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.

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.

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.

Diurnal changes in retinal nerve fiber layer thickness with obstructive sleep apnea/hypopnea syndrome

AIM:To compare the retinal nerve fiber layer(RNFL)thickness in the morning and evening in Thai patients with varying degrees of obstructive sleep apnea/hypopnea syndrome(OSAHS).METHODS:In this cross-sectional study,potential OSAHS patients at Siriraj Hospital underwent polysomnography to determine the severity of OSAHS and an eye examination(including best corrected visual acuity,slit-lamp examination,and Goldmann applanation tonometry).RNFL thickness was recorded once in the morning and once in the evening,using spectral domain optical coherence tomography.Thickness was expressed as an average and given for each quadrant.Patients with ocular or systemic diseases that might affect RNFL thickness were excluded.RESULTS:Forty-one eyes of 41 patients were classified into 4 OSAHS groups.The average and mean RNFL thickness in most of the four quadrants of the severe OSAHS group trended toward being less than those in the comparable quadrants of the other groups in both the morning and evening.In the moderate OSAHS group,the average RNFL thickness and temporal and superior quadrant thickness in the morning were significantly higher than in the evening(P=0.01,P=0.01,and P=0.03,respectively).In the severe OSAHS group,the inferior quadrant thickness in the morning was significantly higher than in the evening(P=0.03).CONCLUSION:The RNFL thickness in the morning was higher than in the evening in moderate OSAHS.

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.

Analysis of peripapillary retinal nerve fiber layer and inner macular layers by spectral-domain optical coherence tomography for detection of early glaucoma

● AIM: To analyze the diagnostic capabilities of peripapillary retinal nerve fiber layer(p RNFL) thickness and segmented inner macular layer(IML) thickness measured by spectraldomain optical coherence tomography for detection of early glaucoma.● METHODS: Fifty-three patients with primary open angle glaucoma(POAG), 60 patients with normal tension glaucoma(NTG) and 32 normal control subjects were enrolled. Thicknesses of p RNFL, total macular layers(TML), and the IML, including macular RNFL(m RNFL) and macular ganglion cell layer(m GCL) were assessed. The areas under the receiver operating characteristic curves(AROC) were calculated to compare the diagnostic power of different parameters.● RESULTS: There were no differences in the parameters of p RNFL, TML, and IML between POAG and NTG groups. The thicknesses of superior and inferior m GCL showed significant correlation with mean deviation of visual field(R2=0.071, P=0.004; R2=0.08, P=0.002). The m GCL thickness significantly correlated with the p RNFL thickness in the superior and inferior quadrants(R2=0.156, P<0.001; R2=0.407, P<0.001). The thickness of the inferior-outer sector of macula had greater AROCs than those in the inferior-inner sector of macula. The AROCs for superior(0.894) and inferior(0.879) p RNFL thicknesses were similar with the AROCs for superior(0.839) and inferior m GCL(0.864) thicknesses. Sensitivities at 80% specificity for global p RNFL, inferior-outer m GCL and inferior-outer m RNFL thicknesses were 0.938, 0.867, and 0.725, respectively.● CONCLUSION: The diagnostic capability of the m GCL thickness is comparable to that of the p RNFL thickness in patients with early glaucoma. The inferior-outer sector of IML has a better diagnostic capability than the inferiorinner sector of IML for detection of early glaucoma.

Optical coherence tomography with or without enhanced depth imaging for peripapillary retinal nerve fiber layer and choroidal thickness

AIM:To assess peripapillary retinal nerve fiber layer(RNFL) and choroidal thickness obtained with enhanced depth imaging(EDI) mode compared with those obtained without EDI mode using Heidelberg Spectralis optical coherence tomography(OCT).METHODS:Fifty eyes of 25 normal healthy subjects and 32 eyes of 20 patients with different eye diseases were included in the study.All subjects underwent 3.4 mm diameter peripapillary circular OCT scan centered on the optic disc using both the conventional and the EDI OCT protocols.The visualization of RNFL and choroidoscleral junction was assessed using an ordinal scoring scale.The paired t-test,intraclass correlation coefficient(ICC),95% limits of agreement(Lo A),and Bland and Altman plots were used to test the agreement of measurements.RESULTS:The visibility score of RNFL obtained with and without EDI was of no significant difference(P=0.532),the visualization of choroidoscleral junction was better using EDI protocol than conventional protocol(P<0.001).Peripapillary RNFL thickness obtained with EDI was slightly thicker than that obtained without EDI(103.25±9.42 μm vs 101.87±8.78 μm,P=0.010).The ICC of the two protocols was excellent with the value of 0.867 to 0.924,the 95% Lo A of global RNFL thickness was between-10.0 to 7.4 μm.Peripapillary choroidal thickness obtained with EDI was slightly thinner than that obtained without EDI(147.23±51.04 μm vs 150.90±51.84 μm,P<0.001).The ICC was also excellent with the value of 0.960 to 0.987,the 95% Lo A of global choroidal thickness was between-12.5 to 19.8 μm.CONCLUSION:Peripapillary circular OCT scan with or without EDI mode shows comparable results in the measurement of peripapillary RNFL and choroidal thickness.

Peripapillary vessel density and retinal nerve fiber layer thickness changes in early diabetes retinopathy

·AIM:To perform a quantitative analysis of the peripapillary vessel density(VD)and retinal nerve fiber layer(RNFL)thickness changes in patients with early stage of diabetic retinopathy(DR).·METHODS:In this case-control study,swept-source optical coherence tomography angiography(SS-OCTA)imaging was used to examine diabetic and age-matched healthy subjects.The optic disc HD 6×6 mm^(2) blood flow imaging scan mode was selected.Automatic software was used to measure the peripapillary VD,capillary vessel density(CVD),and RNLF in an optic nerve head(ONH)filed based on the Garway-Heath map.In addition,the correlation between peripapillary VD,CVD,and RNFL was further investigated.·RESULTS:The cohort consisted of 32 healthy individuals and 72 patients with diabetes(34 eyes with no DR and 38 eyes with mild-moderate NPDR).Peripapillary VD decreased in the mild-moderate NPDR group compared to the control group in most regions(P<0.05).Peripapillary CVD and RNFL thickness were significantly lower in the mild-moderate NPDR group in the superior temporal(ST)quadrants(P=0.018.P=0.030).In the correlation analysis of each region,the RNFL thickness in the NS region was positively correlated with the peripapillary VD and CVD(r=0.233,P=0.05;r=0.288.P=0.015).In the TI region,the RNFL thickness was positively correlated with the peripapillary CVD(r=0.237,P=0.047).·CONCLUSION:The measurement based on the ONH topographic map may be helpful in detecting functional and structural impairments in DR.The peripapillary VD,CVD and RNFL decrease in early DR,and the RNFL thickness altered in association with the CVD or/and VD in some regions.

Different damage patterns of retinal nerve fiber layer and ganglion cell-inner plexiform layer between early glaucoma and non-glaucomatous optic neuropathy

AIM:To compare the damage pattern of the peripapillary retinal nerve fiber layer(pRNFL)and the macular ganglion cell-inner plexiform layer(mGCIPL)between early glaucomatous and non-glaucomatous optic neuropathy(EGON and NGON).METHODS:It is a cross-sectional study.Thirty-eight healthy controls,74 EGONs and 70 NGONs with comparable average pRNFL loss were included.The NGON group included 23 eyes of optic neuritis(ON),13 eyes of hereditary optic neuropathy(HON),19 eyes of toxic optic neuropathy(TON)and 15 eyes of compressive neuropathy(CON).The sectoral pRNFL and mGCIPL thickness obtained by high definition optical coherence tomography were analyzed.RESULTS:Compared to normal controls,the pRNFL thickness in all quadrants showed a decrease in both EGON and NGON group(P<0.001),but the average pRNFL thickness of EGON group was not different to that of NGON group(P=0.94).The inferior and superior pRNFL was thinner in EGON group compared to NGON group(P<0.001).The temporal pRNFL was thinner in NGON group compared to EGON group(P<0.001).No statistically significant difference was found in nasal pRNFL between EGON and NGON.While the nasal pRNFL was thinner in CON than other three types of NGON(P=0.01),no statistically significant difference was found in other three quadrantal pRNFL among the four types of NGON(P>0.05).The mGCIPL of EGON and NGON group were thinner than control group(P<0.001).In EGON group the severest sites of mGCIPL reduction was located at inferotemporal and inferior sectors.While,compared to EGON group,the average mGCIPL of NGON groupwere significantly thinner,especially in superonasal and inferonasal sectors(P<0.001).CONCLUSION:The damage pattern of pRNFL and mGCIPL caused by glaucoma is distinct from other NGON such as ON,TON,HON and CON,and this characteristic damage pattern is helpful in differentiating early glaucoma from other NGON.

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.

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.

Influence of corneal power on circumpapillary retinal nerve fiber layer and optic nerve head measurements by spectral-domain optical coherence tomography

AIM: To evaluate the influence of corneal power on circumpapillary retinal nerve fiber layer(cp RNFL) and optic nerve head(ONH) measurements by spectral-domain optical coherence tomography(SD-OCT).METHODS: Twenty-five eyes of 25 healthy participants(mean age 23.6±3.6y) were imaged by SD-OCT using horizontal raster scans. Disposable soft contact lenses of different powers(from-11 to +5 diopters including 0 diopter) were worn to induce 2-diopter changes in corneal power. Differences in the cp RNFL and ONH measurements per diopter of change in corneal power were analyzed.RESULTS: As corneal power increased by 1 diopter, total and quadrant cp RNFL thicknesses, except for the nasal sector, decreased by-0.19 to-0.32 μm(P<0.01). Furthermore, the disc, cup, and rim areas decreased by-0.017,-0.007, and-0.015 mm2, respectively(P<0.001); the cup and rim volumes decreased by-0.0013 and-0.006 mm^3, respectively(P<0.01); and the vertical and horizontal disc diameters decreased by-0.006 and-0.007 mm, respectively(P<0.001).CONCLUSION: For more precise OCT imaging, the ocular magnification should be corrected by considering both the axial length and corneal power. However, the effect of corneal power changes on cp RNFL thickness and ONH topography are small when compare with those of the axial length.

Visual field defects and retinal nerve fiber layer damage in buried optic disc drusen: a new insight

AIM: To assess the association between buried optic disc drusen(BODD) location using spectral-domain optical coherence tomography(SD-OCT) and the location of associated visual field defects(VFD) using the Garway-Heath mapping.METHODS: This monocentric retrospective crosssectional study was led at the authors’ institution. Adult patients diagnosed with BODD who had complete records with a reliable Humphrey? 24-2 visual field, macular, and papillary OCT were enrolled. Fisher’s exact test was used to measure the association between BODD location and VFD distribution according to Garway-Heath’s mapping.RESULTS: Totally 20 eyes of 15 patients were included(60% females). The median age(interquartile range) was 63(43)y and the median best corrected visual acuity(BCVA) was-0.08(0.08) log MAR. BODD were mostly located in zones A, E, and F. The minimal rim width(MRW) was globally preserved. The retinal nerve fiber layer(RNFL) was predominantly altered in zones D, E, and F. There was a significant correlation between BODD location and that of RNFL alterations in zones D(P=0.03) and E(P=0.025);Moreover, the presence of BODD in the E zone was significantly related to damaged RNFL in the neighbouring sectors D and F(P=0.012;P=0.02 respectively). Sixty-three percent(12/19) of visual fields were abnormal and there was a significant match(Phi=0.7, P=0.009) between drusen location and VFD only in zone D.CONCLUSION: BODD do not only affect young patients and can be more harmful than usually expected, as we found VFD in 63% of cases. There is a correspondence between BODD location, RNFL damage, and VFD distributions. The presence of BODD induces the overestimation of MRW,thereby disrupting its sensitivity as an early indicator of ganglion fibers damage.

Effect of vitamin B12 deficiency anemia on peripapillary retinal nerve fiber layer

AIM:To evaluate the effect of vitamin B12 deficiency anemia(BDA)on peripapillary retinal nerve fiber layer thickness(RNFLT)using spectral domain optical coherence tomography(SD-OCT),and to determine any correlation arising thereof.METHODS:In this cross-sectional observational study,99 eyes of 50 BDA patients of age 18-65 y were compared with 100 eyes of 50 healthy control subjects.All subjects underwent comprehensive clinical,ophthalmic,and hematological evaluation,followed by peripapillary RNFLT assessment using SD-OCT.RESULTS:The mean total,inferior,nasal,and temporal RNFLT were significantly lower in BDA group as compared to control group(P<0.05).The mean total,inferior and nasal RNFLT correlated significantly(P<0.05)with serum Hb%,B12 and mean corpuscular volume(MCV)level(r=0.310,0.435,-0.386 for total;r=0.932,0.481,-0.513 for inferior;r=0.344,0.254,-0.233 for nasal;respectively),while temporal and superior RNFLT quadrant did not show any correlation with any of the hematological parameters(r=0.144,0.167,-0.096;r=0.111,0.070,-0.099;respectively).The mean total RNFLT showed progressive thinning at par with the progression of anemia,except in very severe BDA,where an inverse relationship was documented.CONCLUSION:The mean total,inferior,nasal,and temporal peripapillary RNFLT was significantly thinner in BDA patients.Peripapillary RNFLT thinning seemed to proceed at par with the progression of severity of anemia,except in very sever grade.Early assessment of peripapillary RNFLT may be crucial in BDA patients to prevent potential blinding sequelae.Peripapillary RNFLT thinning in BDA patients should be considered in the differential diagnosis of other non-glaucomatous optic neuropathies,as well.

Retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal miners in northern China:a community-based observational study

AIM:To evaluate retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal mine workers.METHODS:The community-based observational crosssectional study included 4004 participants of a subpopulation of the Kailuan Study.All the study participants underwent structured interviews with a standardized questionnaire,fundus photography and spectral-domain optical coherence tomography(OCT)examinations performed by trained doctors.RESULTS:The retinal nerve fiber layer thickness was significantly higher(P=0.006)and the central macular thickness was lower in coal miners(n=659,51.0±7.8 y)as compared to the control(working above the ground;n=477,51.8±7.5 y;P=0.032).Additionally,the downhole workers showed a significantly thicker retinal artery(P=0.012)and vein diameters(P<0.001).In multivariable regression,a thicker retinal nerve fiber layer was associated with a higher cumulative silica dust exposure(P=0.005)after adjusting for younger age and larger spherical equivalent.In a reverse pattern,a higher cumulative silica dust exposure(P=0.004)was significantly associated with a thicker retinal nerve fiber layer after adjusting for age,high-density lipoproteins and uric acid.Wider retinal vein diameters were associated with higher cumulative silica dust exposure(P=0.036)after adjusting for younger age and larger spherical equivalent.CONCLUSION:The retinal vessels diameters and retinal nerve fiber layer thickness are significantly thicker in long term of coal mining.The results of our study indicate that underground working environment may lead to retinal vessel dilation and inflammation.Thus,ocular examination might be needed within coal miners in order to monitor the occupational eye health as well as the incidence and progression of eye diseases.

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.

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: one year follow-up results

·AIM: To investigate the retinal nerve fiber layer(RNFL)thickness changes in patients with obstructive sleep apnea syndrome(OSAS) for one year follow-up. To discuss the possibility of detecting tendency of glaucoma in this population by using spectral domain optical coherence tomography(3D-OCT-2000 Spectral domain).·METHODS: After polysomnographic study, all subjects(64 OSAS patients and 40 controls) underwent detailed ophthalmological examination. After these examinations,patients with glaucoma and patients who had ophthalmological and/or systemic disease were excluded from the study.Totally, 20 patients in OSAS group and five patients in controls were excluded from the study in the first examination and follow-up period. The RNFL thickness was assessed with OCT. Forty-four OSAS patients and 35 control subjects were followed up for12 mo. RNFL thickness change and OSAS patients were evaluated for severity of disease by Apnea-Hypopnea Index(AHI).·RESULTS: Forty-four OSAS patients and 35 controls were enrolled in the study. Statistically significance was found between OSAS patients and controls at the 12 thmo.Average RNFL thickness was found to be significantly lower in last measurements in OSAS patients when compared with first measurements and control subjects(P <0.001, 0.002, respectively). There was a statistically significant correlation among AHI, and RNFL thickness(P <0.05).·CONCLUSION: The results suggest that the patients with OSAS were related with a proportional decrease in the RNFL thickness. These patients should be followed up regularly for glaucomatous changes. Detecting more RNFL thinning in severe OSAS was important.

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.

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.

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.