Project description:Since the emergence of COVID pandemic, health workers have been facing major challenges every day. Ophthalmology practice has encountered countless modifications in the practice pattern not to jeopardize patient care and at the same time maintain all safety measures to reduce transmission. One such modification we made was the Safe Slit-Lamp Shield (SSS) which has been found to be extremely protective in differentiation to other available shield. Although SSS has a larger surface area when compared to already available shields, it won't compromise the comfort of the clinician at the same time gives satisfactory protection.
Project description:PurposeThe global COVID-19 pandemic has resulted in a renewed focus on the importance of personal protective equipment (PPE) and other interventions to decrease spread of infectious diseases. Although several ophthalmology organizations have released guidance on appropriate PPE for surgical procedures and ophthalmology clinics, there is limited experimental evidence that demonstrates the efficacy of various interventions that have been suggested. In this study, we evaluated high-risk aspects of the slit-lamp exam and the effect of various PPE interventions, specifically the use of a surgical mask and a slit-lamp shield.DesignExperimental simulation study.MethodsThis was a single-center study in a patient simulation population. This study examined the presence of particles in the air near or on a slit-lamp, a simulated slit-lamp examiner, or a simulated patient using a fluorescent surrogate of respiratory droplets.ResultsSimulated coughing without a mask or slit-lamp shield resulted in widespread dispersion of fluorescent droplets during the model slit-lamp examination. Coughing with a mask resulted in the most significant decrease in droplets; however, particles still escaped from the top of the mask. Coughing with the slit-lamp shield alone blocked most of forward particle dispersion; however, significant distributions of respiratory droplets were found on the slit-lamp joystick and table. Coughing with both a mask and slit-lamp shield resulted in the least dispersion to the simulated examiner and the simulated patient. Scanning electron microscopy demonstrated particle sizes of 3-100 μm.ConclusionsMasking had the greatest effect in limiting spread of respiratory droplets, whereas slit-lamp shields and gloves also contributed to limiting exposure to droplets from SARS-CoV-2 during slit-lamp examination.
Project description:PURPOSE:To evaluate the efficacy of slit lamp breath shields to prevent droplet spray from a simulated sneeze. DESIGN:Experimental study to test effectiveness of personal protective equipment. METHODS:The nozzle of a spray gun was adjusted to angularly disperse a mist of colored dye that approximated a patient sneezing on a dimensionally accurate cardboard slit lamp model. We tested the designs of six commercially available breath shields, and one breath shield repurposed from a plastic container lid. Each breath shield was sprayed in a standardized fashion three times and the amount of overspray compared with no shield was quantified. The surface area that was sprayed was calculated using Adobe Photoshop's color range function. The average percentage of overspray of each breath shield was computed in comparison to the control. RESULTS:The breath shields ranged in surface area from 116-1254 cm2 and the amount of overspray varied from 54% to virtually none. Larger breath shields offered better protection than smaller ones. Breath shields attached to the objective lens arm were a better barrier than those hung by the oculars of comparable size. A repurposed plastic lid breath shield was 513cm2, was slightly curved toward the examiner's face, and allowed only 2% overspray. The largest breath shield (1254 cm2) hung near the oculars and prevented essentially all the overspray. CONCLUSION:The performance of different designs of breath shields is variable. Even high functioning shields should be used in conjunction with personal protective equipment including masks, goggles and gloves, and handwashing. Ideally patients should also wear a cloth mask during all slit lamp exams.
Project description:PurposeTo assess the usability and image quality of a smartphone adapter for direct slit lamp imaging.MethodsA single-center, prospective, clinical study conducted in the Department of Ophthalmology at the University Hospital Zurich, Switzerland. The smartphone group consisted of 26 medical staff (consultants, residents, and students). The control group consisted of one ophthalmic photographer. Both groups took images of the anterior and the posterior eye segment of the same proband. The control group used professional photography equipment. The participant group used an Apple iPhone 11 mounted on a slit lamp via a removable SlitREC smartphone adapter (Custom Surgical GmbH, Munich, Germany). The image quality was graded independently by two blinded ophthalmologists on a scale from 0 (low) to 10 (high quality). Images with a score ≥ 7.0/10 were considered as good as the reference images. The acquisition time was measured. A questionnaire on usability and experience in smartphone and slit lamp use was taken by all of the participants.ResultsEach participant had three attempts at the same task. The overall smartphone quality was 7.2/10 for the anterior and 6.4/10 for the posterior segment. The subjectively perceived difficulty decreased significantly over the course of three attempts (Kendall's W). Image quality increased as well but did not improve significantly from take 1 to take 3. However, the image quality of the posterior segment was significantly, positively correlated (Spearman's Rho) with work experience. The mean acquisition time for anterior segment imaging was faster in the smartphone group compared to the control group (156 vs. 206 s). It was vice versa for the posterior segment (180 vs. 151 s).ConclusionSlit lamp imaging with the presented smartphone adapter provides high-quality imaging of the anterior segment. Posterior segment imaging remains challenging in terms of image quality. The adapter constitutes a cost-effective, portable, easy-to-use solution for recording ophthalmic photos and videos. It can facilitate clinical documentation and communication among colleagues and with the patient especially outside normal consultation hours. Direct slit lamp imaging allows for time to be saved and increases the independence of ophthalmologists in terms of patient mobility and the availability of photographic staff.
Project description:Slit lamps are routinely used to examine large numbers of patients every day due to high throughput. Previous, cultivation-based results suggested slit lamps to be contaminated with bacteria, mostly coagulase-negative staphylococci, followed by micrococci, bacilli, but also Staphylococcus aureus. Our study aimed at obtaining a much more comprehensive, cultivation-independent view of the slit lamp bacteriota and its hygienic relevance, as regularly touched surfaces usually represent fomites, particularly if used by different persons. We performed extensive 16S rRNA gene sequencing to analyse the bacteriota, of 46 slit lamps from two tertiary care centers at two sampling sites, respectively. 82 samples yielded enough sequences for downstream analyses and revealed contamination with bacteria of mostly human skin, mucosa and probably eye origin, predominantly cutibacteria, staphylococci and corynebacteria. The taxonomic assignment of 3369 ASVs (amplicon sequence variants) revealed 19 bacterial phyla and 468 genera across all samples. As antibiotic resistances are of major concern, we screened all samples for methicillin-resistant Staphylococcus aureus (MRSA) using qPCR, however, no signals above the detection limit were detected. Our study provides first comprehensive insight into the slit lamp microbiota. It underlines that slit lamps carry a highly diverse, skin-like bacterial microbiota and that thorough cleaning and disinfection after use is highly recommendable to prevent eye and skin infections.
Project description:Purpose This article assesses the efficacy of an instructional video and model eye simulation for teaching slit lamp exam to medical students as compared to traditional preceptor teaching. Methods First through 4th year students from the University of California, San Francisco School of Medicine were recruited via email to participate in the study. Students were randomized into two groups. The experimental "model eye" group watched an instructional video on slit lamp exam, spent 10 minutes practicing on the model eye, then practiced for 25 minutes with a student partner. The control "preceptor teaching" group received 25 minutes of in-person preceptor teaching on slit lamp exam, then spent 25 minutes practicing with a student partner. Students were objectively assessed by a blinded grader who scored their examination skills with a 31-item checklist. Qualtrics surveys that measured student perceptions were distributed before and after the intervention. Results Seventeen medical students participated in the study. Students in the model eye group achieved higher mean objective assessment scores than students in the preceptor teaching group on skills relating to slit lamp set up (1.75, standard deviation [SD] = 0.50 and 1.50, SD = 0.80 out of 2 points, p = 0.03) and on the total score (1.69, SD = 0.6 and 1.48, SD = 0.8 out of 2 points, p < 0.01). Both groups reported a significant increase in their understanding of what a slit lamp is used for ( p < 0.01) and in their confidence using a slit lamp ( p < 0.01). All students felt their skills improved with the workshop, 94% found the workshop to be useful, and 88% enjoyed the workshop, with no intergroup differences on these metrics. Conclusion An instructional video combined with a simulation model is as effective as traditional preceptor teaching of the slit lamp exam. Such a teaching module may be considered as an adjunct to traditional methods.
Project description:PurposePhotobiomodulation (PBM) refers to therapeutic irradiation of tissue with low-energy, 630- to 1000-nm wavelength light. An increasing body of evidence supports a beneficial effect of PBM in retinal disorders. To date, most studies have utilized light-emitting diode irradiation sources. Slit-lamp-mounted retinal lasers produce a coherent beam that can be delivered with precisely defined dosages and predetermined target area; however, the use of retinal lasers raises safety concerns that warrant investigation prior to clinical application. In this study, we determined safe dosages of laser-delivered PBM to the retina.MethodsA custom-designed, slit-lamp-delivered, 670-nm, red/near-infrared laser was used to administer a range of irradiances to healthy pigmented and non-pigmented rat retinas. The effects of PBM on various functional and structural parameters of the retina were evaluated utilizing a combination of electroretinography, Spectral Domain Optical Coherence (SD-OCT), fluorescein angiography, histology and immunohistochemistry.ResultsIn non-pigmented rats, no adverse events were identified at any irradiances up to 500 mW/cm2. In pigmented rats, no adverse events were identified at irradiances of 25 or 100 mW/cm2; however, approximately one-third of rats that received 500 mW/cm2 displayed very localized photoreceptor damage in the peripapillary region, typically adjacent to the optic nerve head.ConclusionsA safety threshold exists for laser-delivered PBM in pigmented retinas and was identified as 500 mW/cm2 irradiance; therefore, caution should be exercised in the dosage of laser-delivered PBM administered to pigmented retinas.Translational relevanceThis study provides important data necessary for clinical translation of laser-delivered PBM for retinal diseases.
Project description:Corneal ulcer is one of the most important ophthalmic emergencies. A portable, recordable, and smartphone-attachable slit-lamp device called the "Smart Eye Camera" (SEC) is introduced to compare evaluating corneal ulcers between the SEC and the conventional slit-lamp. A total of 110 participants were included in the study, consisting of 55 patients with corneal ulcers and 55 age- and gender-matched healthy volunteers as controls. The participants were first subjected to examination by a conventional slit lamp. The video recording with SEC and imaging with a slit lamp were done by a non-medical person. Both SEC videos and slit-lamp photos were reported by two independent ophthalmologists and compared with a slit-lamp examination as a gold standard. The average age of the study participants was 48.85 ± 20.45 years and 68 participants (61.8%) were male. All corneal ulcers were detected by two ophthalmologists using SEC. Ulcer size evaluated in slit lamp and SEC horizontally (Intraclass Correlation Coefficient (ICC); 0.90, 95% CI; 0.84-0.94) and vertically (ICC; 0.90, 95% CI; 0.84-0.94) is correlated about 90%. Hypopyon size (ICC; 0.95, 95% CI; 0.92-0.97), and corneal epithelial defect (CED) size horizontally (ICC; 0.94, 95% CI; 0.91-0.96) and vertically (ICC; 0.94, 95% CI; 0.91-0.96) also correlated about 94%. The infiltration pattern evaluated by SEC was consistent with the pattern evaluated in slit lamps in more than 80% of patients. The SEC is so accurate in diagnosing corneal ulcers and its reliability makes it a valuable telemedicine device.
Project description:In ophthalmology, the availability of many fundus photographs and optical coherence tomography images has spurred consideration of using artificial intelligence (AI) for diagnosing retinal and optic nerve disorders. However, AI application for diagnosing anterior segment eye conditions remains unfeasible due to limited standardized images and analysis models. We addressed this limitation by augmenting the quantity of standardized optical images using a video-recordable slit-lamp device. We then investigated whether our proposed machine learning (ML) AI algorithm could accurately diagnose cataracts from videos recorded with this device. We collected 206,574 cataract frames from 1812 cataract eye videos. Ophthalmologists graded the nuclear cataracts (NUCs) using the cataract grading scale of the World Health Organization. These gradings were used to train and validate an ML algorithm. A validation dataset was used to compare the NUC diagnosis and grading of AI and ophthalmologists. The results of individual cataract gradings were: NUC 0: area under the curve (AUC) = 0.967; NUC 1: AUC = 0.928; NUC 2: AUC = 0.923; and NUC 3: AUC = 0.949. Our ML-based cataract diagnostic model achieved performance comparable to a conventional device, presenting a promising and accurate auto diagnostic AI tool.
Project description:BackgroundCorneal neovascularization (CoNV) is a common sign in anterior segment eye diseases, the level of which can indicate condition changes. Current CoNV evaluation methods are time-consuming and some of them rely on equipment which is not widely available in hospitals. Thus, a fast and efficient evaluation method is now urgently required. In this study, a deep learning (DL)-based model was developed to automatically segment and evaluate CoNV using anterior segment images from a slit-lamp microscope.MethodsA total of 80 cornea slit-lamp photographs (from 80 patients) with clinically manifested CoNV were collected from December 2021 to July 2022 at Tianjin Medical University Eye Hospital. Of these, 60 images were manually labelled by ophthalmologists using ImageJ software to train the vessel segmentation network IterNet. To evaluate the performance of this automated model, evaluation metrics including accuracy, precision, area under the receiver operating characteristic (ROC) curve (AUC), and F1 score were calculated between the manually labelled ground truth and the automatic segmentations of CoNV of 20 anterior segment images. Furthermore, the vessels pixel count was automatically calculated and compared with the manually labelled results to evaluate clinical usability of the automated segmentation network.ResultsThe IterNet model achieved an AUC of 0.989, accuracy of 0.988, sensitivity of 0.879, specificity of 0.993, area under precision-recall of 0.921, and F1 score of 0.879. The Bland-Altman plot between manually labelled ground truth and automated segmentation results produced a concordance correlation coefficient of 0.989, 95% limits of agreement between 865.4 and -562.4, and the vessels pixel count's Pearson coefficient of correlation was 0.981 (P<0.01).ConclusionsThe fully automated network model IterNet provides a time-saving and efficient method to make a quantitative evaluation of CoNV using slit-lamp anterior segment images. This method demonstrates great value and clinical application potential for patient care and future research.