience sample of patients. As part of a general course on emergency ultrasonography, practitioners received a 30-min training session on ocular ultrasound before beginning the study. Trained practitioners submitted ultrasound scans with interpretation on patients with signs and symptoms consistent with retinal detachment. Thirty-one of the 72 practitioners trained submitted ocular ultrasound reports on patients presenting to the Emergency Department with concerns for retinal detachments. EPs achieved a 97% sensitivity (95% confidence interval [CI] 82-100%) and 92% specificity (95% CI 82-97%) on 92 examinations (29 retinal detachments). Disc edema and vitreous hemorrhage accounted for false positives, and a subacute retinal detachment accounted for the only false negative. These data show that trained emergency practitioners can use ocular ultrasound as an adjunct to their clinical assessment for retinal detachment.

Intraoral Approach and K-Wire Fixation of Zygomatic Tripod Fractures

To avoid external facial scar which resulted from ordinary infraorbital and lateral eyebrow incision in surgical treatment of zygomatic tripod fractures, the author used intraoral incision and K-wire fixation method in 37 selected patients. This method contraindicated for the patient with multiple comminuted zygomatic fracture, patient combined with hard palatal fracture, and patient combined with herniated orbital floor fracture. The advantages of this method are simple, no external facial scar, and operate under direct visual field. The postoperative results were satisfactory. Balanced facial symmetry and good cosmetic results were obtained.