Ultra-widefield Imaging Research Articles

Development and Validation of a Deep Learning Model to Predict Axial Length from Ultra-Wide Field Images

Development and Validation of a Deep Learning Model to Predict Axial Length from Ultra-Wide Field Images

Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography.

PurposeTo evaluate the clinical feasibility of peripheral chorioretinal imaging through a front prism on swept-source optical coherence tomography angiography (SS-OCTA).MethodsWe prospectively obtained en face OCTA images using SS-OCTA in 10 eyes of 10 healthy volunteers. For the peripheral chorioretinal imaging, the scanning laser passed and refracted through a 45°−90°−45° right-angle prism. We evaluated the qualitative and quantitative characteristics of chorioretinal vessels in the periphery.ResultsUsing peripheral chorioretinal imaging through a prism, the retinal vasculature was delineated to the equator on the OCTA images, and varices of the vortex vein ampullae were observed on choroidal OCT images. The 3 × 3-mm images revealed three-dimensional morphologies unique to the peripheral vasculature, such as the gap between retinal arterioles and venules in the superficial capillary plexus (SCP) and elliptical and greater lobules in the choriocapillaris layer. Compared with OCTA images obtained without the prism, those obtained through the prism demonstrated an approximately 1.24-fold increase in the lengths in the base apex direction, whereas the lengths in the perpendicular direction showed concordance. The peripheral vessel density (VD) in the inferior quadrant was lower than those in the other quadrants on the SCP and deep capillary plexus, whereas on the SCP images of the macula the lowest VD was observed in the temporal subfield.ConclusionsPeripheral chorioretinal imaging allowed us to generate ultra-widefield panoramic OCTA images and demonstrated morphologic characteristics unique to peripheral chorioretinal vessels.Translational RelevanceOCTA imaging through a front prism can be a technique for acquiring chorioretinal vasculature images in the periphery.

Quantitative analysis of retinal vasculature in normal eyes using ultra-widefield fluorescein angiography.

To quantify the area and density of retinal vascularity by ultra-widefield fluorescein angiography (UWFA). In a retrospective study, UWFA images were obtained using an ultra-widefield imaging device in 42 normal eyes of 42 patients. Central and peripheral steered images were used to define the edge of retinal vasculature by a certified grader. The length from the center of the optic disc to the edge of retinal vascularity (RVL) in each quadrant and the total retinal vascular perfusion area (RVPA) were determined by the grader using OptosAdvance software. The density of retinal vascularity (RVD) was quantified in different zones of central-steered images using Image J software. Among 42 healthy eyes, the values for mean RVL in each quadrant were 19.007±0.781 mm (superior), 18.467±0.869 mm (inferior), 17.738±0.622 mm (nasal) and 24.241±1.336 mm (temporal). The mean RVPA was 1140.117±73.825 mm2. The mean RVD of the total retina was 4.850%±0.638%. RVD varied significantly between different retina zones (P<0.001), and significant differences existed in the RVD values for total retinal area in patients over 50 years old compared to those under 50 years old (P=0.033). No gender difference was found. The UWFA device can be a promising tool for analyzing the overall retinal vasculature and may provide a better understanding of retinal vascular morphology in normal eyes. Aging may be related to lower RVD.

Developing portable widefield fundus camera for teleophthalmology: Technical challenges and potential solutions.

A portable, low cost, widefield fundus camera is essential for developing affordable teleophthalmology. However, conventional trans-pupillary illumination used in traditional fundus cameras limits the field of view (FOV) in a snapshot image, and frequently requires pharmacologically pupillary dilation for reliable examination of eye conditions. This minireview summarizes recent developments in alternative illumination approaches for widefield fundus photography. Miniaturized indirect illumination has been used to enable compact design for developing low cost, portable, widefield fundus camera. Contact mode trans-pars-planar illumination has been validated for ultra-widefield fundus imaging of infant eyes. Contact-free trans-pars-planar illumination has been explored for widefield imaging of adult eyes. Trans-palpebral illumination has been also demonstrated in a smartphone-based widefield fundus imager to foster affordable teleophthalmology.

Ultra-wide field imaging for ophthalmological evaluation of pregnant women with positive serology for toxoplasmosis

Ultra-wide field imaging for ophthalmological evaluation of pregnant women with positive serology for toxoplasmosis

The clinical use of ultra – Wide field imaging and intravenous fluorescein angiography in infants with retinopathy of prematurity

PurposeTo investigate the potential benefits and practicality of ultra – wide field (UWF) imaging and intravenous UWF fluorescein angiography (IV UWF – FA) in infants with retinopathy of prematurity (ROP) using an Optos® California device. MethodsThis retrospective study involved 46 infants with a history of ROP who underwent UWF imaging with or without IV UWF – FA. ROP characteristics were identified using UWF color imaging. Retinal vascular findings following treatment were also assessed at IV UWF – FA analysis. All imaging sessions were performed under topical anesthesia without sedation. Main outcomes were the appearance of ROP at UWF color imaging and IV UWF–FA analysis, including status of ROP, neovascularizations, presence of plus disease, retinal vascular details, and resolution after treatment. ResultsSeven (three girls) of the 46 infants (22 girls) underwent IV UWF–FA. Twelve IV UWF–FA sessions were performed in total. The oldest infant during IV UWF–FA analysis was at 55 postmenstrual weeks. Clinical characteristics of disease were easily identified at UWF color imaging. IV UWF–FA images also clearly revealed non-perfused retinal areas, fluorescein leakage, macular edema, retinal vascular abnormalities, and the status of the peripheral vascular termini. Complications of IV UWF–FA occurred in one infant in the form of patchy yellow skin discoloration around the injection site which completely disappeared on the first day following the procedure. ConclusionsProviding a high resolution panoramic view of the retina in a single image capture with no need for contact with the cornea appear to represent potential advantages of UWF imaging in infants with ROP. IV UWF–FA also seems to be a safe procedure which can be performed under topical anesthesia and that shows detailed retinal vascular alterations in patients with ROP.

Nonmydriatic Ultra-Widefield Fundus Photography in a Hematology Clinic Shows Utility for Screening of Sickle Cell Retinopathy

To determine the feasibility and accuracy of nonmydriatic ultra-widefield (UWF) fundus photographs taken in a hematology clinic setting for screening of sickle cell retinopathy (SCR) DESIGN: Prospective cohort study. This single-site study took place at the Johns Hopkins Sickle Cell Center for Adults and the Wilmer Eye Institute. The study population was 90 eyes of 46 consecutive adults with sickle cell disease (SCD). Bilateral nonmydriatic fundus photos taken by clinic personnel during the participants' routine hematology appointment were graded by 2 masked retina specialists at the Wilmer Eye Institute for the presence of nonproliferative SCR (NPSR) and proliferative sickle retinopathy (PSR). A third retina specialist adjudicated in cases of grader disagreement. All participants underwent the standard dilated fundus examination (DFE) within 2 years of acquisition of UWF photographs. The main outcome measure was the sensitivity and specificity of nonmydriatic UWF images for the detection of NPSR and PSR RESULTS: PSR was noted in 19 of 90 eyes that underwent DFE and in 9 of 67 gradable UWF images. Interrater agreement between the 2 graders was moderate, with κ=0.65 (range 0.43-0.87) for PSR. For gradable UWF photos, the sensitivity and specificity of detecting SCR using the nonmydriatic photos compared with the DFE were 85.2% and 62.5% for NPSR, respectively, and 69.2% and 100% for detection of PSR, respectively. One participant required ophthalmic therapy in both eyes for active sea-fan neovascularization. UWF imaging shows utility in screening for SCR and may help identify patients with PSR who require a DFE and who may benefit from treatment.

Prevalence of Diabetic Eye Diseases in American Indians and Alaska Natives (AI/AN) as Identified by the Indian Health Service’s National Teleophthalmology Program Using Ultrawide Field Imaging (UWFI)

ABSTRACT Purpose Estimates of diabetic eye disease in American Indian and Alaska Natives (AI/AN) vary over time, region, and methods. This article reports recent prevalence of diabetic retinopathy (DR) and diabetic macular edema (DME) in AI/AN served by the Indian Health Services’ (IHS) teleophthalmology program, as identified using ultrawide field imaging (UWFI). Methods This was a retrospective analysis of 2016–2019 clinical data (n = 53,900). UWF images were acquired by certified imagers using a validated protocol, and graded by licensed, certified optometrists supervised by an ophthalmologist. Graders evaluated the extent/severity of retinal lesions in comparison to standard photographs. DR lesions predominantly in any peripheral field were considered “predominantly peripheral lesions” (PPL). The analyses calculated prevalence of any DR, any DME, DR and DME severity, sight-threatening disease, and PPL. Results Patients averaged 56 years of age with a 68 mmol/mol A1c and 55% had had diabetes for 5+ years. Prevalence of any DR, any DME, and sight-threatening disease was 28.6%, 3.0%, and 3.0%. In patients with mild nonproliferative DR, PPL was seen in 25.3%. PPL suggested a more severe level of DR in 8.7% of patients. DR increased with age. DME decreased with age. Males and patients in the Nashville IHS area had more diabetic eye disease. Conclusion AI/AN have a high burden of diabetes and its complications. The IHS is resource-constrained, making accurate disease estimates necessary for resource allocation and budget justifications to Congress. These data update the estimates of diabetic eye disease in Indian Country and suggest that UWFI identifies early DR.

Perspective Distortion Correction for Multi-Modal Registration between Ultra-Widefield and Narrow-Angle Retinal Images.

Multi-modal retinal image registration between 2D Ultra-Widefield (UWF) and narrow-angle (NA) images has not been well-studied, since most existing methods mainly focus on NA image alignment. The stereographic projection model used in UWF imaging causes strong distortions in peripheral areas, which leads to inferior alignment quality. We propose a distortion correction method that remaps the UWF images based on estimated camera view points of NA images. In addition, we set up a CNN-based registration pipeline for UWF and NA images, which consists of the distortion correction method and three networks for vessel segmentation, feature detection and matching, and outlier rejection. Experimental results on our collected dataset shows the effectiveness of the proposed pipeline and the distortion correction method.

CLINICAL AND MORPHOLOGIC FEATURES OF POSTERIOR STAPHYLOMA EDGES BY ULTRA-WIDEFIELD IMAGING IN PATHOLOGIC MYOPIA.

To investigate morphologic features along posterior staphyloma edges in eyes with pathologic myopia using ultra-widefield optical coherence tomography imaging. Highly myopic patients (refractive error < -8 diopters or axial length ≥26.5 mm) were consecutively examined by prototype ultra-widefield optical coherence tomography with a scan width of 23 mm and depth of 5 mm. Staphyloma edges were assessed for scleral, choroidal, and retinal status, as well as measurements of angle size. Findings were correlated with pigmentary changes observed on Optos fundus photography, and multivariate logistic regression analyses were performed. In 164 eyes diagnosed with posterior staphyloma by ultra-widefield optical coherence tomography, choroidal thinning and scleral protrusion were hallmark features of staphyloma edges, observed simultaneously in more than 95% of staphylomatous eyes. Outer neural retinal thinning was observed in 80 eyes (48.8%), whereas 15 eyes (9.1%) showed retinal pigment epithelium damage. The mean angle at the staphyloma edge was 23° ± 12.4° (range 8° to 77°). Larger angles were significant predictors of retinal thinning (adjusted odds ratio: 1.17, confidence interval: 1.09-1.25), and the staphyloma was detected by Optos pseudocolor fundus photography (adjusted odds ratio: 1.08, confidence interval: 1.02-1.15). These morphologic findings may provide a basis for exploring the natural evolution of posterior staphyloma as part of the development of pathologic myopia.

Imaging Modalities Employed in Diabetic Retinopathy Screening: A Review and Meta-Analysis.

Introduction: Urbanization has caused dramatic changes in lifestyle, and these rapid transitions have led to an increased risk of noncommunicable diseases, such as type 2 diabetes. In terms of cost-effectiveness, screening for diabetic retinopathy is a critical aspect in diabetes management. The aim of this study was to review the imaging modalities employed for retinal examination in diabetic retinopathy screening. Methods: The PubMed and Web of Science databases were the main sources used to investigate the medical literature. An extensive search was performed to identify relevant articles concerning “imaging”, “diabetic retinopathy” and “screening” up to 1 June 2021. Imaging techniques were divided into the following: (i) mydriatic fundus photography, (ii) non-mydriatic fundus photography, (iii) smartphone-based imaging, and (iv) ultrawide-field imaging. A meta-analysis was performed to analyze the performance and technical failure rate of each method. Results: The technical failure rates for mydriatic and non-mydriatic digital fundus photography, smartphone-based and ultrawide-field imaging were 3.4% (95% CI: 2.3–4.6%), 12.1% (95% CI: 5.4–18.7%), 5.3% (95% CI: 1.5–9.0%) and 2.2% (95% CI: 0.3–4.0%), respectively. The rate was significantly different between all analyzed techniques (p < 0.001), and the overall failure rate was 6.6% (4.9–8.3%; I2 = 97.2%). The publication bias factor for smartphone-based imaging was significantly higher than for mydriatic digital fundus photography and non-mydriatic digital fundus photography (b = −8.61, b = −2.59 and b = −7.03, respectively; p < 0.001). Ultrawide-field imaging studies were excluded from the final sensitivity/specificity analysis, as the total number of patients included was too small. Conclusions: Regardless of the type of the device used, retinal photographs should be taken on eyes with dilated pupils, unless contraindicated, as this setting decreases the rate of ungradable images. Smartphone-based and ultrawide-field imaging may become potential alternative methods for optimized DR screening; however, there is not yet enough evidence for these techniques to displace mydriatic fundus photography.

Sensitivity and specificity of pseudocolor ultrawide field imaging in comparison to wide field fundus fluorescein angiography in detecting retinal neovascularization in diabetic retinopathy.

To evaluate the diagnostic accuracy of ultrawide pseudocolor retinal photography (pseudocolor UWF) compared to wide field fundus fluorescein angiography (WFFFA) in the detection of retinal neovascularization (NV) and NV of the disc (NVD) in patients with diabetic retinopathy (DR). Diagnostic accuracy observational study evaluating pseudocolor UWF as the index test. The reference standard was WFFFA. Single retinal centre in India. People with severe non-proliferative DR (sNPDR), early proliferative DR (ePDR) or high-risk proliferative DR (HR PDR). Sensitivity and specificity of pseudocolor UWF in the detection of NV. A total of 176 eyes of 94 subjects with sNPDR, ePDR or HR PDR underwent pseudocolor UWF and WFFFA. The sensitivity and specificity of pseudocolor UWF in detecting NVE were 92.5% (95% CI 86.2-96.5) and 81% (95% CI 64.8-92.0), respectively, with moderate interobserver agreement of 0.722 (p value 0.001). The positive predictive value and negative predictive value were 83.0 (71.4-90.5) and 91.5 (84.9-95.3), respectively. Compared to WFFFA as the gold standard, pseudocolor UWF has high sensitivity and specificity in detection of NV in all retinal quadrants and NVD. Therefore, pseudocolor UWF may be used as a non-invasive tool for screening and managing DR.

Ultra-Widefield Imaging of a Patient with Extensive Retinal Arteriovenous Malformation

Ultra-Widefield Imaging of a Patient with Extensive Retinal Arteriovenous Malformation

Peripheral Manifestations in Age Related Macular Degeneration: A Review of Imaging and Findings.

Purpose: To review novel findings in research with ultra-widefield imaging for analysis of peripheral manifestations in macular degeneration (AMD). We introduce the evolving widefield imaging modalities while summarizing the analytical techniques used in data collection of peripheral retinal findings thus far. Our review provides a summary of advancements to date and a commentary on future direction for AMD research. Methods: This is a literature review of all significant publications focused on the relationship between AMD and the retinal periphery conducted within the last two decades. Results and Conclusion: Promising research has been undertaken to elucidate peripheral retinal manifestations in macular degeneration using novel methodology. Advancements in ultra-widefield imaging and fundus autofluorescence have allowed us to elucidate peripheral retinal pigmentary changes, drusen deposition, and much more. Novel grid overlay techniques have been introduced to aid in analyzing these changes for pattern recognition and grouping of findings. This review discusses these findings in detail, providing evidence for the pan-retinal manifestations of AMD. Inter-study discordance in analytical approach highlights a need for more systematic future study.

Peripheral Retinal Degenerations and Idiopathic Epiretinal Membrane: Analysis with Ultra-Wide-Field Scanning Laser Ophthalmoscopy.

Background: The present study examined the relationships among retinal structure, peripheral retinal abnormalities, and epiretinal membrane (ERM) and explored the utility of ultra-wide-field laser scanning ophthalmoscopy in idiopathic ERM assessment. Methods: The study sample comprised 276 eyes of 276 patients. Ultra-wide field fundus imaging was performed without mydriasis using Optos California. Each patient underwent a Goldmann three-mirror contact lens fundus examination. Results: Ultra-wide field laser scanning ophthalmoscopy revealed peripheral retinal degeneration in 84 (54.54%) eyes in the ERM and in 28 (22.95%) eyes in the control group. Goldmann three-mirror contact lens examination revealed peripheral retinal degeneration in 96 (62.33%) eyes in the ERM group and 42 (34.42%) eyes in the control group. Ultra-wide field ophthalmoscopy enabled the detection of nearly 87% of all peripheral retinal lesions in patients with ERM, but it cannot replace fundus examination with a Goldmann triple mirror or ophthalmoscopy with scleral indentation. Conclusions: In most patients, idiopathic ERM coexisted with changes in the peripheral retina. Some of these changes promote retinal detachment. Thus, surgeons should consider the risk of retinal tear during vitrectomy, which increases the scope of surgery and may adversely affect prognosis. Although ultra-wide field imaging is a valuable diagnostic method, it is not a substitute for Goldmann three-mirror contact lens fundus examination or ophthalmoscopy with scleral indentation.

The Role of Ultra-Widefield Fundus Imaging and Fluorescein Angiography in Diagnosis and Treatment of Diabetic Retinopathy.

Early detection and treatment are important for preventing vision loss from diabetic retinopathy. Historically, the gold standard for grading diabetic retinopathy has been based on 7-field 30-degree color fundus photographs that capture roughly the central third of the retina. Our aim was to review recent literature on the role of ultra-widefield (allowing capture of up to 82% of the retina in one frame) fundus imaging in screening, prognostication, and treatment of diabetic retinopathy. Ultra-widefield fundus imaging can capture peripheral retinal lesions outside the traditional 7-field photographs that may correlate with increased risk of diabetic retinopathy progression. The speed and ability to image through undilated pupils make ultra-widefield imaging attractive for tele-ophthalmology screening. Ultra-widefield fluorescein angiography may help guide targeted laser treatment in eyes with proliferative diabetic retinopathy. Ultra-widefield imaging has potential to help shape new diabetic retinopathy screening, staging, and treatment protocols.

Role of Ultra-widefield Imaging in the evaluation of Long-term change of highly myopic fundus.

To evaluate the impact of posterior staphyloma identified using ultra-widefield fundus imaging on the long-term progression of myopic maculopathy in highly myopic patients. In this observational cohort study, highly myopic patients who were followed up for at least 5 years using ultra-widefield fundus imaging were analysed for fundus abnormalities and the progression of myopic maculopathy based on the International Meta-analysis of Pathologic Myopia classification. This study included 390 eyes (210 patients) with the mean follow-up period of 69.2 ± 7.5 months (range, 60-88). Posterior staphyloma was identified in 198 eyes (50.8%) in the baseline ultra-widefield fundus images. The border of staphyloma was not identified within 50° view circle corresponding to conventional fundus photography in 42 eyes (21.2%) with staphyloma, most of that were wide macular type. Progression of myopic maculopathy during follow-up was observed in 202 eyes (51.8%), and eyes with staphyloma were more likely to show progression compared to those without (142/198 [71.7%] versus 60/192 [31.3%]; p < 0.001). In multivariable regression analysis, the presence of posterior staphyloma was an independent risk factor for the progression of myopic maculopathy (p = 0.005). One or more peripheral retinal lesions were observed in 302 eyes (77.4%) and 321 eyes (82.3%) in the baseline and final ultra-widefield fundus images, respectively. Posterior staphyloma was associated with the long-term progression of myopic maculopathy. With a wider field of view, ultra-widefield fundus imaging is useful for identifying the posterior staphyloma and monitoring the progression of myopic maculopathy in highly myopic patients.

A Novel Quantitative Assessment Method of Disease Activity in Susac’s Syndrome Based on Ultra-Wide Field Imaging

ABSTRACT Purpose Susac’s syndrome (ScS) is a rare, potentially life-threatening auto-immune disease. Ophthalmic imaging can depict characteristic branch retinal arteriolar occlusions (BRAO) and arterial wall hyperfluorescences that form one of the three diagnostic pillars of this condition. We aim to demonstrate that ophthalmological ultrawide-field (UWF) imaging allows for a qualitative and quantitative assessment in ScS, with application in diagnostics, monitoring of treatment response, and titration of therapy. Methods In seven ScS patients (♀:♂ = 2:5), with a median age of 36 years, range 18 to 57 years, serial ultrawide-field fluoresceine angiography (UWF-FA) studies were performed, with adjunctive wide-field optical coherence tomography angiography analyses (WF-OCTA) in five patients. Mean follow-up was 12.5 months, range 1 to 46 months. Results In all seven patients, BRAO and arterial wall hyperfluorescences were present in UWF-FA and calculated as a quantitative score of disease activity in fluorescein angiography (DA-FA) during follow-up visits. Treatment response was accessible in follow-up imaging as partial reperfusion of retinal vessels, resolution of arterial wall hyperfluorescences and consequently, in reduction of DA-FA score. While qualitative analysis of WF-OCTA provided further information about retinal micro-perfusion, quantitative analysis did not demonstrate a vectored treatment response as it was accessible in FA. Conclusion DA-FA score, as a comprehensive disease activity parameter in ScS has potential to facilitate optimal communication between subspecialties and thereby treatment success.

Automated detection of retinal exudates and drusen in ultra-widefield fundus images based on deep learning.

Retinal exudates and/or drusen (RED) can be signs of many fundus diseases that can lead to irreversible vision loss. Early detection and treatment of these diseases are critical for improving vision prognosis. However, manual RED screening on a large scale is time-consuming and labour-intensive. Here, we aim to develop and assess a deep learning system for automated detection of RED using ultra-widefield fundus (UWF) images. A total of 26,409 UWF images from 14,994 subjects were used to develop and evaluate the deep learning system. The Zhongshan Ophthalmic Center (ZOC) dataset was selected to compare the performance of the system to that of retina specialists in RED detection. The saliency map visualization technique was used to understand which areas in the UWF image had the most influence on our deep learning system when detecting RED. The system for RED detection achieved areas under the receiver operating characteristic curve of 0.994 (95% confidence interval [CI]: 0.991-0.996), 0.972 (95% CI: 0.957-0.984), and 0.988 (95% CI: 0.983-0.992) in three independent datasets. The performance of the system in the ZOC dataset was comparable to that of an experienced retina specialist. Regions of RED were highlighted by saliency maps in UWF images. Our deep learning system is reliable in the automated detection of RED in UWF images. As a screening tool, our system may promote the early diagnosis and management of RED-related fundus diseases.

Accuracy of automated machine learning in classifying retinal pathologies from ultra-widefield pseudocolour fundus images

AimsAutomated machine learning (AutoML) is a novel tool in artificial intelligence (AI). This study assessed the discriminative performance of AutoML in differentiating retinal vein occlusion (RVO), retinitis pigmentosa (RP) and...