Relationship of Retinal Nerve Fiber Layer Thickness and Retinal Vessel Calibers with Cognitive Impairment in the Asymptomatic Polyvascular Abnormalities Population

Objective Cognitive impairment(CI)in older individuals has a high morbidity rate worldwide,with poor diagnostic methods and susceptible population identification.This study aimed to investigate the relationship between different retinal metrics and CI in a particular population,emphasizing polyvascular status.Methods We collected information from the Asymptomatic Polyvascular Abnormalities Community Study on retinal vessel calibers,retinal nerve fiber layer(RNFL)thickness,and cognitive function of 3,785participants,aged 40 years or older.Logistic regression was used to analyze the relationship between retinal metrics and cognitive function.Subgroups stratified by different vascular statuses were also analyzed.Results RNFL thickness was significantly thinner in the CI group(odds ratio:0.973,95%confidence interval:0.953–0.994).In the subgroup analysis,the difference still existed in the non-intracranial arterial stenosis,non-extracranial carotid arterial stenosis,and peripheral arterial disease subgroups(P<0.05).Conclusion A thin RNFL is associated with CI,especially in people with non-large vessel stenosis.The underlying small vessel change in RNFL and CI should be investigated in the future.

Retinal nerve fiber layer defects and chronic kidney disease:the Kailuan Eye Study

AIM:To investigate whether retinal nerve fiber layer defects(RNFLDs)is a potential risk factor for chronic kidney disease(CKD)in Chinese adults.METHODS:The Kailuan Eye Study was a populationbased study that included 14440 participants.All participants underwent detailed assessments,RNFLDs were diagnosed using color fundus photographs.RESULTS:Overall,12507 participants[8533 males(68.23%)]had complete systemic examination data and at least one evaluable fundus photograph.RNFLDs were found in 621 participants[5.0%;95%confidence interval(CI):4.6%-5.34%],and 70 cases of multiple RNFLDs were found(11.27%).After adjusting multiple factors,RNFLDs was significantly associated with CKD severity,the ORs of CKD stage 3,stage 4 and stage 5 were 1.698,4.167,and 9.512,respectively.Multiple RNFLDs were also associated with CKD severity after adjusting multiple factors,the ORs of CKD stage 3 and stage 5 were 4.465 and 11.833 respectively.Furthermore,2294 participants had CKD(18.34%,95%CI:17.68%-18.99%).After adjusting for other factors,CKD presence was significantly correlated with the presence of RNFLDs.CONCLUSION:The strongest risk factors for RNFLDs are CKD and hypertension.Conversely,RNFLDs can be an ocular feature in patients with CKD.Fundoscopy can help detect systemic diseases,and assessment for RNFLDs should be considered in CKD patients.

Analysis of risk and protective factors associated with retinal nerve fiber layer defect in a Chinese adult population

AIM:To investigate the risk and protective factors associated with the retinal nerve fiber layer defect(RNFLD)in a Chinese adult population.METHODS:This study was a cross-sectional populationbased investigation including employees and retirees of a coal mining company in Kailuan City,Hebei Province.All the study participants underwent a comprehensive systemic and ophthalmic examination.RNFLD was diagnosed on fundus photographs.Binary logistic regression was used to investigate the risk and protective factors associated with the RNFLD.RESULTS:The community-based study included 14440 participants.There were 10473 participants in our study,including 7120 males(68.0%)and 3353 females(32.0%).The age range was 45-108y,averaging 59.56±8.66y.Totally 568 participants had RNFLD and the prevalence rate was 5.42%.A higher prevalence of RNFLD was associated with older age[P<0.001,odds ratio(OR):1.032;95%confidence interval(CI):1.018-1.046],longer axial length(P=0.010,OR:1.190;95%CI:1.042-1.359),hypertension(P=0.007,OR:0.639;95%CI:0.460-0.887),and diabetes mellitus(P=0.019,OR:0.684;95%CI:0.499-0.939).The protective factors of RNFLD were visual acuity(P=0.038,OR:0.617;95%CI:0.391-0.975),and central anterior chamber depth(P=0.046,OR:0.595;95%CI:0.358-0.990).CONCLUSION:In our cross-sectional community-based study,with an age range of 45-108y,RNFLD is associated with older age,longer axial length,hypertension,and diabetes mellitus.The protective factors of RNFLD are visual acuity and central anterior chamber depth.These can help to predict and evaluate RNFLD related diseases and identify high-risk populations early.

Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Chinese school-aged children

AIM:To explore the topographic distribution features of choroidal thickness(CT)and retinal nerve fiber layer thickness(RNFLT),and determine the relationship between CT and ocular parameters in school-aged children.METHODS:The healthy school-aged children with low ametropia or emmetropia in Wenzhou were recruited for this cross-sectional study.With high-density optical coherence tomography(HD-OCT)combined with MATLAB software,the CT and RNFLT values in the macular area were measured at different locations and compared.Statistical analyses were performed to evaluate the correlation between CT and ophthalmic parameters,such as spherical equivalent(SE)and the axial length(AL).RESULTS:A total of 279 school-aged children with8.00±1.35 years of mean age(range,6-10 y)were included.The mean AL was 23.66±0.86 mm.The mean CT in CT-C(264.31±48.93μm)was thicker than that in CT-N1(249.54±50.52μm),and the average CT in the parafoveal region was also thicker than that in CT-N2(235.65±50.63μm).The subfoveal CT also varied substantially across refractive errors(P<0.001),and those with myopia(250.59±47.01μm)exhibited a thinner choroid compared with those with emmetropia(278.74±48.06μm).CT negatively correlated with AL(y=-21.72 x+779.17;R^2=0.1458),and positively correlated with SE(y=15.76 x+271.9;R^2=0.0727.OD;y=18.31 x+269.8;R^2=0.1007.OS).The average RNFLT was thickest in the peripapillary region(236.35±19.03μm),the mean RNFLT-S(131.10±15.16μm)was thicker than the RNFLT-I(128.20±16.59μm),and the mean RNFLT-T(76.54±11.99μm)was thicker than the RNFLT-N(64.28±8.55μm).The variations in the RNFLT between quadrants did differ between those with myopia and emmetropia(P<0.05).CONCLUSION:We establish demographic information for the choroid and RNFLT.These findings provide information that should be considered in future analyses of the CT and RNFLT in OCT studies in school-aged children.

Comparison of the Diagnostic Ability of Retinal Nerve Fiber Layer Thickness Measured using Time Domain and Spectral Domain Optical Coherence Tomography in Primary Open Angle Glaucoma

Purpose:To evaluate and compare the diagnostic ability of retinal nerve fiber layer (RNFL) thickness measurements using time domain (Stratus) and spectral domain (Cirrus HD) optical coherence tomography(OCT).in preperimetric and early primary open angle glaucoma (POAG). Methods:A total of 62 eyes from 62 normal subjects,47 eyes from 47 early perimetric damage POAG patients and 30 eyes from 30 preperimetric glaucoma patients were chosen in the study.All the subjects underwent peripapillary RNFL thickness measurements using Stratus OCT and Cirrus HD-OCT on the same day by a single trained operator.The RNFL thickness measured by Stratus OCT and Cirrus HD-OCT was statistically compared using paired t-tests.The relationship between RNFL thickness measured by two OCT instruments was evaluated using Pearson's correlation coefficient.Areas under the receiver operating characteristic curves (AROC) were calculated and compared. Results:RNFL thickness measured using Stratus OCT was generally thicker than that using Cirrus HD-OCT(P<0.05). A highly significant correlation between the two OCT instruments measurements was found in four quadrants and average RNFL thickness measurements (P<0.001). The average RNFL thickness of Cirrus HD-OCT had significantly(P=0.006) higher diagnostic ability (AROC=0.951) than that of Stratus OCT(AROC=0.881) in preperimetric glaucoma. There were no significant differences between the AROCs for other RNFL thickness parameters from Cirrus HD-OCT and Stratus OCT in preperimetric and early glaucoma(P>0.05). Conclusion: Significant differences and an excellent correlation were noted in terms of RNFL thickness measurements using Stratus OCT and Cirrus HD-OCT. Cirrus HD-OCT presented higher diagnostic ability for preperimetric glaucoma.

Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Wenzhou schoolaged children

AIM:To explore the topographic distribution features of choroidal thickness(CT)and retinal nerve fiber layer thickness(RNFLT),and determine the relationship between CT and ocular parameters in school-aged children.METHODS:The healthy school-aged children with low myopia or emmetropia in Wenzhou were recruited for this cross-sectional study.With high-density optical coherence tomography(HD-OCT)combined with MATLAB software,the CT and RNFLT values in the macular area were measured at different locations and compared.Statistical analyses were performed to evaluate the correlation between CT and ophthalmic parameters,such as spherical equivalent(SE)and the axial length(AL).RESULTS:A total of 279 school-aged children with 8.00±1.35 years of mean age(range,6-10 y)were included.The mean AL was 23.66±0.86 mm.The mean CT in CT-C(264.31±48.93μm)was thicker than that in CT-N1(249.54±50.52μm),and the average CT in the parafoveal region was also thicker than that in CT-N2(235.65±50.63μm).The subfoveal CT also varied substantially across refractive errors(P<0.001),and those with myopia(250.59±47.01μm)exhibited a thinner choroid compared with those with emmetropia(278.74±48.06μm).CT positively correlated with AL(y=11.12 x-4.15;R^2=0.18),and positively correlated with SE(y=90.07 x+17.916;R^2=14.2).The average RNFLT was thickest in the peripapillary region(236.35±19.03μm),the mean RNFLT-S(131.10±15.16μm)was thicker than the RNFLT-I(128.20±16.59μm),and the mean RNFLT-T(76.54±11.99μm)was thicker than the RNFLT-N(64.28±8.55μm).The variations in the RNFLT between quadrants did differ between those with myopia and emmetropia(P<0.05).CONCLUSION:We establish demographic information for the choroid and RNFLT.These findings provide information that should be considered in future analyses of the CT and RNFLT in OCT studies in school-aged children.

The Study of Retinal Nerve Fiber Layer Thickness of Normal Eyes Using Scanning Laser Polarimetry

Purpoe: To evaluate retinal nerve fiber layer (RNFL) thickness measurements in local normal Chinese subjects of different age groups and analyse the correlation of RNFL thickness with age using scanning laser polarimetry (SLP,GDxVCC). To assess the reproducibility of RNFL thickness measurement with GDxVCC. Methods: The RNFL thickness of 67 normal subjects (123 eyes) were measured by GDxVCC. The average TSNIT parameters were calculated. The differences of RNFL thickness between sex,right and left eyes,superior and inferior were compared. The relationship between RNFL thickness and age was analyzed with correlation analysis and linear regression analysis. The intraclass correlation coefficients (ICC) of three images in every eye were calculated. Results: The average peripapillary RNFL thickness at the superior,inferior and whole ellipse regions in 123 eyes of 67 normal subjects were (70.30±6.76)(?)m,(67.35±6.77)(?)m and (56.87±4.53)(?) m,respectively. The average TNSIT standard deviation was 23.68±4.61 and the average inter-eye symmetric value was 0.86±0.11. There were significant difference of RNFL thickness between superior and inferior (t=4.952,P < 0.001). There were significant difference of inferior RNFL thickness and TNSIT standard deviation between right and left eyes (P=0.005 and 0.002),while not significant difference of superior RNFL thickness and whole mean RNFL thickness between right and left eye (P=0.086 and 0.529). There was no significant difference in TSNIT parameters between different genders. There was a slight negative correlation average RNFL thickness in superior sector with age (decreased approximately 0.15 microns per year,P=0.047) in the subjects aged below 60 years old. The ICC values of RNFL thickness were >0.8 in superior,inferior and global. Conclusions: The RNFL thickness can be measured accurately by GDxVCC and the reproducibility of RNFL thickness measurement by GDxVCC is good. There was a slight negative correlation between average RNFL thickness in superior with age. More researches on the effects of age on RNFL thickness by GDxVCC are needed.

Bilateral retinal nerve fiber layer thickness reduction in a 9-year-old myopic boy suffering from unilateral optic neuritis:A case report

BACKGROUND In this paper,we present a 9-year-old boy who demonstrates a complex interplay between myopia progression,axial length(AL)extension,and retinal nerve fiber layer(RNFL)thickness loss in both eyes.Additionally,concurrent optic neuritis has directly impacted RNFL thickness in his right eye,and its potential indirect influence on RNFL and macular ganglion cell layer(mGCL)thickness in his left eye is also noteworthy.CASE SUMMARY A 9-year-old boy with bilateral myopia presented with diminished vision and pain in his right eye due to optic neuritis,while his left eye showed pseudopapilledema.Steroid therapy improved his vision in the right eye,and 16-mo follow-up revealed recovery without recurrence despite myopia progression.Follow-up optical coherence tomography conducted 16 mo later revealed a notable thinning of the RNFL in both eyes,especially along with a reduction in mGCL thickness in the left eye.This intricate interaction between optic neuritis,myopia,and retinal changes underscores the need for comprehensive management,highlighting potential long-term visual implications in young patients.CONCLUSION The progression of myopia and AL extension led to the loss of RNFL thickness in both eyes in a 9-year-old boy.Concurrently,optic neuritis directly affected RNFL thickness in his right eye and may indirectly play a role in the thickness of RNFL and mGCL in his left eye.

Quantifying peripapillary vessel density and retinal nerve fibre layer in type 1 diabetic children without clinically detectable retinopathy using OCTA

AIM:To quantify changes in radial peripapillary capillary vessel density(ppVD)and the peripapillary retinal nerve fiber layer(pRNFL)in children with type 1 diabetes without clinical diabetic retinopathy by optical coherence tomography angiography(OCTA),providing a basis for early retinopathy in children with type 1 diabetes.METHODS:This was a retrospective study.A total of 30 patients(3–14y)with type 1 diabetes without clinical diabetic retinopathy(NDR group)were included.A total of 30 age-matched healthy subjects were included as the normal control group(CON group).The HbA1c level in the last 3mo was measured once in the NDR group.The pRNFL thickness and ppVD were automatically measured,and the mean pRNFL and ppVD were calculated in the nasal,inferior,temporal,and superior quadrants.The changes in ppVD and pRNFL in the two groups were analyzed.RESULTS:Compared with CON group,the nasal and superior ppVDs decreased in the NDR group(all P<0.01).The thickness of the nasal pRNFL decreased significantly(P<0.01),while the inferior,temporal and superior pRNFLs slightly decreased but not significant in the NDR group(all P>0.05).Person and Spearman correlation analysis of ppVD and pRNFL thickness in each quadrant of the NDR group showed a positive correlation between nasal and superior(all P<0.01),while inferior and temporal had no significant correlation(all P>0.05).There was no significant correlation between the HbA1c level and ppVD and pRNFL in any quadrant(all P>0.05).There was no significant correlation between the course of diabetes mellitus and ppVD and pRNFL in any quadrant(all P>0.05).CONCLUSION:ppVD and pRNFL decrease in eyes of children with type 1 diabetes before clinically detectable retinopathy and OCTA is helpful for early monitoring.

Evaluation of peripapillary retinal nerve fiber layer, macula and ganglion cell thickness in amblyopia using spectral optical coherence tomography

AIM:To investigate peripapillary retinal nerve fiber layer (RNFL), macula and ganglion cell layer thicknesses (GCC) in amblyopic eyes with spectral domain optical coherence tomography (SD-OCT). METHODS:Thirty six patients with a history of unilateral amblyopia and thirty two children who had emmetropia without amblyopia were included in this study. In this institutional study, 36 eyes of 36 patients with amblyopia (AE), 36 fellow eyes without amblyopia (FE), and 32 eyes of 32 normal subjects (NE) were included. RNFL, GCC and macular thickness measurements were performed with RS-3000 OCT Retina Scan (Nidek Inc CA. USA). RESULTS:The mean global thicknesses of the RNFL were 113.22 ±21.47, 111.57 ±18.25, 109.96 ±11.31μm in the AE, FE, and NE, respectively. There was no statistically significant difference for mean global RNFL thickness among the eyes (P =0.13). The mean thicknesses of the macula were 258.25±18.31, 258.75±19.54, 248.62±10.57μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of macula among the eyes (P =0.06). The GCC was investigated into two parts:superior and inferior. The mean thicknesses of superior GCC were 102.57 ±13.32, 103.32 ±10.64, 100.52 ± 5.88μm in the AE, FE, and NE, respectively. The mean thicknesses of inferior GCC were 103.82 ±12.60, 107.82 ± 12.33, 105.86±10.79μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of superior and inferior GCC between the eyes (P =0.63, P =0.46). ·CONCLUSION:The macular thicknesses of AE and FE were greater than the NE, although it was not statistically significant. Amblyopia does not seem to have a profound effect on the RNFL, macula and GCC.

Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome

·AIM: To compare the effect of suction on the macular thickness and retinal nerve fiber layer(RNFL) thickness during laser in situ keratomileusis(LASIK) used Ziemer FEMTO LDV femtosecond laser(Ziemer group) and Moria M2 automated microkeratome(Moria group) for flap creation.· METHODS: Fourier-domain optical coherence tomography(FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and RNFL thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser(102 eyes) and the Moria M2microkeratome(102 eyes) before surgery and 30min; 1,3d; 1wk; 1, 3mo; 1y after surgery.· RESULTS: The average foveal thickness and parafoveal retinal thickness 30 min after the surgery were statistically more than that before surgery(Ziemer P 【0.001,P =0.003 and Moria P=0.001, P=0.006) and the effect was less in the Ziemer group than that in the Moria group(P all 【0.05). The ganglion cell complex thickness was not significantly changed in both groups(P all 】0.05). The RNFL thickness was statistically less 30 min after surgery in both groups(P=0.014, P 【0.001), but the influence was less in Ziemer group than that in Moria group(P =0.038).However, the RNFL thickness had recovered to the preoperative level only 1d after surgery.·CONCLUSION: The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.

Retinal vessel diameters and their correlation with retinal nerve fiber layer thickness in patients with pseudoexfoliation syndrome

AIM: To compare retinal artery-vein diameters(RAVDs)of patients with pseudoexfoliation(PSX) syndrome with healthy controls and investigate the correlations between retinal nerve fiber layer(RNFL) thickness parameters and RAVDs.METHODS: Seventeen eyes with PSX and 17 eyes of age-matched controls were included in the study. All participants underwent routine ophthalmological examination, Humphrey visual field and RNFL examination by using Stratus OCT. Retinal images were obtained by using a retinal camera(Topcon 501X).RAVDs were measured from inferior nasal, inferior temporal, superior nasal and superior temporal arcuates by using IMAGEnet software. Superior, inferior, nasal,temporal and average RNFL thicknesses were recorded.RAVDs and RNFL parameters in groups and correlations were analyzed by Mann-Whitney U and Spearmann correlation tests.RESULTS: Only inferior quadrant and average RNFL thickness were detected thinner in the PSX group compared with control group(P =0.009, P =0.038,respectively). No statistically significant difference regarding RAVDs was found between two groups.CONCLUSION: RAVDs seems to be comparable in the PSX and control group. RNFL is thinner in the inferior quadrant in the PSX group. RNFL thickness and RAVDs show significant correlations in both groups. This correlation doesn’t seem to be specific to PSX.

The correlation between rat retinal nerve fiber layer thickness around optic disc by using optical coherence tomography and histological measurements

·AIM: To explore the correlation between the retinal nerve fiber layer (RNFL) thickness by using optical coherence tomography (OCT) and by histological measurements in normal adult rats and optic nerve transected rats. · METHODS: The RNFL thickness of 36 rats was scanned in a circle 3.46mm far from the optic disc by OCT. The two experimental groups were the normal group ( =20 rats) and the optic nerve transected group ( =16 rats). The latter group included 4 groups ( =4 /group) surviving for 1 day, 3, 5 and 7 days. Then the RNFL thickness of the same retina area was also measured by NF -200 immunohistochemical staining method. Linear regression was used to analyze the correlation between the data obtained from these two methods. ·RESULTS: The RNFL thickness of normal right eyes around optic disc by OCT was 72.35 ±5.71μm and that of the left eyes was 72.65 ±5.88μm ( =0.074). The RNFL thickness of the corresponding histological section by immunohistochemistry was 37.54 ±4.05μm (right eyes) and 37.38 ±4.23μm (left eyes) ( =0.059). There was a good correlation between the RNFL thickness measured by OCT and that measured by histology (R 2 =0.8131). After optic nerve transection, the trend of the RNFL thickness was thinner with the prolonged survival time. The correlation of the thickness detected by the above two methods was approximately (R 2 =0.8265). Value of the RNFL thickness in rats around optic disc measured by OCT was obviously higher than that measured by common histological measurement in normal adult rats and optic nerve transected rats. ·CONCLUSION: The RNFL thickness measured by OCT has a strong correlation with that measured by histological method. Through OCT scanning, we found that the thickness of RNFL gradually becomes thinner in a time-dependent manner.

Reproducibility of peripapillary retinal nerve fiber layer thickness measurements with Cirrus HD-OCT in glaucomatous eyes

AIM: To assess the reproducibility of Cirrus high-definition optical coherence tomography(HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA) for analysis of peripapillary retinal nerve fiber layer(RNFL) thickness in glaucomatous eyesMETHODS: Forty-five eyes(one eye from each glaucomatous patient) were imaged with Cirrus HD-OCT.Each eye was imaged three times by two separate operators. Intraclass correlation coefficient(ICC),coefficient of variation(CV), and test-retest variability were evaluated for both intraobserver and interobsever measurementsRESULTS: In intraobserver measurements, the average RNFL thickness ICC was 0.983. CV and test-retest variability were 2.3% and 4.4 μm respectively. In quadrants ICC ranged from 0.886 to 0.956, the lowest associated with nasal quadrant and CV ranged from 3.6%to 7.7%. In interobsever measurements, the average RNFL thickness ICC was 0.979. CV and test-retest variability were 2.4% and 4.5 μm respectively. In quadrants ICC ranged from 0.886 to 0.957, the lowest associated with nasal quadrant and CV ranged from 3.8%to 8.6%.CONCLUSION: The reproducibility of Cirrus OCT for RNFL thickness is sufficiently good to be useful clinically as a measure of glaucoma progression.

Comparison of peripapillary retinal nerve fiber layer thickness between myopia severity groups and controls

AIM： To compare the peripapillary retinal nerve fiber layer（RNFL） thickness measured via optical coherence tomography（OCT） between different groups of myopia severity and controls. METHODS： This was a prospective cross-sectional study. All subjects underwent a full ophthalmic examination, refraction, visual field analysis and A-scan biometry. Myopic patients were classified as low myopia（LM） [spherical equivalent（SE） from greater than-0.5 D, up to-3.0 D], moderate myopia（MM; SE greater than-3.0 D, up to-6.0 D） and high myopia（HM; SE greater than-6.0 D）. The control group consisted of emmetropic（EM） patients（SE from ＋0.5 D to-0.5 D）. A Zeiss Cirrus HD-OCT machine was used to measure the peripapillary RNFL thickness of both eyes of each subject. The mean peripapillary RNFL thickness between groups was compared using both analysis of variance and analysis of covariance.RESULTS： A total of 403 eyes of 403 subjects were included in this study. The mean age was 31.48±10.23 y. There were 180（44.7%） eyes with EM, 124（30.8%） with LM, 73（18.1%） with MM and 26（6.5%） with HM. All groups of myopia severity had a thinner average RNFL than the EM group, but after controlling for gender, age, and axial eye length, only the HM group differed significantly from the EM group（P=0.017）. Likewise, the superior, inferior and nasal RNFL was thinner in all myopia groups compared to controls, but after controlling for confounders, only the inferior quadrant RNFL was significantly thinner in the HM group, when compared to the EM group（P=0.017）. CONCLUSION： The average and inferior quadrant RNFL is thinner in highly myopic eyes compared to emmetropic eyes. Refractive status must be taken into consideration when interpreting the OCT of myopic patients, as RNFL thickness varies with the degree of myopia.

Changes of peripapillary vascular density and its correlation with nerve fiber layer thickness in patients with unilateral retinal vein occlusion

Objective:To observe the changes of peripapillary vascular density(VD)and its correlation with retinal nerve fiber layer(RNFL)thickness in patients with unilateral retinal vein occlusion(RVO)by optical coherence tomography angiography(OCTA).Methods:Prospective case-control study.Thirty-two patients(32 eyes)with RVO diagnosed at the Eye Hospital of China Academy of Chinese Medical Sciences from September 2020 to June 2021 were selected.Another 32 outpatients(32 eyes)with normal ocular examination were selected as the normal control group.Optic disc blood flow imaging was performed in all subjects using the OCTA to measure peripapillary RNFL thickness,peripapillary vessel density,optic disc area,and disc rim area.The correlation between peripapillary vascular density and RNFL,optic disc area and disc rim area in eyes with unilateral RVO was analyzed.Results:Compared with the normal control group,the prevalence of hypertension was higher in the unilateral RVO group,and the difference was statistically significant(P<0.05).Compared with the normal control group,the overall,inferior and temporal RNFL thickness around the optic disc was thinner in patients with unilateral RVO,and the difference was statistically significant(P<005).Compared with the normal control group,the overall VD,internal ring,external ring and inferior VD around the optic disc were slightly decreased in patients with unilateral RVO,and the differences were statistically significant(P<0.05).The results of Pearson correlation analysis indicated that RNFL thickness was positively correlated with peripapillary global VD(r=0.648,P<0.001),RNFL thickness was positively correlated with intrapapillary ring VD(r=0.427,P=0.015),and RNFL thickness was positively correlated with peripapillary VD(r=0.666,P<0.001).Conclusion:The results showed that the RNFL thickness around the optic disc was thinner in patients with unilateral RVO,especially in the inferior and temporal area,and the full area VD around the optic disc was decreased,especially in the internal ring,external ring and inferior area.In patients with unilateral RVO,peripapillary RNFL was positively correlated with peripapillary global,internal ring and external ring VD.

Optical coherence tomography evaluation of retinal nerve fiber layer thickness in non-arteritic anterior ischemic optic neuropathy and primary open angle glaucoma:a systematic review and Meta-analysis

AIM:To assess the differences in average and sectoral peripapillary retinal nerve fiber layer(p RNFL)thickness using spectral domain optical coherence tomography(SD-OCT)in patients with non-arteritic anterior ischemic neuropathy(NAION)compared with those with primary open angle glaucoma(POAG).METHODS:A comprehensive literature search of the Pub Med,Cochrane Library,and Embase databases were performed prior to October,2021.Studies that compared the p RNFL thickness in NAION eyes with that in POAG eyes with matched mean deviation of the visual fields were included.The weighted mean difference(WMD)with 95%confidence interval(CI)was used to pool continuous outcomes.RESULTS:Ten cross-sectional studies(11 datasets)comprising a total of 625 eyes(278 NAION eyes,347 POAG eyes)were included in the qualitative and quantitative analyses.The pooled results demonstrated that the superior p RNFL was significantly thinner in NAION eyes than in POAG eyes(WMD=-6.40,95%CI:-12.22 to-0.58,P=0.031),whereas the inferior p RNFL was significant thinner in POAG eyes than in NAION eyes(WMD=11.10,95%CI:7.06 to 15.14,P≤0.001).No difference was noted concerning the average,nasal,and temporal p RNFL thickness(average:WMD=1.45,95%CI:-0.75 to 3.66,P=0.196;nasal:WMD=-2.12,95%CI:-4.43 to 0.19,P=0.072;temporal:WMD=-1.24,95%CI:-3.96 to 1.47,P=0.370).CONCLUSION:SD-OCT based evaluation of inferior and superior p RNFL thickness can be potentially utilized to differentiate NAION from POAG,and help to understand the different pathophysiological mechanisms between these two diseases.Further longitudinal studies and studies using eight-quadrant or clock-hour classification method are required to validate the obtained findings.

Role of Retinal Nerve Fiber Layer Thickness and Optic Disk Measurement by OCT onEarly Diagnosis of Glaucoma

Purpose:.Glaucoma is an eye disease that can lead to irreversible optic nerve damage and cause blindness. Optical coherence tomography.(OCT) allows an early diagnosis of glaucoma by the measurements of the retinal nerve fiber and optic disc parameters.A retrospective study was designed to analyze the effects of the measurement of the retinal nerve fiber layer(RNFL) thickness and the optic disc tomography by spectraldomain OCT on the early diagnosis of suspected glaucoma and primary open angle glaucoma(POAG).Methods:.This was a clinical case-control study. The RNFL thickness around the optic disc and optic disk tomographic parameters of the control(n=51, 98 eyes), suspected glaucoma(n=81,.146 eyes), and POAG groups(n=55, 106 eyes) were measured by OCT. The parameters included superior, inferior, nasal and temporal mean RNFL thickness,.disc area(DA), cup area(CA), rim area(RA), disc volume(DV),cup volume(CV), rim volume(RV), cup / disc area ratio(CA / DA), rim / disc area ratio(RA / DA), cup / disc volume ratio(CV / DV) and rim / disc volume ratio(RV / DV).Results: Superior, nasal, and mean RNFL parameters, DA,CA,RA, DV, CV, CA / DA, RA / DA, CV / DV and RV / DV significantly differed among three groups by single-factorial ANOVA. Inferior and temporal RNFL thickness significantly differed between the control and POAG groups. No significant difference was observed in RV among three groups. In the POAG group,.the maximum area under the ROC curve(AROC) of mean RNFL thickness was 0.845. The maximum AROC of optic disk parameters was RA / DA(0.998), followed by CA / DA(0.997). The AROC of CA, RA, CV, and DV were all > 0.900.Conclusion:.OCT may serve as a useful diagnostic modality in distinguishing suspected glaucoma from POAG.

Helvacioglu reproducibility index: a new algorithm to evaluate the effects of misalignments on the measurements of retinal nerve fiber layer by spectraldomain OCT

AIMTo evaluate the effect of misalignment on the measurements of retinal nerve fiber layer (RNFL) by spectral-domain optical coherence tomography (OCT).METHODSA total of 42 eyes from 21 healthy young subjects underwent RNFL measurements with RTVue spectral-domain OCT (Optovue Inc., Fremont, California, USA). Two baseline measurements with perfectly aligned central circle to the borders of the optic nerve and four misaligned measurements which were misaligned towards to four quadrants were taken. The differences in RNFL between the baseline and misaligned measurements were analyzed with a new algorithm called Helvacioglu reproducibility index (HRI) which is designed to measure the reproducibility of the scans by evaluating the RNFL changes in the four main quadrants.RESULTSThe average RNFL scores of the first two baseline measurements have good correlation (c=0.930) and good reproducibility scores (0.15&#x000b1;0.07). Superior misaligned measurements had significantly lower superior quadrant score and higher inferior quadrant score, similar nasal and little higher temporal scores (P1, P2&#x0003c;0.001, P3=0.553, P4=0.001). Inferior misaligned measurements had significantly higher superior quadrant score and lower inferior quadrant score with similar temporal and little lower nasal scores (P1, P2&#x0003c;0.001, P3=0.315, P4=0.016). Nasal misaligned measurements had significantly higher temporal quadrant score and lower nasal quadrant score with little lower superior and inferior scores (P1, P2, P4&#x0003c;0.001, P3=0.005). Temporal misaligned measurements had significantly higher nasal quadrant score and lower temporal quadrant score with similar superior and little higher inferior scores (P1, P2&#x0003c;0.001, P3=0.943, P4=0.001).CONCLUSIONGood alignment of the central circle to the borders of optic nerve is crucial to have correct and repeatable RNFL measurements. Misalignment to a quadrant resulted in falsely low readings at that quadrant and falsely high readings at the opposite quadrant.