Intelligent diagnosis of retinal vein occlusion based on color fundus photographs

AIM:To develop an artificial intelligence(AI)diagnosis model based on deep learning(DL)algorithm to diagnose different types of retinal vein occlusion(RVO)by recognizing color fundus photographs(CFPs).METHODS:Totally 914 CFPs of healthy people and patients with RVO were collected as experimental data sets,and used to train,verify and test the diagnostic model of RVO.All the images were divided into four categories[normal,central retinal vein occlusion(CRVO),branch retinal vein occlusion(BRVO),and macular retinal vein occlusion(MRVO)]by three fundus disease experts.Swin Transformer was used to build the RVO diagnosis model,and different types of RVO diagnosis experiments were conducted.The model’s performance was compared to that of the experts.RESULTS:The accuracy of the model in the diagnosis of normal,CRVO,BRVO,and MRVO reached 1.000,0.978,0.957,and 0.978;the specificity reached 1.000,0.986,0.982,and 0.976;the sensitivity reached 1.000,0.955,0.917,and 1.000;the F1-Sore reached 1.000,0.9550.943,and 0.887 respectively.In addition,the area under curve of normal,CRVO,BRVO,and MRVO diagnosed by the diagnostic model were 1.000,0.900,0.959 and 0.970,respectively.The diagnostic results were highly consistent with those of fundus disease experts,and the diagnostic performance was superior.CONCLUSION:The diagnostic model developed in this study can well diagnose different types of RVO,effectively relieve the work pressure of clinicians,and provide help for the follow-up clinical diagnosis and treatment of RVO patients.

Dexamethasone implant for refractory macular edema secondary to diabetic retinopathy and retinal vein occlusion

AIM:To evaluate the efficacy,timing of retreatment and safety of dexamethasone(DEX)implant on macular edema(ME)secondary to diabetic retinopathy(DME)and retinal vein occlusion(RVO-ME)patients who were refractory to anti-vascular endothelial growth factor(VEGF)treatment.METHODS:This retrospective study included 37 eyes received at least one DEX implant treatment for DME or RVO-ME between January 1,2019,and January 1,2023.These refractory DME and RVO-ME cases received at least 5 anti-VEGF injections and failure to gain more than 5 letters or a significant reduction in central retinal thickness(CRT).The best corrected visual acuity(BCVA)and CRT were measured at baseline,and at 1,3,4 and 6mo post-DEX implant injection.Adverse events such as elevated intraocular pressure(IOP)and cataract were recorded.RESULTS:For RVO cases(n=22),there was a significant increase in BCVA from 0.27±0.19 to 0.35±0.20 at 6mo post-DEX injection(P<0.05)and CRT decreased from 472.1±90.6 to 240.5±39.0μm at 6mo(P<0.0001).DME cases(n=15)experienced an improvement in BCVA from 0.26±0.15 to 0.43±0.20 at 6mo post-DEX implant injection(P=0.0098),with CRT reducing from 445.7±55.7 to 271.7±34.1μm at 6mo(P<0.0001).Elevated IOP occurred in 45.9%of patients but was well-controlled with topical medications.No cases of cataract or other adverse events were reported.CONCLUSION:DEX implants effectively improve BCVA and reduce CRT in refractory DME and RVO-ME.Further research with larger cohorts and longer follow-up periods is needed to confirm these findings and assess long-term outcomes.

Comparative Quantitative Analysis of Retinal Superficial Capillary Plexus in Patients with Retinal Vein Occlusion and Unaffected Fellow Eyes

Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered from unaffected fellow eyes. Methods: The examined patients were classified into 2 groups: group 1—eyes with established retinal vein occlusion (n = 29) and group 2—unaffected fellow eyes of patients with retinal vein occlusion (n = 24). The scanning protocol “Angiography 3 × 3 mm” of Zeiss Cirrus HD-OCT 6000, AngioPlex Metrix was used to evaluate the retinal superficial capillary plexus. The analyzed parameters were vascular density and perfusion density, as well as the area, perimeter, and circularity of the foveolar avascular zone (FAZ). Results: The comparative analysis of FAZ parameters at the superficial capillary plexus (SCP) between group 1 (eyes with retinal vein occlusion) and group 2 (unaffected fellow eyes) showed significant results for the three parameters, respectively area (p = 0.003), perimeter (p ≤ 0.001), and circularity (p = 0.011) of FAZ. The comparative analysis of the vascular network at SCP in patients with diagnosed retinal vein occlusion and unaffected fellow eyes showed significant results for vascular density (VD) in the central (p = 0.038) and inner (p ≤ 0.001) zones as well as total VD (p ≤ 0.001) were statistically significant. Moreover, the results obtained in the study of vascular perfusion (VP) indicated significant results in the inner zone (p ≤ 0.001) and total VP (p = 0.001). Vascular perfusion in the central zone (p = 0.116) was the only parameter not to meet significant results. Conclusion: The current study observed a significant enlargement of the FAZ and loss of its circularity, along with a reduction in vascular network parameters at the superficial retinal capillary plexus level.

Comparison of efficacy of conbercept,aflibercept,and ranibizumab ophthalmic injection in the treatment of macular edema caused by retinal vein occlusion:a Meta-analysis

AIM:To evaluate and compare the anatomical and functional outcomes and negative effects of the three anti-vascular endothelial growth factor(VEGF)drugs in the treatment of macular edema(ME)due to retinal vein occlusion(RVO)based on the evidence pooled from current clinical trials and observational studies.METHODS:A systematic literature search was conducted on nine online databases from inception until April 30,2022.The main endpoints were best corrected visual acuity(BCVA),central macular thickness(CMT),and adverse events(AEs).Cumulative Meta-analysis was conducted to synthesize the outcomes of the drugs.The retrieved data were analyzed using Stata software(version 12.0).RESULTS:A total of 20 studies comprising 1674 eyes met the inclusion criteria to the Meta-analysis.It was observed that conbercept and aflibercept had better visual acuity effects compared with ranibizumab at 1mo[weight mean difference(WMD)=-0.03,P=0.001;WMD=-0.05,P=0.019],but the effects were not different from that of ranibizumab at 6mo.Moreover,there was not statistically significant dif ference in the propor tion of patients gaining≥15 letters at 12-24mo between aflibercept and ranibizumab[odds ratio(OR)=1.16,P=0.427].Conbercept had higher mean CMT change effects at 1mo(WMD=-14.43,P=0.014)and 6mo(WMD=-35.63,P≤0.001)compared with ranibizumab.Meanwhile,the mean CMT change effects at 1mo(WMD=-10.14,P=0.170),6mo(WMD=-26.98,P=0.140)and 12-24mo(WMD=-12.34,P=0.071)were comparable among the groups.Similarly,AEs were not significantly different among the treatments(OR=0.75,P=0.305;OR=1.04,P=0.89).The stability of effect size of mean BCVA and CMT improved with the increase in sample size.Aflibercept and conbercept required fewer injections compared with ranibizumab.CONCLUSION:This is the first study to evaluate the efficacy and AEs of intravitreal administration of conbercept,ranibizumab,and aflibercept in the treatment of RVOME.Intravitreal aflibercept or conbercept results in better mean change in vision and CMT reduction compared with ranibizumab.Conbercept can be considered to be a promising and innovative drug with good anti-VEGF effects.

Long-term outcomes of anti-VEGF treatment with 5+PRN regimen for macular edema due to central retinal vein occlusion

AIM:To assess the long-term outcomes of treating macular edema(ME)associated with central retinal vein occlusion(CRVO)with a regimen of“5+pro re nata(PRN)”.METHODS:This retrospective study included 27 eyes of 27 patients with ME associated with non-ischemic CRVO(non-iCRVO group,n=15)and ischemic CRVO(iCRVO group,n=12).The eyes were treated with five consecutive intravitreal injections of conbercept or ranibizumab,followed by reinjections as needed or PRN.Retinal laser photocoagulation or intravitreal dexamethasone implants(DEX)were implemented in both groups when necessary.The best-corrected visual acuity(BCVA,logMAR)and central retinal thickness(CRT)were recorded at baseline,at 1,2,3,4,5,6,and 12mo,and at the final visit.The efficacy rates of BCVA and CRT before and after treatment were calculated.The number of injections at each visit and the incidence of adverse events were also recorded.RESULTS:The patients,aged 59.4±15.1y,were followed up for 24.7±8.8mo(range:15-42mo).After treatment,BCVA improved significantly from 1.04±0.56 logMAR at baseline to 0.59±0.36 logMAR(P=0.038)at the final visit in all patients.Both the non-iCRVO and the iCRVO groups achieved improved BCVA compared to the baseline at all visit points,but there was no statistical significance(P=0.197 and 0.33,respectively).The mean CRT was statistically reduced compared to baseline at all visit points in all the eyes and in both groups(all P<0.001).The apparent effective rate was 22.22% for BCVA and 37.04% for CRT after the first injection,48.15%for BCVA and 62.96% for CRT after 5 consecutive injections,and 74.08% for BCVA and 100% for CRT at the end of follow up.The average number of injections in all patients was 9.0±2.4 at 12mo and 14.9±8.1 finally with no statistical significance between both groups(P>0.05).Laser treatment was applied to all eyes in the iCRVO group,while only 5 patients in the noniCRVO group.Six patients in the non-iCRVO group and 3 patients in the iCRVO group had a drug switch.DEX was applied to 4 eyes in the non-iCRVO group and 5 eyes in the iCRVO group.CONCLUSION:The 5+PRN anti-vascular endothelial growth factor(VEGF)regimen is found to be safe and effective for both iCRVO and non-iCRVO,especially in the iCRVO group.The best regimen for such patients needs to be further investigated.Adjuvant laser therapy and DEX are necessary in some cases.

Differential analysis of aqueous humor cytokine levels in patients with macular edema secondary to diabetic retinopathy or retinal vein occlusion

AIM:To evaluate the difference and the correlation between the concentrations of cytokines in the aqueous humor of eyes with macular edema secondary to diabetic retinopathy(DR)or retinal vein occlusion(RVO).METHODS:This is a retrospective case control study.The aqueous humor samples were collected during intravitreal injection of anti-vascular endothelial growth factor(VEGF)for patients diagnosed with macular edema secondary to DR(DME)or RVO(RVO-ME)at Xijing Hospital from August 2021 to July 2022.Meanwhile,aqueous humor samples during vitrectomy from patients with idiopathic macular hole(IMH)were also collected and served as controls.The aqueous humor concentrations of VEGF,platelet-derived factor(PDGF),interleukin(IL)-6,IL-8,IL-18,tumor necrosis factor-α(TNF-α)and monocyte chemoattractant protein 1(MCP-1)were measured with Human Premixed Multi-Analyte Kit(Luminex).The difference of the aqueous cytokines and the correlation between the two diseases were analyzed.RESULTS:A total of 40 eyes of 38 patients were enrolled in the study,including 13 eyes of 11 DME patients(DME group),16 eyes of 16 RVO-ME patients(RVO-ME group)and 11 eyes of 11 IMH patients(control group).The VEGF,PDGF,IL-6,IL-8,and MCP-1 levels of the aqueous humor were higher in both DME and RVO-ME groups compared with the control group(all P<0.05),the levels of TNF-αwas higher in the DME group than in the control group(P<0.05).The VEGF,IL-6,MCP-1,and TNF-αlevels in the aqueous humor were significantly higher in the DR group than those in the RVO group(all P<0.05).Correlation analyses revealed that there were complex positive correlations between IL-6,IL-8,IL-18,MCP-1,and TNF-αlevels in the aqueous humor of eyes with two diseases.CONCLUSION:Although ischemic and inflammatory factors are similarly involved in the pathogenesis of DME and RVO-ME,the roles of these factors are more significant or more likely to be activated in DR patients,suggesting different treatment strategies should be considered for the two diseases.

Optical coherence tomography angiography for macular microvessels in ischemic branch retinal vein occlusion treated with conbercept:predictive factors for the prognosis

AIM:To evaluate the predicative factors of visual prognosis using optical coherence tomography angiography(OCTA)in ischemic branch retinal vein occlusion(BRVO)patients with macular edema(ME)after anti-vascular endothelial growth factor(VEGF)treatment.METHODS:In this retrospective analysis,data from 60 patients(60 eyes)with a definite diagnosis of ischemic BRVO with ME by fundus fluorescein angiography(FFA)were studied.The eyes with ME according to spectral domain optical coherence tomography(SD-OCT)underwent intravitreal conbercept(IVC)and 3+pro re nata(PRN)regimen.The injection times were recorded.Two weeks after injection,fundus laser photocoagulation was performed in the non-perfusion area of the retina.The patients were followed up once a month for 6mo.The bestcorrected visual acuity(BCVA),foveal avascular zone(FAZ),and A-circularity index(AI),at 6mo and the baseline were compared.RESULTS:All patients showed significant improvement in BCVA from 0.82±0.32 to 0.39±0.11 logMAR(P<0.001).The mean central macular thickness(CMT)significantly decreased from 476.22±163.54 to 298.66±109.23μm.Both the FAZ area and AI at 6mo were significantly higher than those at the baseline:the FAZ area increased(0.38±0.02 vs 0.39±0.02 mm^(2),P<0.05);the AI increased(1.27±0.02 vs 1.31±0.01,P=0.000).The baseline BCVA showed a significantly positive correlation with the baseline FAZ area,FAZ perimeter(PERIM)and AI,final visual gain(FVG)and injection times,respectively(P<0.001).FVG showed a significantly negative correlation with the FAZ area,PERIM,AI and injection times,but a significantly positive correlation with vessel densities(VDs)300μm area around FAZ(FD-300;P<0.001).Injection times was positively correlated with the baseline FAZ area,and AI,but inversely correlated with the baseline FD-300(P<0.001).However macular ischemia was noted in 5 cases during follow-up.CONCLUSION:Using OCTA to observe macular ischemia and quantify parameters can better predict the final visual prognosis of patients before treatment.The changes in FAZ parameters may influence the visual prognosis and injection times.

Effect of a novel tyrosine kinase inhibitor nintedanib on bFGF and VEGF concentrations in a rabbit retinal vein occlusion model

AIM:To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor(bFGF)and vascular endothelial growth factor(VEGF)simultaneously for retinal vascular disease in vivo.METHODS:After a laser induced rabbit retinal vein occlusion(RVO)model was made,0.5 mg of nintedanib was injected intravitreally in the left eye on the third day while the right eye was as a control.Intracameral samples were taken on the day before laser treatment and days 1,3,7,14,21,and 28 after treatment.Enzyme-linked immunosorbent assay(ELISA)was used to test the bFGF and VEGF-A concentrations in the aqueous humor.RESULTS:Both bFGF and VEGF-A rose significantly on the third day after laser treatment in both eyes.In the control eye the bFGF concentration peaked on the 14th day while the VEGF-A concentration dropped rapidly soon after the third day.After nintadanib injection in the study eye,both bFGF and VEGF-A showed a significant reduction on the 4th day(7th day after laser treatment)when compared to the control eye,and kept on low level in the following several weeks.CONCLUSION:Intravitreal injection of nintedanib can inhibit the expression of bFGF and VEGF in the process of RVO model to a certain extent,which is expected to become a new method for the treatment of retinal vascular diseases or fibrotic diseases.

Central Retinal Vein Occlusion in Healthy Young Adults Following COVID-19 Vaccination: Case Series

Our aim is to report 4 cases of central retinal vein occlusion following COVID-19 vaccine administration. In this case series, 4 patients between 23-32 years of age presented to us with unilateral central retinal vein occlusion after 2-15 days of getting vaccinated against COVID-19. One patient was a known case of hypertension and 1 was hypothyroid. All the patients had disc swelling, flame shaped haemorrhages, dilated and tortuous blood vessels in the retina. One patient had cystoid macular edema and was treated with intravitreal ranibizumab. As there were no positive systemic risk factors or incidents, COVID-19 vaccines might have an association with the central retinal vein occlusion in these cases. .

Microvascular changes after conbercept therapy in central retinal vein occlusion analyzed by optical coherence tomography angiography

AIM: To investigate microvascular changes in eyes with central retinal vein occlusion(CRVO) complicated by macular edema before and after intravitreal conbercept injection and evaluate correlations between these changes and best-corrected visual acuity(BCVA) and retinal thickness. METHODS: Twenty-eight eyes of 28 patients with macular edema caused by CRVO were included in this retrospective study. All patients received a single intravitreal conbercept injection to treat macular edema. BCVA and the results of optical coherence tomography angiography(OCTA) automatic measurements of the vessel density in the superficial(SCP) and deep retinal capillary plexus(DCP), the foveal avascular zone(FAZ) area, the FAZ perimeter(PERIM), the vessel density within a 300-μm wide ring surrounding the FAZ(FD-300), the acircularity index(AI), the choriocapillaris flow area, and retinal thickness were recorded before and at one month after treatment and compared with the results observed in age-and sexmatched healthy subjects. RESULTS: The vessel density in the SCP and DCP, the FD-300, and the flow area of the choriocapillaris were allsignificantly lower in CRVO eyes than in healthy eyes, while the AI and retinal thickness were significantly higher(all P<0.05). After treatment, retinal thickness was significantly decreased, and the mean BCVA had markedly improved from 20/167 to 20/65(P=0.0092). The flow area of the choriocapillaris was also significantly improved, which may result from the reduction of shadowing effect caused by the attenuation of macular edema. However, there were no significant changes in SCP and DCP vessel density after treatment. The flow area of the choriocapillaris at baseline was negatively correlated with retinal thickness.CONCLUSION: OCTA enables the non-invasive, layerspecific and quantitative assessment of microvascular changes both before and after treatment, and can therefore be used as a valuable imaging tool for the evaluation of the follow-up in CRVO patients.

Therapeutic potential of intravitreal pharmacotherapy in retinal vein occlusion

Retinal vein occlusion (RVO) is the most common visually disabling disease affecting the retina after diabetic retinopathy. Although the disease entity has long been known, its management is still controversial. Macular edema is the main reason for decreased visual acuity (VA) in this retinal vascular disorder. Recently the vitreous cavity has increasingly been used as a reservoir of drugs for the direct treatment of macular edema through intravitreal injection route. The most widely injected drugs so far have been triamcinolone acetonide (TA) and bevacizumab. The objective of this review is to evaluate the evidence and discuss the rationale behind the recent suggestions that intravitreal pharmacotherapy by corticosteroids and anti-vascular endothelial growth factors may be useful in the treatment of retinal vein occlusion.

Intravitreal anti-VEGF agents, oral glucocorticoids, and laser photocoagulation combination therapy for macular edema secondary to retinal vein occlusion: preliminary report

AIM： To evaluate the efficacy and safety of combined anti-vascular endothelial growth factor （VEGF） agents, oral glucocorticoid, and laser photocoagulation therapy for macular edema （ME） secondary to retinal vein occlusion （RVO）. METHODS： This study included 16 eyes of 16 patients with RVO-associated ME. Patients were initially treated with oral prednisone and an intravitreal anti-VEGF agent. Two weeks later, patients underwent standard laser photocoagulation. Best-corrected visual acuity （BCVA）, central retinal thickness （CRT）, and retinal vessel oxygenation were examined over 12mo. RESULTS： Patients received 1.43＋0.81 anti-VEGF injections. Mean baseline and 12-month IogMAR BCVA were 0.96±0.51 （20/178） and 0.31±0.88 （20/40）, respectively, in eyes with central retinal vein occlusion （CRVO） （P〈0.00）, and 1.02±0.45 （201209） and 0.60±0.49 （20/80）, respectively, in eyes with branch retinal vein occlusion （BRVO） （P〈0.00）. At 12mo, CRT had significantly decreased in eyes with CRVO （P〈0.00） and BRVO （P〈0.00）. Venous oxygen saturation had significantly increased in eyes with CRVO （P〈0.00） and BRVO （P〈0.00）. No examined parameters were significantly different between the 2 RVO groups. No serious adverse effects occurred. CONCLUSION： Anti-VEGF, glucocorticoid, and photocoagulation combination therapy improves visual outcome, prolongs therapeutic effect, and reduces the number of intravitreal injections in eyes with RVO- associated ME.

Visual acuity after intravitreal ranibizumab with and without laser therapy in the treatment of macular edema due to branch retinal vein occlusion:a 12-month retrospective analysis

AIM:To identify factors contributing to visual improvement after treatment of macular edema(ME)secondary to branch retinal vein occlusion(BRVO),and to assess the interaction between laser therapy and intravitreal ranibizumab(IVR).METHODS:We retrospectively reviewed the medical records of patients who had been treated for BRVO-related ME at our hospital.Records were traceable for at least 12 mo,and evaluated factors included age,sex,medical history,smoking history,treatment methods,foveal hemorrhage,and change in visual acuity.Treatments included laser therapy,IVR,sub-Tenon’s capsule injection of triamcinolone(STTA),a combination,or no intervention.Multivariate logistic regression analysis and interaction terms were used to assess the clinical efficacy of the treatments,and odds ratios(OR)and 95%confidence intervals(CI)were calculated.RESULTS:Seventy-three patients(34 men,39 women;73 eyes)with a mean age of 69.4±12.1 y were included.Patients who underwent IVR monotherapy,laser monotherapy,and STTA+laser had significantly higher best corrected visual acuity at 12 mo compared to baseline(P<0.001,<0.001,and 0.019,respectively).Logistic regression analysis without interaction terms found that IVR was a significant visual acuity recovery factor(adjusted OR:3.89,95%CI:1.25-12.1,P=0.019).Adjusted OR using an interaction model by logistic regression was 16.6(95%CI:2.54-108.47,P=0.003)with IVR treatment,and 8.25(95%CI:1.34-50.57,P=0.023)with laser treatment.No interaction was observed(adjusted OR:0.07,95%CI:0.01-0.75,P=0.029).CONCLUSION:IVR contributes to improvements in visual acuity at 12 mo in ME secondary to BRVO.No interaction is observed between laser therapy and IVR treatments.

Characteristics of retinal vein occlusion with final vision better than 78 letters after sequential therapy with ranibizumab and triamcinolone acetate

AIM： To analyze the reasons that may lead to the different vision result by combining the ranibizumab and triamcinolone acetate（TA） in sequence to treat macular edema in retinal vein occlusion（RVO）.METHODS： Ranibizumab and TA were combined in sequence to treat 43 patients with macular edema secondary to RVO.Six months after the treatment,patients with central fovea thickness（CFT） less than 300 μm in optical coherence tomography（OCT） were collected into Groups I and II,based on vision acuity（VA） better than 78 letters or less than 60 letters.The age,baseline VA,duration from onset to treatment,CFT at the baseline,sub-retinal fluid（SRF）,sub-foveal exudates and injection times of TA and ranibizumab were taken into comparison.RESULTS： The mean age of the subjects was 46.4y in Group I but 57.5y in Group II.The difference of age was significant between groups（P〈0.01）.The mean baseline VA was 51.4 letters in Group I and 43.9 letters in Group II（P〈0.05）.The baseline CFT were 670.9 μm in Group I with SRF in 54.3% patients and 678.1 μm in Group II with SRF in 52.9%（P〉0.05）.The mean number of injections of TA was 0.9 and the mean number of injections of ranibizumab was 2.3 in Group I but 1.7 and 2.9 respectively in Group II.The treatment times of ranibizumab had no difference between the 2 groups（P〉0.05） but the difference of TA injection times was significant（P〈0.05）.Subfoveal exudates at final stage happened in no subjects in Group I but in 45.83% subjects in Group II.CONCLUSION： This combined treatment is safer than TA injection and cheaper than ranibizumab injection alone.Younger patients and earlier treatment will help to get better vision outcome.Subfoveal exudates at the final stage have significant relationship with vision outcome.No relationship existed between the baseline CFT,SRF and the vision outcome.

Real-world outcomes of anti-vascular endothelial growth factor therapy for retinal vascular vein occlusion in Tibet,China

AIM: To evaluate the outcomes of intravitreal antivascular endothelial growth factor(anti-VEGF) agents for patients with retinal vein occlusion(RVO) related-macular edema(ME) in Tibetan.METHODS: A retrospective, observational, single-center study. The demographic and clinical data of 90 RVO Tibetan patients(93 eyes) treated with either ranibizumab or conbercept in Tibet Autonomous Region People’s Hospital from Jan 2018 to December 2019 were collected.RESULTS: The mean patient age was 56.8±10.6y, 45(50%) of them were female. The mean living altitude was 3867.8±567.9 m. At the last visit, the best-corrected visual acuity(BCVA) significantly increased(52.2±21.8 letters) in comparison with the baseline(38.2±24.1 letters, P<0.001);while the central retinal thickness(CRT) significantly reduced(245.5±147.6 μm) in comparison with the baseline(504.1±165.2 μm, P<0.001). The 43.0% of the eyes gained≥15 letters, 60.2% of the eyes gained ≥10 letters, and 78.5% of the eyes gained ≥5 letters. No vision loss was noted in 92.5% of the eyes, 4 eyes lost more than 10 letters during follow-up period. The mean number of injections was 2.4±1.8. No severe ocular or systemic adverse events related to either the drug or injection were noted.CONCLUSION: Anti-VEGF therapy is effective and safe in Tibetan patients for the treatment of RVO related ME.

Approved pharmacotherapy for macular edema secondary to branch retinal vein occlusion:A review of randomized controlled trials in dexamethasone implants,ranibizumab,and aflibercept

There are three approved pharmacotherapies for treating macular edema secondary to branch retinal vein occlusion(BRVO), including corticosteroids(dexamethasone implants) and anti-vascular endothelial growth factor(VEGF)(ranibizumab and aflibercept). They all show superior ability to improve vision and reduce macular thickness, comparing with sham injections or macular grid laser treatment. There is no severe ocular or systemic adverse reaction reported in studies associated with anti-VEGF for macular edema after BRVO. Intraocular pressure elevation and cataract aggravation should be addressed after intravitreal dexamethasone implants. Single intravitreal dexamethasone implant had effective duration as long as four to six months. Intravitreal anti-VEGF requires six monthly injections as loading doses, and then PRN regimen needed according to functional and anatomical changes. Ozurdex and ranibizumab reduce not only macular edema, but also the probability of retinal ischemia and neovascularization in patient s with BRVO. Prompt treatment with these agents can lead to a better outcome.

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

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

Evaluation of hyperreflective foci as a prognostic factor of visual outcome in retinal vein occlusion

AIM：To evaluate the potential role of hyperreflective foci（HF） as a prognostic indicator of visual outcome in patients with macular edema（ME） due to retinal vein occlusion（RVO）.METHODS：We retrospectively reviewed 50 eyes of 50 patients with ME due to ischemic central retinal vein occlusion（CRVO）,non-ischemic CRVO and branch retinal vein occlusion（BRVO） who were treated with anti-vascular endothelial growth factor（anti-VEGF） at Beijing Tongren Eye Center from January 2013 to July 2016.All patients underwent best-corrected visual acuity（BCVA）,spectral domain optical coherence tomography（SD-OCT） at baseline and follow-up.Such factors were evaluated and compared among three groups as baseline and final BCVA,central retinal thickness（CRT）,external limiting membrane（ELM） status and the numbers of HF in different position.Multiple linear regression analysis was employed to analyze the relationship between baseline HF and final BCVA.Changes of HF before and after treatment were evaluated too.RESULTS：Among three groups,HF could be located in each retinal layers,as well as in vitreous cavity.The mean HF in outer retinal layer（ORL） at baseline was 5.29±8.48 in ischemic CRVO with intact ELM,1.93±2.76 in non-ischemic CRVO,and 1.75±2.05 in BRVO.With disrupted ELM,the mean HF in ORL increased.There was statistically difference of HF in ORL between intact and disrupted ELM.The numbers of HF in ORL were associated with poor visual outcome among three groups.However,HF in inner retinal layer（IRL） and vitreous cavity were not associated with poor visual outcome.Meanwhile,the baseline HF in ORL and vitreous cavity reduced significantly in nonischemic CRVO and BRVO after anti-VEGF treatment.CONCLUSION：The numbers of HF in ORL are prognostic factors associated with the final BCVA in patients with ME due to RVO after anti-VEGF treatment.

Comparison of one and three initial monthly intravitreal ranibizumab injection in patients with macular edema secondary to branch retinal vein occlusion

AIM： To compare three initial monthly intravitreal ranibizumab（IVR） injections followed by pro re nata（PRN） dosing with one initial monthly IVR injections followed by PRN dosing for macular edema（ME） secondary to branch retinal vein occlusion（BRVO）.METHODS： Forty-two eyes of 42 patients who had IVR injections for BRVO were retrospectively studied. Eighteen eyes received 1 initial IVR injection（1＋PRN group） and 24 eyes received 3 monthly IVR injections（3＋PRN）. At 1, 3, 6 and 12mo; spectral-domain optical coherence tomography（SD-OCT） was performed. Central macular thickness（CMT）, the integrity of the external limiting membrane（ELM）, the presence of subretinal fluid, cyst size, the presence of inner segment/outer segment（IS/OS） defect were determined.RESULTS： At baseline the mean CMT was 521.3±153.2 μm in the 3＋PRN group while it was 438.1±162.4 μm in 1＋PRN group. At the final visit, mean CMT was 278.3±87.8 μm in the 3＋PRN group and 285.2±74.2 μm in the 1＋PRN group（P=0.079）. The changes in CMT over the entire study period were also comparable in both groups（243±160 μm in the 3＋PRN group, and 152.9±175.3 μm in the 1＋PRN group; P=0.090）. At baseline, best-corrected visual acuity（BCVA） was 0.92±0.60 logarithm of the minimal angle of resolution（logMAR） in the 3＋PRN group, while it was 0.72±0.46 logMAR in the 1＋PRN group. Final BCVA was 0.42±0.55 logMAR in the 3＋PRN group and 0.38±0.50 logMAR in the 1＋PRN group（P=0.979）. Additionally, the BCVA changes from baseline to final visit were not significantly different（-0.50±0.45 logMAR in the 3＋PRN group, and-0.33±0.39 logMAR in the 1＋PRN group; P=0.255）.CONCLUSION： No significant differences in the anatomical or functional results are found between 3＋PRN and 1＋PRN regimens in the patients receiving ranibizumab for ME secondary to BRVO. Intact IS/OS and baseline BCVA are good predictor of the visual gain, while baseline CMT is a good predictor of the anatomical gain.

Study of retinal vessel oxygen saturation in ischemic and non-ischemic branch retinal vein occlusion

AIM：To explore how oxygen saturation in retinal blood vessels is altered in ischemic and non-ischemic branch retinal vein occlusion（BRVO）.·METHODS：Fifty BRVO eyes were divided into ischemic（=26）and non-ischemic（=24）groups,based on fundus fluorescein angiography.Healthy individuals（=52 and=48,respectively）were also recruited as controls for the two groups.The mean oxygen saturations of the occluded vessels and central vessels were measured by oximetry in the BRVO and control groups.·R ESULTS：In the ischemic BRVO group,the occluded arterioles oxygen saturation（Sa O2-A,106.0%±14.3%）,instead of the occluded venule oxygen saturation（Sa O2-V,60.8%±9.4%）,showed increases when compared with those in the same quadrant vessels（Sa O2-A,86.1%±16.5%）in the contralateral eyes（〈0.05）.The oxygen saturations of the central vessels showed similar trends with those of the occluded vessels.In the non-ischemic BRVO group,the occluded and central Sa O2-V and Sa O2-A showed no significant changes.In both the ischemic and non-ischemic BRVOs,the central Sa O2-A was significantly increased when compared to healthy individuals.·CONCLUSION：Obvious changes in the occluded and central Sa O2-A were found in the ischemic BRVO group,indicating that disorders of oxygen metabolism in the arterioles may participate in the pathogenesis of ischemic BRVO.