Detection sensitivity of fluorescence lifetime imaging ophthalmoscopy for laser-induced selective damage of retinal pigment epithelium.

PURPOSE: To investigate the sensitivity of fluorescence lifetime imaging ophthalmoscopy (FLIO) to detect retinal laser spots by comparative analysis with other imaging modalities. METHODS: A diode laser with a wavelength of 514 nm was applied with pulse durations of 5.2, 12, 20, and 50 µs. The laser pulse energy was increased so that the visibility of the laser spot by slit-lamp fundus examination (SL) under the irradiator's observation covers from the subvisible to visible range immediately after irradiation. The irradiated areas were then examined by fundus color photography (FC), optical coherence tomography (OCT), fundus autofluorescence (AF), FLIO, and fluorescein angiography (FA). The visibility of a total of over 2200 laser spots was evaluated by two independent researchers, and effective dose (ED) 50 laser pulse energy values were calculated for each imaging modality and compared. RESULTS: Among examined modalities, FA showed the lowest mean of ED50 energy value and SL the highest, that is, they had the highest and lowest sensitivity to detect retinal pigment epithalium (RPE)-selective laser spots, respectively. FLIO also detected spots significantly more sensitively than SL at most laser pulse durations and was not significantly inferior to FA. AF was also often more sensitive than SL, but the difference was slightly less significant than FLIO. CONCLUSION: Considering its high sensitivity in detecting laser spots and previously reported potential of indicating local wound healing and metabolic changes around laser spots, FLIO may be useful as a non-invasive monitoring tool during and after minimally invasive retinal laser treatment.

Clinical and genetic features in autosomal recessive bestrophinopathy in Chinese cohort.

PURPOSE: To provide a genotype and phenotype characterization of the BEST1 mutation in Chinese patients with autosomal recessive bestrophinopathy (ARB) through multimodal imaging and next-generation sequencing (NGS). METHODS: Seventeen patients from 17 unrelated families of Chinese origin with ARB were included in a retrospective cohort study. Phenotypic characteristics, including anterior segment features, were assessed by multimodal imaging. Multigene panel testing, involving 586 ophthalmic disease-associated genes, and Sanger sequencing were performed to identify disease-causing variants. RESULTS: Among 17 ARB patients, the mean follow-up was 15.65 months and average onset age was 30.53 years (range: 9-68). Best corrected visual acuity ranged from light perception to 0.8. EOG recordings showed a typically decreased Arden ratio in 12 patients, and a normal or slightly decreased Arden ratio in two patients. Anterior features included shallow anterior chambers (16/17), ciliary pronation (16/17), iris bombe (13/17), iridoschisis (2/17), iris plateau (1/17), narrow angles (16/17) and reduced axial lengths (16/17). Sixteen patients had multiple bilateral small, round, yellow vitelliform deposits distributed throughout the posterior pole, surrounding the optic disc. Initial diagnoses included angle-closure glaucoma (four patients), Best disease (three patients), and central serous chorioretinopathy secondary to choroidal neovascularization (CNV) (one patient), with the remainder diagnosed with ARB. Fourteen patients underwent preventive laser peripheral iridotomy, four of whom also received combined trabeculectomy and iridotomy in both eyes for uncontrolled intraocular pressure. One patient received intravitreal conbercept for CNV. Overall, 15 distinct disease-causing variants of BEST1 were identified, with 14 (82.35%) patients having missense mutations. Common mutations included p. Arg255-256 and p. Ala195Val (both 23.68%), with the most frequent sites in exons 7 and 5. CONCLUSIONS: This study provides a comprehensive characterization of anterior segment and genetic features in ARB, with a wide array of morphological abnormalities. Findings are relevant for refining clinical practices and genetic counseling and advancing pathogenesis research.

A method to determine the retinal radiant exposure caused by ophthalmoscopy.

PURPOSE: To introduce a method to calculate retinal irradiance caused by ophthalmoscopy. This may be used to verify the compliance of an instrument with the radiation limits set by light hazard standards. The proposed method is simpler to use and less prone to error than the methods currently found in the light hazard standards. METHODS: The optical properties of the standardised human eye, specified by current light hazard standards, are used to calculate the magnification of an aerial image of the retinal surface by the combination of the optics of eye and the auxiliary lens used for ophthalmoscopy. The magnification of the aerial image is used to transform the spectral irradiance of the instrument illumination source to retinal irradiation values. The spectral irradiance of the instrument illumination source can be measured directly as the aerial image is located in the focal plane of the viewing optics of the ophthalmoscope. These spectral irradiation values are then processed using weightings specified by current light hazard standards to give a weighted irradiance which is converted directly to a retinal irradiance value. RESULTS: A single formula is provided to calculate the retinal irradiance using the processed, measured spectral irradiance values of the illumination source. CONCLUSION: The new method introduced here is simpler to use, requires fewer physical measurements and is less likely to introduce measurement error than that currently found in light hazard standards. The only physical measurement that needs to be taken is the illumination source spectral irradiance measured in the viewing focal plane of the instrument. These values are weighted using given in the light hazard standards. The combined irradiance value is then converted to retinal irradiance using the formula given in this paper.

Effectiveness of simulation models and digital alternatives in training ophthalmoscopy: A systematic review.

PURPOSE: Traditional direct ophthalmoscopy (TDO) is the oldest method of fundus examination; however, it has fallen out of use due to its technical difficulty and limitations to clinical utility, amidst the advent of potentially better options. A spectrum of new technologies may help in addressing the shortcomings of TDO: simulation mannequins with non-tracked TDO, simulation models with tracked TDO, and smartphone ophthalmoscopy (SFO). METHODOLOGY: A systematic search of PubMed, Embase, and Cochrane databases for all studies evaluating usage of simulation mannequins/models and SFO in ophthalmology education was performed, from inception till April 2023 with no language restriction. We ensured that we included all possible relevant articles by performing backward reference searching of included articles and published review articles. RESULTS: We reviewed studies on non-tracked TDO (n = 5), tracked TDO (n = 3) and SFO (n = 12). Non-tracked TDO and SFO were superior in training competency relative to control (TDO on real eyes). Intriguingly, tracked TDO was non superior to controls. SFO appears to enhance the learning effectiveness of ophthalmoscopy, due to real-time projection of the retina view, permitting instantaneous and targeted feedback. Learners reported improved ergonomics, including a wider field of view and more comfortable viewing distance. Retention of images and recordings permitted the audit of learning and paves the way for storage of such images in patients' electronic medical record and rapid dissemination for specialist referral. CONCLUSIONS: Smartphone ophthalmoscopy (SFO) permits integration of both the practice and learning of ophthalmoscopy, and the auditing of both. These advantages over traditional methods (with simulation or otherwise) may lead to a paradigm shift in undergraduate ophthalmology education. However, the nascency of SFO necessitates preservation of traditional techniques to tide through this period of transition.

Structural and functional analysis of retinal vasculature in HANAC syndrome with a novel intronic COL4A1 mutation.

PURPOSE: Mutations of the COL4A1 gene, a major structural protein of vessels, may cause hereditary angiopathy with nephropathy, aneurysms and muscle cramps (HANAC) syndrome. The vascular structure and function of patients with HANAC is poorly known. Here, we report a family with HANAC syndrome associated to a previously unreported mutation in COL4A1. The structure and function of retinal vessels were detailed by adaptive optics ophthalmoscopy (AOO) and optical coherence tomography (OCT) angiography. METHODS: Clinical data from six affected individuals (43 to 72 years old) from a single family comprising two generations were collected. Imaging charts including conventional fundus imaging, OCT-angiography and AOO in static and dynamic (flicker) mode were reviewed. DNA sequencing was done in the proband. RESULTS: DNA sequencing of the proband revealed a heterozygous deletion of COL4A1 (NM_001845) at position 1120 in the intron 20 resulting in the loss of splicing donor site for exon 20 (c.1120 + 2_1120 + 8del heterozygote). Four patients had arterial hypertension, and three had kidney dysfunction, one of which under dialysis. By fundus examination, five had typical retinal arteriolar tortuosity with arteriolar loops. Wall-to-lumen ratio of arteries was within normal limits, that is, lower than expected for hypertensive patients. Several foci of arteriolar irregularities were noted in the two oldest patients. In three affected subjects, evaluation of the neurovascular coupling showed a higher flicker-induced vasodilation than a control population (6 % to 11 %; n < 5 %). CONCLUSIONS: Structural and dynamic analysis of retinal vessels in a HANAC family bearing a previously unreported intronic COL4 mutation was done. In addition to arteriolar tortuosity, we found reduced wall-to-lumen ratio, arteriolar irregularity and increased vasodilatory response to flicker light. These abnormalities were more marked in the oldest subjects. This abnormal flicker response affected also non-tortuous arteries, suggesting that microvascular dysfunction extends beyond tortuosity. Such explorations may help to better vascular dysfunction related to HANAC and hence better understand the mechanisms of end-organ damage.

An optimized method for retrograde labelling and quantification of rabbit retinal ganglion cells.

Rabbits are a commonly used animal model in glaucoma research, but their application has been limited by the techniques used to assess optic nerve injury (ONI). Our study devised an optimized method for retrograde labelling and analysing rabbit retinal ganglion cells (RGCs). This method involved improvements over the conventional method regarding the stereotaxic device, the positioning of superior colliculi, the target of axonal tracer delivery, and the visualization and analysis of labelled RGCs. To evaluate its efficacy, eight New Zealand White rabbits were divided into naïve and ONI groups. Unilateral limbal buckling surgery was performed in each animal of the ONI group to induce chronic ocular hypertension (OHT). The animals of both groups were injected with indocyanine green (ICG) into the interstice between the superior colliculus and occipital lobe on each side of the brain, and their eyes were examined by confocal scanning laser ophthalmoscopy (CSLO) after 48 h. The acquired images were then analysed to quantify the number of ICG-labelled RGCs in these eyes and their loss induced by OHT. To verify the identity and changes of the labelled RGCs, the retinas of the rabbits were subjected to immunofluorescence analyses. In addition, three animals were subjected to a second ICG labelling after 12 months to determine the influence of this procedure on the long-term viability of the labelled RGCs. Our results showed that ICG-labelled RGCs were detected by CSLO throughout the retinas of all animals. These RGCs showed a distinctly higher density below the ONH and were defective in sectorial areas in OHT eyes. Their average number in the cell counting area was 3989.2 ± 414.2 and 4023.3 ± 603.4 in the right and left eyes, respectively, of the naïve animals and 2590.9 ± 1474.2 and 3966.7 ± 24.0 in the OHT and non-OHT eyes, respectively, of the ONI animals. Immunofluorescence analyses showed positive staining with Brn3a and RBPMS in the ICG-labelled RGCs and sectorial defects of the cells in the OHT eyes, similarly as observed by CSLO. The second ICG labelling after 12 months in three animals showed no appreciable changes in RGC density compared with the first one. In summary, the optimized method of rabbit RGC retrograde labelling is reliable and accurate in both naïve and ONI animals and offers an approach for longitudinal observation of RGCs in the same eyes, which suggests its potential as a powerful tool for glaucoma and optic nerve research.

Optogenetic therapy restores retinal activity in primate for at least a year following photoreceptor ablation.

All retina-based vision restoration approaches rely on the assumption that photoreceptor loss does not preclude reactivation of the remaining retinal architecture. Whether extended periods of vision loss limit the efficacy of restorative therapies at the retinal level is unknown. We examined long-term changes in optogenetic responsivity of foveal retinal ganglion cells (RGCs) in non-human primates following localized photoreceptor ablation by high-intensity laser exposure. By performing fluorescence adaptive optics scanning light ophthalmoscopy (AOSLO) of RGCs expressing both the calcium indicator GCaMP6s and the optogenetic actuator ChrimsonR, it was possible to track optogenetic-mediated calcium responses in deafferented RGCs over time. Fluorescence fundus photography revealed a 40% reduction in ChrimsonR fluorescence from RGCs lacking photoreceptor input over the 3 weeks following photoreceptor ablation. Despite this, in vivo imaging revealed good cellular preservation of RGCs 3 months after the loss of photoreceptor input, and histology confirmed good structural preservation at 2 years. Optogenetic responses of RGCs in primate persisted for at least 1 year after the loss of photoreceptor input, with a sensitivity index similar to optogenetic responses recorded in intact retina. These results are promising for all potential therapeutic approaches to vision restoration that rely on preservation and reactivation of RGCs.

The yield of ophthalmoscopy as a screening tool for intracranial pathology in pediatric headache.

Headache is a common complaint in children who present at the pediatric emergency department (PED). Serious conditions such as intracranial tumors and idiopathic intracranial hypertension (IIH) should be rapidly ruled out. Ophthalmoscopy for the presence of papilledema has long been considered critical to the assessment of headaches in children; however, the yield of this procedure is poorly validated. This retrospective study implemented a computerized search of the medical records of a single tertiary center to identify all children aged 2-18 years who presented at the PED complaining of headache between 2007 and 2017. The clinical, demographic, radiographic, and laboratory data were analyzed. Of the 948 children aged 2-18 years who presented at the PED complaining of headache, 536 had an ophthalmoscopy examination carried out by an ophthalmologist. Forty-one had papilledema, of whom 7 had an intracranial tumor, 15 had IIH, and 9 had optic nerve head drusen. Of the 495 children without papilledema, 3 had intracranial tumor, and 11 had IIH. The sensitivity and specificity of papilledema for the diagnosis of intracranial tumor were 70% and 93.5%, respectively, with an NPV and PPV of 99.4% and 17.1%, respectively. The sensitivity and specificity of papilledema for the diagnosis of intracranial pathology in general were 61.1% and 96.2%, respectively, with an NPV and PPV of 97.2% and 53.7%, respectively.  Conclusion: Assessment by ophthalmoscopy for papilledema in children presenting to the PED with headache had high sensitivity and high specificity, thus reinforcing the importance of ophthalmoscopy as a screening tool in these children. What is Known: • Headache is a common complaint in children. Serious intracranial pathologies need to be rapidly excluded. • Ophthalmoscopy for the presence of papilledema is commonly used as a screening tool for intracranial pathology, but this procedure is poorly validated. What is New: • Ophthalmoscopy for the assessment of papilledema in children who present with headache to the pediatric emergency department is shown to exhibit sensitivity and specificity for the diagnosis of intracranial pathology.

Revisiting the oil droplet sign in keratoconus: Utility for early keratoconus diagnosis and screening.

PURPOSE: An annular dark shadow (ADS) reflex has been observed while performing direct ophthalmoscopy on subjects with keratoconus. This study describes a method that may serve as a diagnostic technique for early keratoconus and may be used as a quantitative measure of severity. METHODS: Healthy keratoconic subjects and keratoconus suspects underwent corneal tomography and a full ocular examination. Keratoconus severity was graded based on Belin ABCD criteria. An iPhone camera was connected to a direct ophthalmoscope to take a picture of the eye. The height of the ASD was measured using the AutoCAD software. Differences between subject groups were evaluated by chi-squared and Mann-Whitney tests. Spearman correlation compared ocular parameters and the height of the ADS. A multiple stepwise linear regression was used to predict the height of the ADS based on clinical parameters. RESULTS: Fifty-eight subjects participated in this study: 37 healthy controls (37 eyes) and 21 keratoconics or keratoconus suspects (37 eyes). The ADS was present in all keratoconic and keratoconus-suspect eyes but in none of the controls. The height of the ADS was significantly correlated with keratoconus severity. Front corneal surface root mean square of higher order aberrations, sphere and anterior radius of curvature from the front apex curve are significant predictors of the height of the ADS. CONCLUSIONS AND RELEVANCE: The ADS may be a useful method to diagnose keratoconus and keratoconus-suspect cases and serve as a grading and follow-up method for tracking disease severity.

Multi-scale Bottleneck Residual Network for Retinal Vessel Segmentation.

Precise segmentation of retinal vessels is crucial for the prevention and diagnosis of ophthalmic diseases. In recent years, deep learning has shown outstanding performance in retinal vessel segmentation. Many scholars are dedicated to studying retinal vessel segmentation methods based on color fundus images, but the amount of research works on Scanning Laser Ophthalmoscopy (SLO) images is very scarce. In addition, existing SLO image segmentation methods still have difficulty in balancing accuracy and model parameters. This paper proposes a SLO image segmentation model based on lightweight U-Net architecture called MBRNet, which solves the problems in the current research through Multi-scale Bottleneck Residual (MBR) module and attention mechanism. Concretely speaking, the MBR module expands the receptive field of the model at a relatively low computational cost and retains more detailed information. Attention Gate (AG) module alleviates the disturbance of noise so that the network can concentrate on vascular characteristics. Experimental results on two public SLO datasets demonstrate that by comparison to existing methods, the MBRNet has better segmentation performance with relatively few parameters.

Practical applications of vitreous imaging for the treatment of vitreous opacities with YAG vitreolysis.

PURPOSE: To demonstrate the methodology and efficacy of using scanning laser ophthalmoscopy (SLO) and dynamic optical coherence tomography (OCT) to identify and treat symptomatic vitreous floaters using yttrium-aluminum garnet laser vitreolysis (YLV). METHODS: This is a case series highlighted from a cross sectional retrospective study conducted at the Vitreous Retina Macula Specialists of Toronto. Forty eyes from thirty-five patients were treated with YLV between November 2018 and December 2020 for symptomatic floaters and imaged with SLO and dynamic OCT. Patients were re-treated with YLV if they reported ongoing significant vision symptoms during follow-up which correlated to visible opacities on exam and or imaging. Three cases will be highlighted to present the practical applications of SLO and dynamic OCT imaging for YLV treatment. RESULTS: Forty treated eyes were enrolled in this study, with twenty-six eyes (65%) requiring at least one repeat YLV treatment following the first treatment due to ongoing symptomatic floaters. Following the first YLV, there was a significant improvement in overall mean best corrected visual acuity compared to before treatment (0.11 ± 0.20 LogMAR units vs. 0.14 ± 0.20 LogMAR units, p = 0.02 (paired t test)). Case 1 demonstrates a dense, solitary vitreous opacity that has been localized with dynamic OCT imaging to track its movements and retinal shadowing with the patient's eye movements. Case 2 shows the utility of adjusting the fixation target to monitor the movement of vitreous opacities in real-time. Case 3 exhibits an association between decreased symptom burden and vitreous opacity density after YLV. CONCLUSION: Image-guided YLV facilitates the localization and confirmation of vitreous opacities. SLO and dynamic OCT of the vitreous can provide a real-time evaluation of floater size, movement, and morphology, to help clinicians target treatment and monitoring of symptomatic floaters.

Fundoscopy use in neurology departments and the utility of smartphone photography: a prospective prevalence and crossover diagnostic accuracy study amongst neurology inpatients.

BACKGROUND AND PURPOSE: Although fundoscopy is a crucial part of the neurological examination, it is challenging, under-utilized and unreliably performed. The aim was to determine the prevalence of fundus pathology amongst neurology inpatients and the diagnostic accuracy of current fundoscopy practice compared with systematic screening with smartphone fundoscopy (SF) and portable non-mydriatic fundus photography (NMFP). METHODS: This was a prospective cross-sectional surveillance and diagnostic accuracy study on adult patients admitted under neurology in an Australian hospital. Inpatients were randomized to initial NMFP (RetinaVue 100, Welch Allyn) or SF (D-EYE) followed by a crossover to the alternative modality. Images were graded by neurology doctors, using telemedicine consensus neuro-ophthalmology NMFP grading as the reference standard. Feasibility parameters included ease, comfort and speed. RESULTS: Of 79 enrolled patients, 14.1% had neurologically relevant pathology (seven, disc pallor; one, hypertensive retinopathy; three, disc swelling). The neurology team performed direct ophthalmoscopy in 6.6% of cases and missed all abnormalities. SF had a sensitivity of 30%-40% compared with NMFP (45.5%); however, it had a lower rate of screening failure (1% vs. 13%, p < 0.001), a shorter examination time (1.10 vs. 2.25 min, p < 0.001) and a slightly higher patient comfort rating (9.2 vs. 8/10, p < 0.001). CONCLUSION: Our study demonstrates a clinically significant prevalence of fundus pathology amongst neurology inpatients which was missed by current fundoscopy practices. Portable NMFP screening appears more accurate than SF, whilst both are diagnostically superior to routine fundoscopic practice, feasible and well tolerated by patients.

Application of a 3D-printed eye model for teaching direct ophthalmoscopy to undergraduates.

PURPOSE: This study aims to design an eye model that can simulate the fundus for teaching direct ophthalmoscopy and to evaluate its effectiveness. METHODS: We first used 3D printing materials to make an eye model and then randomly assigned 92 undergraduates into group A (model-assisted training group) and group B (traditional training group) to test our model. After the same training time, real patients were used to test the students, with 120 s as the examination time limit. We recorded the students' ability to clearly see the optic disk, the time to determine the cup-to-disk ratio, and whether they were correct. RESULTS: Forty-three students in group A (93.48%) successfully saw the fundus, while 21 in group B (45.65%) succeeded. The difference between the two groups was 47.83% (95% confidence interval, 29.59-66.07%, P < 0.0001). The median time to see the fundus was 29s (95% confidence interval 23-45 s) in group A, while an estimated minimum time in group B was 80 s, indicating that group A was significantly faster than group B (P < 0.0001). CONCLUSIONS: This 3D-printed eye model significantly improved the students' study interest, study efficiency, and study results and is worthy of being promoted.

Factors affecting image magnification in indirect ophthalmoscopy with Volk or similar lenses and a biomicroscope.

PURPOSE: To explore the factors affecting the linear magnification of the intermediate fundus image during indirect ophthalmoscopy with a slit-lamp biomicroscope. METHODS: A simple paraxial model, based on a 'reduced' eye and a 'thin' ophthalmoscopy lens, is used to develop equations showing the effects of the power and ametropia of the eye, and the equivalent power and position of the ophthalmoscopy lens on fundus magnification. Predicted magnifications are compared with practical results found in earlier published experimental studies, which used Volk ophthalmoscopy lenses in conjunction with physical model eyes with adjustable levels of axial ametropia. RESULTS: The model's magnification predictions, as a function of the eye's ametropia, are in good agreement with previous experimental measurements, provided that the equivalent powers of the Volk lenses are used rather than their labelled nominal powers. Magnification values typically change by approximately ±10% over the practical range of each parameter if other parameters are held constant. In particular, normal variations in the equivalent power of the adult emmetropic eye result in magnifications which range from about 90-120% of the nominal value given for an eye power of +60.00 D. It is demonstrated that the recommended working distances for different powers of Volk ophthalmoscopy lenses approximate optimal matching between the various pupils of the eye-Volk lens-slit-lamp biomicroscope system. CONCLUSIONS: All the parameters considered have marked effects on magnification. The magnification values quoted by manufacturers can be regarded as only approximations of those which may be found in practice. Better estimates of magnification can be obtained by inserting the appropriate parameter values into the equations derived in this paper, using, where appropriate, the equivalent power of the indirect ophthalmoscopy lens, rather than the lens' labelled, 'nominal' power.

Investigating Biomarkers for USH2A Retinopathy Using Multimodal Retinal Imaging.

Pathogenic mutations in USH2A are a leading cause of visual loss secondary to non-syndromic or Usher syndrome-associated retinitis pigmentosa (RP). With an increasing number of RP-targeted clinical trials in progress, we sought to evaluate the photoreceptor topography underlying patterns of loss observed on clinical retinal imaging to guide surrogate endpoint selection in USH2A retinopathy. In this prospective cross-sectional study, twenty-five patients with molecularly confirmed USH2A-RP underwent fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT) and adaptive optics scanning laser ophthalmoscopy (AOSLO) retinal imaging. Analysis comprised measurement of FAF horizontal inner (IR) and outer (OR) hyperautofluorescent ring diameter; SD-OCT ellipsoid zone (EZ) and external limiting membrane (ELM) width, normalised EZ reflectance; AOSLO foveal cone density and intact macular photoreceptor mosaic (IMPM) diameter. Thirty-two eyes from 16 patients (mean age ± SD, 36.0 ± 14.2 years) with USH2A-associated Usher syndrome type 2 (n = 14) or non-syndromic RP (n = 2) met the inclusion criteria. Spatial alignment was observed between IR-EZ and OR-ELM diameters/widths (p < 0.001). The IMPM border occurred just lateral to EZ loss (p < 0.001), although sparser intact photoreceptor inner segments were detected until ELM disruption. EZ width and IR diameter displayed a biphasic relationship with cone density whereby slow cone loss occurred until retinal degeneration reached ~1350 µm from the fovea, beyond which greater reduction in cone density followed. Normalised EZ reflectance and cone density were significantly associated (p < 0.001). As the strongest correlate of cone density (p < 0.001) and best-corrected visual acuity (p < 0.001), EZ width is the most sensitive biomarker of structural and functional decline in USH2A retinopathy, rendering it a promising trial endpoint.

Building Clinical Skills Teaching Materials: A Study of Cognitive Task Analysis Versus Free Recall Instruction to Teach Canine Indirect Ophthalmoscopy.

Ophthalmoscopy is a core component of a complete ophthalmic examination. Due to its complex technical aspects and patients becoming uncooperative if the procedure is prolonged, it can be a difficult skill for a novice to learn and develop proficiency in. Skills instruction is typically provided by subject matter experts (SMEs) through free recall without an agreed-upon instructional framework. This can lead to unintentional omission of essential steps and knowledge required to perform skills correctly. Cognitive task analysis (CTA) allows for construction of standardized instructional protocols that encompass the knowledge and skills experts apply when performing tasks. The objectives of this study were to (a) develop a CTA-based teaching protocol for canine indirect ophthalmoscopy and (b) compare the steps verbalized or demonstrated by SMEs during free recall instruction versus those ultimately identified by CTA. Four SMEs participated in free recall instructional sessions and interviews used for the development of a CTA-based teaching protocol for novice learners. The CTA-based protocol identified 66 steps and sub-steps considered essential for successfully performing canine indirect ophthalmoscopy. During instructional sessions, SMEs on average failed to verbalize 57.1% of clinical knowledge steps, did not verbalize or demonstrate 68.3% and 9.5% of action steps, and did not verbalize or demonstrate 73.2% and 40.4% of decision steps, respectively. This study demonstrates that SMEs teaching indirect ophthalmoscopy by free recall may unintentionally omit important steps, suggesting that compared with free recall, CTA may generate more comprehensive and thus potentially more effective instructional materials for teaching technical skills in veterinary medicine.

Automatic Diagnosis of Diabetic Retinopathy Stage Focusing Exclusively on Retinal Hemorrhage.

Background and Objectives: The present study evaluated the detection of diabetic retinopathy (DR) using an automated fundus camera focusing exclusively on retinal hemorrhage (RH) using a deep convolutional neural network, which is a machine-learning technology. Materials and Methods: This investigation was conducted via a prospective and observational study. The study included 89 fundus ophthalmoscopy images. Seventy images passed an image quality review and were graded as showing no apparent DR (n = 51), mild nonproliferative DR (NPDR; n = 16), moderate NPDR (n = 1), severe NPDR (n = 1), and proliferative DR (n = 1) by three retinal experts according to the International Clinical Diabetic Retinopathy Severity scale. The RH numbers and areas were automatically detected and the results of two tests-the detection of mild-or-worse NPDR and the detection of moderate-or-worse NPDR-were examined. Results: The detection of mild-or-worse DR showed a sensitivity of 0.812 (95% confidence interval: 0.680-0.945), specificity of 0.888, and area under the curve (AUC) of 0.884, whereas the detection of moderate-or-worse DR showed a sensitivity of 1.0, specificity of 1.0, and AUC of 1.0. Conclusions: Automated diagnosis using artificial intelligence focusing exclusively on RH could be used to diagnose DR requiring ophthalmologist intervention.

Prospective evaluation of medical student accuracy conducting direct ophthalmoscopy with an unmodified iPhone X.

PURPOSE: To evaluate fundus examination accuracy of medical students when using an unmodified iPhone X or a direct ophthalmoscope in comparison to a staff ophthalmologist's retinal examination. METHODS: In this prospective comparative analysis, patients underwent dilated fundus examination by novice medical trainees using either an unmodified iPhone X or standard direct ophthalmoscope. The primary outcome was the mean difference and degree of agreement in cup-to-disc ratio between student examination and the staff ophthalmologist's cup-to-disc observation. RESULTS: A total of 18 medical students conducted 230 retinal examinations, 117 with the iPhone X and 113 with the direct ophthalmoscope. A greater proportion of students were unable to report cup-to-disc ratio using the iPhone X (81.2%) vs direct ophthalmoscope (30.1%). Student examination of cup-to-disc ratio led to a systematic bias (95% limits of agreement) of + 0.16 (-0.22 to + 0.54) and + 0.10 (-0.36 to + 0.56) with the iPhone X and direct ophthalmoscope, respectively. iPhone X and direct ophthalmoscope student observation concordance for optic disc colour (88.7 and 82.4%, respectively) and contour (68.3 and 74.2%, respectively) demonstrated low agreement with staff ophthalmologist findings. Student iPhone X observations demonstrated lower agreement with staff findings compared to direct ophthalmoscope observations for spontaneous venous pulsations (Cohen's Kappa = -0.044 vs 0.099). CONCLUSION: Amongst medical trainees, optic disc visualization using an unmodified iPhone X was inferior to the direct ophthalmoscope. When able to visualize the optic nerve head, there was no significant difference in reported cup-to-disc ratio between modalities. However, both modalities demonstrated poor reliability in comparison to staff ophthalmologist findings.

Analgesia for retinopathy of prematurity screening: A systematic review.

BACKGROUND AND AIMS: Premature neonates require regular ophthalmological examination, generally indirect ophthalmoscopy, to screen for retinopathy of prematurity (ROP). Conventional analgesia is provided with topical anesthetic eyedrops and oral sugar solution, but neonates still experience significant pain. Here, the literature base was examined to evaluate the usefulness of other pharmacological analgesics. MATERIALS AND METHODS: A systematic review was undertaken, adhering to a PROSPERO preregistered protocol in accordance with PRISMA guidelines (identifier CRD42022302459). Electronic databases were searched for primary research articles on pharmacological pain interventions used for ROP screening in neonates. The primary outcome measure was pain scores recorded using validated pain scoring tools, with and without pharmacological interventions in neonates during eye examination. For analysis, studies were separated into two categories: topical anesthesia and alternative pharmacological treatments. RESULTS: Eleven studies met the inclusion criteria. Topical analgesia, oral paracetamol, and intranasal fentanyl were found to be effective in reducing the pain of eye examination. Oral morphine and inhaled nitrous oxide had no significant effect on premature infant pain profile (PIPP) scores during indirect ophthalmoscopy. DISCUSSION: In addition to topical anesthesia, premedication with oral paracetamol is recommended during screening examination for ROP. The routine use of fentanyl is not recommended due to the risk of potential side effects. Non-pharmacological measures, such as sweet oral solutions and comfort techniques should also be employed. Further research is required to determine whether the use of nitrous oxide has a role, and to develop a safe and effective analgesic strategy to fully ameliorate the pain of ROP screening.

Uncorrected refractive error in a university community.

Aims and Background: To determine the prevalence and pattern of uncorrected refractive error among staff of a Nigerian university. Patient and Methods: A cross-sectional study of consecutive staff of the University of Nigeria, Nsukka, Nigeria who presented for a 10-day free eye screening program. Demographic data and data on eye care awareness and knowledge were obtained with a combination of self-administered and interviewer-administered questionnaires in the English language. Clinical examinations included visual acuity taken at 6 m with Snellen's chart; noncontact tonometry; pen-torch eye examination; and direct ophthalmoscopy; autorefraction and subjective refraction. Results: One thousand and eighty-three subjects aged 18-82 years (mean = 44.1 ± 12.15 years) comprising 568 females (52.4%) and 515 males (47.6%) were screened. Eighty-nine subjects (8.3%) were visually impaired and five subjects (0.5%) were blind. Three hundred and fifty-six subjects were diagnosed with refractive error (356/1083; 32.9%), out of which 149 subjects (41.9%) were uncorrected. The prevalence of uncorrected refractive error in this study population was 13.8%. Astigmatism was the commonest refractive error, whereas hypermetropia and hypermetropic astigmatism were the commonest spherical and astigmatic errors, respectively. Conclusion: A significant proportion of the staff of this Nigerian university still lives with uncorrected refractive error with its attendant consequences. Regular eye checks should be done by the staff of our universities and effort should be intensified in eye care awareness creation among the populace, including the apparently enlightened communities.