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Automatic detection of diabetic retinopathy and its progression in sequential fundus images of patients with diabetes
摘要： Regular screening by fundus images is known to be effective in detecting the early signs of diabetic retinopathy (DR). Early detection and timely treatment of DR are crucial to prevent the development of sight-threatening DR and visual loss. Due to global increase in the prevalence of diabetes from the current 425 million to 629 million in 2045, also the number of people with DR are estimated to triple from 2005 to 2050. Thus, the workload required for screening for DR will increase tremendously. Novel technological solutions and interventions might fortunately ease this challenging task in the future. We have developed an algorithm to detect early DR and its progression in the chronological follow-up fundus images to minimize the time-consuming evaluation of the images by a trained nurse or an ophthalmologist.
关键词： progression,diabetic retinopathy,fundus images,automatic detection,diabetes
更新于2025-09-23 15:21:01
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Asymmetry of Retinopathy of Prematurity Border in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity Study
摘要： Purpose: To measure the location of the retinopathy of prematurity (ROP) border in a sample of premature infants who developed ROP and determine location for predicting subsequent development of referral-warranted ROP (RW-ROP, defined as Stage 3 ROP, zone I ROP, or plus disease) or treated ROP. Design: Secondary analysis of data from an observational cohort study, The Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study. Subjects: Infants with birth weight (BW) less than 1251g with at least one exam and image session at ≤34 weeks postmenstrual age (PMA) with ROP not meeting RW-ROP, and at least one subsequent exam at ≥36 weeks PMA. Methods: The 5-image set from the first imaging session for each eligible eye was mosaicked, and measurements of the ROP border in each mosaicked image were made using Image J. Measurements were compared among 3 groups of eyes with ROP: (1) never developed RW-ROP or received treatment, (2) developed RW-ROP but did not receive treatment, and (3) received treatment; using analysis of variance and linear trend tests that accounted for the inter-eye correlation. Main outcome measures: RW-ROP, treated ROP Results: 317 eyes from 217 infants with mean BW 755g, mean GA 25 weeks, and mean PMA 33 weeks at first exam met study criteria. Of 211 (66.6%) eyes with sufficient quality images for grading, 147 (69.7%) did not develop RW-ROP or receive treatment, 36 (17.1%) developed RW-ROP not requiring treatment, and 28 (13.3%) received treatment for ROP. Among all eyes, the disc-to-ROP border distance followed a consistent pattern, with nasal < inferior < superior < temporal. Eyes that developed RW-ROP or underwent treatment had significantly shorter nasal and temporal disc-to-ROP border distances and smaller areas of retina within the ROP border. In multivariate analysis adjusted by BW and GA, nasal ROP border distance was a significant predictor of developing treated ROP (OR=0.86 for every 10 pixel increase in distance, p=0.002). Conclusions: ROP is located asymmetrically around the optic disc and is closest to the optic disc nasally. Location of ROP nasally at first imaging is a significant predictor of developing treated ROP.
关键词： retinopathy of prematurity,ROP,asymmetry,telemedicine,optic disc
更新于2025-09-23 15:21:01
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<p>532-nm Subthreshold Micropulse Laser for the Treatment of Chronic Central Serous Retinopathy</p>
摘要： Introduction: Subthreshold micropulse laser treatment with a 532 nm (532-SML) wavelength has been suggested as a treatment option for the treatment of chronic central serous retinopathy (cCSR). The objective is to present its effects and complications. Methods: We present a retrospective cohort study of cCSR patients submitted to 532-SML. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) parameters – central macular thickness, subfoveal outer nuclear layer, external limiting membrane, ellipsoid band, interdigitation band, subretinal ?uid and choroidal thickness – were evaluated before and 12 weeks after treatment. A power of 50%, a duty cycle of 5%, exposure time of 200 ms and a spot size of 160 μm were the applied laser parameters. Results: We included 26 eyes. Overall there were no signi?cant changes in visual acuity (median 0.20 (IQR 0) logMAR before and after treatment) or SD-OCT parameters. However, visual bene?ts occurred in 42.3% (n=11) of the patients and in half of the cases, subretinal ?uid was completely reabsorbed. There were no complications. Conclusion: In this study, 532-SML was overall ineffective on cCSR as it did not lead to signi?cant changes in the overall median visual acuity and SD-OCT parameters. However, some patients may have bene?ted functionally and anatomically from the treatment; further investigation is necessary to understand the potential of 532-SML.
关键词： 532 nm wavelength,subthreshold micropulse laser,outer retina bands,SD-OCT,central serous retinopathy
更新于2025-09-23 15:19:57
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Foveal microvasculature, refractive errors, optical biometry and their correlations in school-aged children with retinopathy of prematurity after intravitreal antivascular endothelial growth factors or laser photocoagulation
摘要： Aims To compare the differences and to assess the correlations regarding to foveal microvasculature, refractive errors and optical biometry in children with history of type 1 retinopathy of prematurity (ROP) treated with either laser photocoagulation or intravitreal injection of antivascular endothelial growth factors (anti-VEGF). Methods This is a retrospective and comparative case series. Measurements of fovea microvasculature included the retinal thickness and subfoveal choroid thickness, the size of fovea avascular zone (FAZ), the fovea, parafovea and perifoveal vessel density (VD). Measurements of refractive errors and optical biometry included spherical equivalent, astigmatism, cornea curvature, anterior chamber depth (ACD), lens thickness and axial length (AXL). Results A total 47 eyes in 25 children were studied (22 laser-treated eyes from 12 children and 25 anti-VEGF treated eyes from 13 children). Laser-treated eyes had significantly smaller FAZ (p=0.004), higher fovea VD, lower parafoveal VD (p=0.02 and 0.01 in superficial capillary plexus; p=0.05 and 0.01 in deep capillary plexus), thicker inner retinal thickness (p=0.002). Laser-treated eyes had significantly higher degree of myopia (p=0.01). Regarding to optical biometry, laser-treated eyes had significant steeper cornea curvature, shallower ACD and thicker lens (p=0.01, 0.01 and 0.02, respectively) but no differences in AXL was noted (p=0.58). Significant correlations presented between inner retina thickness and FAZ to anterior segment variables. Conclusion In school-aged children with history of type 1 ROP, despite similar visual acuity outcome, those who underwent anti-VEGF injection had favourable developmental outcomes compared with laser photocoagulation. Significant correlations exist between fovea microvasculature and optical biometric components.
关键词： laser photocoagulation,anti-VEGF,foveal microvasculature,retinopathy of prematurity,optical biometry,refractive errors
更新于2025-09-23 15:19:57
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Subthreshold yellow micropulse laser for treatment of diabetic macular edema: Comparison between fixed and variable treatment regimen
摘要： Purpose: To compare the efficacy between fixed and variable treatment regimens of subthreshold yellow micropulse laser for the treatment of diabetic macular edema. Methods: This is a retrospective, comparative, 12-month study of 39 eyes: 24 eyes received fixed treatment regimen of subthreshold micropulse laser treatment and 15 eyes underwent variable treatment regimen of subthreshold micropulse laser, all eyes were followed up for 12 months. Subthreshold micropulse laser was performed with the following parameters: 100 μm spot size on slit lamp, 5% duty cycle of 0.2 s, and 250 mW power. To choose the power of the variable treatment regimen of subthreshold micropulse laser group, continuous laser power was titrated to a barely visible burn and then switched to MicroPulse mode, multiplying the test burn power by 4 and using a 5% duty cycle of 0.2 s. Main outcomes included changes in central macular thickness and best-corrected visual acuity. Results: At baseline, the mean LogMAR best-corrected visual acuity was 0.297 ± 0.431 in the variable treatment regimen of subthreshold micropulse laser group and 0.228 ± 0.341 in the fixed treatment regimen of subthreshold micropulse laser group. At the end of follow-up, the mean LogMAR best-corrected visual acuity was 0.289 ± 0.473 (p = 0.785) and 0.245 ± 0.376 (p = 0.480) in the variable and fixed treatment regimens of subthreshold micropulse laser groups, respectively. Similarly, central macular thickness decreased in both groups after treatment; at baseline, the mean central macular thickness was 371.06 ± 37.8 in the variable treatment regimen of subthreshold micropulse laser group and improved to 325.60 ± 110.0 μm (p = 0.025) at the end of the follow-ups, while it was 342.30 ± 35.4 in the fixed treatment regimen of subthreshold micropulse laser group and improved to 308.51 ± 67.5 (p = 0.037). Conclusion: Both treatment regimens are effective for the treatment of mild center-involving diabetic macular edema: fixed treatment appears more suitable minimizing treatment time and reducing the possible errors due to wrong titration in the switch from continuous to micropulse mode.
关键词： Diabetic retinopathy,retina,diabetic macular edema,cystoid macular edema (CME),retina—medical therapies,retinal pathology/research
更新于2025-09-23 15:19:57
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Serum VEGF and Ang-2 Levels in Infants Before and After Laser Treatment for Retinopathy of Prematurity
摘要： Objectives: To investigate VEGF and Ang-2 level changes in the systemic circulation after laser photocoagulation in premature infants with ROP. Methods: Eleven infants (4 girls and 7 boys) had serum levels determined for VEGF and Ang-2, collected 1 day prior to and 7 days after ROP laser therapy. Serum levels of VEGF and Ang-2 were quantified by enzyme-linked immunosorbent assay (ELISA). Results: Serum VEGF levels were significantly lower at 7 days after laser therapy compared to that at 1 day prior to laser therapy (p ? 0.045). Serum Ang-2 levels increased significantly at 7 days after laser therapy compared with that at 1 day prior to laser therapy (p ? 0.046). Conclusions: Serum VEGF levels in patients with ROP were suppressed and Ang-2 levels elevated significantly after laser therapy. The results suggest that changes in VEGF and Ang-2 serum levels may reflect regression and treatment of ROP.
关键词： angiopoietin 2,premature infants,serum levels,Retinopathy of prematurity,vascular endothelial growth factor
更新于2025-09-23 15:19:57
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[IEEE 2018 International Conference on Soft-computing and Network Security (ICSNS) - Coimbatore, India (2018.2.14-2018.2.16)] 2018 International Conference on Soft-computing and Network Security (ICSNS) - A Survey for Diabetic Retinopathy
摘要： Diabetic retinopathy has ended up a exceptionally common eye illness which causes visual deficiency among individuals. This Study on diabetic retinopathy makes a great examination of how diverse strategy is they to identify. It may offer assistance to identify the malady as early as conceivable and allow them a conceivable treatment. Identifying the exudates in early organize can avoid a vision misfortune. Retinal blood vessel are recognized and utilized for them to detect. Due to the growing prevalence of metabolic disorders, ask for diabetic retinopathy (DR) screening stages is steeply growing. Early location and treatment of DR are key open wellbeing mediations that can significantly decrease the probability of vision misfortune. Current DR screening programs regularly utilize retinal fundus photography, which depends on gifted perusers for manual DR appraisal. Be that as it may, this is labor- intensive and endures from irregularity over destinations. Subsequently, there has been a later multiplication of robotized retinal picture investigation computer program that may potential
关键词： retina,Diabetic retinopathy,exudates,Image Segmentation
更新于2025-09-23 15:19:57
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The Effects of Diabetic Retinopathy Stage and Light Flicker on Inner Retinal Oxygen Extraction Fraction
摘要： PURPOSE. We determined the effects of light ?icker and diabetic retinopathy (DR) stage on retinal vascular diameter (D), oxygen saturation (SO2), and inner retinal oxygen extraction fraction (OEF). METHODS. Subjects were categorized as nondiabetic control (NC, n ? 42), diabetic with no clinical DR (NDR; n ? 32), nonproliferative DR (NPDR; n ? 42), or proliferative DR (PDR; n ? 14). Our customized optical imaging system simultaneously measured arterial and venous D (DA, DV) and SO2 (SO2A, SO2V) before and during light ?icker. Inner retinal OEF was derived from SO2 values. Light ?icker–induced ratios of metrics (DAR, DVR, SO2AR, SO2VR, OEFR) were calculated. RESULTS. Arterial D was larger in NPDR compared to NC (P ? 0.01) and PDR (P ? 0.002), whereas DV was similar among groups (P ? 0.16). Light ?icker increased DA and DV (P (cid:2) 0.004), but DAR and DVR were similar among groups (P ? 0.09). Arterial SO2 was higher in all groups compared to NC (P (cid:2) 0.02) and higher in PDR compared to NDR and NPDR (P<0.001). Arterial SO2 did not change with light ?icker (P ? 0.1). Venous SO2 was higher in NPDR and PDR compared to NC and NDR (P (cid:2) 0.02). Light ?icker increased SO2V in NC, NDR, and PDR (P (cid:2) 0.003), and SO2VR was lower in NPDR compared to NC and NDR (P (cid:2) 0.05). Inner retinal OEF was lower in NPDR compared to NDR and PDR (P (cid:2) 0.02). Light ?icker decreased OEF (P (cid:2) 0.03), but OEFR was greater in NPDR compared to NC and NDR (P (cid:2) 0.03). CONCLUSIONS. The ?ndings of alterations in retinal D, SO2, OEF, and their light ?icker–induced responses at stages of DR may be useful to elucidate the pathophysiology of DR.
关键词： light ?icker stimulation,inner retinal oxygen extraction fraction,diabetic retinopathy,retina
更新于2025-09-23 15:19:57
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Severity analysis of diabetic retinopathy in retinal images using hybrid structure descriptor and modified CNNs
摘要： Imaging which plays a central role in the diagnosis and treatment planning of diabetic retinopathy and severity is an important diagnostic indicator in treatment planning and results assessment. Retinal image classification is an increasing attention among researchers in the field of computer vision, as it plays an important role in disease diagnosis. Computer Aided Diagnosis (CAD) is in wide practice in clinical work for the location and anticipation of different kinds of variations; the automated image classification systems used for such applications must be significantly efficient in terms of accuracy since false detection may lead to fatal results. Another requirement is the high convergence rate which accounts for the practical feasibility of the system. The overall classification accuracy of the proposed HTF with MCNNs is 98.41%, but the existing methods HTF with SVM and HTF with CNNs produce 97.84% and 96.65% respectively.
关键词： Segmentation,SVM,Medical image processing,Microaneurysms,Diabetic retinopathy,Classification
更新于2025-09-23 15:19:57
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Do microvascular changes occur preceding neural impairment in early-stage diabetic retinopathy? Evidence based on the optic nerve head using optical coherence tomography angiography
摘要： Aims To evaluate the microvascular and neural differences of the optic nerve head (ONH) between type 2 diabetes mellitus (T2DM) subjects and controls. Methods This was a cross-sectional observational study. One hundred and eight eyes of 108 T2DM subjects with or without diabetic retinopathy (DR) (54 preclinical DR and 54 mild-to-moderate DR) were included. Fifty-two eyes of 52 healthy subjects were included as controls. The 4.5-mm Angio Disc scan mode and the ganglion cell complex scan mode were performed with all participants using AngioVue software 2.0 of the optical coherence tomography angiography (OCTA) device. Results Regarding ONH radial peripapillary capillary (RPC) density, the peripapillary region was mainly significantly reduced in the No-DR (NDR) group. Moreover, the RPC density of the peripapillary region and the inside optic disc area were significantly reduced in the non-proliferative DR (NPDR) group. When compared to the controls, significantly reduced peripapillary capillary density in six sections was observed in the NPDR group. However, reduced density was observed in only two sections in the NDR group. The NPDR group had significantly increased focal loss volume (FLV) and reduced peripapillary RNFL thickness in the inferior nasal section compared to those in the controls, but similar changes were not observed in the NDR group. A regression model identified RPCs inside the optic disc as a significant parameter in early-stage DR detection. In the NPDR group, BCVA showed a significantly negative correlation with RPCs inside the optic disc and a significantly positive correlation with FLV. Conclusions OCTA findings of the ONH area may provide evidence that microvascular changes occur preceding neural impairment in early-stage DR. However, further researches are still needed to support the statement. Reduced ONH perfusion inside the optic disc may be one of the crucial biomarkers in early-stage DR detection and is a possible sensitive visual acuity predictor in early-stage DR subjects. With the ONH mode, OCTA may be a more promising tool in DR screening.
关键词： Neural impairment,Optical coherence tomography angiography,Optic nerve head,Microvascular changes,Diabetic retinopathy
更新于2025-09-19 17:15:36