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Romanian Journal of Ophthalmology 2023Diabetic retinopathy (DR) is a vision-threatening complication of diabetes, necessitating early and accurate diagnosis. The combination of optical coherence tomography... (Review)
Review
Diabetic retinopathy (DR) is a vision-threatening complication of diabetes, necessitating early and accurate diagnosis. The combination of optical coherence tomography (OCT) imaging with convolutional neural networks (CNNs) has emerged as a promising approach for enhancing DR diagnosis. OCT provides detailed retinal morphology information, while CNNs analyze OCT images for automated detection and classification of DR. This paper reviews the current research on OCT imaging and CNNs for DR diagnosis, discussing their technical aspects and suitability. It explores CNN applications in detecting lesions, segmenting microaneurysms, and assessing disease severity, showing high sensitivity and accuracy. CNN models outperform traditional methods and rival expert ophthalmologists' results. However, challenges such as dataset availability and model interpretability remain. Future directions include multimodal imaging integration and real-time, point-of-care CNN systems for DR screening. The integration of OCT imaging with CNNs has transformative potential in DR diagnosis, facilitating early intervention, personalized treatments, and improved patient outcomes. DR = Diabetic Retinopathy, OCT = Optical Coherence Tomography, CNN = Convolutional Neural Network, CMV = Cytomegalovirus, PDR = Proliferative Diabetic Retinopathy, AMD = Age-Related Macular Degeneration, VEGF = vascular endothelial growth factor, RAP = Retinal Angiomatous Proliferation, OCTA = OCT Angiography, AI = Artificial Intelligence.
Topics: Humans; Diabetic Retinopathy; Tomography, Optical Coherence; Macular Edema; Vascular Endothelial Growth Factor A; Artificial Intelligence; Neural Networks, Computer; Macular Degeneration; Diabetes Mellitus
PubMed: 38239418
DOI: 10.22336/rjo.2023.63 -
The Journal of Craniofacial Surgery Jan 2024To investigate the clinical characteristics and treatment strategy of anterior circulation aneurysm presenting with cerebral ischemia.
OBJECTIVE
To investigate the clinical characteristics and treatment strategy of anterior circulation aneurysm presenting with cerebral ischemia.
METHODS
We performed a retrospective review of patients with intracranial anterior circulation aneurysms presenting with cerebral ischemia examined in the Fifth Ward of the Neurosurgery Department of Tianjin Huanhu Hospital between September 2016 and September 2023. Data were reviewed for age, sex, presentation, type and size, location, treatment modalities, postoperative complications, clinical and imaging outcomes, and follow-up outcomes.
RESULTS
Among the 13 patients, there were 8 males and 5 females (1.6:1). Their presentations included ischemic stroke (69.23%, 9/13) and transient ischemic attack (TIA) (30.77%, 4/13). The aneurysms were dissecting (46.15%, 6/13), saccular (30.77%, 4/13), and saccular combined with thrombosis (23.08%, 3/13) in shape. There were 6 giant aneurysms, 4 large aneurysms, and 3 microaneurysms. Three (23.08%, 3/13) aneurysms were located at the internal carotid artery (ICA) and 10 (76.92%, 10/13) were located in the middle cerebral artery (MCA). A preoperative magnetic resonance perfusion (MRP) examination was performed in all patients, and 9 (69.23%, 9/13) patients showed hypoperfusion. Treatment modalities included stent-assisted embolization, direct clipping, clipping combined with bypass, resection combined with bypass, isolated combined with bypass, proximal occlusion combined with bypass, and the internal carotid artery constriction combined with bypass. Twelve (92.31%, 12/13) patients had no postoperative complications, and temporary complications occurred in 1 (7.69%, 1/13) patient. Aneurysms disappeared in 11 cases and shrank in 2 cases postoperatively. All patients were followed up for 1 to 72 months. We found no new cerebral infarction, no subarachnoid hemorrhage, and no recurrence or enlargement of aneurysms during the follow-up.
CONCLUSIONS
Intracranial anterior circulation aneurysm presenting with cerebral ischemia is rare. Saccular aneurysms with wide neck or thrombosis and dissected aneurysms of the anterior circulation may result in cerebral ischemic attack caused by distal vascular embolism. Individualized treatment should be performed, and cerebral revascularization is an effective treatment for patients with intracranial anterior circulation aneurysms presenting with cerebral ischemia.
PubMed: 38227639
DOI: 10.1097/SCS.0000000000009944 -
Asian Journal of Neurosurgery Dec 2023This study compared intraoperative findings with preoperative computed tomography angiography (CTA) and computational fluid dynamics (CFD) analysis of perianeurysmal...
This study compared intraoperative findings with preoperative computed tomography angiography (CTA) and computational fluid dynamics (CFD) analysis of perianeurysmal findings for the indication of possible vessel wall thinning. Participants comprised 38 patients with unruptured middle cerebral artery aneurysms treated by surgical clipping at our hospital between May 2020 and April 2021. We defined parent artery radiation sign (PARS) as the presence of each of the following three findings in CFD analysis based on preoperative CTA: (1) impingement of the stream line on the outer parent vessel wall of the aneurysm; (2) radiation of wall shear stress vectors outwards from the same site; and (3) increased wall pressure compared with the surrounding area. CFD analysis showing PARS was compared with intraoperative findings. In all nine cases with PARS, no morphological abnormalities were found in the same area on CTA. However, intraoperative findings showed thinning of the parent artery wall in one of the nine cases and formation of a very small mass in three cases, differing from CTA findings. All nine patients underwent additional clipping and/or wrapping and coating at the site of PARS. Detecting thinning of the vessel wall or the presence of a microaneurysm may be difficult in endovascular therapy, which is based on the visualization of the vessel lumen. CFD analysis suggests the necessity of confirming findings for the vessel wall around an aneurysm by direct manipulation, as the presence of PARS may indicate partial thinning of the vessel wall or formation of a microaneurysm.
PubMed: 38161604
DOI: 10.1055/s-0043-1771367 -
Journal of Personalized Medicine Dec 2023The objective of this study was to determine the correlation between topographic vessel density (VD) and retinal thickness (RT) reductions induced by vascular...
Correlation between Topographic Vessel Density and Retinal Thickness Changes in Patients with Diabetic Macular Edema Treated with Anti-VEGF Therapy: Is It a Suitable OCTA Biomarker?
The objective of this study was to determine the correlation between topographic vessel density (VD) and retinal thickness (RT) reductions induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA). This was a prospective, interventional case series. VD and RT measurements were separately taken in four parafoveal subfields at baseline and after six months of treatment. This correlation was statistically assessed using Spearman's rho correlation coefficient after adjustment for multiple comparisons. The study included a total of 48 eyes in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (±3.5) to 44.6% (±3.2) in the superficial capillary plexus and from 50 (±3.3) to 49% (±3.9) in the deep capillary plexus). Statistically significant reductions in RT were observed in all ETDRS sectors ( < 0.0001). No significant association was found between RT and VD, even when analyzing responders and non-responders separately. After six months of anti-VEGF treatment, no significant correlation was observed between the topographic VD and RT values. These findings suggest that reductions in VD values may not solely result from a reduction in microaneurysms, also being affected by the repositioning of displaced vessels due to edema and a reduction in their caliber. Therefore, VD changes may not be a suitable indirect OCTA biomarker of microaneurysm turnover and treatment response.
PubMed: 38138945
DOI: 10.3390/jpm13121718 -
Bioengineering (Basel, Switzerland) Dec 2023Diabetic retinopathy (DR) is a microvascular complication of diabetes. Microaneurysms (MAs) are often observed in the retinal vessels of diabetic patients and represent...
Diabetic retinopathy (DR) is a microvascular complication of diabetes. Microaneurysms (MAs) are often observed in the retinal vessels of diabetic patients and represent one of the earliest signs of DR. Accurate and efficient detection of MAs is crucial for the diagnosis of DR. In this study, an automatic model (MA-YOLO) is proposed for MA detection in fluorescein angiography (FFA) images. To obtain detailed features and improve the discriminability of MAs in FFA images, SwinIR was utilized to reconstruct super-resolution images. To solve the problems of missed detection of small features and feature information loss, an MA detection layer was added between the neck and the head sections of YOLOv8. To enhance the generalization ability of the MA-YOLO model, transfer learning was conducted between high-resolution images and low-resolution images. To avoid excessive penalization due to geometric factors and address sample distribution imbalance, the loss function was optimized by taking the Wise-IoU loss as a bounding box regression loss. The performance of the MA-YOLO model in MA detection was compared with that of other state-of-the-art models, including SSD, RetinaNet, YOLOv5, YOLOX, and YOLOv7. The results showed that the MA-YOLO model had the best performance in MA detection, as shown by its optimal metrics, including recall, precision, F1 score, and AP, which were 88.23%, 97.98%, 92.85%, and 94.62%, respectively. Collectively, the proposed MA-YOLO model is suitable for the automatic detection of MAs in FFA images, which can assist ophthalmologists in the diagnosis of the progression of DR.
PubMed: 38135996
DOI: 10.3390/bioengineering10121405 -
Indian Journal of Ophthalmology Jan 2024To assess the utility of pre-defined imaging biomarkers on optical coherence tomography (OCT) and OCT angiography (OCTA) in patients with diabetic macular edema (DME)... (Clinical Trial)
Clinical Trial
PURPOSE
To assess the utility of pre-defined imaging biomarkers on optical coherence tomography (OCT) and OCT angiography (OCTA) in patients with diabetic macular edema (DME) following anti-vascular endothelial growth factor (anti-VEGF) therapy in determining visual and anatomical outcomes.
METHODS
In this prospective, non-randomized, and interventional study, 17 patients with treatment-naive DME were included. OCT biomarkers [size/reflectivity of cysts, disorganization of retinal inner layers, integrity of ellipsoid zone or external limiting membrane, subfoveal serous retinal detachment, hyper-reflective foci (HRF)] and OCTA [vascular density (VD), foveal avascular zone (FAZ), and total micro-aneurysms in superficial capillary plexus and deep capillary plexus (DCP)] were analyzed at baseline and after three monthly intravitreal anti-VEGF injections. Response was defined as a decrease of 10% or more in central macular thickness from the baseline after three injections.
RESULTS
13/17 (76.47%) patients were categorized as responders to anti-VEGF therapy. Non-responders had significantly greater hyper-reflectivity of cysts (P = 0.015), larger cystic spaces (P = 0.023), and an increased number of HRF (P = 0.04) at baseline. On OCTA, non-responders showed larger FAZ in DCP (1.35 ± 0.21 versus 1.14 ± 0.28 mm2) (P = 0.042) and lower VD (61.17 ± 0.45 versus 62.73 ± 3.32) in DCP at baseline. At 3 months, the VD increased in responders (63.10 ± 3.42) compared to a decrease in non-responders (60.82 ± 1.13) (P = 0.032).
CONCLUSIONS
Non-responders show a higher number of micro-aneurysms, larger FAZ, and lower VD in the DCP on OCTA and higher cyst hyper-reflectivity and HRF and larger cystic spaces on OCT imaging.
Topics: Humans; Macular Edema; Diabetic Retinopathy; Endothelial Growth Factors; Prospective Studies; Fluorescein Angiography; Retrospective Studies; Tomography, Optical Coherence; Biomarkers; Cysts; Aneurysm; Retinal Vessels; Diabetes Mellitus
PubMed: 38131536
DOI: 10.4103/IJO.IJO_893_23 -
Acta Ophthalmologica Dec 2023To compare detection rates of microaneurysms (MAs) on high-speed megahertz optical coherence tomography angiography (MHz-OCTA), fluorescein angiography (FA) and colour...
PURPOSE
To compare detection rates of microaneurysms (MAs) on high-speed megahertz optical coherence tomography angiography (MHz-OCTA), fluorescein angiography (FA) and colour fundus photography (CF) in patients with diabetic retinopathy (DR).
METHODS
For this exploratory cross-sectional study, MHz-OCTA data were acquired with a swept-source OCT prototype (A-scan rate: 1.7 MHz), and FA and CF imaging was performed using Optos® California. MA count was manually evaluated on en face MHz-OCTA/FA/CF images within an extended ETDRS grid. Detectability of MAs visible on FA images was evaluated on corresponding MHz-OCTA and CF images. MA distribution and leakage were correlated with detectability on OCTA and CF imaging.
RESULTS
47 eyes with severe DR (n = 12) and proliferative DR (n = 35) were included. MHz-OCTA and CF imaging detected on average 56% and 36% of MAs, respectively. MHz-OCTA detection rate was significantly higher than CF (p < 0.01). The combination of MHz-OCTA and CF leads to an increased detection rate of 70%. There was no statistically significant association between leakage and MA detectability on OCTA (p = 0.13). For CF, the odds of detecting leaking MAs were significantly lower than non-leaking MAs (p = 0.012). Using MHz-OCTA, detection of MAs outside the ETDRS grid was less likely than MAs located within the ETDRS grid (outer ring, p < 0.01; inner ring, p = 0.028). No statistically significant difference between rings was observed for CF measurements.
CONCLUSIONS
More MAs were detected on MHz-OCTA than on CF imaging. Detection rate was lower for MAs located outside the macular region with MHz-OCTA and for leaking MAs with CF imaging. Combining both non-invasive modalities can improve MA detection.
PubMed: 38126128
DOI: 10.1111/aos.16619 -
American Journal of Ophthalmology Case... Mar 2024To report two cases of diabetic macular edema (DME) treated with intravitreal faricimab injections (IVFs), including the assessment of retinal microaneurysms and extent...
PURPOSE
To report two cases of diabetic macular edema (DME) treated with intravitreal faricimab injections (IVFs), including the assessment of retinal microaneurysms and extent of retinal capillary non-perfusion using fluorescein angiography (FA) and indocyanine green angiography (IA).
OBSERVATIONS
Case 1: A 72-year-old man presented with aflibercept-resistant DME in the left eye, with a best-corrected visual acuity (BCVA) of 20/16. FA showed areas of retinal capillary non-perfusion and focal leakage in the macular area of the left eye. IA revealed numerous microaneurysms in the temporal region of the macula. Four consecutive monthly IVFs were administered to the left eye, and DME eventually diminished. After the loading phase, the BCVA was maintained at 20/16 with reduced visual distortion. FA showed improvement of macular leakage and stable retinal capillary non-perfusion areas, and the foveal avascular zone was clearly observed. The disappearance of numerous microaneurysms was confirmed on IA images.Case 2: An 80-year-old woman developed DME with macular vein occlusion in the left eye after panretinal laser photocoagulation for proliferative diabetic retinopathy. The patient's BCVA was 20/32. DME was resistant to subtenon triamcinolone injections. FA revealed focal areas of retinal capillary non-perfusion and persistent leakage in the macular area of the left eye. IA revealed scattered microaneurysms within the retinal arcade. Four consecutive monthly IVFs were administered to the left eye, and DME eventually diminished. After the loading phase, the BCVA was maintained at 20/32. FA showed improvement of macular leakage and stable retinal capillary non-perfusion areas. The reduction of microaneurysms was confirmed on IA images.
CONCLUSIONS AND IMPORTANCE
These case reports highlight the potential of faricimab as an alternative anti-vascular endothelial growth factor drug for treatment-resistant DME, including reduction of retinal microaneurysms and stabilization of the areas of retinal capillary non-perfusion. However, continuation of a robust treatment regimen may be required to achieve these objectives.
PubMed: 38116329
DOI: 10.1016/j.ajoc.2023.101973 -
International Journal of Ophthalmology 2023To evaluate the efficacy of retinal laser photocoagulation and intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) for hemorrhagic retinal...
AIM
To evaluate the efficacy of retinal laser photocoagulation and intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) for hemorrhagic retinal arterial macroaneurysm (RAM).
METHODS
This was a retrospective clinical study. Patients with hemorrhagic RAM were divided into 4 groups defined by different treatments: a retinal laser photocoagulation therapy monotherapy group, an anti-VEGF intravitreal injection monotherapy group, a laser and anti-VEGF combination therapy group, and an observation group. Visual acuity (VA), central macular thickness (CMT), and retinal hemorrhage area (RHA) were collected.
RESULTS
Forty-seven eyes of 47 patients were enrolled. VA improved and had a significant difference between baseline and final in each treatment group (logMAR; laser group: 1.90±0.53 1.05±0.63, <0.001; anti-VEGF group: 1.75±0.63 1.12±0.54, =0.009; combination group: 1.76±0.38 1.01±0.52, <0.001); however, VA decreased and had no significant difference in observation group (1.63±0.51 1.76±0.61, =0.660). CMT decreased and had a significant difference between baseline and final in each group (laser group: 815.16±310.83 252.05±83.90 µm, <0.001; anti-VEGF group: 725.00±290.79 203.56±69.89 µm, =0.001; combination group: 595.50±186.51 253.13±55.06 µm, =0.001; observation group: 758.88±195.65 267.00±120.90 µm, =0.001). RHA were 28.99±28.15, 25.94±11.58, 19.64±8.97, and 27.45±13.76 mm in laser group, anti-VEGF group, combination group and observation group, respectively. RHA was statistically correlated with final VA (=0.032) in the observation group.
CONCLUSION
Both laser and anti-VEGF treatments are effective for hemorrhagic RAM. Combination therapy reduces the number of injections of anti-VEGF. RHA is a visual prognosis predictor in the natural history of hemorrhagic RAM.
PubMed: 38111952
DOI: 10.18240/ijo.2023.12.17 -
Computers in Biology and Medicine Feb 2024Diabetic retinopathy is the main cause of blindness, and lesion segmentation is an important basic work for the diagnosis of this disease. The main lesions include soft...
Diabetic retinopathy is the main cause of blindness, and lesion segmentation is an important basic work for the diagnosis of this disease. The main lesions include soft and hard exudates, microaneurysms, and hemorrhages. However, the segmentation of these four types of lesions is difficult because of their variability in size and contrast, and high intertype similarity. Currently, many network models have problems, such as a large number of parameters and complex calculations, and most segmentation models for diabetic retinopathy focus only on one type of lesion. In this study, a lightweight algorithm based on BiSeNet V2 was proposed for the segmentation of multiple lesions in diabetic retinopathy fundus. First, a hybrid attention module was embedded in the semantic branch of BiSeNet V2 for 8- and 16-fold downsampling, which helped reassign deep feature-map weights and enhanced the ability to extract local key features. Second, a ghost feature-mapping unit was used to optimize the traditional convolution layers and further reduce the computational cost. Third, a new loss function based on the dynamic threshold loss function was applied to supervise the training by adjusting the training weights of the high-loss difficult samples, which enhanced the model's attention to small goals. In experiments on the IDRiD dataset, we conducted an ablation study to verify the effectiveness of each component and compared the proposed model, BiSeNet V2-Pro, with several state-of-the-art models. In comparison with the baseline BiSeNet V2, the segmentation performance of BiSeNet V2-Pro improved by 12.17 %, 11.44 %, and 8.49 % in terms of Sensitivity (SEN), Intersection over Union (IoU), and Dice coefficient (DICE), respectively. Specifically, IoU of MA reaches 0.5716. Compared with other methods, the segmentation speed was significantly improved while ensuring segmentation accuracy, and the number of model parameters was lower. These results demonstrate the superiority of BiSeNet V2-Pro in the multi-lesion segmentation of diabetic retinopathy.
Topics: Humans; Diabetic Retinopathy; Algorithms; Fundus Oculi; Semantics; Image Processing, Computer-Assisted; Diabetes Mellitus
PubMed: 38109836
DOI: 10.1016/j.compbiomed.2023.107854