Ultra-Widefield OCT Angiography.

Optical Coherence Tomography Angiography (OCTA), a functional extension of OCT, has the potential to replace most invasive fluorescein angiography (FA) exams in ophthalmology. So far, OCTA's field of view is however still lacking behind fluorescence fundus photography techniques. This is problematic, because many retinal diseases manifest at an early stage by changes of the peripheral retinal capillary network. It is therefore desirable to expand OCTA's field of view to match that of ultra-widefield fundus cameras. We present a custom developed clinical high-speed swept-source OCT (SS-OCT) system operating at an acquisition rate 8-16 times faster than today's state-of-the-art commercially available OCTA devices. Its speed allows us to capture ultra-wide fields of view of up to 90 degrees with an unprecedented sampling density and hence extraordinary resolution by merging two single shot scans with 60 degrees in diameter. To further enhance the visual appearance of the angiograms, we developed for the first time a three-dimensional deep learning based algorithm for denoising volumetric OCTA data sets. We showcase its imaging performance and clinical usability by presenting images of patients suffering from diabetic retinopathy.

Feasibility and tolerability of ophthalmic virtual reality as a medical communication tool in children and young people.

PURPOSE: Virtual reality (VR) can be useful in explaining diseases and complications that affect children in order to improve medical communications with this vulnerable patient group. So far, children and young people's responses to high-end medical VR environments have never been assessed. METHODS: An unprecedented number of 320 children and young people were given the opportunity to interact with a VR application displaying original ophthalmic volume data via a commercially available tethered head-mounted display (HMD). Participants completed three surveys: demographics and experience with VR, usability and perceived utility of this technology and the Simulator Sickness Questionnaire. The second survey also probed participants for suggestions on improvements and whether this system could be useful for increasing engagement in science. RESULTS: A total of 206 sets of surveys were received. 165 children and young people (84 female) aged 12-18 years (mean, 15 years) completed surveys that could be used for analysis. 69 participants (47.59%) were VR-naïve, and 76 (52.41%) reported that they had previous VR experience. Results show that VR facilitated understanding of ophthalmological complications and was reasonably tolerated. Lastly, exposure to VR raised children and young people's awareness and interest in science. CONCLUSIONS: The VR platform used was successfully utilized and was well accepted in children to display and interact with volume-rendered 3D ophthalmological data. Virtual reality (VR) is suitable as a novel image display platform in ophthalmology to engage children and young people.

Self-reported confidence with ocular examination and management of eye diseases by general medical practitioners.

AIMS: The aim of the study is to determine the confidence of general practitioners (GPs) with ophthalmic exam and management of eye diseases. MATERIALS AND METHODS: Using self-administered questionnaire, information on sociodemographics, medical practice experience, confidence with eye exam, and management of eye diseases was obtained from GP at the General Outpatient Department. Responses on level of confidence were ranked with Likert scale and analyzed with the Statistical Package for Social Science, version 23. RESULTS: Twenty-two GPs with mean medical practice experience of 17.4 ± 8.5 years participated. Twelve (54.5%) GPs routinely examined patients' eyes. Pen torch assessment of ocular surface was most commonly performed eye exam, 1 (4.6%) did visual acuity, while none performed ophthalmoscopy. Seventeen (77.3%) GPs rated themselves average or higher in interpreting pen torch examination of ocular surface. Expressed diagnostic confidence was highest for pterygium, 19 (86.4%), and low for interpreting visual acuity, 8 (36.4%); 13 (59.1%) were confident with diagnosing cataract. While all GPs (100.0%) were not confident with diagnosing and managing posterior segment diseases, 19 (86.4%) felt that they could confidently manage allergic and bacterial conjunctivitis, respectively. Seventeen (77.3%) GPs thought their undergraduate exposure in ophthalmology was inadequate and 21 (95.5%) felt that update courses in ophthalmology were necessary. CONCLUSIONS: Half of the GPs performed eye examination. Self-reported confidence in ophthalmoscopy, diagnosis, and management of posterior segment diseases was low among GPs. Diagnostic confidence was highest for pterygium. Continuing ophthalmic education and provision of basic ophthalmic equipment are recommended to improve confidence of GP in management of ocular disorders.

Recent developments in regenerative ophthalmology.

Regenerative medicine (RM) is one of the most promising disciplines for advancements in modern medicine, and regenerative ophthalmology (RO) is one of the most active fields of regenerative medicine. This review aims to provide an overview of regenerative ophthalmology, including the range of tools and materials being used, and to describe its application in ophthalmologic subspecialties, with the exception of surgical implantation of artificial tissues or organs (e.g., contact lens, artificial cornea, intraocular lens, artificial retina, and bionic eyes) due to space limitations. In addition, current challenges and limitations of regenerative ophthalmology are discussed and future directions are highlighted.

Stepping up infection control measures in ophthalmology during the novel coronavirus outbreak: an experience from Hong Kong.

PURPOSE: Coronavirus disease (COVID-19) has rapidly emerged as a global health threat. The purpose of this article is to share our local experience of stepping up infection control measures in ophthalmology to minimise COVID-19 infection of both healthcare workers and patients. METHODS: Infection control measures implemented in our ophthalmology clinic are discussed. The measures are based on detailed risk assessment by both local ophthalmologists and infection control experts. RESULTS: A three-level hierarchy of control measures was adopted. First, for administrative control, in order to lower patient attendance, text messages with an enquiry phone number were sent to patients to reschedule appointments or arrange drug refill. In order to minimise cross-infection of COVID-19, a triage system was set up to identify patients with fever, respiratory symptoms, acute conjunctivitis or recent travel to outbreak areas and to encourage these individuals to postpone their appointments for at least 14 days. Micro-aerosol generating procedures, such as non-contact tonometry and operations under general anaesthesia were avoided. Nasal endoscopy was avoided as it may provoke sneezing and cause generation of droplets. All elective clinical services were suspended. Infection control training was provided to all clinical staff. Second, for environmental control, to reduce droplet transmission of COVID-19, installation of protective shields on slit lamps, frequent disinfection of equipment, and provision of eye protection to staff were implemented. All staff were advised to measure their own body temperatures before work and promptly report any symptoms of upper respiratory tract infection, vomiting or diarrhoea. Third, universal masking, hand hygiene, and appropriate use of personal protective equipment (PPE) were promoted. CONCLUSION: We hope our initial experience in stepping up infection control measures for COVID-19 infection in ophthalmology can help ophthalmologists globally to prepare for the potential community outbreak or pandemic. In order to minimise transmission of COVID-19, ophthalmologists should work closely with local infection control teams to implement infection control measures that are appropriate for their own clinical settings.

State of the eye health system in the Pacific: is medical technology available and used by mid-level eye care workers?

INTRODUCTION: The aim of this study is to describe the availability, use and comfort with ophthalmic equipment and medications by mid-level eye care workers in Papua New Guinea and Pacific Island countries and territories as indicators of the state of eye care in the Pacific. METHODS: Health information system data, from a workforce support program to Pacific mid-level eye care workers, were analysed for availability and comfort with use of ophthalmic equipment and topical medications. RESULTS: For refraction equipment, access was excellent (98% for retinoscopes and trial lenses) 'very frequent use' range was 42-74% and 'high comfort of use' range was 54-86%. Equipment for ocular health assessment is widely available (slit lamps 67%), with high comfort levels (78-100% 'very comfortable'). Over 70% of respondents have access to topical diagnostic medications, 98% have access to at least one type of antibiotic drops and 63% have access to at least one topical corticosteroid. CONCLUSION: Overall, trained mid-level eye care workers in the Pacific seem well equipped for ocular health and refractive assessments. Comfort levels are encouraging, but also highlight areas for continuing professional development. Access to ophthalmic medications appears acceptable in the region for low morbidity anterior segment conditions.

Measurement of Carotenoids in Perifovea using the Macular Pigment Reflectometer.

The macular pigment reflectometer (MPR) objectively measures the overall macular pigment optical density (MPOD) and further provides the lutein optical density (L-OD) and zeaxanthin optical density (Z-OD) in the central 1 degree of the fovea. A modification of the technique was developed to evaluate in vivo carotenoid density eccentric to the fovea. An adjustable track system with red LED lights was placed 6.1 m away from the participant to facilitate ocular fixation. Lights were spaced appropriately to create increments of 1 degree retinal disparity during the reflectometry measurements. All reflectometry measurements were obtained with pupillary dilation. The mean MPR-MPOD value for the central measurement was 0.593 (SD 0.161) with an L-OD to Z-OD ratio of 1:2.61. The MPR-MPOD value at 1 degree was 0.248 and the mean MPR-MPOD value at 2 degrees in the parafoveal region was 0.143. The L-OD to Z-OD ratio at 1 degree and 2 degrees off center was 1.38:1.0 and 2.08:1.0, respectively. The results demonstrate that MPOD measurements obtained using the MPR decrease as a function of retinal eccentricity and that there is a higher concentration of zeaxanthin centrally compared to lutein. The L-OD to Z-OD ratio changes with foveal eccentricity, with twice more lutein than zeaxanthin at 2 degrees off center. Our technique successfully provides a quick in vivo method for the measurement of macular pigment optical density at various foveal eccentricities. The results agree with prior published in vivo and in vitro xanthophyll carotenoid density distribution measurements.

Piezoelectric 3D bioprinting for ophthalmological applications: process development and viability analysis of the technology.

Piezoelectric inkjet 3D bioprinting technology is a viable technique for ophthalmological applications. It provides versatility, high sensibility and accuracy, required in ophthalmological procedures. A process flow for biofabrication was described in detail and validated, using piezoelectric inkjet technology, for ophthalmological applications, in vitro and in situ, based on complex images. Ophthalmological problems were documented by diagnostic examinations and were fed to the flow as complex images. The Concept Mapping methodology and the Conceptual Design approach were utilized to elaborate the 3D bioprinting process flow. It was developed a bioink with corneal epithelial cells. To simulate an in situ bioprinting process, eyes of pigs were selected as the substrate to print the cells. Print scripts used the digitally treated images. In order to print on predefined locations, alignment devices and sample holders were built. The proposed process flow has shown to be a potential tool for the biofabrication of ophthalmological solutions.

Hand hygiene and instrument sanitization in ophthalmology clinics.

PURPOSE OF REVIEW: This article reviews the various challenges in infection control in eye clinics and successful measures taken to prevent nosocomial infections. RECENT FINDINGS: The Center for Disease Control recommends hand-washing when hands are visibly soiled, and after direct contact with patients, and inanimate objects such as medical equipment. Published studies have identified poor hygiene in clinical settings as a major cause of nosocomial outbreaks, particularly in cases of epidemic keratoconjunctivitis (EKC). Some studies of EKC outbreaks are able to support direct observation of hygiene lapses with molecular analysis that can match viral strains on particular instruments to those found in infected patients. Although most studies are about adenoviral infection and tonometer use, researchers have found viral and bacterial loads on other common surfaces, indicating a need for further research. SUMMARY: Proper hygiene in eye clinics requires special attention because of the potential to examine many patients at a time and because multiple instruments are often used during a single exam. Studies reinforce the link between hygiene and outbreak prevention, and more research can be done to determine the specific links between certain instruments and nosocomial infections.

[Treatment of congenital ptosis in a low-income country: polypropylene frontalis sling at the African Institute of Tropical Ophthalmology]. / Traitement du ptosis congénital dans un pays à faible revenu : suspension du releveur au muscle frontal par le polypropylène à l'Institut d'Ophtalmologie tropicale de l'Afrique (IOTA).

INTRODUCTION: Treatment of congenital ptosis is exclusively surgical; the frontalis sling method is most appropriate when the ptosis is severe, with no upper eyelid levator function. This surgery typically utilizes various materials (autologous fascia lata, silicone, nylon, or polypropylene bands, etc.). MATERIALS AND METHODS: This was a retrospective descriptive study of 22 children under 16 years of age, treated for congenital ptosis by frontalis suspension of the levator muscle of the upper eyelid using the polypropylene technique, between January 1, 2014 and June 30, 2017 at the African Institute of Tropical Ophthalmology teaching hospital. RESULTS: In our study, the surgical result (prior to correction of recurrences) was satisfactory in 81.82 % of cases, with a recurrence rate of 13.64 %. The mean follow-up was 14 months, ranging from 4 to 25 months. DISCUSSION: The use of polypropylene provides encouraging results in ptosis surgery, while also offering the advantage of being low cost and more available. Its use in developing countries deserves special attention.

Soft dry electroophthalmogram electrodes for human machine interaction.

Current soft surface electrodes have attracted more and more attentions owing to their potential applications in biological signal monitoring, human-machine interaction (HMI) and Internet of Things (IoT). The paper presents that soft dry electrode based on polydimethylsiloxane-carbon black (PDMS-CB) conductive polymer is designed and fabricated to continuous, long-term, stable electroophthalmogram (EOG) signal recordings for HMI applications. The features corresponding to the different eye motions are extracted from the EOG data via the soft dry electrodes. Linear discriminant analysis (LDA) recognition algorithms are proposed to recognize eye motion behaviors for controlling the motion of the mobile robots. Experiment results have been demonstrated that LDA recognition algorithm achieves a relatively high recognition accuracy of 90.63% for recognizing four eye movements ('Up', 'Down', 'Right', and 'Left'). The control commands are generated with different eye motions and transmitted to the mobile robot through WiFi communication unit, which the mobile robot is successfully controlled. The soft dry electrodes have the potential in a comfortable, simple, wearable and wireless control of rehabilitation devices.

Multilayered rule-based expert system for diagnosing uveitis.

Uveitis is a condition caused by inflammation of the uvea, which is the middle layer of the eye. Uveitis can result in swelling or destruction of the eye tissue, which can lead to visual impairment or blindness [1]. Many diseases, either systemic or localized to the eye, are associated with the symptoms of uveitis. Thus, it is often hard to determine the underlying disease responsible for uveitis, especially when the signs and symptoms are unclear. Additionally, there are few experts on uveitis, especially in poor and developing countries. In this paper, we design and build a rule-based expert system to diagnose uveitis. The main motivation for developing this expert system was to mitigate the lack of human experts by helping general ophthalmologists achieve a correct diagnosis with minimal time and effort. Furthermore, the system can act as a good educational tool for newly graduated doctors, guiding their work with their patients and supporting their diagnostic decisions. The novel multilayer design of the system allows flexibility and ease of scaling to new cases in the future. Many techniques were used to improve the system's diagnostic flexibility and overcome incomplete user input. Tests of the system have yielded promising results.

Smartphone-Based Device in Exotic Pet Medicine.

This article reviews the use of the smartphone in exotic pet medicine. The mobile app is the most instinctive use of the smartphone; however, there are very limited software dedicated to the exotic pet specifically. With an adapter, the smartphone can be attached to a regular endoscope and acts as a small endoscopic unit. Additional devices, such as infrared thermography or ultrasound, can be connected to the smartphone through the micro-USB port. The medical use of the smartphone is still in its infancy in veterinary medicine but can bring several solutions to the exotic pet practitioner and improve point-of-care evaluation.

Visual Acuity Assessment and Vision Screening Using a Novel Smartphone Application.

OBJECTIVES: To evaluate a smartphone-based application's (Peek Acuity) ability to assess visual acuity and screen for ocular conditions in children, we compared visual acuity assessment between Peek Acuity and the pediatric ophthalmology examination and evaluated Peek Acuity's ability to identify children with referable ocular conditions. STUDY DESIGN: We prospectively recruited 111 children age 3-17 years, presenting to a pediatric ophthalmology clinic, who could follow instructions. Monocular visual acuity assessments by Peek Acuity and standard clinical methods were performed in randomized order. We compared visual acuity assessments between methods using intraclass correlation coefficient (ICC) and evaluated Peek Acuity's ability to identify children with referable ocular conditions. RESULTS: ICC comparing visual acuity assessed between methods was 0.88 (95% CI 0.83-0.92) for first and 0.85 (95% CI 0.78-0.89) for second eyes examined. ICC among 3 to 5-year-olds (preschool-age children) was 0.88 (95% CI 0.77-0.94) for first and 0.45 (95% CI 0.13-0.68) for second eyes examined. Peek Acuity had a sensitivity of 83%-86% for decreased vision and 69%-83% for referable ocular disease. Sensitivity was highest among 3 to 5-year-olds with decreased vision, 93%-100%. CONCLUSIONS: Overall, Peek Acuity visual acuity assessment correlated well with visual acuity assessed by standard clinical methods, though preschool-age children appeared more susceptible to examination fatigue. Peek Acuity performed adequately as a screening tool and had the greatest sensitivity among those with decreased vision and preschool-age children. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03212222.

A trial of a mechanical device for the treatment of blepharospasm.

BACKGROUND: Idiopathic blepharospasm (IB) is a rare but well-characterised adult onset focal dystonia that may cause severe visual disability. The most effective treatment is with periodic injections of botulinum toxin (BTX) into the pre-tarsal and/or pre-septal orbicularis oculi muscles bilaterally. However, even with treatment, practical visual function often remains compromised. A subset of IB sufferers find that eye opening improves with a focal unilateral digital pressure usually on a specific point on the temple. This is known as a 'sensory trick'. We have developed a spectacle mounted device ('Pressop') to apply continuous individually localised focal pressure on the temple to mimic the effect of finger pressure. The aim of the study was to determine if the 'sensory trick' could be replicated by Pressop and if the interval between BTX treatments could thereby be extended. SUBJECTS/METHODS: Study participants had three clinic visits-an initial screening assessment, a visit 2 weeks before the next injection was due when the device was fitted, and one 2 weeks later to assess the response to Pressop. A CDQ 24 and device-specific feedback questionnaire were completed and comparison photographs were taken. Repeat BTX injections were administered at the third visit. RESULTS: Of 58 patients with typical IB recruited to the trial, 39 reported an effective focal finger pressure sensory trick. 56 completed the trial, more than 50% of whom reported some benefit using Pressop; 18% had substantial improvement, sustained for up to 5 years. Improvement could occur in those without an effective sensory trick, therefore there was no significant correlation between using a sensory trick and benefiting from 'Pressop'. There was a trend towards the responders having greater improvement in CDQ24 total score than non-responders but this was not statistically significant. CONCLUSIONS: We recommend a trial of this simple safe device as a means of augmenting visual function in all IB patients.