Peripapillary Nerve Fiber Layer Research Articles

Utility of ganglion cells for the evaluation of anterior visual pathway pathology: a review.

The management of optic neuropathy is fundamental to neuro-ophthalmic practice. Following the invention of the ophthalmoscope, clinicians, for a century or more, relied upon fundus examination in the evaluation of optic neuropathy. However, the advent of optical coherence tomography, based on the principle of backscattering of light and interferometry, has revolutionized the analysis of optic nerve and retinal disorders. Optical coherence tomography has proven of particular value in the measurement, at the micron level, of the peripapillary retinal nerve fibre layer and the ganglion cell layer. These measurements have proven critical in the differential diagnosis and monitoring of optic neuropathy. Specifically, thinning of the peripapillary nerve fibre layer provides evidence of axonal loss affecting any sector of the optic nerve. Thinning of the macular ganglion cell layer, on the other hand, shows a more precise correlation with visual deficits due to retrograde degeneration following optic nerve damage, although limited to central retina. In daily practise, optical coherence tomography is of great value in assessing the diagnosis, prognosis and response to treatment in optic neuropathy. Particular advances have been made, for example, in the assessment of optic neuritis, papilloedema and chiasmal compression which have translated to everyday practice. As with any other imaging technology the clinician must have a clear understanding of acquisition artefacts. A further issue is the relatively limited normative database in sub-populations such as the young and individuals with a refractive error > + 5 or < -5 dioptres.

Papillary and peripapillary vascular densities and corresponding correlation with peripapillary retinal thicknesses using optical coherence tomography angiography in healthy children and adolescents

To evaluate the peripapillary retinal thickness (PPRT), vascular density (PPVD), and disc vascular density (PVD) and their correlations in normal healthy children using optical coherence tomography angiography (OCTA). This was a cross-sectional study of 70 eyes from 36 normal healthy children aged 6–18 years who performed optic nerve head scans using OCTA. The PPRT included the peripapillary nerve fiber layer (PP-RNFLT), inner retina (PP-IRT), middle retinal thickness, and outer retinal thicknesses. The PP-RNFLT and PP-IRT were not significantly different between males and females. Superior nasal peripapillary RNFLT and IRT were significantly affected by age (ANOVA, P > 0.05). The PP-IRT and PP-RNFLT were lower in the 7–11 years old group in comparison with the other 3 groups (Post hoc Tukey test, P value < 0.05). Age and sex-matched PVD were not correlated with PPVD (partial correlation, P > 0.05). PPRT was not correlated with PVD, PPVD, superficial and deep retinal vascular densities, and choroidal vascular density. This study demonstrated that PPRT appears to change during growth in childhood. Superior nasal PPRT was affected more in the groups, decreasing from less than 7 years old to 7–11 years old and then back to pre-reduction values after 11 years old.

Predictive visual field outcomes after optic chiasm decompressive surgery by retinal vessels parameters using optical coherence tomography angiography.

To evaluate the predictive value of superficial retinal capillary plexus (SRCP) and radial peripapillary capillary (RPC) for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer (pRNFL) and ganglion cell complex (GCC). This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery. Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness pre- and post-operatively and with healthy controls. Logistic regression models were used to assess the relationship between preoperative GCC, pRNFL, SRCP, and RPC parameters and visual field recovery after surgery. The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls. Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values. The best predictive GCC and pRNFL models were based on the superior GCC [area under the curve (AUC)=0.866] and the tempo-inferior pRNFL (AUC=0.824), and the best predictive SRCP and RPC models were based on the nasal SRCP (AUC=0.718) and tempo-inferior RPC (AUC=0.825). There was no statistical difference in the predictive value of the superior GCC, tempo-inferior pRNFL, and tempo-inferior RPC (all P>0.05). Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion. This reduction persists despite the recovery of the visual field after decompression surgery. GCC, pRNFL, and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.

Are there any differences in the retina and optic nerve anatomies in attention deficit hyperactivity disorder?

Aims/Purpose: To compare different macular, peripapillary and papillary parameters between attention deficit hyperactivity disorder (ADHD) and normotypical subjects.Methods: In this observational, prospective, case–control study a group of 50 subjects with ADHD were compared with a group of 50 normotypical subjects (controls). Both groups underwent a complete ophthalmological study and optical coherence tomography (OCT) measurements including thickness of the entire retina, inner and outer layers thickness at the macula using 1–3‐6 mm Early Treatment Diabetic Retinopathy Study (ETDRS) grid, peripapillary nerve fibre layer (pRFNL) thickness and Bruch's membrane opening‐minimum rim width (BMO‐MRW) parameters. Both eyes, the right and the left one, were compared independently between both groups.Results: When analysing the macula, it was seen a diffuse thinning of complete retina, inner retina and outer retina presenting symmetrical thinning patterns in both eyes in ADHD. The thickness of all pRNFL sectors were also significantly reduced in both eyes in ADHD in all the quadrants. However, BMO‐MRW parameters did not show any differences in any eye between both groups.Conclusions: Attention deficit hyperactivity disorder is associated with a diffuse thinning of the entire retina, inner retina and outer retina, furthermore pRNFL was also significantly reduced in both eyes.

Neurodegeneration with Brain Iron Accumulation Disorders and Retinal Neurovascular Structure.

The unique neurovascular structure of the retina has provided an opportunity to observe brain pathology in many neurological disorders. However, such studies on neurodegeneration with brain iron accumulation (NBIA) disorders are lacking. To investigate NBIA's neurological and ophthalmological manifestations. This cross-sectional study was conducted on genetically confirmed NBIA patients and an age-gender-matched control group. The thickness of retinal layers, central choroidal thickness (CCT), and capillary plexus densities were measured by spectral domain-optical coherence tomography (SD-OCT) and OCT angiography, respectively. The patients also underwent funduscopy, electroretinography (ERG), visual evoked potential (VEP), and neurological examination (Pantothenate-Kinase Associated Neurodegeneration-Disease Rating Scale [PKAN-DRS]). The generalized estimating equation model was used to consider inter-eye correlations. Seventy-four patients' and 80 controls' eyes were analyzed. Patients had significantly decreased visual acuity, reduced inner or outer sectors of almost all evaluated layers, increased CCT, and decreased vessel densities, with abnormal VEP and ERG in 32.4% and 45.9%, respectively. There were correlations between visual acuity and temporal peripapillary nerve fiber layer (positive) and between PKAN-DRS score and disease duration (negative), and scotopic b-wave amplitudes (positive). When considering only the PKAN eyes, ONL was among the significantly decreased retinal layers, with no differences in retinal vessel densities. Evidence of pachychoroid was only seen in patients with Kufor Rakeb syndrome. Observing pathologic structural and functional neurovascular changes in NBIA patients may provide an opportunity to elucidate the underlying mechanisms and differential retinal biomarkers in NBIA subtypes in further investigations. © 2023 International Parkinson and Movement Disorder Society.

Association of eye strain with dry eye and retinal thickness.

The purpose of this cohort study was to investigate the association between the prevalence of abnormal ocular examination results and the common visual symptoms of eye strain, blurred vision and photophobia. Consecutive first-visit outpatients with best-corrected visual acuity better than 20/30 in both eyes were enrolled and those with a history of intra-ocular lens implantation and glaucoma were excluded. Dry eye-related examinations and retinal thickness measurement were conducted. The odds ratio (OR) was calculated with logistic regression analyses of ocular data in relation to the presence of visual symptoms. A total of 6078 patients (3920 women, mean age 49.0 ± 20.4 years) were analyzed. The prevalence of each symptom was 31.8% for eye strain, 22.5% for blurred vision and 16.0% for photophobia. A significant risk factor for eye strain was short tear break-up time (TBUT) (OR 1.88), superficial punctate keratitis (SPK) (OR 1.44), and thickness of ganglion cell complex (GCC) (OR 1.30). Risk factors for blurred vision were short TBUT (OR 1.85), SPK (OR 1.24) and GCC (OR 0.59). Risk factors for photophobia were short TBUT (OR 1.77) and SPK (OR 1.32). Schirmer test value, peripapillary nerve fiber layer thickness and full macular thickness were not associated with the tested symptoms. The current study successfully identified female gender, short TBUT, and SPK as significant risk factors for eye strain, blurred vision, and photophobia with considerable ORs.

Impact of coronary artery bypass grafting surgery on the chorioretinal biomicroscopic characteristics.

Most patients with cardiovascular disorders suffer from coronary artery diseases, which can be treated successfully using coronary artery bypass grafting (CABG). One of the unpleasant events following CABG is postoperative vision loss (POVL). Vulnerability of retinal vessels to hemodynamic changes, an expectable event following CABG, may contribute to the development of POVL, which might be associated with the changes in the choroidal and retinal structures. To investigate postoperative changes in chorioretinal and peripapillary nerve fiber layer (NFL) thickness, and progression of diabetic and hypertensive retinopathy after CABG. In this prospective, cross-sectional study, 49 eyes in 25 candidates for CABG underwent both ophthalmic and cardiovascular examinations within 6 mo prior to and 9 mo after surgery. Among the study participants, 56% were male with a mean age of 62.84 years ± 10.49 years (range 33-80 years). Diabetes mellitus was observed in eight participants (32%). None of the patients suffered from postoperative anterior or posterior ischemic optic neuropathy, central retinal artery occlusion, and cortical blindness. The mean value of the preoperative best corrected visual acuity was 0.11 ± 0.10 logMAR (range, 0-0.4), which worsened to 0.15 ± 0.08 logMAR (range, 0-0.4) after CABG (P = 0.031). No significant difference was observed between the pre- and postsurgical choroidal (P = 0.853) and macular (P = 0.507) thickness, NFL thickness in the subfoveal (P > 0.999) and peripapillary areas (P = 0.659), as well as the severity of diabetic and hypertensive retinopathy. CABG may reduce visual acuity without affecting ocular structures. Postoperative vision reduction might be attributable to molecular or cellular variations, changes in visual pathway function, or central nervous system.

Investigation of retinal layers thicknesses in autism spectrum disorder and comparison with healthy siblings and control group

BackgroundThis study aimed to evaluate the segmented peripapillary retina nerve fiber layer (RNFL) and all neurosensorial retinal layer thicknesses of children with autism spectrum disorder (ASD) and compare these parameters with healthy siblings and control by spectral domain optical coherence tomography (SD-OCT). Methods41 children with ASD, 38 healthy siblings and 43 healthy control were included. Peripapillary RNFL thickness, total macula, inner retinal layers [including macular RNFL, ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL)] and outer retinal layers [including outer plexiform layer (OPL), outer nuclear layer (ONL)] thickness of all participants were measured by SD-OCT. First, the average inner and outer retina layer values were compared between the three groups. Secondly, subsegmental analysis was performed on the layers whose average value was statistically significant. Segmental analysis of all retinal layer thicknesses was evaluated in 9 distinct macular areas defined based on the Early Treatment Diabetic Retinopathy Study Group (ETDS). ResultsAll inner retinal layers thicknesses in children with ASD were found thicker than healthy siblings and control groups. Consistent with these results, the average total macular thickness was statistically significantly thicker in ASD than in healthy siblings and control groups. ConclusionAll inner retinal layers were thicker in ASD. Since the retina originates from the same place as the central nervous system, this might reflect the brain abnormalities seen in individuals with ASD.

Sector-Based Regression Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography.

This cross-sectional study aimed to investigate the sectoral variance of optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters across eyes with varying degrees of refractive error. Healthy participants, including individuals with axial ametropia, enrolled in the Hong Kong FAMILY cohort were imaged using the Avanti/AngioVue OCT/OCTA system. The OCT and OCTA parameters obtained include peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), and macular ganglion cell complex thickness (GCCT). Sectoral measurements of NFLT, NFLP-CD, and GCCT were based on sectors and hemispheres. A total of 1339 eyes from 791 participants were stratified based on spherical equivalent refraction: high myopia (<-6 D), low myopia (-6 D to -1 D), emmetropia (-1 D to 1 D), and hyperopia (>1 D). Multivariable broken stick regression models, accounting for age, sex, and signal strength, showed that all NFLT sectors except temporally, the inferior GCCT hemisphere, and half of the NFLP-CD sectors were more affected by ametropia-related covariates than the corresponding global parameters. As expected, the false-positive rates in those sectors were elevated. Finally, sector-specific axial length (AL) and spherical equivalent (SE) adjustments helped reduce the elevated false-positive rates. The effect of optical magnification is even more prominent among sectors than the global parameters. AL- and SE-based adjustments should be individualized to each sector to mitigate this magnification bias effectively. Identifying sectoral differences among diagnostic parameters and adopting these sector-based adjustments into commercial OCT systems will hopefully reduce false-positive rates related to refractive error.

Influencia de la longitud axial ocular en el grosor de la capa de fibras nerviosas peripapilar medido con tomografía de coherencia óptica

BackgroundOptical coherence tomography (OCT) allows the measurement of the peripapillary optic nerve fiber layer (RNFL) thickness. The effect of ocular axial length (AL) on RNFL thickness measurement may be relevant in the interpretation of OCT results in diagnosing optic nerve diseases. PurposesTo assess the influence of ocular AL on RNFL thickness and on optic disc topographic parameters (optic disc area, rim area and cup volume) measured by OCT, in healthy individuals. MethodA sample of 109 healthy eyes classified into three groups according to AL (A: AL <22mm; B: AL 22–24.5mm; C: AL >24.5mm) was studied. RNFL thickness and optic disc topographic parameters were measured using Swept-Source OCT Triton (Topcon Corporation, Tokyo, Japan) and were compared between groups using a variance analysis. Correlation between the AL and the study variables was performed using a Pearson's correlation coefficient test. ResultsThe RNFL thickness was lower in eyes with higher AL in the superior (r=−0.41; p<0.001), inferior (r=0.58; p<0.001) and nasal (r=−0.43; p<0.001) quadrants, in the mean value of the RNFL (r=−0.49; p<0.001), optic disc area (r=−0.40; p<0.001) and rim area (r=−0.25; p=0.01). ConclusionAL is negatively correlated with RNFL thickness and optic disc topographic parameters measured by Swept-Source OCT Triton (Topcon).

Ocular axial length influence on peripapillary retinal nerve fiber layer thickness measurement with optical coherence tomography

BackgroundOptical coherence tomography (OCT) allows the measurement of the peripapillary optic nerve fiber layer (RNFL) thickness. The effect of ocular axial length (AL) on RNFL thickness measurement may be relevant in the interpretation of OCT results in diagnosing optic nerve diseases. PurposeTo assess the influence of ocular AL on RNFL thickness and on optic disc topographic parameters (optic disc area, rim area and cup volume) measured by OCT, in healthy individuals. MethodsA sample of 109 healthy eyes classified into 3 groups according to AL (A: AL<22mm; B: AL 22−24.5mm; C: AL>24.5mm) was studied. RNFL thickness and optic disc topographic parameters were measured using Swept-Source OCT Triton (Topcon) and were compared between groups using a variance analysis. Correlation between the AL and the study variables was performed using a Pearson's correlation coefficient test. ResultsThe RNFL thickness was lower in eyes with higher AL in the superior (r=−0.41; p<0.001), inferior (r=0.58; p<0.001) and nasal (r=−0.43; p<0.001) quadrants, in the mean value of the RNFL (r=−0.49; p<0.001), optic disc area (r=−0.40; p<0.001) and rim area (r=−0.25; p=0.01). ConclusionsAL is negatively correlated with RNFL thickness and optic disc topographic parameters measured by Swept-Source OCT Triton (Topcon).

Tamoxifen related chorioretinal structural changes

Purpose To evaluate the vascular structure of the choroid and each retinal layer in patients with breast cancer on tamoxifen therapy and compare them with healthy subjects. Materials and Methods 124 eyes of 62 patients with breast cancer who were on tamoxifen therapy (group 1) and 80 eyes of 40 healthy controls (group 2) were included in this prospective cohort study. The structure of the choroid was evaluated using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) and choroidal binarisation. Spectral-domain OCT (SD-OCT) was performed to analyse the peripapillary nerve fibre layer thickness (pRNFL) and each retinal layer thickness. A subgroup analysis was performed based on chemotherapy history in Group 1. All parameters were compared between Group 1 and the healthy controls and between the subgroups of Group 1. Results The subfoveal choroidal thickness and temporal and nasal directions were increased in Group 1 when compared with Group 2 (p < 0.05, each comparison). Choroidal vascularity index was significantly decreased in Group 1 compared with Group 2 (63.15 ± 3.11% and 65.37 ± 4.63%, p < 0.001). There were no significant differences in each retinal layer, pRNFL thickness, and choroid structural parameters between the subgroups of Group 1. Conclusions Increased choroidal thickness may be the initial finding of subclinical tamoxifen-induced retinopathy. Patients with breast cancer undergoing tamoxifen therapy may be screened prior to tamoxifen therapy and followed during treatment by SD-OCT.

OCT in Neuroophthalmology

Optical coherence tomography (OCT) has become the most important innovation in ophthalmology over the last 30 years and is used routinely, especially in the diagnosis of retinal and glaucomatous diseases. It is fast, non-invasive and reproducible. Since the procedures can offer such a high resolution that the individual retinal layers can be visualised and segmented, this examination technique has also found its way into neuroophthalmology. Especially the peripapillary nerve fibre layer (RNFL) and the ganglion cell layer (GCL) provide valuable diagnostic and prognostic information in cases of visual pathway disease and morphologically unexplained visual disorders. OCT is helpful in determining the cause of optic disc swelling and EDI-OCT can reliably detect buried, non-calcified drusen. This article is intended to provide the reader with an overview of current and future applications of OCT in neuroophthalmology and knowledge of possible pitfalls.

Evaluation of the lamina cribrosa in different stages of diabetic retinopathy.

To evaluate the relationship of the peripapillary retina nerve fiber layer (RNFL) and lamina cribrosa (LC) with diabetic retinopathy (DR) in type 2 diabetes mellitus (DM) cases. Prospective comparative study. This study included 50 non-DR (Group 1), 55 non-proliferative diabetic retinopathy (NPDR) (Group 2), 28 DM cases with proliferative diabetic retinopathy (PDR) (Group 3) and 45 healthy volunteers (Group 4). All participants were evaluated with visual acuity, intraocular pressure (IOP) with Goldman applanation tonometry, anterior segment biomicroscopy, 24 - 2 visual field testing, and dilated fundus examination. Retinal nerve fiber layer (RNFL) thickness, lamina cribrosa thickness (LCT) and anterior lamina cribrosa depth (ALCD) were examined by spectral-domain optical coherence tomography (OCT). There was no difference between the groups in terms of age and gender. Visual acuity (p < 0.001) was significantly different between the groups, while IOP (p = 0.068) was similar. Mean (p = 0.010), superior-temporal (p = 0.024), and superior-nasal (p = 0.011) RNFL thickness decreased significantly in correlation with the stage of DR. LCT decreased significantly as the stage of DR progressed in both vertical and horizontal radial OCT scans (p < 0.001). ALCD was not different between groups (p = 0.954 for horizontal scan, p = 0.867 for vertical scan). Peripapillary RNFL and LCT significantly decreases as the DR stage progresses. The biomechanical effects of the LC may also be responsible for diabetes-induced neurodegeneration.

Retrospective Analysis of Prognostic Value of Optical Coherence Tomography Angiography for the Development of Glaucomatous Damage - One Year Follow-Up Retrospective Observational Cohort Analysis.

Detecting glaucoma damage progression is an essential component of follow-ups in glaucoma patients. It is still unclear which of the currently available and routinely used parameters of glaucoma damage heralds the loss of retinal ganglion cells first. We analysed local hospital data on primary open-angle glaucoma (POAG) patients and looked for correlations between the optical coherence tomography (OCT) structural, OCT angiography (OCTA), and visual field (VF) parameters. Results of eye examinations of POAG patients at baseline, 6 months, and 12 months were analysed. Inclusion criteria were, apart from the diagnosis of POAG, availability and quality of all modalities of examination data and no surgical intervention on the eyes during the observation period. Data on VF mean defect (MD), OCT peripapillary nerve fibre layer (RNFL), OCT macular ganglion cell layer, and OCTA, peripapillary and in the macula, were parameters of interest. Correlations of structural (OCT and OCTA) on one, and functional parameters (VF MD) on the other side, at baseline and as changing over time (first 6 months vs. second 6 months) were performed. All together, data from 78 eyes of 78 POAG patients were included in the analysis. Correlations at baseline were all highly significant (Spearman's r-coefficients between 0.31 and 0.8, all p < 0.05). None of the correlations of parameter changes over time were significant (all p > 0.05). Whereas a robust correlation was observed at baseline between the structural (OCT and OCTA) and functional (VF MD) parameters, none of the examination modality could predict a change in the other modalities during the 1-year period. Results confirm the necessity of regularly performing both the structural and functional examinations in our glaucoma patients.

Is preclinical diabetic retinopathy in diabetic nephropathy individuals more severe?

To analyse the retinal vessel density and thickness characteristics of diabetic nephropathy (DN) individuals with preclinical diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA). This retrospective case-control study included 88 eyes of 88 type 2 DM patients with preclinical DR [44 non-DN (NDN) and 44 DN]. OCTA images and data were acquired using AngioVue 2.0 of the spectral domain OCT device. The foveal avascular zone (FAZ) area, superficial capillary plexus (SCP) and deep capillary plexus vessel densities, ganglion cell complex (GCC) and full retinal thicknesses, peripapillary capillary density and nerve fibre layer (RNFL) thickness were compared between the NDN and DN groups. The relationship between each renal function parameter and each OCTA parameter was analysed. SCP vessel density, GCC thickness and full retinal thickness were significantly reduced in DN individuals compared to NDN individuals [(NDN versus DN) SCP vessel density: 46.65 ± 3.84% versus 44.35 ± 5.25%, p=0.030; GCC thickness: 100.79 ± 5.92 μm versus 93.28 ± 8.66 μm, p<0.001; full retinal thickness: whole area: 287.04 ± 13.62 μm versus 277.71 ± 15.10 μm, p=0.005). Within the peripapillary area, capillary density was also significantly reduced in the whole area (50.19 ± 3.10% versus 47.46 ± 5.93%, p=0.016) and some sectors in the DN group, though RNFL thickness was only decreased in some sectors. For all individuals, estimated glomerular filtration rate (eGFR) correlated significantly with most OCTA parameters and then showed a significantly negative correlation with FAZ area (β=-16.43, p=0.039) in multivariate linear regression analysis. In the NDN group, eGFR showed a significantly negative correlation with FAZ area (β=-18.746, p=0.048) and a significantly positive correlation with SCP vessel density (β=0.580, p=0.036). Preclinical DR may be more severe in DN individuals than in NDN individuals with regard to microvascular and microstructural impairment. Moreover, eGFR may be a good indicator for retinal microvascular impairment.

Oftalmopatisiz Hipertiroidik Hastalarda Optik Cohorens Tomografi Bulguları

Aim The aim of this study is to compare the choroidal, retinal, and peripapillary nerve fiber layer thickness of the patients diagnosed with hyperthyroidism but did not develop ophthalmopathy with the euthyroid patients.&#x0D; Material and Methods: Thyroid stimulating hormone (TSH), freeT3 (fT3) and freeT4 (fT4) tests of the patients were analyzed. Cases who came in with symptoms of hyperthyroidism and had a TSH lower than 0.5 mu/L were included to the study. Retinal thickness (RT), retinal nerve fiber layer (RNFL) thickness, and choroidal thickness (CT) were calculated by means of spectral domain optical coherence tomography.&#x0D; Results: A total of 82 participants, covering 40 (49%) hyperthyroid patients and 42 (51%) euthyroid healthy individuals, were examined. In terms of RT measurements, T500,T1000,T1500 and N1500 values were found to be lower in the HT group compared to the control group, and they were statistically significant (p

Peripapillary nerve fiber layer in patients with iron deficiency anemia: A cross-sectional study in a tertiary eye care center in Central India.

The aim of this study is to evaluate the effect of iron-deficiency anemia (IDA) on peripapillary retinal nerve fiber layer (RNFL) thickness using spectral-domain optical coherence tomography (SD-OCT). The study was conducted at tertiary eye care center in Central India. This study was a prospective, cross-sectional, case-control, and observational study. In the present study, 58 eyes of patients with IDA were compared with 58 eyes of healthy individuals. All individuals underwent a thorough hematological, clinical, and ophthalmic examination, followed by peripapillary RNFL analysis using SD-OCT. A total of 116 eyes were included in the study. The average RNFL thickness (RNFLT) in the cases was 97.26 ± 5.96, and 102.32 ± 6.26 (P = 0.005) in controls. There was a significant RNFL loss in the temporal (66.76 ± 6.1, P = 0.02), superior (119.66 ± 10.47, P = 0.01), nasal (73.59 ± 9.52, P = 0.003), and inferior (129.05 ± 10.96, P = 0.001) quadrants in the cases and controls. Serum hemoglobin, iron, ferritin, total iron-binding capacity, and transferrin saturation were lower in the cases (P < 0.05). A positive correlation was observed between average RNFLT and hemoglobin (r = 0.321), iron (r = 0.122), ferritin (r = 0.152), and transferrin (r = 0.190) levels. In patients with IDA, RNFLT was decreased in all quadrants compared to normal healthy individuals. The inferior and nasal RNFL showed a significant decrease in thickness. The presence of myopia, glaucoma, and diabetic and hypertensive retinopathy can exert an additive effect in the thinning of RNFLs and cause significant visual loss; hence, the correction of anemia is essential. There is a pressing need to raise public and health professional awareness of these problems and their prevention, diagnosis, and management.

Evaluation of Peripapillary and Macular Nerve Fiber Layer Thickness in Paediatric Glaucoma Suspects

Introduction: Glaucoma patients are known to have optic disc cupping, leading to loss of retinal ganglion cell axons. This peripapillary nerve thinness is known to be associated with glaucoma in adult patients. Hence, we intended to evaluate the peripapillary and macular nerve fiber thickness in eyes of pediatric glaucoma suspects using spectral domain optical coherence tomography (OCT). Methods: This cross-sectional analytical study included 44 eyes of 22 paediatric glaucoma suspects, who were compared with 40 eyes of 20 normal paediatric eyes. Pearson correlation coefficients were calculated to assess the relations between the peripapillary retinal nerve fiber layer (RNFL) thickness and ganglion cell complex (GCC). Receiver Operating Characteristics (ROC) curve was plotted for OCT parameters in both the groups along with area under the curve (AUC) calculation. P values &lt; 0.05 were considered as statistically significant. Results: We found the RNFL to be thickest in the superior, inferior, nasal and temporal quadrants in both glaucoma suspects and normal group. When compared among quadrants in RNFL, all the values in different quadrants were statistically significant from each other and in between groups with p &lt; 0.01. The RNFL thickness was statistically different in glaucoma when compared with normal in superior, temporal, and nasal quadrants however, no statistically significant difference was found in inferior quadrant RNFL. The largest AUC for discrimination of glaucoma suspect eyes from normal in peripapillary RNFL in was nasal quadrant in right eye, followed by temporal quadrant whereas it was largest in superior followed by nasal quadrants then average in left eye. However, AUC for discrimination of glaucoma suspects from normal in GCC was poor. Conclusions: Glaucoma suspect paediatric eyes showed significant thinning in peripapillary nerve fiber layer thickness compared to normal subjects.

Regression-Based Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography.

PurposeThe purpose of this study was to correct refractive error-associated bias in optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters.MethodsOCT and OCTA imaging were obtained from participants in the Hong Kong FAMILY cohort. The Avanti/AngioVue OCT/OCTA system was used to measure the peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), macular ganglion cell complex thickness (GCCT), and macular superficial vascular complex vascular density (SVC-VD). Healthy eyes, including ones with axial ametropia, were enrolled for analysis.ResultsA total of 1346 eyes from 792 participants were divided into 4 subgroups: high myopia (<−6D), low myopia (−6D to −1D), emmetropia (−1D to 1D), and hyperopia (>1D). After accounting for age, sex, and signal strength, multivariable regression showed strong dependence in most models for NFLT, GCCT, and NFLP-CD on axial eye length (AL), spherical equivalent (SE) refraction, and apparent optic disc diameter (DD). Optical analysis indicated that AL-related transverse optical magnification variations predominated over anatomic variations and were responsible for these trends. Compared to the emmetropic group, the false positive rates were significantly (Chi-square test P < 0.003) elevated in both myopia groups for NFLT, NFLP-CD, and GCCT. Regression-based adjustment of these diagnostic parameters with AL or SE significantly (McNemar test P < 0.03) reduced the elevated false positive rates.ConclusionsMyopic eyes are biased to have lower NFLT, GCCT, and NFLP-CD measurements. AL- and SE-based adjustments were effective in mitigating this bias.Translational RelevanceAdoption of these adjustments into commercial OCT systems may reduce false positive rates related to refractive error.