Smartphone pupillometry for detection of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH) that can change the trajectory of recovery and is associated with morbidity and mortality. Earlier detection of vasospasm could improve patient outcomes. Our objective is to evaluate the accuracy of smartphone-based quantitative pupillometry in the detection of radiographic vasospasm and delayed cerebral ischemia (DCI) after aSAH. MATERIALS AND METHODS: We prospectively collected pupillary light reflex (PLR) parameters from patients with aSAH admitted to a neurocritical care unit at a single hospital twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter, minimum pupil diameter, percent change in pupil diameter, latency in beginning of pupil constriction to light, mean constriction velocity, maximum constriction velocity, and mean dilation velocity. Two-tailed t-tests for independent samples were performed to determine changes in average concurrent PLR parameter values between the following comparisons: (1) patients with and without radiographic vasospasm (defined by angiography with the need for endovascular intervention) and (2) patients with and without DCI. RESULTS: 49 subjects with aSAH underwent 323 total PLR recordings. For PLR recordings taken with (n=35) and without (n=241) radiographic vasospasm, significant differences were observed in MIN (35.0 ± 7.5 pixels with vasospasm versus 31.6 ± 6.2 pixels without; p=0.002). For PLR recordings taken with (n=43) and without (n=241) DCI, significant differences were observed in MAX (48.9 ± 14.3 pixels with DCI versus 42.5 ± 9.2 pixels without; p<0.001). CONCLUSIONS: Quantitative smartphone pupillometry has the potential to be used to detect radiographic vasospasm and DCI after aSAH.

Optimization of handheld spectrally encoded coherence tomography and reflectometry for point-of-care ophthalmic diagnostic imaging.

Significance: Handheld optical coherence tomography (HH-OCT) systems enable point-of-care ophthalmic imaging in bedridden, uncooperative, and pediatric patients. Handheld spectrally encoded coherence tomography and reflectometry (HH-SECTR) combines OCT and spectrally encoded reflectometry (SER) to address critical clinical challenges in HH-OCT imaging with real-time en face retinal aiming for OCT volume alignment and volumetric correction of motion artifacts that occur during HH-OCT imaging. Aim: We aim to enable robust clinical translation of HH-SECTR and improve clinical ergonomics during point-of-care OCT imaging for ophthalmic diagnostics. Approach: HH-SECTR is redesigned with (1) optimized SER optical imaging for en face retinal aiming and retinal tracking for motion correction, (2) a modular aluminum form factor for sustained alignment and probe stability for longitudinal clinical studies, and (3) one-handed photographer-ergonomic motorized focus adjustment. Results: We demonstrate an HH-SECTR imaging probe with micron-scale optical-optomechanical stability and use it for in vivo human retinal imaging and volumetric motion correction. Conclusions: This research will benefit the clinical translation of HH-SECTR for point-of-care ophthalmic diagnostics.

Repeatability of Noninvasive Break-Up Time Measurements using Keratograph Oculus 3.

AIM: The primary aim of this study is to evaluate the repeatability of noninvasive break-up time (NIBUT) measurement by keratograph when it is determined from one, two or three partial measurements, and to recommend a suitable methodology for practice. Another goal is to verify that repeated measurements do not affect the measured value. MATERIAL AND METHODS: Thirty-eight healthy volunteers (30 women and 8 men) aged between 19 and 50 years old were included in the study, in which only one eye of each volunteer was measured. The study was designed as a prospective one. Each subject adapted to the local conditions of the laboratory for 15 minutes and subsequently underwent two series of NIBUT measurements (test, retest) on an OCULUS 3 Keratograph. The minimum time interval between the two series was 10 minutes, in which each series contained three partial measurements approximately 3 three measurements in the given series. Repeatability was assessed by a Bland-Altman analysis and expressed as a repeatability coefficient. In every case, only the time of the first break-up of the tear film was monitored. RESULTS: The statistical analysis did not show statistically significant differences both between partial measurements of NIBUT in the individual series (p = 0.92, p = 0.81) and when comparing all six measurements (p = 0.95). The mean values of the partial measurements ranged from 13.6 s to 14.4 s. The repeatability coefficients were found to be 15.0 s, 12.1 s and 10.0 s for methodologies A, B and C, respectively. A supplementary analysis for 12 eyes with low NIBUT (< 10 s) showed statistically significantly better repeatability in this group, with coefficients of 7.0 s (methodology A), 6.0 s (B) and 4.6 s (C). CONCLUSION: Determination of NIBUT from three consecutive measurements (with a sufficient interval of ideally a few minutes) significantly improves repeatability. Such repeated NIBUT measurements do not have a significant effect on the measured value. The mentioned methodology for measuring NIBUT on a keratograph can be recommended for use in practice.

Combining Fresnel and block prisms to measure large angles of strabismic deviation.

PURPOSE: A method was developed to measure strabismic angles >50Δ by stacking commercially available Fresnel and block prisms in the same direction ("piggyback prisms"). METHODS: With a laser pointer (wavelength of 532 nm) as the light source, the deviation of the laser spot produced by the stacked prisms was measured on a tangent screen placed 100 cm away from the prisms. To the obtained data with combinations of Fresnel prisms (5Δ-40Δ) and block prisms (10Δ-50Δ), a cubic surface function was fitted by polynomial regression. RESULTS: The combined effect of stacked prisms was always greater than the arithmetic sum of the labeled values of two prisms (by up to 66Δ), increasing exponentially with each prism power and reaching the maximum of 156Δ for the Fresnel/block combination of 30Δ/50Δ. We obtained contour plots to evaluate the optically induced additivity error and constructed look-up tables for quickly determining the combined effect of the prisms based on their labeled values. CONCLUSIONS: Stacking prisms is a practical method to evaluate a large strabismic angle that cannot be measured by any single prism and is especially useful in dealing with severely paralytic strabismus.

Dual-Mode Imaging System for Early Detection and Monitoring of Ocular Surface Diseases.

The global prevalence of ocular surface diseases (OSDs), such as dry eyes, conjunctivitis, and subconjunctival hemorrhage (SCH), is steadily increasing due to factors such as aging populations, environmental influences, and lifestyle changes. These diseases affect millions of individuals worldwide, emphasizing the importance of early diagnosis and continuous monitoring for effective treatment. Therefore, we present a deep learning-enhanced imaging system for the automated, objective, and reliable assessment of these three representative OSDs. Our comprehensive pipeline incorporates processing techniques derived from dual-mode infrared (IR) and visible (RGB) images. It employs a multi-stage deep learning model to enable accurate and consistent measurement of OSDs. This proposed method has achieved a 98.7% accuracy with an F1 score of 0.980 in class classification and a 96.2% accuracy with an F1 score of 0.956 in SCH region identification. Furthermore, our system aims to facilitate early diagnosis of meibomian gland dysfunction (MGD), a primary factor causing dry eyes, by quantitatively analyzing the meibomian gland (MG) area ratio and detecting gland morphological irregularities with an accuracy of 88.1% and an F1 score of 0.781. To enhance convenience and timely OSD management, we are integrating a portable IR camera for obtaining meibography during home inspections. Our system demonstrates notable improvements in expanding dual-mode image-based diagnosis for broader applicability, effectively enhancing patient care efficiency. With its automation, accuracy, and compact design, this system is well-suited for early detection and ongoing assessment of OSDs, contributing to improved eye healthcare in an accessible and comprehensible manner.

Basics, benefits, and pitfalls of pupillometers assessing visual function.

Numerous commercially and non-commercially available pupillometers are nowadays able to assess various biological functions in humans, by evaluating pupils' dynamics in response to specific stimuli. However, the use of pupillometers for ophthalmic afferent evaluations (i.e., photoreceptoral responses) in real-world settings is relatively limited. Recent scientific and technological advances, coupled with artificial intelligence methods have improved the performance of such devices to objectively detect, quantify, and classify functional disturbances of the retina and the optic nerve. This review aims to summarize the scientific principles, indications, outcomes, and current limitations of pupillometry used for evaluation of afferent pathways in ophthalmic clinical settings.

Quantitative Pupillometry: Clinical Applications for the Internist.

From the time of Galen, examination of the pupillary light reflex has been a standard of care across the continuum of health care. The growing body of evidence overwhelmingly supports the use of quantitative pupillometry over subjective examination with flashlight or penlight. At current time, pupillometers have become standard of care in many hospitals across 6 continents. This review paper provides an overview and rationale for pupillometer use and highlights literature supporting pupillometer-derived measures of the pupillary light reflex in both neurological and non-neurological patients across the health care continuum.

New disposable esthesiometer (KeraSenseⓇ) to improve diagnosis and management of neurotrophic keratitis.

PURPOSE: To validate the use, repeatability, and reproducibility of a new, cost-effective, disposable, sterile device (KeraSenseⓇ, Dompè farmaceutici SpA, Milan Italy) compared to Cochet-Bonnet (CB) esthesiometer. Secondly, to identify a simple, safe, rapid, and low-cost test to diagnose neurotrophic keratitis (NK). METHODS: 16 patients with diagnosis of NK stage I, 25 patients with diabetes mellitus (DM), and 26 healthy subjects were included in the study. Corneal sensitivity (CS) was assessed by CB and KeraSenseⓇ. Repeatability, accuracy, and reproducibility of the novel disposable aesthesiometer were assessed. Specificity, sensitivity, and cut-off value for NK diagnosis were calculated by ROC curve analysis. RESULTS: All NK patients showed a CS ≤ 40 mm, while none of the healthy patients showed a CS value < 50 mm. Significant agreement was found between CB measurements and the single use esthesiometer evaluations of CS (p < 0.001). Repeatability evaluations of the single use esthesiometer showed 100% agreement between different measurements (p < 0.001). Reproducibility evaluations showed 99.6% concordance between different operators (p < 0.001). A 55 mm value of the single use esthesiometer was adequate to exclude an NK diagnosis, while all NK patients showed a value ≤ 35 mm. CONCLUSIONS: Corneal hypo/anaesthesia is considered the hallmark of NK. The use of the novel single-use esthesiometer will allow for a diagnostic improvement in NK, sparing time and guaranteeing patients' safety. Diabetic patients despite normal corneal findings may show impairment of CS, suggesting a preclinical stage of NK, requiring a close follow-up.

Pupil size measurements with a multifunctional aberrometer/coherence interferometer/tomographer and two infrared-based pupillometers.

PURPOSE: To compare precision of pupil size measurements of a multifunctional device (Pentacam AXL Wave [Pentacam]) and 2 infrared-based pupillometers (PupilX, Colvard) and to compare repeatability of Pentacam and PupilX. SETTING: Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany. DESIGN: Prospective, comparative trial. METHODS: Pupil diameter of healthy eyes was measured with Colvard once and Pentacam without glare (WO) and with glare (WG), PupilX in 0, 1, and 16 lux 3 times each. In a second series, measurements with Pentacam WO and PupilX in 0.06 and 0.12 lux were assessed. RESULTS: 36 eyes of participants aged 21 to 63 years were included. Mean pupil diameter was 6.05 mm with Colvard, 5.79 mm (first series), 5.50 mm (second series) with Pentacam WO, 3.42 mm WG, 7.26 mm PupilX in 0, 4.67 mm 1, 3.66 mm 16, 6.82 mm in 0.06, and 6.39 mm in 0.12 lux. Measurements with Pentacam WO were significantly different to PupilX in 0, 0.06, 0.12, and 1 lux (all P < .001), but not to Colvard ( P = .086). Pupil size measured with Pentacam WG and PupilX in 16 lux was not significantly different ( P = .647). Consecutive measurements with Pentacam WO and WG had mean SD of 0.23 mm and 0.20 mm, respectively, and with PupilX 0.11 in 0, 0.24 mm 1, and 0.20 mm in 16 lux. CONCLUSIONS: Pentacam provided good assessment of pupil size but was not equivalent to PupilX in low lighting conditions. Repeatability was more favorable for Pentacam.

Diagnóstico da retinopatia diabética por inteligência artificial por meio de smartphone / Diagnosis of diabetic retinopathy by artificial intelligence using smartphone

RESUMO Objetivo: Obter imagens de fundoscopia por meio de equipamento portátil e de baixo custo e, usando inteligência artificial, avaliar a presença de retinopatia diabética. Métodos: Por meio de um smartphone acoplado a um dispositivo com lente de 20D, foram obtidas imagens de fundo de olhos de pacientes diabéticos; usando a inteligência artificial, a presença de retinopatia diabética foi classificada por algoritmo binário. Resultados: Foram avaliadas 97 imagens da fundoscopia ocular (45 normais e 52 com retinopatia diabética). Com auxílio da inteligência artificial, houve acurácia diagnóstica em torno de 70 a 100% na classificação da presença de retinopatia diabética. Conclusão: A abordagem usando dispositivo portátil de baixo custo apresentou eficácia satisfatória na triagem de pacientes diabéticos com ou sem retinopatia diabética, sendo útil para locais sem condições de infraestrutura.

ABSTRACT Introduction: To obtain fundoscopy images through portable and low-cost equipment using artificial intelligence to assess the presence of DR. Methods: Fundus images of diabetic patients' eyes were obtained by using a smartphone coupled to a device with a 20D lens. By using artificial intelligence (AI), the presence of DR was classified by a binary algorithm. Results: 97 ocular fundoscopy images were evaluated (45 normal and 52 with DR). Through AI diagnostic accuracy around was 70% to 100% in the classification of the presence of DR. Conclusion: The approach using a low-cost portable device showed satisfactory efficacy in the screening of diabetic patients with or without diabetic retinopathy, being useful for places without infrastructure conditions.

Corneal biomechanics and glaucoma beyond the bidirectional impact of intraocular pressure and corneal deformation response / Biomecânica corneana e glaucoma além do impacto bididirecional da pressão intraocular e da resposta da deformação corneana

ABSTRACT The purpose of this study was to highlight the impact of biomechanical corneal response in available in vivo tonometry methods for glaucoma management. Systematic review of non-contact air-puff tonometers that analyzes the corneal deformation response, with special focus on the investigation of the correlation of derived parameters with intraocular pressure measurements. The two actual and commercially available in vivo corneal tonometers provide promising information about biomechanical characteristics of the cornea and its relation to glaucoma, allowing the development of new protocols to evaluate, diagnose, and manage this disease.

RESUMO O objetivo deste estudo é destacar o impacto da resposta biomecânica corneana em métodos de tonometria in vivo disponíveis para o manejo do glaucoma. Trata-se de revisão sistemática de tonômetros de ar que analisa a resposta à deformação corneana, com foco especial na investigação da correlação dos parâmetros derivados com as medições da pressão intraocular. Os dois tonômetros mais recentes e comercialmente disponíveis fornecem informações promissoras sobre as características biomecânicas da córnea e sua relação com o glaucoma, permitindo o desenvolvimento de novos protocolos para avaliar, diagnosticar e controlar a doença.

Handheld fundus camera performance, image quality and outcomes of diabetic retinopathy grading in a pilot screening study.

PURPOSE: To compare the performance and image quality of the handheld fundus camera to standard table-top fundus cameras in diabetic retinopathy (DR) screening. The reliability and diagnostic accuracy of DR grading performed by an ophthalmologist and a photographer reader were evaluated. MATERIALS AND METHODS: 157 patients with diabetes, attending screening or follow-up of DR, were evaluated by fundus photographs taken in mydriasis by Optomed Aurora and Canon or Zeiss Visucam fundus cameras. The image quality and the severity of DR were evaluated independently by an ophthalmologist and experienced photographer. The sensitivity, specificity and reliability of the assessments were determined. RESULTS: 1884 fundus images from 314 eyes were analysed. In 53% of all eyes, DR was not present. 10% had mild non-proliferative diabetic retinopathy (NPDR), 16% moderate NPDR, 6% severe NPDR and 16% proliferative diabetic retinopathy (PDR). The DR grading outcomes by Aurora highly equalled to those of Canon or Zeiss (κ = 0.93, 95% CI 0.91 to 0.94), and there was almost perfect agreement in grading between the ophthalmologist and photographer (κ = 0.96, 95% CI 0.95 to 0.97). The image quality of Aurora was sufficient for reliable assessment according to both graders in 84-88% of the cases. CONCLUSION: The Optomed Aurora fundus camera seems appropriate for DR screening. The sufficient image quality and high diagnostic accuracy for DR grading are supportive for a less expensive and easily transportable screening system for DR. Immediate image grading carried out by a photographer would further improve and speed up the screening process in all settings.

Bulbar Redness and Dry Eye Disease: Comparison of a Validated Subjective Grading Scale and an Objective Automated Method.

SIGNIFICANCE: In this study, assessments of conjunctival redness were performed to evaluate whether patients with or without dry eye disease (DED) could be discriminated based on this measure. Our findings suggest that subjectively grading redness by quadrant, as opposed to automated en face measurements, may be more suitable for this purpose. PURPOSE: This study aimed to quantify bulbar redness using the validated bulbar redness (VBR) grading scale and an automated objective method (Oculus Keratograph 5M; K5M) in participants with DED and non-DED controls. METHODS: Participants with DED (Ocular Surface Disease Index score ≥20 and Oxford scale corneal staining ≥2) and controls (Ocular Surface Disease Index score ≤10 and corneal staining ≤1) attended two study visits. In part 1A of visit 1, baseline bulbar redness was graded with the VBR scale in each conjunctival quadrant of both eyes, followed by automated measurements of temporal and nasal redness with the K5M. This was immediately followed by part 1B, during which a topical vasoconstrictor was instilled into both eyes. Redness assessments were repeated 5 and 30 minutes after instillation with both instruments. Participants returned 14 days later for visit 2, where the same assessments as for visit 1A were repeated. RESULTS: Seventy-four participants (50 DED and 24 controls) completed the study. There were statistically significant differences in redness between the DED and control groups when assessed with the VBR scale (14/16 comparisons; all, P < .05), whereas no significant differences in K5M-derived redness between the DED and non-DED groups were found at any location or time point. Both subjective and objective instruments detected statistically significant reductions in redness 5 and 30 minutes after instillation of the vasoconstrictor (all, P < .01). CONCLUSIONS: Although both subjective and objective instruments were sensitive to detecting changes in redness induced by vasoconstriction, statistically significant differences in redness between DED and control groups were only found using the VBR scale.

Influence of Artificial Tears on Keratometric Measurements in Cataract Patients.

PURPOSE: To assess the influence of artificial tears of different viscosity on K-readings prior to cataract surgery. DESIGN: Prospective randomized crossover, before-and-after clinical study. METHODS: Setting: Department of Ophthalmology, Medical University of Vienna. PATIENT POPULATION: A total of 123 eyes of 80 patients prior to cataract surgery were assigned to 2 groups based on normal and dry eyes. INTERVENTION: Two native baseline keratometries were followed by instillation of either high- or low-viscosity eye drops. Keratometry was repeated 30 seconds, 2 minutes, and 5 minutes after instillation. MAIN OUTCOME MEASURES: Influence of eye drops of different viscosity in normal and dry eyes on short time K-readings. RESULTS: Repeatability between native baseline measurements was high (standard deviation = 0.02 mm in normal and in dry eyes). In normal and dry eyes, a statistically significant increase in measurement variability after instillation of both low-viscosity and high-viscosity eye drops was observed (P < .01). Measurement variability was most pronounced between baseline measurement and 30 seconds and diminished over time. Variability of K-readings appeared higher in dry eyes compared with normal eyes. Astigmatism changed more than 0.5 diopters in 13.2% of normal eyes and 34.4% in dry eyes using eye drops of high viscosity. CONCLUSION: Tear film-stabilizing eye drops prior to keratometry measurements influenced K-readings significantly, especially in dry eyes. A time period of more than 5 minutes should be allowed to pass after instillation of eye drops. The higher the viscosity of the eye drops, the stronger the influence and the longer its persistence.

Red reflex technique training simulator in newborns / Simulador para o treinamento da técnica do reflexo vermelho em recém-nascidos

Abstract: Introduction: The Red Reflex Test (RRT) consists of visualizing the reflection that light causes in the retina when it passes through the pupil. It is a screening test for pathologies that can lead to blindness, which still have great social and economic impact on families and the government. Teaching through simulators allows students and health professionals to acquire and improve their clinical skills. Objective: The aim of the study is to develop a low-cost dummy, 3D printed and based on the Arduino platform, for the training of the red reflex technique (RRT) in newborns and evaluate its educational effectiveness. Method: A RRT dummy was presented to 7 expert judges: 6 pediatricians and 1 ophthalmologist to evaluate its applicability in medical learning. For this purpose, they used a 14-item Likert scale of 5 points. Subsequently, 40 individuals participated in a course: 33 medical students, 5 pediatric residents, a nurse and a general physician. The participants were randomly assigned to two groups: control (CG) and experimental (EG) group. Each group consisted of 20 participants. The EG went through 4 stages: 1) theoretical background; 2) handling of the simulator; 3) simulated clinical practice and; 4) evaluation in real-life patients. Whereas the CG went through the following teaching methodological processes: 1) theoretical background; 2) direct training in real-life patients and; 4) practical evaluation in a real-life patient. After each respective group intervention, both groups were assessed on their learning in 40 newborns at Santa Casa de Misericórdia do Pará Foundation in Belém, state of Pará, Brazil. Results: At the judges' evaluation regarding the simulator positive items (design, similarity, interest, relevance, content, memorization, didactics, previous reminiscence, comprehension and application), 49.2% answered 'strongly agree' and 44.4%, 'agree'. Regarding the negative questions (difficulty in understanding, information overload, abstraction, difficulty in handling and clarity of operation), 40.0% answered 'strongly disagree', and 57.1%, 'disagree'. The judges were 94.9% favorable to the use of the simulator in medical education. However, comparing the two groups of students, regarding the time of exam, the results showed no statistically significant difference (p-value = 0.29). Conclusions: The dummy showed its applicability for the learning of RRT, with the advantage of being able to perform the exam without having to disturb a real-life patient.

Resumo: Introdução: O Teste do Reflexo Vermelho (TRV) consiste em visualizar o reflexo que a luz causa na retina ao passar pela pupila. Dessa forma, o TRV tria patologias que levam à cegueira e pode reduzir o impacto social e econômico das famílias e do governo. O ensino por meio de simuladores permite que estudantes e profissionais de saúde adquiram e melhorem as habilidades clínicas. Objetivos: Este estudo teve como objetivos desenvolver um manequim de baixo custo, impresso em 3D e baseado na plataforma Arduino, para o treinamento do TRV em recém-nascidos e avaliar a eficácia educacional desse exame. Métodos: Um manequim do TRV foi apresentado a sete juízes especialistas - seis pediatras e um oftalmologista - que avaliaram a aplicabilidade do teste na aprendizagem médica. Para isso, utilizaram a escala Likert de 14 itens de 5 pontos. Posteriormente, 40 participantes participaram de um curso: 33 estudantes de Medicina, cinco residentes em pediatria, uma enfermeira e um médico generalista. Dividiram-se aleatoriamente os participantes em dois grupos: controle (GC) e experimental (GE). Cada grupo foi composto por 20 participantes. Submeteu-se o GC ao ensino convencional em pacientes reais. O GE passou por quatro etapas: 1. fundamentação teórica, 2. manipulação do simulador, 3. prática clínica simulada e 4. avaliação nos pacientes reais. No GC, adotaram-se os seguintes passos: 1. fundamentação teórica, 2. treinamento direto em pacientes reais e 3. avaliação em pacientes reais. Após a intervenção de cada grupo, os dois grupos foram avaliados quanto à aprendizagem em 40 recém-nascidos da Fundação Santa Casa de Misericórdia do Pará, em Belém, no Pará. Resultados: Na avaliação dos juízes em relação aos itens positivos para o simulador (design, similaridade, interesse, relevância, conteúdo, memorização, didática, reminiscência anterior, compreensão e aplicação), 49,2% afirmaram que concordavam fortemente e 44,4% mencionaram apenas que concordavam. Nas questões negativas (dificuldade de entendimento, sobrecarga de informação, abstração, dificuldade de manuseio e clareza de operação), 40,0% discordaram fortemente e 57,1% discordaram. Os juízes concordaram em 94,9% a favor do uso do simulador na educação médica. Porém, comparando os dois grupos de estudantes, em relação ao tempo de exame, os resultados não mostraram diferença estatisticamente significante (p = 0,29). Conclusão: O manequim mostrou aplicabilidade na aprendizagem do TRV, com a vantagem de realizar o exame sem que o paciente real fosse incomodado.