Ganglion Cell Complex Thickness Research Articles

Comparison of focal loss volume, global loss volume, retinal nerve fiber layer thickness, and corneal epithelial thickness in eyes with glaucoma and suspicious optic discs

Abstract: PURPOSE: The purpose of this study was to study the role of the focal loss volume (FLV), global loss volume (GLV), and other spectral-domain optical coherence tomography (SD-OCT) parameters in early diagnosis of glaucomatous damage. METHODS: A retrospective study included records of 34 eyes with early glaucoma (Group A) and 17 eyes with suspicious optic discs (Group B). Retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and corneal thickness parameters were assessed by the SD OCT (RTVue SD-OCT). These included the FLV, GLV, in addition to RNFL thickness, cup/disc ratio, GCC thickness, and anterior segment OCT for assessment of central corneal thickness and central corneal epithelial thickness. Data from both groups were subjected to statistical analysis. RESULTS: The FLV and GLV had the highest areas under the receiver operating characteristic curve in Group A eyes. FLV had higher (97.2%) specificity and was the earliest parameter to be affected by glaucomatous damage, followed by GLV. Moreover, Group A eyes had significant thinning of the RNFL (91.59 μm) compared to Group B (118.18 μm), and GCC thickness was also significantly thinner in Group A (92.07 μm) than in Group B (110.54 μm). Interestingly, Group A eyes had thinner corneal epithelium (nonsignificant) than Group B. CONCLUSION: FLV and GLV were of the greatest value in the assessment of early glaucomatous GCC degeneration.

The association of islet autoantibodies with the neural retinal thickness and microcirculation in type 1 diabetes mellitus with no clinical evidence of diabetic retinopathy.

To examine the association between islet autoantibodies (IAbs) and the retinal neurovascular changes in type 1 diabetes mellitus (T1DM) with no diabetic retinopathy (NDR). This cross-sectional study measured the neural retinal structure and microvascular density of 118 NDR eyes using spectral-domain optical coherence tomography angiography. Retinal structure parameters included retinal thickness (RT), inner retinal thickness (iRT), retina never fibral layer thickness (RNFL thickness), ganglion cell complex thickness (GCC thickness), and loss volume of GCC. Microvascular parameters included vessel density of superficial capillary plexus (sVD), vessel density of deep capillary plexus, and vessel density of choroid capillary plexus. Comparison and correlation analyses of these OCTA parameters were made with various IAbs, including glutamic acid decarboxylase antibody (GADA), tyrosine phosphatase-related islet antigen 2 antibody (IA2A), and zinc transporter 8 antibody (ZnT8A). A general linear model was used to understand the association of IAbs with the retina parameters. The IAb positive (IAbs +) group, which included 85 patients, had thinner RT (235.20 ± 18.10mm vs. 244.40 ± 19.90mm at fovea, P = 0.021) and thinner iRT (120.10 ± 9.00mm vs. 124.70 ± 6.90mm at parafovea, P = 0.015), compared with the IAb negative (IAbs-) group comprising 33 patients. Furthermore, a more severe reduction of RT was demonstrated in the presence of multiple IAbs. Among the three IAbs, GADA was the most significant independent risk factor of all-round RT decrease (β = -0.20 vs. -0.27 at fovea and parafovea, respectively, P < 0.05), while titers of IA2A negatively affect sVD in the parafovea (β = -0.316, P = 0.003). IAbs are associated with neural retinal thinning and microcirculation reduction in T1DM patients before the clinical onset of diabetic retinopathy.

Impact of Acute Ocular Hypertension on Retinal Ganglion Cell Loss in Mice.

To assess the correlation between intraocular pressure (IOP) levels and retinal ganglion cell (RGC) loss across different fixed-duration episodes of acute ocular hypertension (AOH). AOH was induced in Thy1-YFP-H transgenic mice by inserting a needle connected to a saline solution container into the anterior chamber. Thirty-one groups were tested, each comprising three to five mice exposed to IOP levels ranging from 50 to 110mm Hg in 5/10mm Hg increments for 60/90/120minutes and a sham control group. The YFP-expressing RGCs were quantified by confocal scanning laser ophthalmoscopy, whereas peripapillary ganglion cell complex thickness was measured using spectral-domain optical coherence tomography. Changes in RGC count and GCCT were determined from values measured 30days after AOH relative to baseline (before AOH). In the 60-minute AOH groups, RGC loss varied even when IOP was increased up to 110mm Hg (36.8%-68.2%). However, for longer durations (90 and 120minutes), a narrow range of IOP levels (60-70mm Hg for 90-minute duration; 55-65mm Hg for 120-minute duration) produced a significant difference in RGC loss, ranging from <25% to >90%. Additionally, loss of YFP-expressing RGCs was comparable to that of total RGCs in the same retinas. Reproducible RGC loss during AOH depends on precise durations and IOP thresholds. In the current study, the optimal choice is an AOH protocol set at 70mm Hg for a duration of 90minutes. This study can assist in determining the optimal duration and intensity of IOP for the effective utilization of AOH models.

Structural changes in the retina as a potential biomarker in Parkinson's disease: an approach from optical coherence tomography.

Parkinson's disease (PD) presents challenges in early diagnosis and follow-up due to the lack of characteristic findings. Recent studies suggest retinal changes in PD are possibly indicative of neurodegeneration. We explored these changes using optical coherence tomography (OCT) to assess retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness. Thirty PD and non-PD patients were matched according to demographic characteristics and OCT and clinical evaluations to rule out other neurodegenerative and visual diseases. We observed a significant thinning of the RNFL in patients diagnosed with PD compared to non-PD patients (p = 0.015). Additionally, this reduction in RNFL thickness was found to correlate with the severity of the disease (p = 0.04). The OCT serves as a tool for quantifying neurodegeneration in PD, showing a significant correlation with disease severity. These findings suggest that OCT could play a crucial role as a potential biomarker in the diagnosis and monitoring of PD.

Comparison of diagnostic capability of macular ganglion cell complex vs retinal fiber layer thickness in primary open angle glaucoma patients of Indian origin.

Comparison of diagnostic capability of macular ganglion cell complex thickness vs. retinal nerve fiber layer (RNFL) thickness in patients of primary open-angle glaucoma (POAG). This cross-sectional observational study was carried out between June 2021 and October 2022 at a tertiary care hospital in North India. A total of 118 eyes were included in the study with 30 control and the rest 88 eyes with POAG were divided into three groups based on visual field loss Group 1 (30 eyes): early field loss with mean deviation (MD) < -6 dB; Group 2 (30 eyes): moderate field loss with MD -6 to -12 dB; and Group 3 (28 eyes): severe field loss with MD > -12 dB. Optical coherence tomography (OCT) scans to measure RNFL loss and ganglion cell inferior plexiform layer (GCIPL) loss were taken for each patient. Categorical variables were analyzed using either the Chi-square test or Fisher's exact test. A receiver operating characteristics analysis was calculated to determine optimal cut-off values of superior, inferior, and average GCIPL and RNFL for determining the severity of field loss as compared to controls (30 normal eyes). In the mild field loss group the sensitivity of superior, inferior, and average GCIPL was 86.7, 96.7, and 96.7%, respectively. Similarly, the specificity was 96.7, 93.3, and 100%, respectively. In the same group, the sensitivity of superior, inferior, and average RNFL was 70, 93, and 66%, respectively. Similarly, the specificity was 46.7, 83.3, and 70%, respectively. In the moderate and severe groups, the results were comparable. The sensitivity and specificity of GCIPL loss are significantly better than that of RNFL parameters in the mild field loss group.

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.

Effect of Focal Laser Photocoagulation on the Ganglion Cell Complex Thickness in Acute Central Serous Chorioretinopathy.

This study investigated the changes in the ganglion cell complex (GCC) of patients with acute central serous chorioretinopathy (CSC) following focal laser photocoagulation (FLP) and sought to determine its correlation with visual acuity (VA). Our retrospective study was conducted on 30 patients diagnosed with acute CSC between January 2015 and April 2022, who underwent FLP within 3 months of symptom onset. The study assessed GCC changes by measuring the thickness of its inner retinal layers-retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) using optical coherence tomography (OCT). GCC thickness was compared between the affected and unaffected eyes and a healthy control group. VA was also assessed at baseline and at 1, 3, and 6 months post-treatment. VA showed significant improvement from 0.20 ± 0.14 at baseline to 0.10 ± 0.12 logMAR at 6 months post-treatment (p = 0.003). There was no significant change in GCC thickness over the 6-month period. No significant differences in GCC thickness were observed when comparing CSC eyes with fellow eyes or with normal controls at any time point. Final VA was significantly related only to baseline VA, with no correlation found with other factors, including RNFL, GCL, and IPL thickness. In summary, for patients with acute CSC undergoing FLP, our findings indicate that there is no significant change in GCC thickness detectable by OCT before and after the resolution of subretinal fluid (SRF), despite improvements in VA post-laser treatment. This suggests that any potential impact of FLP on GCC thickness may be minimal and not discernible with the current measurement methods, such as OCT, emphasizing that VA improvements may be primarily associated with alterations in the outer retina rather than the inner retina. Further studies with extended follow-up durations are warranted to evaluate any potential long-term changes in GCC.

Melatonin ameliorates retinal ganglion cell senescence and apoptosis in a SIRT1-dependent manner in an optic nerve injury model

Melatonin is involved in exerting protective effects in aged-related and neurodegenerative diseases through a silent information regulator type 1 (SIRT1)-dependent pathway. However, little was known about the impact of melatonin on retinal ganglion cell (RGC) senescence and apoptosis following optic nerve crush (ONC). Thus, this study aimed to examine the effects of melatonin on RGC senescence and apoptosis after ONC and investigate the involvement of SIRT1 in this process. To study this, an ONC model was established. EX-527, an inhibitor of SIRT1, was injected intraperitoneally into mice. And melatonin was administrated abdominally into mice after ONC every day. Hematoxylin & eosin staining, retina flat-mounts and optical coherence tomography were used to evaluate the loss of retina cells/neurons. Pattern electroretinogram (p-ERG) was performed to evaluate the function of RGCs. Immunofluorescence and western blot were used to evaluate protein expression. SA-β-gal staining was employed to detect senescent cells. The results demonstrated that melatonin partially rescued the expression of SIRT1 in RGC 3 days after ONC. Additionally, melatonin administration partly rescued the decreased RGC number and ganglion cell complex thickness observed 14 days after ONC. Melatonin also suppressed ONC-induced senescence and apoptosis index. Furthermore, p-ERG showed that melatonin improved the amplitude of P50, N95 and N95/P50 following ONC. Importantly, the protective effects of melatonin were reversed when EX-527 was administered. In summary, this study revealed that melatonin attenuated RGC senescence and apoptosis through a SIRT1-dependent pathway after ONC. These findings provide valuable insights for the treatment of RGC senescence and apoptosis.

Individual vs simultaneous macular and optic disc measurements with spectral domain optical coherence tomography in glaucoma and healthy eyes

We assessed the repeatability and agreement of ganglion cell complex (GCC) in the macular area and the peripapillary retinal nerve fiber layer (ppRNFL) with individual and combined macula and disc scans. The macular GCC and ppRNFL thicknesses from 34 control eyes and 43 eyes with glaucoma were measured with the Canon Optical Coherence Tomography (OCT) HS-100. Two repeated measurements were performed with both scan modes. The repeatability limit (Rlim) and agreement analysis were performed. The individual scan showed better repeatability than the combined scan in both groups. However, the differences in the Rlim for the GCC in most sectors were lower than 3 μm (axial resolution of the OCT), and this was larger than 3 μm for most of the ppRNFL sectors. The mean differences in the thickness between both scan modes for the GCC and ppRNFL measurements were less than 3 and 6 μm, respectively. The interval of the limits of agreement was about 10 μm in some sectors for the GCC, and about 40 and 60 μm in some sectors in controls and glaucoma eyes, respectively. Both scan modes showed good repeatability in both groups. The agreement results suggest that the scan modes cannot be used interchangeably.

Longitudinal changes in optical coherence tomography angiography characteristics in normal-tension glaucoma with or without high myopia.

To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters. We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL. Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non-highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD. NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure-function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes.

Detecting Fast Progressors: Comparing a Bayesian Longitudinal Model to Linear Regression for Detecting Structural Changes in Glaucoma

PurposeDemonstrate that a novel Bayesian hierarchical spatial longitudinal (HSL) model identifies macular superpixels with rapidly deteriorating ganglion cell complex (GCC) thickness more efficiently than simple linear regression (SLR). DesignProspective cohort study. SettingTertiary glaucoma center. Subjects111 eyes (111 patients) with moderate to severe glaucoma at baseline and ≥4 macular optical coherence tomography scans and ≥2 years of follow-up. Observation ProcedureSuperpixel-patient-specific GCC slopes and their posterior variances in 49 superpixels were derived from our latest Bayesian HSL model and Bayesian SLR. A simulation cohort was created with known intercepts, slopes, and residual variances in individual superpixels. Main outcome measuresWe compared HSL and SLR in the fastest progressing deciles on i) proportion of superpixels identified as significantly progressing in the simulation study and compared to SLR slopes in cohort data; ii) root mean square error (RMSE), and SLR/HSL RMSE ratios. ResultsCohort- In the fastest decile of slopes per SLR, 77% and 80% of superpixels progressed significantly according to SLR and HSL, respectively. The SLR/HSL posterior SD ratio had a median of 1.83, with 90% of ratios favoring HSL. SimulationHSL identified 89% significant negative slopes in the fastest progressing decile vs. 64% for SLR. SLR/HSL RMSE ratio was 1.36 for the fastest decile of slopes, with 83% of RMSE ratios favoring HSL. ConclusionThe Bayesian HSL model improves the estimation efficiency of local GCC rates of change regardless of underlying true rates of change, particularly in fast progressors.

Evaluation of the macular sensitivity and retinal ganglion cell layer in unilateral amblyopia.

To assess macular sensitivity and fixation pattern obtained by microperimetry and ganglion cell complex (GCC) obtained by optical coherence tomography (OCT) in cases with unilateral amblyopia and to compare with control. The study was conducted with 30 patients with amblyopia, aged 5-18 years, and 30 control eyes of healthy children in the same age group. Participants underwent full ophthalmological examination. Macular sensitivity, stabilization, and location of fixation values were measured using microperimetry. The GCC values were obtained by OCT. Measurements were compared between amblyopic eyes, fellow eyes, and controls. Any correlation between GCC, macular sensitivity, and fixation was investigated. P < 0.05 was considered statistically significant. The mean age was 10.13 ± 3.49 years in the amblyopia group and 11.53 ± 2.7 years in the control group. Three groups were formed: amblyopic eyes (Group 1, n = 30), fellow eyes (Group 2, n = 30), and control eyes (Group 3, n = 30). The macular sensitivity values were found highest in the control group (P = 0.007). Bivariate contour ellipse area 1, which is the numerical value of fixation stabilization, was measured to be the lowest in the control group (P < 0.0001). In the analysis among the three groups, no significant difference was observed in terms of the GCC (P = 0.229). In the correlation analyses, a significant correlation was detected between macular sensitivity and GCC values in amblyopic eyes. In amblyopic eyes, the macular sensitivity was significantly lower and the GCC thickness was found to be in a positive correlation with macular sensitivity.

Correlation between serum biomarkers, brain volume, and retinal neuronal loss in early-onset Alzheimer's disease.

To compare the peripapillary retinal nerve fiber layer (pRNFL), retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) thickness measurement in early-onset Alzheimer's disease (EOAD) and controls using spectral domain optical coherence tomography (SD-OCT). We also assessed the relationship between SD-OCT measurements and cognitive measures, serum biomarkers for Alzheimer's disease (AD), and cerebral microstructural volume. pRNFL, RNFL, and GCC thicknesses were measured in 43 EOAD and 42 controls using SD-OCT. Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were used to assess cognitive status, magnetic resonance imaging (MRI) tool was used to quantify cerebral microstructural volume, and serum biomarkers were quantified from peripheral blood. EOAD patients had thinner pRNFL (P < 0.001), RNFL (P = 0.008), and GCC (P = 0.018) thicknesses compared to controls after adjusting for multiple factors. pRNFL thickness correlated (P = 0.016) with serum t-tau level. Serum Aβ42 (P < 0.05) concentration correlated with RNFL thickness. Importantly, occipital lobe volume (P = 0.010) correlated with GCC thicknesses in EOAD patients. Our findings suggest that retinal thickness may be useful markers for assessing neurodegenerative processin EOAD.

Sectorial Ganglion Cell Complex Thickness as Biomarker of Vision Outcome in Patients With Dominant Optic Atrophy.

Dominant optic atrophy (DOA) is an inherited condition caused by autosomal dominant mutations involving the OPA-1 gene. The aim of this study was to assess the relationship between macular ganglion cell and inner plexiform layer (GC-IPL) thickness obtained from structural optical coherence tomography (OCT) and visual outcomes in DOA patients. The study recruited 33 patients with confirmed OPA-1 heterozygous mutation and DOA. OCT scans were conducted to measure the GC-IPL thickness. The average and sectorial Early Treatment Diabetic Retinopathy Study (ETDRS) charts (six-sector macular analysis to enhance the topographical analysis) centered on the fovea were considered. Several regression analyses were carried out to investigate the associations between OCT metrics and final best-corrected visual acuity (BCVA) as the dependent variable. The mean BCVA was 0.43 ± 0.37 logMAR, and the average macular GC-IPL thickness was 43.65 ± 12.56 µm. All of the GC-IPL sectors were significantly reduced and correlated with BCVA. The univariate linear regression and the multivariate stepwise regression modeling showed that the strongest association with final BCVA was observed with the internal superior GC-IPL thickness. Dividing patients based on BCVA, we found a specific pattern. Specifically, in patients with BCVA ≤ 0.3 logMAR, the external superior and inferior sectors together with the internal superior were more significant; whereas, for BCVA > 0.3 logMAR, the external superior sector and internal superior sector were more significant. The study identified OCT biomarkers associated with visual outcomes in DOA patients. Moreover, we assessed a specific OCT biomarker for DOA progression, ranging from patients in the early stages of disease with more preserved GC-IPL sectorial thickness to advanced stages with severe thinning.

Longitudinal changes in the ganglion cell complex thickness in acute central serous chorioretinopathy using spectral-domain optical coherence tomography

In this retrospective longitudinal cohort study, we investigated the temporal changes in the peripapillary retinal nerve fiber layer (pRNFL) and inner retinal thickness in patients with acute central serous chorioretinopathy (CSC) using spectral-domain optical coherence tomography (SD-OCT). We followed up with these patients for 6 months, and during this period, the thickness of the pRNFL and the ganglion cell complex (GCC) in CSC patients were compared with the eyes of normal healthy individuals. The study also examined the correlation between the pRNFL thickness, GCC thickness, and visual acuity. The research sample consisted of 67 patients (43 male and 24 female) with an average age of 49.72 ± 9.87 years. The initial findings showed no significant differences in the pRNFL and GCC thickness between the study and fellow eye, study and normal healthy eyes, and fellow and normal healthy eyes. There was no significant difference in the pRNFL and GCC thickness when comparing the study eye with the fellow eye for 6 months. In the study eye, no significant difference was observed when comparing the initial GCC and pRNFL thickness with those at 1, 3, and 6 months. Visual acuity improved significantly from 0.18 ± 0.23 logMAR to 0.04 ± 0.06 logMAR (p < 0.001). The GCC and pRNFL thickness did not significantly affect visual acuity. In conclusion, acute CSC patients did not show significant changes in the pRNFL and inner retinal thickness, suggesting that the GCC and pRNFL do not substantially influence the short-term visual prognosis in these patients.

A Bayesian Hierarchical Spatial Longitudinal Model Improves Estimation of Local Macular Rates of Change in Glaucomatous Eyes.

Demonstrate that a novel Bayesian hierarchical spatial longitudinal (HSL) model improves estimation of local macular ganglion cell complex (GCC) rates of change compared to simple linear regression (SLR) and a conditional autoregressive (CAR) model. We analyzed GCC thickness measurements within 49 macular superpixels in 111 eyes (111 patients) with four or more macular optical coherence tomography scans and two or more years of follow-up. We compared superpixel-patient-specific estimates and their posterior variances derived from the latest version of a recently developed Bayesian HSL model, CAR, and SLR. We performed a simulation study to compare the accuracy of intercept and slope estimates in individual superpixels. HSL identified a significantly higher proportion of significant negative slopes in 13/49 superpixels and a significantly lower proportion of significant positive slopes in 21/49 superpixels than SLR. In the simulation study, the median (tenth, ninetieth percentile) ratio of mean squared error of SLR [CAR] over HSL for intercepts and slopes were 1.91 (1.23, 2.75) [1.51 (1.05, 2.20)] and 3.25 (1.40, 10.14) [2.36 (1.17, 5.56)], respectively. A novel Bayesian HSL model improves estimation accuracy of patient-specific local GCC rates of change. The proposed model is more than twice as efficient as SLR for estimating superpixel-patient slopes and identifies a higher proportion of deteriorating superpixels than SLR while minimizing false-positive detection rates. The proposed HSL model can be used to model macular structural measurements to detect individual glaucoma progression earlier and more efficiently in clinical and research settings.

The ganglion cell complex thickness and visual function in leber hereditary optic neuropathy

Purpose: To evaluate the ganglion cell complex (GCC) thickness using the Iowa Reference Segmentation Algorithm in individuals with chronic Leber hereditary optic neuropathy (LHON) and to assess its relation to visual acuity, visual field sensitivity, and Estermann score.Methods: In this study, a total of 17 patients (34 eyes) aged 16–72 with chronic LHON were enrolled. Visual acuity, visual fields, and Optic coherence tomography (OCT) were performed. Visual fields was evaluated with Estermann and a custom central 30‐degree test, both performed monocularly with the Octopus 900 Haag‐Streit Diagnostics. OCT imaging was performed using a Canon OCT HS‐100 to measure the retinal ganglion cell complex (GCC) thickness. The raw OCT images were exported to IOWA Reference Algorithm and the GCC segmentation was rechecked and manually recorrected if needed. The thickness obtained from the Iowa Reference Algorithms was analysed and compared against the automated segmentation provided by the OCT's inbuilt segmentation algorithm. The correlation between the GCC thickness from 9 ETDRS sectors and the visual function were analysed.Results: On average the automated segmentation overestimated GCC thickness by 23.8 μm for all sectors. Macular central GCC correlated significantly with both visual field sensitivity and Estermann points missed (r = −0.486 and −0.396 respectively). Macular middle sector GCC thickness correlated significantly with visual acuity and visual field sensitivity (r = −0.586 and −0.396 respectively). GCC thickness in outer macular sector correlated significantly only with visual acuity (r = −0.471).Conclusions: In patients with chronic LHON, GCC thickness in central and middle sectors of macula correlates well with the visual function. OCT imaging and precise ganglion cell thickness evaluations in the macula can provide useful information about the structural damage and level of visual impairment in chronic LHON patients.

Patterns of ganglion cell complex defects and association with functional status in glaucoma patients and suspects

Aims/Purpose: To evaluate the frequency and patterns of ganglion cell complex (GCC) defects by spectral‐domain, high‐resolution optical coherence tomography (OCT) in POAG patients and suspects. Secondary endpoint was to analyse and compare the peripapillary retinal nerve fibre layer (RNFL) and GCC thickness as well as the visual field parameters among each GCC defect pattern.Methods: This was a cross‐sectional study and included 220 patients with POAG and suspects. The OCT printouts were analysed by two examiners who carefully searched for GCC defects and in common agreement stratified them into 10 different patterns. GCC thickness, retinal nerve fibre layer (RNFL) thickness were determined for every participant from the exams; mean deviation (MD) and pattern standard deviation (PSD) values were retrieved from automated perimetry exams for every patient. The structural and functional variables were compared among the groups.Results: The sample comprised 91 eyes of 47 patients. The most frequent GCC defect pattern was the minimal (39.1%). It affected more women than man at a rate of 1.4 and was associated with early disease (p &lt; 0.001). The least frequent were inferior and superior confined (2.2% and 1.1% respectively); both were associated with moderate disease (MD = 10.0 dB, p &lt; 0.001). The temporal raphe sign was observed in 5.5% of eyes and was associated with early disease (MD = −5.0 db).Conclusions: In this cohort of Brazilians patients with POAG and suspects, the minimal pattern was the most prevalent GCC defect and was noticed in eyes with early disease. Clinicians should pay special attention to this defect when evaluation eyes with suspicious looking optic disc and POAG patients with early disease.

Evaluation of Ganglion Cell-Layer Complex and Macular Vessel Density in Amblyopic Eyes with Optical Coherence Tomography Angiography.

Purpose: This study aimed to compare and quantify the ganglion cell complex (GCC), macular thickness, and vessel density (VD) in amblyopic eyes and their corresponding fellow eyes using optical coherence tomography angiography (OCTA). Methods: This cross-sectional study analyzed 32 unilateral amblyopic patients, examining both of their eyes. The study assessed parameters such as GCC thickness, macular thickness (total, inner, and outer layers), and VD in the optic nerve and macular region using spectral-domain OCTA. Results: This study analyzed data from 30 unilateral amblyopic patients with a mean age of 28.7 ± 18.3 years. Amblyopic eyes had lower mean best-corrected visual acuity compared with healthy eyes. However, no significant differences were found in retinal nerve fiber layer (RNFL) thickness, GCC thickness, and overall retinal thickness between amblyopic and fellow eyes when accounting for factors such as axial length and signal strength index. In patients older than 30 years, amblyopic eyes had a higher global loss volume (GLV) compared with fellow eyes (p = 0.02). In addition, blood VD within the optic disc and superficial/deep capillary plexuses in different macular regions were significantly lower in amblyopic eyes compared with fellow eyes. Conclusions: This study found significant differences in VD and the GLV index between amblyopic eyes and healthy eyes, particularly in older patients. However, there were no notable differences in macular thickness and RNFL thickness. Further research is needed to determine the clinical relevance of these findings.

Effect of systemic sclerosis on macular anatomy

Aims/Purpose: Systemic sclerosis, also known as scleroderma, is a rare autoimmune disease that involves the hardening of the skin and also hinders the blood supply by occluding the small arteries and capillaries that carry blood to the tissues. Our aim was to compare the retinal thickness of different segmentations at the macula.Methods: In this pilot study 22 eyes from subjects with systemic sclerosis were compared with 22 eyes from healthy subjects (controls). All participants underwent a complete ophthalmological study and optical coherence tomography (OCT) measurements (Spectralis, Heidelberg Engineering, Germany) including complete retina, inner and outer layers, intermediate retinal layers (inner nuclear layer + outer plexiform layer + outer nuclear layer) and ganglion cell complex thickness (macular retinal nerve fibre layer + ganglion cell layer + inner plexiform layer) at the macula using Early Treatment Diabetic Retinopathy Study (ETDRS) grid so foveal, parafoveal and perifoveal subfields were measured. The values of the thickness of each segmentation in relation to the thickness of the complete retina (considered layer segmentation thickness divided by complete retina thickness) were also compared.Results: Best‐corrected visual acuity was lower in systemic sclerosis group but age, gender, spherical equivalent, intraocular pressure and axial length did not show any differences between both groups. Diffuse thinning in parafovea of complete retina, inner retina, outer retina, intermediate retina and ganglion cell complex was found in systemic sclerosis group. Fovea is also thinner in complete retina and intermediate retina in systemic sclerosis group. When considering the comparisons of the results in relation to complete retina thickness no differences were found between groups.Conclusions: Systemic sclerosis induces the thinning specially in the parafovea of all the considered macular segmentations alike.