Algorithm of automatic identification of diabetic retinopathy foci based on ultra-widefield scanning laser ophthalmoscopy

AIM:To propose an algorithm for automatic detection of diabetic retinopathy(DR)lesions based on ultra-widefield scanning laser ophthalmoscopy(SLO).METHODS:The algorithm utilized the FasterRCNN(Faster Regions with CNN features)+ResNet50(Residua Network 50)+FPN(Feature Pyramid Networks)method for detecting hemorrhagic spots,cotton wool spots,exudates,and microaneurysms in DR ultra-widefield SLO.Subimage segmentation combined with a deeper residual network FasterRCNN+ResNet50 was employed for feature extraction to enhance intelligent learning rate.Feature fusion was carried out by the feature pyramid network FPN,which significantly improved lesion detection rates in SLO fundus images.RESULTS:By analyzing 1076 ultra-widefield SLO images provided by our hospital,with a resolution of 2600×2048 dpi,the accuracy rates for hemorrhagic spots,cotton wool spots,exudates,and microaneurysms were found to be 87.23%,83.57%,86.75%,and 54.94%,respectively.CONCLUSION:The proposed algorithm demonstrates intelligent detection of DR lesions in ultra-widefield SLO,providing significant advantages over traditional fundus color imaging intelligent diagnosis algorithms.

Deep-learning classifier with ultrawide-field fundus ophthalmoscopy for detecting branch retinal vein occlusion

AIM: To investigate and compare the efficacy of two machine-learning technologies with deep-learning(DL) and support vector machine(SVM) for the detection of branch retinal vein occlusion(BRVO) using ultrawide-field fundus images. METHODS: This study included 237 images from 236 patients with BRVO with a mean±standard deviation of age 66.3±10.6 y and 229 images from 176 non-BRVO healthy subjects with a mean age of 64.9±9.4 y. Training was conducted using a deep convolutional neural network using ultrawide-field fundus images to construct the DL model. The sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) and area under the curve(AUC) were calculated to compare the diagnostic abilities of the DL and SVM models. RESULTS: For the DL model, the sensitivity, specificity, PPV, NPV and AUC for diagnosing BRVO was 94.0%(95%CI: 93.8%-98.8%), 97.0%(95%CI: 89.7%-96.4%), 96.5%(95%CI: 94.3%-98.7%), 93.2%(95%CI: 90.5%-96.0%) and 0.976(95%CI: 0.960-0.993), respectively. In contrast, for the SVM model, these values were 80.5%(95%CI: 77.8%-87.9%), 84.3%(95%CI: 75.8%-86.1%), 83.5%(95%CI: 78.4%-88.6%), 75.2%(95%CI: 72.1%-78.3%) and 0.857(95%CI: 0.811-0.903), respectively. The DL model outperformed the SVM model in all the aforementioned parameters(P<0.001). CONCLUSION: These results indicate that the combination of the DL model and ultrawide-field fundus ophthalmoscopy may distinguish between healthy and BRVO eyes with a high level of accuracy. The proposed combination may be used for automatically diagnosing BRVO in patients residing in remote areas lacking access to an ophthalmic medical center.

Role of wide-field autofluorescence imaging and scanning laser ophthalmoscopy in differentiation of choroidal pigmented lesions

·AIM:Toevaluatethe diagnostic properties of wide-field fundus autofluorescence(FAF) scanning laser ophthalmoscope(SLO) imaging for differentiating choroidal pigmented lesions.·METHODS: A consecutive series of 139 patients were included, 101 had established choroidal melanoma with13 untreated lesions and 98 treated with radiotherapy.Thirty-eight had choroidal nevi. All patients underwent a full ophthalmological examination, undilated wide-field imaging, FAF and standardized US examination. FAF images and imaging characteristics from SLO were correlated with the structural findings in the two patient groups.·RESULTS: Mean FAF intensity of melanomas was significantly lower than the FAF of choroidal nevi. Only 1out of 38 included eyes with nevi touched the optic disc compared to 31 out of 101 eyes with melanomas. In 18 out of 101 melanomas subretinal fluid was seen at the pigmented lesion compared to none seen in eyes with confirmed choroidal nevi. In 'green laser separation', a trend towards more mixed FAF appearance of melanomas compared to nevi was observed. The mean maximal and minimal transverse and longitudinal diameters of melanomas were significantly higher than those of nevi.·CONCLUSION: Wide-field SLO and FAF imaging may be an appropriate non-invasive diagnostic screening tool to differentiate benign from malign pigmented choroidal lesions.

Adaptive optics scanning laser ophthalmoscopy in fundus imaging, a review and update

Adaptive optics scanning laser ophthalmoscopy（AOSLO） has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics（AO） and AO-SLO. Then it compares AO-SLO with conventional imaging methods（fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography） and other AO techniques（adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherence tomography）. Furthermore, an update of current research situation in AO-SLO is made based on different fundus structures as photoreceptors（cones and rods）, fundus vessels, retinal pigment epithelium layer, retinal nerve fiber layer, ganglion cell layer and lamina cribrosa. Finally, this review indicates possible research directions of AO-SLO in future.

Non-simulator-based techniques in teaching direct ophthalmoscopy for medical students: a systematic review

Non-simulator-based examination methods of the fundal examination have shown to be cost-effective.We reviewed different non-simulator-based direct fundoscopy examination methods used in undergraduate curricula and their outcomes.PubMed(MEDLINE) and Cochrane Database of Systematic Reviews were searched using standard Medical Subject Heading(MeSH) terms ophthalmoscopy,medical education,undergraduate medical education,medical student,educational assessment and learning.The search included publications until 28^(th)February 2019.We obtained 34 articles after screening abstracts;of them,12 articles were included in the qualitative synthesis.The studies were comprised of diverse teaching methods which included fundal photograph matching with corresponding eye,continuous education using community-based eye clinics,formal instructions and demonstrations prior to skills training,ophthalmoscopy skills practice using eye pathologies,teaching versus conventional ophthalmoscopy and group-based teaching.We concluded that non-simulator-based techniques such as use of fundal photograph matching of an eye of a volunteer,introduction to eye pathologies,smaller student groups and formal instructions with video demonstrations prior to skills training were highly effective in teaching direct ophthalmoscopy for undergraduate medical students.

AB038.Assessing a novel approach to teaching ophthalmoscopy to medical student

Background:To determine if practice using an online fundus photograph program results in a long-term increase in proficiency with the direct ophthalmoscope in medical students.Methods:This study was a prospective medical education trial.Students were enrolled to participate in an objective structured clinical examination(OSCE)using five patients with ocular findings.Students who matched a minimum of 6 discs 17 months prior to the study were assigned to the intervention group and were compared to students who did not participate in the exercise.Participants:46 second-year medical students at Queen’s University:15 in the intervention group,31 in the control group.Students were evaluated using the Queen’s University Ophthalmoscopy OSCE Checklist(QUOOC).Students were asked to calculate the cup-to-disc ratio,comment on disc margins and if there was any macular pathology.Students participated in a summative OSCE as part of the curriculum in which all students attempted to match fundus photographs.Results:Students in the intervention group performed significantly better on the QUOOC with a mean score of 78.3%(+/−4.2%)compared to the control who had a mean score of 69.4%[+/−4.2%(P=0.007)].The intervention group was significantly more accurate at matching optic nerve photographs with 100%(15/15)of the students correctly identifying the correct optic nerve on first attempt compared to 53.3%(16/30)in the control group(P=0.0014).Conclusions:The use of an online peer fundus photograph program leads to a long-term increase in examination technique,proficiency in ophthalmoscopy and accuracy at matching optic nerve photographs.

Retinal displacement after closure of idiopathic macular hole

Objective: To study the foveal displacement during the closure of idiopathic macular holes(MHs).Methods: Thirty-seven idiopathic MH patients treated by pars plana vitrectomy and internal limiting membrane peeling were studied prospectively.Locations of MH center and foveal pit were measured by optic coherence tomography.Retinal displacement was observed using confocal scanning laser ophthalmoscopy.Results: A total of 40 eyes were included in this study and MHs were closed in 37 eyes(92.5%).The confocal scanning laser ophthalmoscopy showed that all of the retinal capillaries in the superior, inferior, nasal and temporal sides of the MHs moved toward the optic nerve head(ONH).The optic coherence tomography results showed that the mean nasal displacements of foveal pits were(102.9±61.2),(109.6±53.1), and(137.0±52.0) μm at 3, 6 and 12 months, respectively.And the mean vertical displacements were(55.9±49.4),(61.4±57.8) and(67.8±54.3) μm, respectively.Post-operative foveal pits were located in the nasal side of the MH centers.The extension of retina and nasal to the MH were in opposite directions: the nasal hole margin moved toward the MH, but the retina located closer to the ONH moved toward the ONH.The fellow eyes of three patients developed into idiopathic MH during the follow-up period and operations were performed for all of the three patients.Conclusion: Our results showed that center of macula does not move when an idiopathic MH develops, but it moves toward ONH during closure of hole; thus, new fovea is in nasal side of original fovea.

Neuroretinitis: Update on a visual emergency and role of technology in its diagnosis

Neuroretinitis is one of the forms of optic neuritis characterized by swelling of optic nerve head and adjoining retinal nerve fiber layer resulting in a macular star configuration. The underlying pathophysiology involves increased permeability of disc vasculature, but the etiology is not fully defined. Neuroretinitis may occur due to an infectious process involving the disc, a postviral or autoimmune mechanism or sometimes idiopathic. Technological advances like ophthalmoscopy, slit-lamp examination, fluorescein angiography, magnetic resonance imaging and immunodiagnostic tests all come handily and are often imperative in making an accurate diagnosis. Conditions mimicking neuroretinitis include papilledema, anterior ischemic optic neuropathy, and infiltration of the optic disc by tumor and systemic hypertension. Neuroretinitis is usually a self-limited disorder with a good visual prognosis. Treatment of neuroretinitis is required only when there is an underlying infectious or inflammatory condition.

Ocular Toxoplasmosis: A Case Report

Report a case of a male patient with a macular scar compatible with ocular toxoplasmosis (OT) in right eye (RE) and review the relevant literature on this disease. A patient, who attended for a routine contact lens follow up, presented with amblyopic exotropia without any ocular disease. Best-corrected visual acuity of the affected eye was 20/40 with constant and mono-fixation exotropia. Ophthalmoscopic assessment revealed a macular scar compatible with OT. OT is the leading cause of infection in the posterior segment. Inactive cases could be asymptomatic and diagnosis requires a complete eye examination, providing a correct diagnosis and patient management.

Malaria Retinopathy among Under-Five Children with Severe and Uncomplicated Malaria in a Tertiary Health Institution in Southwest Nigeria: A Comparative Study

Introduction: Malaria retinopathy refers to retinal abnormalities unique to malaria resulting from prolonged parasitization by Plasmodium falciparum. Identifying these features and treating them promptly could prevent lethal complications of malaria. Therefore, this study was conducted to identify and compare retinal findings in severe and uncomplicated malaria. Methods: A cross-sectional study of 260 subjects was equally divided into two groups of severe and uncomplicated malaria. Direct ophthalmoscopy was done at recruitment for all subjects. Information on sociodemographics, physical examination, nutritional status, and retinal abnormalities were recorded. A p-value Results: There were 141 (54.2%) males and 70 (26.9%) aged between 13 - 24 months. Severe anaemia, multiple convulsions, prostration, and cerebral malaria were the predominant forms of severe malaria. Twenty-three (17.7%) subjects with severe malaria and none with uncomplicated malaria had retinopathy. Retinal whitening (17.7%), vessel changes (16.2%), and retinal haemorrhages (5.4%) were the major forms of retinopathy. Retinopathy occurred in 43.8% of those with cerebral malaria. Retinal whitening and vessel changes were significantly associated with multiple convulsions, cerebral malaria, and metabolic acidosis;retinal haemorrhage was associated with cerebral malaria and haemoglobinuria (p = 0.022) and vessel changes with hypoglycaemia (p = 0.037). Cerebral malaria was an independent predictor of retinal whitening (p = 0.004) and vessel changes (p = 0.008) while haemoglobinuria was an independent predictor of retinal haemorrhages (p = 0.007). Conclusion: Ophthalmoscopy is an important examination in children with severe malaria which could assist in early detection and with prompt treatment, reduce morbidities and mortalities.

Correlation Factor Analysis of Retinal Microvascular Changes in Patients With Essential Hypertension

Objectives To investigate correlation between retinal microvascular signs and essential hypertension classification. Methods The retinal microvascular signs in patients with essential hypertension were assessed with the indirect biomicroscopy lens, the direct and the indirect ophthalmoscopes were used to determine the hypertensive retinopathy grades and retinal arteriosclerosis grades. The rank correlation analysis was used to analysis the correlation these grades with the risk factors concerned with hypertension. Results Of 72 cases with essential hypertension, 28 cases complicated with coronary disease, 20 cases diabetes, 41 cases stroke, 17 cases renal malfunction. Varying extent retinal arterioscleroses were found in 71 cases, 1 case with retinal hemorrhage, 2 cases with retina edema, 4 cases with retinal hard exudation, 5 cases with retinal hemorrhage complicated by hard exudation, 2 cases with retinal hemorrhage complicated by hard exudation and cotton wool spot, 1 case with retinal hemorrhage complicated by hard exudation and microaneurysms, 1 case with retinal edema and hard exudation, 1 case with retinal microaneurysms, 1 case with branch retinal vein occlusion. The rank correlation analysis showed that either hypertensive retinopathy grades or retinal arteriosclerosis grades were correlated with risk factor lamination of hypertension （r=0.25 or 0.31, P 〈0.05）, other correlation factors included age and blood high density lipoprotein concerned about hypertensive retinopathy grades or retinal arteriosclerosis grades, but other parameters, namely systolic or diastolic pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, fasting blood glucose, blood urea nitrogen and blood creatinine were not confirmed in this correlation analysis （P 〉 0.05）. Conclusions Either hypertensive retinopathy grade or retinal arteriosclerosis grade is close with the hypertension risk factor lamination, suggesting that the fundus examination of patients with hypertension plays a important part in predicting the incidence of cardiovascular events.