Comparison of macular changes according to the etiology of optic neuritis:a cross-sectional study

AIM:To compare the macular structure including foveal thickness among patients with optic neuritis(ON)according to the etiology and to investigate the possible correlation between structural and visual outcomes METHODS:In this retrospective cross-sectional study,the clinical data of patients with aquaporin-4 immunoglobulin G-related ON(AQP4 group,40 eyes),myelin oligodendrocyte glycoprotein IgG-related ON(MOG group,31 eyes),and multiple sclerosis-related ON(MS group,24 eyes)were obtained.The retinal thickness of the foveal,parafoveal and perifoveal regions were measured.Visual acuity(VA),visual field index and mean deviation were measured as visual outcomes.RESULTS:The AQP4 group showed a significantly thinner fovea(226.4±13.4μm)relative to the MOG(236.8±14.0μm,P=0.015)and MS(238.9±14.3μm,P=0.007)groups.The thickness in the parafoveal area also was thinner in the AQP4 group,though the difference in perifoveal retinal thickness was not significant.Foveal thickness was correlated with VA in the AQP4 group(coefficientρ=-0.418,P=0.014),but not in the MOG and MS groups(P=0.218 and P=0.138,respectively).There was no significant correlation between foveal thickness and visual field test in all three groups.CONCLUSION:The significant thinning in the fovea and parafoveal areas in the AQP4 group compared to the MOG and MS groups are found.Additionally,macular changes in AQP4-ON show a significant correlation with VA.The results provide the possibility that retinal structural damage could reflect functional damage in AQP4-ON,distinct from MOGON and MS-ON.

Automatic fovea detection and choroid segmentation for choroidal thickness assessment in optical coherence tomography

AIM:To develop an automated model for subfoveal choroidal thickness(SFCT)detection in optical coherence tomography(OCT)images,addressing manual fovea location and choroidal contour challenges.METHODS:Two procedures were proposed:defining the fovea and segmenting the choroid.Fovea localization from B-scan OCT image sequence with three-dimensional reconstruction(LocBscan-3D)predicted fovea location using central foveal depression features,and fovea localization from two-dimensional en-face OCT(LocEN-2D)used a mask region-based convolutional neural network(Mask R-CNN)model for optic disc detection,and determined the fovea location based on optic disc relative position.Choroid segmentation also employed Mask R-CNN.RESULTS:For 53 eyes in 28 healthy subjects,LocBscan-3D’s mean difference between manual and predicted fovea locations was 170.0μm,LocEN-2D yielded 675.9μm.LocEN-2D performed better in non-high myopia group(P=0.02).SFCT measurements from Mask R-CNN aligned with manual values.CONCLUSION:Our models accurately predict SFCT in OCT images.LocBscan-3D excels in precise fovea localization even with high myopia.LocEN-2D shows high detection rates but lower accuracy especially in the high myopia group.Combining both models offers a robust SFCT assessment approach,promising efficiency and accuracy for large-scale studies and clinical use.

Aflibercept combined with triamcinolone acetonide in the treatment of diabetic macular edema:optical coherence tomography and optical coherence tomography angiography

AIM:To analyze the relationship between optical coherence tomography(OCT)and OCT angiography(OCTA)imaging in patients with diabetic macular edema(DME)who are treated with a combination of aflibercept and triamcinolone acetonide(TA).METHODS:A total of 76 eyes newly diagnosed DME were included in this study.They were randomly assigned to receive either aflibercept or a combination of aflibercept and TA.Injections once a month for a total of three injections.Central macular thickness(CMT),number of hyperreflective foci(HRF),height of subretinal fluid(SRF),and area of foveal avascular zone(FAZ)were evaluated using OCT and OCTA at baseline and after each monthly treatment.RESULTS:Both groups showed improvement in best corrected visual acuity(BCVA)and reduction in macular edema after treatment,and the difference in BCVA between the two groups was statistically significant after each treatment(P<0.05).The difference in CMT between the two groups was statistically significant after the first two injections(P<0.01),but not after the third injection(P=0.875).The number of HRF(1mo:7.41±8.25 vs 10.86±7.22,P=0.027;2mo:5.33±6.13 vs 9.12±8.61,P=0.034;3mo:3.58±3.00 vs 6.37±5.97,P=0.007)and height of SRF(1mo:82.39±39.12 vs 105.77±42.26μm,P=0.011;2mo:36.84±10.02 vs 83.59±37.78μm,P<0.01;3mo:11.57±3.29 vs 45.43±12.60μm,P<0.01)in combined group were statistically significant less than aflibercept group after each injection,while the area of FAZ showed no significant change before and after treatment in both groups.CONCLUSION:The combination therapy of aflibercept and TA shows more significant effects on DME eyes with decreased HRF and SRF.However,both aflibercept and combination therapy show no significant change in the area of FAZ.

Retinal capillary plexus in Parkinson’s disease using optical coherence tomography angiography

AIM:To evaluate the alterations of the retinal microvasculature and foveal avascular zone in patients with Parkinson’s disease(PD)using optical coherence tomography angiography(OCT-A).METHODS:A retrospective study of PD patients examined in the Ophthalmology Department of the General Hospital of Athens,“Georgios Gennimatas”from March 2021 to March 2022 was conducted.Totally 44 patients with PD were included and 18 healthy controls were examined,hence a total of 124 eyes were enrolled in the study.The foveal and parafoveal superficial and deep capillary plexus vascular density(fSCP-VD,fDCP-VD,pSCP-VD,pDCP-CD)and foveal avascular zone(FAZ)were quantified with OCTA.Optical coherence tomography(OCT)was used to measure macular thickness.Our statistical analysis was conducted by using a mixed effect linear regression model.RESULTS:After adjustment for age and gender,the mean parafoveal superficial capillary plexus vascular density(pSCP-VD)and mean parafoveal deep capillary plexus vascular density(pDCP-VD)were significantly decreased in individuals with PD(P<0.001 in both)by-2.35(95%CI-3.3,-1.45)and-7.5(95%CI-10.4,-4.6)respectively.fSCP-VD and fDCP-VD didn’t approach statistical significance.The FAZ area and perimeter were significantly decreased(P<0.001 in both)by-0.1 mm^(2)(95%CI-0.13,-0.07)and-0.49 mm^(2)(95%CI-0.66,-0.32)respectively.Circularity didn’t approach statistical significance.Central retinal thickness(CRT)was significantly decreased in individuals with PD(P<0.001)by-23.1μm(95%CI-30.2,-16)and temporal retinal thickness(TRT)was decreased(P=0.025)by-11μm(95%CI-22,-1.5)while nasal retinal thickness(NRT)only approached statistical significance(P=0.066).CONCLUSION:The mean pSCP-VD,pDCP-VD,CRT and TRT are significantly decreased and FAZ is altered in individuals with PD.These findings can be potentially used as biomarkers for the diagnosis and evaluation of early PD.

Automatic segmentation of foveal avascular zone based on adaptive watershed algorithm in retinal optical coherence tomography angiography images

The size and shape of the foveal avascular zone(FAZ)have a strong positive correlation with several vision-threatening ret inovascular diseases.The identification,segmentation and analysis of FAZ are of great significance to clinical diagnosis and treatment.We presented an adaptive watershed algorithm to automatically extract F AZ from retinal optical coherence tomography angiography(OCTA)images.For the traditional watershed algorithm,"over-segmentation"is the most common problem.FAZ is often incorrectly divided into multiple regions by redundant"dams".This paper analyzed the relationship between the"dams"length and the maximum inscribed circle radius of FAZ,and proposed an adaptive watershed algorithm to solve the problem of"over-segmentation".Here,132 healthy retinal images and 50 diabetic retinopathy(DR)images were used to verify the accuracy and stability of the algorithm.Three ophthal-mologists were invited to make quan titative and qualitative evaluations on the segmentation results of this algorithm.The quantitative evaluation results show that the correlation coffi-cients between the automatic and manual segmentation results are 0.945(in healthy subjects)and 0.927(in DR patients),respectively.For qualitative evaluation,the percentages of"perfect segmentation"(score of 3)and"good segmentation"(score of 2)are 99.4%(in healthy subjects)and 98.7%(in DR patients),respectively.This work promotes the application of watershed algorithm in FAZ segmentation,making it a useful tool for analyzing and diagnosing eye diseases.

Superficial foveal avascular zone area changes before and after idiopathic epiretinal membrane surgery

To investigate the foveal morphological changes and foveal avascular zone（FAZ）area before and after epiretinal membrane（ERM）surgery.Twenty-two eyes with treatmentnaive ERM were included in this retrospective study.The central foveal thickness（CFT）and FAZ area were measured via swept-source optical coherence tomography（SS-OCT）and OCT angiography pre-and postoperatively.The unaffected fellow eyes were used as controls.The preoperative superficial FAZ area was significantly smaller in patients（0.08±0.04 mm^2）than in controls（0.33±0.09 mm^2;P〈0.001）.The postoperative superficial FAZ（0.12±0.06 mm^2）area was significantly greater than the preoperative area（P〈0.001）.The preoperative superficial FAZ area was strongly negatively correlated with CFT（P〈0.001,rho=-0.763）.ERM induced significant foveal morphological changes and reduction of the superficial FAZ area.Foveal thickness was restored and FAZ area increased postoperatively.However,the process is rather slow and the recovery is incomplete.

Predictors of short-term outcomes related to central subfield foveal thickness after intravitreal bevacizumab for macular edema due to central retinal vein occlusion

AIM：To investigate the predictive factors for shortterm effects of intravitreal bevacizumab injections on central subfield foveal thickness（CSFT）in patients with macular edema（ME）secondary to central retinal vein occlusion（CRVO）.·METHODS：This was a retrospective study in 60 eyes treated with intravitreal bevacizumab injections for ME due to CRVO.Follow-up was three months.The Early Treatment Diabetic Retinopathy Study（ETDRS）score and CSFT measured by spectral-domain optical coherence tomography（SD-OCT）were used to observe the changes in best-corrected visual acuity（BCVA）.Baseline BCVA,CSFT,age,CRVO duration and the presence of cystoid macular edema（CME）or subretinal fluid（SRF）were analyzed as potential predictive factors of the effects of intravitreal bevacizumab injections.·R ESULTS：BCVA improved from 0.9 log MAR at baseline to 0.6 log MAR at 3mo,which was associated with a significant reduction in CSFT from 721μm to 392μm 3mo after injection.About 50%of CME cases and more than90%of SRF cases responded to treatment with a complete resolution at 3mo.Age（=0.036）and low baseline CSFT（=0.037）were associated with a good 3-month prognosis.Patients〉60 years old achieved better CME resolution（=0.031）and lower CSFT at 3mo（305μm 474μm,=0.003）.·CONCLUSION：Intravitreal bevacizumab significantly improved visual acuity and CSFT in patients with CRVO after 3mo.Older age and lower baseline CSFT were good predictors of short-term CSFT outcomes.The retinal thickness response to bevacizumab might depend on the resolution of CME rather than SRF.

Foveal thickness reduction after anti-vascular endothelial growth factor treatment in chronic diabetic macular edema

AIM：To report foveal thickness reduction in eyes with resolution of macular edema and recovery of a foveal depression after one-year of anti-vascular endothelial growth factor（anti-VEGF） therapy for center-involving diabetic macular edema（DME）.METHODS：Foveal thickness was assessed with optical coherence tomography to determine the central subfield foveal thickness（CSFT） and macular volume in 42 eyes with DME（CSFT〉275 μm）. Evaluations also included measurement of best-corrected visual acuity（BCVA）, and were performed at baseline, and upon foveal depression recovery achieved after 12 monthly intravitreal injections of either 1.5 mg/0.06 mL bevacizumab（n=21） or 0.5 mg/0.05 mL ranibizumab（n=21）. Data was compared to 42 eyes of normally sighted, non-diabetic, healthy individuals with similar age, gender and race distributions.RESULTS：Mean baseline BCVA was 0.59±0.04 and 0.32± 0.03 log MAR（P〈0.001） after treatment and resolution of DME, with all, but 3 eyes, showing BCVA improvement. Mean CSFT before treatment was 422.0±20.0 μm, and after treatment, decreased to 241.6±4.6 μm（P〈0.001）, which is significantly thinner than CSFT found in control subjects（272.0±3.4 μm; P〈0.001）. Moreover, in 33/42 DM eyes（79%）, CSTF was thinner than the matched control eye. Macular volume showed comparable results, but with lower differences between groups（control：8.5±0.4 mm^3; DME：8.2±1.0 mm^3; P=0.0267）.CONCLUSION：DME eyes show significantly lower foveal thickness than matched controls after DME resolution achieved with one-year anti-VEGF therapy. Further investigation into the reasonsfor this presumable retinal atrophy using fluorescein angiography and functional parameters as well as establishing possible predictors is warranted. This finding should be considered during the treatment of DME.

Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.

Widefield optical coherence tomography of foveal dragging in retinopathy of prematurity

Dear Editor,Despite substantial advances in neonatal medicine, retinopathy of prematurity (ROP) continues to be a serious therapeutic challenge⑴.Visual acuity loss in patients with ROP has been associated with structural retinal abnormalities (including retinal detachment, retinal folds, and pigmentary retinopathy), cataract, glaucoma, and amblyopia due to refractive error or strabismus[2].

Various configuration types of the foveal avascular zone with related factors in normal Chinese adults with or without myopia assessed by swept-source OCT angiography

·AIM:To describe the morphological characteristics of foveal avascular zone(FAZ)in normal Chinese adults with or without myopia by swept-source optical coherence tomography angiography(SS-OCTA)and analyze the possible associated factors.·METHODS:Normal Chinese adults with or without myopia aged between 18 and 60 y were recruited into the study.One eye in each individual was randomly selected for scanning using SS-OCTA.FAZ parameters,central retinal thickness(CRT)and central choroidal thickness(CCT)were then analyzed.Correlations between systemic and ocular variables and FAZ parameters were subsequently evaluated.The subgroup analysis based on refractive error was also carried out.·RESULTS:In total,127 eyes out of 127 normal subjects were finally included in the study(mean age29.5±8.22 y,61 males and 66 females).The pattern of FAZ was variable:round configuration in 28 eyes(22%),quadrilateral configuration in 23 eyes(18%),pentagonal configuration in 20 eyes(16%),oval configuration in 15 eyes(12%),triangular configuration in 6 eyes(5%)and irregular configuration in 35 eyes(28%).The mean area of FAZ was0.37±0.12 mm^(2).Females had a larger FAZ(0.41±0.11 mm^(2)vs0.32±0.11 mm^(2))compared with that of males(P<0.01).All myopic individuals showed smaller FAZ area and perimeter compared with that of normal individuals(P<0.01).There was no obvious correlation between age and FAZ.In the univariate regression analysis,both axial length(AL)and refractive error were significantly related to FAZ parameters.However,only CRT showed negative correlation with FAZ in the multivariate regression analysis.·CONCLUSION:The pattern of FAZ configuration in normal Chinese adults with or without myopia is highly variable.Establishing quantitative parameters of FAZ would not only provide details of macular pathophysiology but could possibly contribute as a biomarker in disease staging.

Automatic quantification of superficial foveal avascular zone in optical coherence tomography angiography implemented with deep learning

An accurate segmentation and quantification of the superficial foveal avascular zone(sFAZ)is important to facilitate the diagnosis and treatment of many retinal diseases,such as diabetic retinopathy and retinal vein occlusion.We proposed a method based on deep learning for the automatic segmentation and quantification of the sFAZ in optical coherence tomography angiography(OCTA)images with robustness to brightness and contrast(B/C)variations.A dataset of 405 OCTA images from 45 participants was acquired with Zeiss Cirrus HD-OCT 5000 and the ground truth(GT)was manually segmented subsequently.A deep learning network with an encoder–decoder architecture was created to classify each pixel into an sFAZ or non-sFAZ class.Subsequently,we applied largestconnected-region extraction and hole-filling to fine-tune the automatic segmentation results.A maximum mean dice similarity coefficient(DSC)of 0.976±0.011 was obtained when the automatic segmentation results were compared against the GT.The correlation coefficient between the area calculated from the automatic segmentation results and that calculated from the GT was 0.997.In all nine parameter groups with various brightness/contrast,all the DSCs of the proposed method were higher than 0.96.The proposed method achieved better performance in the sFAZ segmentation and quantification compared to two previously reported methods.In conclusion,we proposed and successfully verified an automatic sFAZ segmentation and quantification method based on deep learning with robustness to B/C variations.For clinical applications,this is an important progress in creating an automated segmentation and quantification applicable to clinical analysis.

Change in foveal position based on age and axial length in high myopic eyes

AIM：To evaluate the influence of age and axial length（AL） on the position of the fovea in patients with high myopia（HM）.METHODS：In this prospective study,96 patients（186 eyes） with HM were consecutively recruited from the Third Affiliated Hospital of Nanchang University.DRI-OCT Atlantis,fundus imaging,and IOL Master were used in this study.Three indices were measured：the distance between the fovea and the optic nerve head（ONH） center（DFO）,the vertical distance between the fovea and the horizontal line pass of the ONH center（VDFO）,and the horizontal distance between the fovea and the vertical line pass of the ONH center（HDFO）.These measurements were used to analyze the effects of different age groups（A1,A2,A3 groups） and AL（AL1,AL2,AL3,AL4 groups） on these indices.RESULTS：The results showed that there was no statistical significance in DFO among the age and AL groups（F=0.46,0.37;P=0.62,0.76,respectively）.In HDFO,there was also no statistical significance among the age and AL groups（F=0.10,0.48;P=0.90,0.69,respectively）.In VDFO,however,the difference in the age and AL groups was statistically significant（F=3.21,3.12;P=0.04,0.02,respectively）.Thus,VDFO were correlated with age and AL（r=0.21,0.23,all P〈0.01）,while HDFO and DFO were not correlated with age and AL（r=0.30,P〉0.05）.CONCLUSION：In high myopia,the foveal position changes mainly in the vertical direction along with factors of age and AL.

Restoration of outer segments of foveal photoreceptors after resolution of malignant hypertensive retinopathy

Dear Sir,I am Dr. Xiao-Qiang Liu, from the Department of Ophthalmology, Shanghai Tenth People’s Hospital,Tongji University School of Medicine, Shanghai, China. I write to report a case of malignant hypertensive retinopathy demonstrated by spectral domain optical coherence

Quantitative Assessment of Foveal Avascular Zone in Patients with Early and Intermediate Nonexudative Age-Related Macular Degeneration Using Optical Coherence Tomography-Angiography

Optical coherence tomography-angiography (OCT-A) is a relatively new non-invasive imaging technique which provides three-dimensional visualization of the retinal and choroidal microvasculature. Recently, OCT-A is widely used in the diagnosis of age-related macular degeneration (AMD). Purpose: To compare 3 quantitative indexes of foveal avascular zone (FAZ)—area (A), perimeter (Pm), and circularity (C) in patients with early and intermediate nonexudative AMD and healthy subjects using OCT-A. Methods: Eighty-nine patients with nonexudative AMD (n = 89 eyes) were enrolled in the study. They were compared with sex- and age-matched control group of 66 healthy subjects (n = 66 eyes). The patients with nonexudative AMD were divided into 2 subgroups—early AMD (n = 42 eyes) and intermediate AMD (n = 47 eyes). All participants underwent OCT-A (3 × 3 mm scans, Cirrus HD-OCT, Angioplex, Carl Zeiss Meditec, Dublin, CA). Results: There was no statistically significant difference in all 3 assessed indexes between the early AMD subgroup and the control group (A ? P = 0.139;Pm ? P = 0.230;and C ? P = 0.191). There was also no statistically significant difference in all 3 assessed indexes between the intermediate AMD subgroup and the control group (A ? P = 0.106, Pm ? P = 0.124, and C ? P = 0.102, respectively). Conclusions: According to our results from the assessment of FAZ in patients with early and intermediate AMD, we hypothesize that macular perfusion remains fairly unchanged in the nonexudative stages of the disease. OCT-A is a reliable technique for visualizing and quantifying FAZ in patients with nonexudative AMD.

Morphological and functional changes in the macular area in diabetic macular edema after a single intravitreal injection of aflibercept

AIM:To evaluate the changes in macular morphology and function after a single intravitreal injection of aflibercept in diabetic macular edema(DME)using optical coherence tomography angiography(OCTA)and MP-3 microperimetry.METHODS:Twenty-eight patients(42 eyes)diagnosed with DME were treated with intravitreal injection of aflibercept.The changes in best corrected visual acuity(BCVA),central retinal thickness(CRT),foveal avascular zone(FAZ)area,vessel density of superficial retinal capillary plexus(SVD),vessel density of deep retinal capillary plexus(DVD),mean light sensitivity(MLS),2°fixation rate(P1),4°fixation rate(P2),and other indicators 1mo after treatment were compared;of these,BCVA was conver ted into logarithm of the minimum angle of resolution(logMAR),and the correlation among the factors was analyzed.RESULTS:After treatment,logMAR BCVA was 0.47±0.24,which was significantly better than that before treatment(0.63±0.28,P<0.001).The CRT was 359.21±107.87μm after treatment,which was significantly lower than before treatment(474.10±138.20μm,P<0.001).The FAZ area,SVD,and DVD were not significantly changed after treatment compared with the baseline.MLS was 22.16±4.20 dB after treatment,which was significantly higher than before treatment(19.63±4.23 dB,P<0.001).P2 significantly increased after treatment than before treatment(P=0.007).P1 had no significant change after treatment than before treatment(P=0.086).CONCLUSION:A single intravitreal injection of aflibercept effectively reduces macular edema and improves retinal sensitivity,fixation stability,and visual acuity,possibly without causing significant changes in the retinal vascular condition in a short time.

Retinal thickness and vascular parameters using optical coherence tomography in Alzheimer's disease:a meta-analysis

Examining the retinal tissue has the potential to provide a unique method and technique to quantify Alzheimer’s disease-related changes in participants at various stages of the disease.In this metaanalysis,we aimed to investigate the association of various optical coherence tomography parameters with Alzheimer’s disease and whether retinal measurements can be used to diffe rentiate between Alzheimer’s disease and control subjects.Scientific databases including Google Schola r,Web of Science,and PubMed were systematically searched for published articles that evaluated retinal nerve fiber layer thickness and retinal microvascular network in Alzheimer’s disease and control subjects.Seventy-three studies(5850 participants,including 2249 Alzheimer’s disease patients and 3601controls) were included in this meta-analysis.Relative to controls,Alzheimer’s disease patients had a significantly lower global retinal nerve fiber layer thickness(standardized mean difference [SMD]=-0.79,95% confidence intervals [CI]:-1.03 to-0.54,P <0.00001) as well as each quadrant being thinner in Alzheimer’s disease versus controls.Regarding macular paramete rs,values measured by optical coherence tomography were significantly lower in Alzheimer’s disease than controls for macular thickness(pooled SMD:-0.44,95% CI:-0.67 to-0.20,P=0.0003),foveal thickness(pooled SMD=-0.39,95% CI:-0.58 to-0.19,P <0.0001),ganglion cell inner plexiform layer(SMD=-1.26,95% CI:-2.24 to-0.27,P=0.01) and macular volume(pooled SMD=-0.41,95% CI-0.76 to-0.07,P=0.02).Analysis using optical coherence tomography angiography parameters revealed mixed results between Alzheimer’s disease and controls.Superficial vessel density(pooled SMD=-0.42,95% CI:-0.68 to-0.17,P=0.0001) and deep vessel density(pooled SMD=-0.46,95% CI:-0.75 to-0.18,P=0.001) were found to be thinner in Alzheimer’s disease patients whereas the foveal avascular zone(SMD=0.84,95% CI:0.17-1.51,P=0.01) was larger in controls.Vascular density and thickness of various retinal laye rs were decreased in Alzheimer’s disease patients compared to controls.Our results provide evidence for optical coherence tomography technology having the potential to detect retinal and microvascular changes in patients diagnosed with Alzheimer’s disease and aid in monito ring and early diagnosis methods.

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.

Evaluation of macular choroidal and microvascular network changes by activity scores and serum antibodies in thyroid eye patients and healthy subjects

AIM:To investigate the choroidal thickness and the microvascular network changes around the macula in thyroid eye disease(TED)patients at different stages and the relationship of those changes with risk factors,serum antibodies and the severity of TED.METHODS:A total of 85 participants were enrolled.All participants underwent ophthalmology and endocrinology examinations.Subfoveal choroidal thickness(SFCT),superficial(s)and deep(d)foveal avascular zone(FAZ)area,mean(m)and central(c)superficial vascular density(SVD),deep vascular density(DVD)measurements of the enrolled cases were performed with Topcon swept source optical coherence tomography(OCT)/OCT angiography(OCTA)DRI OCT Triton.Multiple linear regression analysis was used to explore the associations between SFCT,FAZ area,SVD,DVD and the relevant factors of TED.RESULTS:Those with active TED patients had higher c-DVD and m-DVD levels(P<0.05),however there is no statistically significant difference in SFCT between active and stable TED patients.Among the serum antibodies,it was observed that s-FAZ and d-FAZ increased,c-SVD and m-SVD decreased in patients with high thyroid stimulating hormone-receptor autoantibodies(TRAB)level,whereas SFCT thickened in patients with high levels of both TRAB and human thyroglobulin(hTG).There was no significant difference in SFCT,FAZ,SVD and DVD measurement at gender,between hyperthyroid and euthyroid patients and among those with or without thyroid papillary carcinoma.CONCLUSION:The results show that both disease activation and serum antibodies differentially affect both superficial and deep retinal vascular density.It has also been shown that high serum antibody levels affect choroidal thickness independent of clinical activity.

Evaluation of childhood developing via optical coherence tomography-angiography in Qamdo,Tibet,China:A prospective cross-sectional,school-based study

BACKGROUND Optical coherence tomography angiography(OCTA)is a new and reliable machine used to evaluate retinal structure and macular perfusion in children.The use of OCTA under bad condition such as high altitude,low atmospheric oxygen,and low humidity,in children is rarely.AIM To quantify the macular micro-vasculature in healthy children of various ages using OCTA in Qamdo.METHODS Design:Prospective cross-sectional,school-based study.Three hundred and fortyseven normal students from 9 schools in 4 different areas in Qamdo were included.OCTA was performed on a 3 mm×3 mm area centered on the macular region and macular cube 512×128 showed details in macular.Early treatment of diabetic retinopathy study Vessel Flow Density(VD)of the macular central vascular plexus density(CVD),inner vascular plexus density(IVD),full vascular plexus density(FVD),and the size of the foveal avascular zone(FAZ)were measured.All these results corrected by t/s=3.382×0.01306×(axial length-1.82).The differences were compared among various ages,sexes and living environments.RESULTS The mean FAZ area in all eyes was 0.27 mm^(2)±0.12 mm^(2).The mean foveal thickness(MFT)in the macular cube was 227.64μm±23.51μm.Compared with girls,boys had a lager FAZ(P=0.0029).Among the different age groups,MFT(P<0.001)and FVD(P<0.0001),IVD(P<0.0001),and CVD(P=0.0050)increased with age.FAZ areas were not correlated with age(P=0.8853)or others(MFT,area).CONCLUSION OCTA can use to evaluate macular perfusion in children.Our data bridge the gap between structural OCT and perfusion density in children in high altitude.Even though these were not a longitudinal study,it may provide us with hints about retina development during puberty and clinical implications of OCTA in children.