Segmentation of retinal microaneurysms in fluorescein fundus angiography images by a novel three-step model.

Introduction: Microaneurysms serve as early signs of diabetic retinopathy, and their accurate detection is critical for effective treatment. Due to their low contrast and similarity to retinal vessels, distinguishing microaneurysms from background noise and retinal vessels in fluorescein fundus angiography (FFA) images poses a significant challenge. Methods: We present a model for automatic detection of microaneurysms. FFA images were pre-processed using Top-hat transformation, Gray-stretching, and Gaussian filter techniques to eliminate noise. The candidate microaneurysms were coarsely segmented using an improved matched filter algorithm. Real microaneurysms were segmented by a morphological strategy. To evaluate the segmentation performance, our proposed model was compared against other models, including Otsu's method, Region Growing, Global Threshold, Matched Filter, Fuzzy c-means, and K-means, using both self-constructed and publicly available datasets. Performance metrics such as accuracy, sensitivity, specificity, positive predictive value, and intersection-over-union were calculated. Results: The proposed model outperforms other models in terms of accuracy, sensitivity, specificity, positive predictive value, and intersection-over-union. The segmentation results obtained with our model closely align with benchmark standard. Our model demonstrates significant advantages for microaneurysm segmentation in FFA images and holds promise for clinical application in the diagnosis of diabetic retinopathy. Conclusion: The proposed model offers a robust and accurate approach to microaneurysm detection, outperforming existing methods and demonstrating potential for clinical application in the effective treatment of diabetic retinopathy.

Comparison of widefield swept-source optical coherence tomographic angiography and fluorescein fundus angiography for detection of retinal neovascularization with diabetic retinopathy.

BACKGROUND: To compare vitreous angiomosaic images (VAMIs), obtained by widefield swept-source optical coherence tomographic angiography (wfSS-OCTA) and the image of fluorescein fundus angiography (FFA) in the identification of retinal neovascularization (NV) in patients with diabetic retinopathy (DR). METHODS: In this prospective observational study, severe non-proliferative diabetic retinopathy (NPDR) or proliferative DR (PDR) patients were included. All patients underwent FFA and wfSS-OCTA. The number of NVs identified by wfSS-OCTA VAMIs using five fixations 12 × 12 mm montage scans and the resembling FFA images were compared. RESULTS: Fifty-three eyes of 29 patients were enrolled. NVs were detected in 25 eyes by using FFA, including 9 NVs of the disc (NVDs) and 72 NVs elsewhere (NVEs), and in 29 eyes by OCTA, including 11 NVDs and 90 NVEs. The detection rate of NV and NVD of OCTA was comparable to that of FFA (p > 0.05), and the level of agreement was excellent (κ = 0.850, κ = 0.754). Using FFA as the gold standard, the sensitivity for detection of NV by OCTA was 100.0%, specificity was 85.7%, the positive-predictive value was 86.2%, and the negative-predictive value was 100.0%. Compared with FFA, OCTA was superior in terms of the number of NVEs identified (p = 0.024). When we excluded images of patients treated with anti-vascular endothelial growth factor (VEGF) intravitreal therapy for < 3 months, OCTA was comparable to FFA in terms of the number of NVEs discovered (p = 0.203), with excellent agreement (intraclass correlation coefficient = 0.941). CONCLUSIONS: WfSS-OCTA is an independent non-invasive alternative to FFA for NV discovery, NVD detection, and individual NVE identification, particularly in patients with PDR who have a history of prior treatment with anti-VEGF.

IRVAN syndrome: A case report and a literature review.

Introduction and Importance: Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome is a rare retinal defect. It has a female predominance. The staging of IRVAN was defined depending on ocular criteria. Case presentations: A 30-year-old female patient presented with floaters in the left eye. One year later, it was diagnosed with Fluorescein fundus angiography (FFA) at stage Ⅲ of IRVAN syndrome. After one year, the right eye was affected, diagnosed at stage Ⅱ, and successfully treated with heavy Pan-Retinal Photocoagulation (PRP). Clinical discussion: IRVAN Syndrome is an extremely rare retinal defect which has female predominance. The etiology of this syndrome still idiopathic. The most encountered symptoms are blurred vision and vision loss. FFA is the best diagnostic investigation to reveal the retinal abnormalities. Many suggested protocols were mentioned to treat IRVAN Syndrome. Our experience suggests IRVAN Syndrome a differential diagnosis for patients with floaters, and assures that PRP is an affective curement for late stages of IRVAN Syndrome. Conclusions: Heavy PRP was used successfully for stage II and III. The case emphasizes the importance of early diagnosis to assert the complications. Furthermore, IRVAN syndrome should be considered as a differential diagnosis in patients with floaters. Therefore, heavy PRP is highly recommended as a suitable treatment for IRVAN syndrome.

Diagnostic value of OCTA and FFA in central serous chorioretinopathy complicated with choroidal neovascularization: a meta-analysis / 中华实验眼科杂志

Objective:To systematically evaluate the diagnostic value of optical coherence tomography angiography (OCTA) and fluorescein fundus angiography (FFA) for choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC).Methods:PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Internet (CNKI), VIP database and Wanfang Database were searched for literature published from January 1991 to March 2020 with CSC patients as subjects and OCTA and FFA as diagnostic methods of CNV.The quality of the included literature was evaluated with Australian JBI tool.A meta-analysis was performed using Review Manager 5.3 software.The source of heterogeneity was identified by age and total number of samples subgroup analysis.Results:Nine studies with a total sample size of 374 eyes were enrolled.The quality score of 8 studies was greater than 14.The detection rate of CNV in CSC by OCTA was higher than that by FFA [odds ratio( OR)=3.99, 95% confidence interval( CI): 1.44-11.07, P<0.001].Studies with sample size >40 showed no heterogeneity ( I2=49%, P=0.14), suggesting that sample size might be a source of heterogeneity.Publication bias was found by funnel plot. Conclusions:OCTA has a higher detection rate of CNV secondary to CSC than FFA, and it can be used as a routine inspection method.

Characteristic changes of macular microvascular structure in central retinal vein occlusion / 中华实验眼科杂志

Objective:To explore the microvasculature changes in macular area of central retinal vein occlusion (CRVO) patients with macular edema (ME).Methods:A cross-sectional study was conducted.Fifteen patients with monocular ME secondary to CRVO (30 eyes) and 15 age- and gender-matched normal subjects (15 eyes) were enrolled in The Second Affiliated Hospital of Chongqing Medical University from November 2017 to March 2019.Best corrected visual acuity (BCVA), intraocular pressure, slit lamp microscope with pre-set lens, color fundus photography and optical coherence tomography (OCT) were performed in all subjects.The central macular thickness (CMT), foveal avascular zone (FAZ) area, FAZ perimeter, acircularity index (AI), vessel density of superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP) in 3 mm×3 mm macular area were measured by optical coherence tomography angiography instrument and compared between different groups.The correlation between BCVA, CMT and microvascular structural parrameters in ME eyes of CRVO patients was analyzed by Pearson linear correlation test.This study protocol adhered to the Declaration of Helsinki and was approved by the Ethics Committee of The Second Affiliated Hospital of Chongqing Medical University (No.2018-211).Written informed consent was obtained from each subject before any medical examination.Results:Compared with contralateral eyes, the FAZ area and FAZ perimeter of ME eyes were significantly increased, and AI, the vessel density of SCP and DCP were significantly decreased (all at P<0.01).Compared with normal control eyes, the FAZ area and FAZ perimeter of contralateral eyes of CRVO patients were significantly increased, and AI, the vessel density of DCP were significantly decreased (all at P<0.05).In ME eyes, the BCVA LogMAR was positively correlated with FAZ area and FAZ perimeter ( r=0.614, 0.609; both at P<0.05), and was negatively correlated with AI and vessel density of SCP ( r=-0.517, -0.593; both at P<0.058).In ME eyes, CMT was positively correlated with FAZ area and FAZ perimeter ( r=0.523, 0.610; both at P<0.05), and was negatively correlated with AI and the vessel density of SCP ( r=-0.537, -0.608; both at P<0.05). Conclusions:The characteristic microvascular change in ME secondary to CRVO eyes is the decrease of blood flow caused by the decrease of capillaries in fovea, and the same change in blood flow also exists in their contralateral eyes.The degree of ME and visual function damage are correlated with the degree of foveal damage and the blood flow in fovea.

Repurposing bortezomib for choroidal neovascularization treatment via antagonizing VEGF-A and PDGF-D mediated signaling.

Neovascular age-related macular degeneration (neoAMD) is the leading cause of blindness in AMD and manifests as choroidal neovascularization (CNV). Anti-vascular endothelial growth factor (VEGF) therapies are the mainstay treatments but with limited efficacy and cause detrimental effects on the retina after long-term application. These disadvantages warrant alternative strategy. Herein, we examined the effect on CNV by intravitreal injection of bortezomib, a reversible proteasome inhibitor, and further dissected the mechanism. Krypton red Laser was used to create CNV model in mice. The angiogenesis volume was assessed in choroidal flat-mount with isolectin GS-IB4 labeling and the leakage was examined with fluorescein fundus angiography. Injection of Borsub inhibited angiogenesis in the CNV model which was dose-dependent; the injection significantly inhibited leakage as well. Furthermore, Borsub injection reduced the contents of VEGF-A, macrophage chemotactic factor 1 (MCP-1), and platelet-derived growth factor (PDGF)-D but not PDGF-B, examined by enzyme-linked immunosorbent assay, in choroid/retinal pigment epithelium (RPE) tissue. These injections also reduced phospho-VEGFR-2 and phospho-PDGFRß in choroid/RPE tissue examined by immunoblotting. Moreover, Borsub inhibited the recruitment of mural cells or macrophages to laser-injured spots. Injection of Borsub indicated negative effect on scotopic and photopic responses recorded by electroretinogram. Altogether, intravitreal injection of Borsub significantly reduced CNV by antagonizing VEGF-A/Flk-1 and PDGF-D/PDGFRß pathways without impacting electroretinography parameters. Thus, Borsub may offer an invaluable therapy for the prevention and treatment of neoAMD.

Application of ophthalmic methods in age-related macular degeneration / 国际眼科杂志(Guoji Yanke Zazhi)

As the increasing population aging,the incidence of age-related macular degeneration is increasing,blinding rate also increasing,so it is very important for the early diagnosis and treatment of age-related macular degeneration.There are many methods to check the aging macular degeneration,such as fundus angiography,optical coherence tomography (OCT),visual field and multifocal electroretinogram (mfERG).In recent years,many emerging ophthalmic methods have emerged and are gradually applied to clinical diagnosis,including optic coherence tomography angiography (OCTA).The function of these methods has its unique advantages,but there are also limitations.This paper will review these existing methods.

Evaluation and types of fundus characters in systemic lupus erythematosus / 眼科新进展

Objective To analyze the clinical characteristics of fundus changes in systemic lupus erythematosus (SLE) patients.Methods Color fundus and FFA were performed in 27 SLE patients (54 eyes) with fundus abnormalities.Clinical characteristics were analyzed.SLE disease activity index (SLEDAI) was evaluated in the patients.SLEDAI was analyzed by SPSS 19.0 Student-t test.Results Four clinical types were found in 27 patients.Capillary obstruction was found in 28 eyes of 14 patients,retinal artery occlusion in 11 eyes of 6 patients,retinal vein occlusion in 7 eyes of 6 patients,choroidal vessel obstruction in 2 eyes of 1 patient.SLEDAI was evaluated in 24 patients.SLEDAI in 5 patients with retinal artery occlusion was (25.6 ± 2.2) scores,which was significantly higher than other patients(18.2 ± 2.9)scores (P ＜0.05).Conclusion This clinical typing scheme may help to know fundus abnormalities in SLE patient,and it may be related to SLE activity.SLEDAI in patients with retinal artery occlusion is higher than other patients.

Spectral-domain optical coherence tomography characteristics of acute central serous chorioretinopathy / 中华眼底病杂志

Objective To observe the characteristics of spectral-domain optical coherence tomography (SD-OCT) for leakage point in acute central serous chorioretinopathy (CSC).Methods A total of 21 acute CSC patients (21 eyes) were enrolled in this retrospective study,including 17 men (17 eyes) and 4 women (5 eyes).The mean age was (47.3±8.8) years (range 35-66 years).The mean duration was (1.6±0.8) months (range 0.5-3.0 months).All patients were underwent mydriatic fundus photography,SD-OCT examination and fluorescein fundus angiography (FFA).SD-OCT and FFA images were carefully compared to observe the SD-OCT examination characteristics of fluorescence leakage point.Results 21/21 eyes had one fluorescein leakage point.In addition to serous retinal detachment,leakage point in the SD-OCT examination showed retinal pigment epithelium (RPE) protrusion in 10 eyes (47.6 ％),RPE detachment in 7 eyes (33.3 ％),highly reflective areas suggesting fibrinous exudate in the subretinal space in 3 eyes (14.3 ％),and RPE defect in 1 eye (4.8 ％).Conclusion The SD-OCT characteristics of acute CSC include RPE protrusion,RPE detachment,highly reflective areas suggesting fibrinous exudate in the subretinal space and RPE defect.

Application of OCT angiography in ophthalmology / 国际眼科杂志(Guoji Yanke Zazhi)

Optical coherence tomography angiography (OCTA) is a new technology of angiography in recent years.In addition to the advantages of traditional OCT,it can observe blood flow in different retinal and choroidal segmentation slab.By using the pseudo-color,abnormal vascular structure can be distinguished from normal vascular structure of the retina.Dye injection is not needed with OCTA,which is different from fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA).OCTA provides more and more accurate blood flow information.However,like other biometric technology,OCTA has its limitations and shortcomings.This review will analyze and summarize the operating principle of OCTA,its application in ophthalmology,as well as its advantages and limitations.

A Case of Uveal Colobomas Showing Marked Left-Right Difference in Diabetic Retinopathy.

PURPOSE: Congenital uveal colobomas, including inferior iris and choroidal colobomas, are associated with microcornea and microphthalmia and often show left-right differences (laterality). The purpose of this study was to report a case of choroidal coloboma associated with left-right differences in diabetic retinopathy (DR). CASE: This study reports a 59-year-old male with bilateral iris and choroidal colobomas. The colobomatous area in the patient's right eye extended to the macula, and his right eye had been amblyopic since birth. The colobomatous area in his left eye was less extensive and did not involve the macula. Examination of the patient's left eye revealed multiple hemorrhages and hard exudates in the macula due to DR, but examination of his right eye showed almost no changes in DR, thus revealing a marked left-right difference. Optical coherence tomography showed more extensive retinal thinning in the patient's right eye than in his left eye. Fluorescein fundus angiography revealed a retinal nonperfusion area only in the left eye, and panretinal photocoagulation was subsequently performed. CONCLUSION: Our findings show that the reason for the left-right difference in DR was attributed to the more severe choroidal coloboma and retinal thinning in the patient's right eye compared to his left eye, thus reducing oxygen demand, as is also seen in eyes with severe myopia.

Characteristics of optical coherence tomography image in diabetic optic neuropathy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To analyze the characteristics of optical coherence tomography ( OCT ) in diabetic optic neuropathy ( DON ) retrospectively. ●METHODS:Retrospective study. A total of 175 cases of type ll diabetes with fundus lesions from Dec. 2013 to Dec. 2015 were selected and the clinical information was collected. These cases were diagnosed by consultation between Departments of Ophthalmology and Endocrinology in the Second Affiliated Hospital of Xi′an Jiao Tong University. The results of body examination were recorded and cases were examined by color fundus photography, fluorescein fundus angiography ( FFA) and OCT. All these data were analyzed. ●RESULTS: A total of 49 cases ( 90 eyes, 25. 7%) were diagnosed DON through FFA which manifested abnormal fluorescence in optic papilla. Results of OCT showed:among 90 eyes of DON patients, 15 eyes ( 16. 7%) had normal optic nerve form; 20 eyes(22. 2%) of excavation of optic disc became smaller or disappeared, with prelaminar tissue and peripapillary retinal nerve fiber layer (RNFL) swelling;26 eyes (28. 9%) manifested optic cup deep and cup/disc ratio increasing;18 eyes (20. 0%) had tissue hyperplasia in the hollow or on the surface of optic disc; 11 eyes(12. 3%) had symptoms including vitreous traction optic papilla and optic disc rim rising. DON eyes which had similar fluorescence features could manifest different tissue morph by OCT. ●CONCLUSION: FFA defines DON by change of blood circulation in optic nerve. However, OCT can show differences of tissue morph of optic nerve that FFA fails to do. So OCT can manifest the causes and sites of optic neuropathy more clearly and also provide basis for treatment. The advantages of OCT are conducive to reviews and curative effect tracking among DON patients and these advantages including noninvasive, convenient, inexpensive and repeatable.

Clinical manifestations of syphilitic chorioretinitis: a retrospective study.

BACKGROUND: Syphilitic chorioretinitis can produce severe vision loss. However, the clinical manifestations of syphilitic chorioretinitis are still unclear, particularly during different stages. Herein, we will present our diagnostic technique for syphilitic chorioretinitis. METHODS: This retrospective study recruited 109 cases; we performed a clinical evaluation including case history, serology analysis, fundus photography, fluorescein fundus angiography with or without indocyanine green angiography, auto-fluorescence, and optical coherence tomography. RESULTS: 109 were diagnosed with acute syphilitic posterior placoid chorioretinitis by fundus photograph that revealed filthy, yellowish-white lesions. For autofluorescence, during early-stage syphilitic chorioretinitis, hyperfluorescence could be observed. During the convalescence stage, the fluorescence became hypofluorescence or disappeared. Fluorescein fundus angiography indicated early-stage transmitted fluorescence or hypofluorescence. During the venous stage, the lesion area had fluorescent leakage, mostly accompanied by retinal vasculitis. During the late stage, speckle staining was observed with optic disc fluorescence. Hypofluorescence or undistinguishable fluorescence was seen at an early stage with indocyanine green angiography. At an advanced stage, the lesion had obvious hypofluorescence. Optical coherence tomography indicated various inner segment/outer segment damage, accompanied by retinal pigment epithelium impairment. The inner segment/outer segment alteration could be lessened with treatment. CONCLUSIONS: The clinical manifestations of syphilitic chorioretinitis include impaired vision, shadow blocking, or photopsia of one or both eyes. Fundus photography, fluorescein fundus angiography with or without indocyanine green angiography, autofluorescence, and optical coherence tomography could be useful accessory examinations. Autofluorescence and optical coherence tomography could be the main examinations for monitoring disease progression.

Flourescein Angiogram and Funduscopic Features of Radiation Induced Retinopathy: A Descriptive Value of Retinopathy Severity in Patients with Nasopharyngeal Carcinoma

Radiation retinopathy (RR) is a known complication after radiotherapy for Nasopharyngeal Carcinoma (NPC). This study aims to relate the relationship of RR and radiation dose in patients with NPC through assessment with clinical funduscopy and fundus fluorescein angiogram (FFA). A cross sectional study was conducted on patients with NPC who had completed radiotherapy treatment in the Oncology Clinic, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Eighty two eyes of 42 patients were examined and the prevalence of RR was found to be 35.4%. The severity of RR is strongly associated with the dose of radiation to the retina (Spearman correlation value=0.48; p<0.001). The common features of RR assessed by FFA were telangiectatic vessels (26.2%) and capillary non-perfusion (14.3%). Retinal neovasularization occurred in 10.7% of eyes. The level of visual deterioration correlated with the severity of RR with 26% of eyes experiencing a visual acuity of 6/18 or worse. More than one third of patients developed RR, with radiation maculopathy being the commonest cause for significant visual loss. FFA is a useful tool in detecting early signs of radiation retinopathy and maculopathy. Keywords:

Clinical features of acute retinal pigment epitheltis / 国际眼科杂志(Guoji Yanke Zazhi)

Abstract?AlM:To analyze of the clinical features of acute retinal pigment epitheltis ( ARPE) .?METHODS: The clinical data of 36 ARPE patients ( 40 eyes) attending this center from January 2008 to January 2014 were reviewed retrospectively. Of them, 21 patients (58.3%) were male (male :female=1:0. 71). The mean age was 40. 92±7. 13 years old (range:17~60y). The mean best-corrected visual acuity (BCVA) was 0. 50±0. 26 with a range of 0. 3 ~ 1. 0. Thirty-two patients were unilateral cases. All the patients were examined for BCVA, funds photography, fluorescein fundus angiography ( FFA ) , optical coherence tomography ( OCT) . FFA was shown as three types: type ▏ to multiple black light or grape variety fluorescent spot; Type II for l lesions visible fluorescence leakage; Type Ⅲ lesions with choroid neovascularization ( CNV ) . OCT was the following three forms: multiple RPE lesions layer reflection intermittent, proliferation ( type ▏); pigment epithelial detachment with limitations neural epithelium ( typeII);types l and ll with CNV ( type Ⅲ) .?RESULTS: Ocular fundus showed that the lesions were multiple dark-gray spots with a dark circumscribed area at the macular or nearby in all 40 eyes. FFA showed:21 eyes were type ▏, 17 eyes were type II and 2 eyes were typeⅢ, BCVA between type ▏ and type II was statistically significant (P0. 05). OCT showed 21 eyes wwere type ▏, 17 eyes were type II and type Ⅲ 2 eyes. BCVA average between type▏ andIIwas statistically significant (P0. 05).?CONCLUSlON:ARPE fundus demonstrated the multiple dark gray discrete lesions, the degree of visual impairment related with the presence of pigment epithelial barrier and lesion location. OCT and FFA characterized three types. FFA is shown asblack light orgrape variety fluorescent spot, and is the basis of diagnosis. OCT can display the lesions organization form of each layer clearly. lt plays a more and more important role in the diagnosis and differential diagnosis of ARPE.

Bilateral Common Carotid Artery Occlusion in the Rat as a Model of Retinal Ischaemia.

Ocular ischaemic syndrome is a devastating eye disease caused by severe carotid artery stenosis. The purpose of the study was to develop a reliable rat model for this syndrome by means of common carotid artery occlusion and a controllable needle suture method. Adult Wistar rats were subjected to common carotid artery occlusion and sham surgery. The common carotid artery was ligated unilaterally or bilaterally with needles of different diameters, and ocular arterial filling time was examined by fluorescein fundus angiography at different time points. Haematoxylin-eosin staining of vessels and degree of stenosis were considered outcome measures. The ocular blood flow was monitored and measured by laser doppler flowmetry. Needles with a diameter of 0.4 mm were more effective in developing severe stenosis of the common carotid arteries compared with needles of other diameters. Bilateral common carotid artery occlusion was a more effective model than unilateral occlusion. The arterial filling time was significantly increased at 14 and 21 days after ligation (5.75 ± 0.45 and 6.27 ± 0.95 s, respectively) compared with arterial filling time before surgery (5.22 ± 0.64 s). The total blood flow in the sham surgery group was significantly higher than in the bilateral common carotid artery occlusion group. The fundus blood flow was statistically different between the two groups, whereas that of the anterior segment was not. In conclusion, the authors have established a rat model of ocular ischaemic syndrome via a controllable needle suture method, which was reliable up to 2-3 weeks after surgery.

A case of cilioretinal artery occlusion resembling hemicentral retinal artery occlusion.

A 77-year-old man presented with an inferior hemivisual field defect in the left eye. Funduscopy revealed well demarcated retinal edema of the superior quadrant resembling hemicentral retinal artery occlusion. Further, the upper and inferior retinal arteries emerged separately from the optic disc. Fluorescein angiography demonstrated a marked filling delay of the upper retinal artery. We repeated fluorescein angiography, which showed that the involved upper retinal artery was a cilioretinal artery having an earlier dye appearance than the lower retinal artery. We suggest that when cases of hemicentral retinal artery occlusion are encountered, vascular architecture at the optic disc should be evaluated carefully.

Analysis of Fluorescein Fundus Angiography for Central Serous Choroidoretinopathy / 昆明医科大学学报

The pictures of 78 cases (86 eyes) of central serous choroidoretinopathy taken by fluorescein fundus angiography were anslyzed in this article. The results based on the observation of leaking shape showed that the jet type was more during the early period of illness, whereas the spread type was more during the late period of illness. It is significant to diagnose and treat central serous choroidoretinopathy with fluorescein fundus angiography.