-
BMJ Open Quality May 2021Ophthalmologists were concerned about the risk of SARS-COV-2 transmission via droplets given the close proximity to the patient during slit lamp examination. There is a...
Ophthalmologists were concerned about the risk of SARS-COV-2 transmission via droplets given the close proximity to the patient during slit lamp examination. There is a need to design a simple, low-cost, waterproof breath shield to minimise risk of infection.Dimensions of the Haag-Streit slit lamp (model BM 900) were recorded to guide accurate design of the breath shield. A questionnaire was circulated among slit lamp users on their perceived risk and concern about SARS-CoV-2 transmission and their perception of how effective different designs of breath shields would be at protecting them from an infection. A number of breath shield prototypes were designed and trialled. Plan, Do, Study, Act (PDSA) cycles were used to improve the design. Materials used to create the breath shields included transparent A3 laminating pouches and laminator, two sheets of A4 paper, scissors, hole punch and a ruler. The breath shield was designed to fit over the objective lens on the slit lamp after temporarily removing the standard, manufacturer-provided breath shield, before replacing it. The breath shields were cleaned after every patient with alcohol wipes and removed for deep cleaning with hand soap and water after each session. We used a proof of concept experiment using fluorescein instilled spray to test the effectiveness of each breath shield at preventing droplet transmission to the slit lamp user.Following four PDSA cycles, a breath shield that is user-friendly, easy to clean was produced. The percentage of confidence that the final design would be effective at preventing droplet transmission increased from 5.6% to 80%.Implementation of a low cost, simple to make, transparent, waterproof breath shield together with other forms of person protective equipment (PPE) creates a safe working environment for clinicians and patients. This intervention can be readily replicated and modified for other slit lamp models.
Topics: COVID-19; Disease Transmission, Infectious; Equipment Design; Humans; Protective Devices; SARS-CoV-2; Slit Lamp; Slit Lamp Microscopy
PubMed: 34035129
DOI: 10.1136/bmjoq-2021-001361 -
Graefe's Archive For Clinical and... Oct 2020Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic...
PURPOSE
Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic examination. The main objective of the present work is to demonstrate how CoV deposited droplets are projected during biomicroscopy and to discuss what kind of precautions should be taken in ophthalmic practice.
METHODS
A coupled fluid-structure system comprising smoothed particle hydrodynamics and the finite element method has been built to assess the projection of droplets spreading from an infected person. Different conditions based on the maximum exit flow velocity from the infector's mouth during the ophthalmic examination were modeled.
RESULTS
During exhalation, for which the exit flow is ~ 1000 mm/s, the average horizontal distance of the flow front was ~ 200 mm while individual particles can reach up to ~ 500 mm. In case of coughing or sneezing (corresponding to an exit flow of ~ 12,000 mm/s), the average horizontal distance of the flow front was ~ 1300 mm.
CONCLUSION
During the ophthalmic examination, the proximity to the patient's nose and mouth was observed to be less than the horizontal distance of flow front particles. Even though mounted breath shields are used, particles flew beyond the shield and contaminate the ophthalmologist. Compared with the current protective breath shields, the use of a larger shield with a minimum radius of 18 cm is needed to decrease viral transmission.
Topics: Aerosols; Air Microbiology; Betacoronavirus; COVID-19; Coronavirus Infections; Eye Diseases; Humans; Infection Control; Inhalation Exposure; Pandemics; Particle Size; Particulate Matter; Physical Examination; Pneumonia, Viral; Rheology; SARS-CoV-2; Slit Lamp; Slit Lamp Microscopy
PubMed: 32588166
DOI: 10.1007/s00417-020-04815-4 -
Rhode Island Medical Journal (2013) Feb 2021Cri-du-chat (CdC) is a 5p chromosomal deletion syndrome. CdC has numerous systemic associations but only a few ocular manifestations have been documented. In this report...
Cri-du-chat (CdC) is a 5p chromosomal deletion syndrome. CdC has numerous systemic associations but only a few ocular manifestations have been documented. In this report we present novel ocular findings of peripheral avascular retina and retinal hemorrhages in a full-term female infant, born to non-consanguineous parents, who had clinical features of cri-du-chat syndrome and genetic confirmation. The retinal hemorrhages resolved. However, the temporal avascular retina in our full-term patient remained. Further analysis of the 5p locus showed 3 genes: CTNND2, SEMA5A and SLC6A18 that not only fit our patient's external phenotype and ophthalmoscopic findings of retinal hemorrhages, but were also key in proper ocular development and neurogenesis, suggesting a genetic contribution by the short-arm of chromosome 5 to proper retinal maturation. Given these findings and their association with cri-du-chat, special attention on screening examinations should include a thorough evaluation of retinal vascularization in CdC patients, even in full-term neonates.
Topics: Chromosome Deletion; Cri-du-Chat Syndrome; Female; Humans; Infant; Infant, Newborn; Phenotype; Retinal Diseases
PubMed: 33517598
DOI: No ID Found -
Neurology Jan 2016To delineate the factors contributing to overdiagnosis of idiopathic intracranial hypertension (IIH) among patients seen in one neuro-ophthalmology service at a tertiary...
OBJECTIVE
To delineate the factors contributing to overdiagnosis of idiopathic intracranial hypertension (IIH) among patients seen in one neuro-ophthalmology service at a tertiary center.
METHODS
We retrospectively reviewed new patients referred with a working diagnosis of IIH over 8 months. The Diagnosis Error Evaluation and Research taxonomy tool was applied to cases referred with a diagnosis of IIH and a discrepant final diagnosis.
RESULTS
Of 1,249 patients, 165 (13.2%) were referred either with a preexisting diagnosis of IIH or to rule out IIH. Of the 86/165 patients (52.1%) with a preexisting diagnosis of IIH, 34/86 (39.5%) did not have IIH. The most common diagnostic error was inaccurate ophthalmoscopic examination in headache patients. Of 34 patients misdiagnosed as having IIH, 27 (27/34 [79.4%]; 27/86 [31.4%]) had at least one lumbar puncture, 29 (29/34 [85.3%]; 29/86 [33.7%]) had a brain MRI, and 8 (8/34 [23.5%]; 8/86 [9.3%]) had a magnetic resonance/CT venogram. Twenty-six had received medical treatment, 1 had a lumbar drain, and 4 were referred for surgery. In 8 patients (8/34 [23.5%]; 8/86 [9.3%]), an alternative diagnosis requiring further evaluation was identified.
CONCLUSIONS
Diagnostic errors resulted in overdiagnosis of IIH in 39.5% of patients referred for presumed IIH, and prompted unnecessary tests, invasive procedures, and missed diagnoses. The most common errors were inaccurate ophthalmoscopic examination in headache patients and thinking biases, reinforcing the need for rapid access to specialists with experience in diagnosing optic nerve disorders. Indeed, the high prevalence of primary benign headaches and obesity in young women often leads to costly and invasive evaluations for presumed IIH.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Diagnostic Errors; Diagnostic Techniques, Ophthalmological; Female; Humans; Male; Middle Aged; Pseudotumor Cerebri; Retrospective Studies; Unnecessary Procedures; Young Adult
PubMed: 26718577
DOI: 10.1212/WNL.0000000000002318 -
Digital Health 2022We previously demonstrated the non-inferiority of a synchronous (real-time) telemedicine model (compared to gold standard in-person examination) for pediatric...
We previously demonstrated the non-inferiority of a synchronous (real-time) telemedicine model (compared to gold standard in-person examination) for pediatric ophthalmology consultations using a Polycom conferencing system, smart glasses, digital slit lamp, and digital indirect ophthalmoscope. Although we acknowledge there is a learning curve associated with becoming proficient with this system, we believe implementation of a synchronous telemedicine model is advantageous to both patient and provider in the right care setting. In conducting 348 such examinations over the course of our study and dozens of subsequent examinations after the implementation of our model in the community, we have gleaned many insights into optimizing the experience and efficiency. We wish to share these insights to help guide those interested in adopting such a model to expand access to specialists for underserved patients or improve efficiencies in their practice.
PubMed: 35935712
DOI: 10.1177/20552076221117744 -
Optica Sep 2018Adaptive optics scanning laser ophthalmoscopy (AOSLO) has enabled in vivo visualization and enhanced understanding of retinal structure and function. Current generation...
Adaptive optics scanning laser ophthalmoscopy (AOSLO) has enabled in vivo visualization and enhanced understanding of retinal structure and function. Current generation AOSLOs have a large footprint and are mainly limited to imaging cooperative adult subjects. To extend the application of AOSLO to new patient populations, we have designed the first portable handheld AOSLO (HAOSLO) system. By incorporating a novel computational wavefront sensorless AO algorithm and custom optics, we have miniaturized our HAOSLO to weigh less than 200 grams. HAOSLO imaged the cones closest to the fovea with a handheld probe in adults and captured the first AO-enhanced image of cones in infants.
PubMed: 31745495
DOI: 10.1364/OPTICA.5.001027 -
Journal of Clinical Medicine May 2020A methodology that applies hyperspectral imaging (HSI) on ophthalmoscope images to identify diabetic retinopathy (DR) stage is demonstrated. First, an algorithm for HSI...
A methodology that applies hyperspectral imaging (HSI) on ophthalmoscope images to identify diabetic retinopathy (DR) stage is demonstrated. First, an algorithm for HSI image analysis is applied to the average reflectance spectra of simulated arteries and veins in ophthalmoscope images. Second, the average simulated spectra are categorized by using a principal component analysis (PCA) score plot. Third, Beer-Lambert law is applied to calculate vessel oxygen saturation in the ophthalmoscope images, and oxygenation maps are obtained. The average reflectance spectra and PCA results indicate that average reflectance changes with the deterioration of DR. The G-channel gradually decreases because of vascular disease, whereas the R-channel gradually increases with oxygen saturation in the vessels. As DR deteriorates, the oxygen utilization of retinal tissues gradually decreases, and thus oxygen saturation in the veins gradually increases. The sensitivity of diagnosis is based on the severity of retinopathy due to diabetes. Normal, background DR (BDR), pre-proliferative DR (PPDR), and proliferative DR (PDR) are arranged in order of 90.00%, 81.13%, 87.75%, and 93.75%, respectively; the accuracy is 90%, 86%, 86%, 90%, respectively. The F1-scores are 90% (Normal), 83.49% (BDR), 86.86% (PPDR), and 91.83% (PDR), and the accuracy rates are 95%, 91.5%, 93.5%, and 96%, respectively.
PubMed: 32466524
DOI: 10.3390/jcm9061613 -
Scientific Reports Nov 2019The invention and advancement of biological microscopy depends critically on an ability to accurately simulate imaging of complex biological structures embedded within...
The invention and advancement of biological microscopy depends critically on an ability to accurately simulate imaging of complex biological structures embedded within complex scattering media. Unfortunately no technique exists for rigorous simulation of the complete imaging process, including the source, instrument, sample and detector. Monte-Carlo modelling is the gold standard for the modelling of light propagation in tissue, but is somewhat laborious to implement and does not incorporate the rejection of scattered light by the microscope. On the other hand microscopes may be rigorously and rapidly modelled using commercial ray-tracing software, but excluding the interaction with the biological sample. We report a hybrid Monte-Carlo optical ray-tracing technique for modelling of complete imaging systems of arbitrary complexity. We make the software available to enable user-friendly and rigorous virtual prototyping of biological microscopy of arbitrary complexity involving light scattering, fluorescence, polarised light propagation, diffraction and coherence. Examples are presented for the modelling and optimisation of representative imaging of neural cells using light-sheet and micro-endoscopic fluorescence microscopy and imaging of retinal vasculature using confocal and non-confocal scanning-laser ophthalmoscopes.
PubMed: 31676825
DOI: 10.1038/s41598-019-51850-1 -
Transplantation Proceedings Jun 2022The process of capturing and classifying the viability of corneal tissue for corneal transplantation is complex. The biomicroscopic examination is one of the techniques...
BACKGROUND
The process of capturing and classifying the viability of corneal tissue for corneal transplantation is complex. The biomicroscopic examination is one of the techniques used to evaluate the quality of corneal tissues. The aim of this study was to analyze the relationship between the evaluation criteria used in biomicroscopic examination using a slit lamp and the classification of the quality of corneal tissue.
METHODS
This is a longitudinal, retrospective cohort study, performed at the Human Ocular Tissue Bank in the state of Rio Grande do Norte, Brazil. The sample consisted of 419 corneas donated between 2005 to 2016.
RESULTS
After the evaluation, the 419 corneas were classified as excellent (8 -1.91%), good (217 - 51.79%), regular (85 - 20.29%), and bad (109 - 26.01%). The classification of corneal quality attributed by ophthalmologists considered 13 criteria: senile arch, scars, epithelial defect, epithelial exposure, stromal infiltrate, subepithelial opacity, pterygium, Descemet's folds, stromal edema, stromal streak, cornea guttata, specular reflex, and cell loss endothelial. The quality of the cornea classified as excellent and good showed a statistically significant association (P value < .05) with senile arch, scar, epithelial defect, epithelial exposure, Descemet's folds, stromal edema, stromal streak, cornea guttata, specular reflex, and losses of endothelial cells; they had evaluated criteria that were absent or slightly present.
CONCLUSIONS
The evaluation of the corneal quality for corneal transplantation should involve the implementation of reliable techniques and trained, qualified professionals. There is a need to create evaluation instruments that consider the criteria according to their degree of interference in the quality of corneal tissue.
Topics: Cicatrix; Cornea; Edema; Endothelial Cells; Humans; Retrospective Studies; Slit Lamp
PubMed: 35811151
DOI: 10.1016/j.transproceed.2022.03.030 -
Clinical Ophthalmology (Auckland, N.Z.) 2023To better understand the sensory impact of retinal exam components typically experienced by infants undergoing various retinopathy of prematurity staging examinations,...
PURPOSE
To better understand the sensory impact of retinal exam components typically experienced by infants undergoing various retinopathy of prematurity staging examinations, adults concerned for infant welfare and exam quality underwent similar exams to compare their perceived stress.
PATIENTS AND METHODS
Adults directly involved with ROP exams and infant stress reduction had cardiac monitoring and concomitant ordinal self symptom-score (1-10 Likert) during 15 components of the exam including lid speculum, various scleral depressors, indirect ophthalmoscopy, goniolens and direct ophthalmoscopy and retinal photography (Phoenix ICON) with or without topical anesthesia.
RESULTS
Nine adults provided impressions and cardiac rhythm gathered supine over 15 minutes. Pain score for topical anesthetic 2 was less than for tropicamide 4. Lid specula numb scored a median 2 level (from 1 to 10) pain but without anesthetic scored 6. The goniolens numb scored 3. Scleral depression numb scored 3-4 but increased to 7 without topical anesthesia. Direct ophthalmoscope scored 3 through the goniolens and the retinal camera scored 4 pain. Brightness with low 350 Lux indirect scored 6-8 numb and 9 brightness without anesthetic. Full bright indirect, direct ophthalmoscope and the retinal camera all had Lux of 3000-4000 and were scored brightness 9, 7 and 10, respectively. Adults had minimal oculocardiac reflex during on-globe retinal examination methods (range 98% to 102%).
CONCLUSION
Topical anesthesia provided a moderate reduction in pain during on-globe lid-speculum, scleral depressed indirect examination. There was a synergistic augmented sensory response between pain and brightness. Adults did not show the bradycardia typically elicited by retinal examinations in premature infants.
PubMed: 37465272
DOI: 10.2147/OPTH.S418150