Ganglion Cell Complex Thickness Research Articles

Characteristic deviations of the optic disc and macula in optic nerve hypoplasia based on OCT.

The purpose of this study was to evaluate the optic disc and macula in a large cohort of patients with different severity of optic nerve hypoplasia (ONH) using high-resolution spectral domain optical coherence tomography (SD-OCT). In total, 36 patients (52 ONH eyes and 17 fellow eyes in unilateral cases) and 45 healthy right eyes from 45 controls were evaluated. All patients underwent an examination to confirm the diagnosis. SD-OCT images of the disc and macula were obtained and analysed both quantitatively and qualitatively. OCT in ONH eyes demonstrated a shorter disc diameter (1061 ± 375 μm vs. 1751 ± 221 μm, p < 0.001), shallower mean cup depth (427 ± 171 μm vs. 551 ± 152 μm, p = 0.01), thinner ganglion cell complex (GCC) perifoveally (47.3 ± 13.0 μm, 60.8 ± 6.0 μm, p < 0.001) and reduced foveal depth (61 ± 36 μm, 119 ± 19 μm, p < 0.001) compared to control eyes. Qualitative analysis showed that 1/3rd of ONH eyes lacked signs of an optic cup, and 2/3rd had reduced or no sign of a foveal pit. Fellow eyes had shorter disc diameter (1446 ± 404 μm vs. 1751 ± 221 μm, p = 0.004) and reduced foveal depth (93 ± 27 μm vs. 119 ± 19 μm, p < 0.001) but similar GCC thickness (60.8 ± 7.1 μm vs. 60.8 ± 6.0 μm, p = 0.738) compared to controls. Disc diameter showed the best correlation with visual acuity in ONH eyes (ρ = 0.517, p < 0.001). ONH eyes have reduced GCC thickness and reduced or no foveal pit. Fellow eyes in presumed unilateral cases have a smaller disc diameter and reduced foveal depth compared to controls, suggesting the possibility of subclinical/mild disease. However, GCC thickness was normal. The correlation between structure and visual function is not always straightforward.

MP-3 microperimeter in early primary open angle glaucoma with a new pattern.

To investigate macular microperimetry in patients with early primary open angle glaucoma (POAG) using a new custom-made pattern, and analyze the characteristics of macular sensitivity. This case-control study included 38 patients with POAG, who were divided into pre-perimetric glaucoma (18 eyes of 18 patients), early-stage (20 eyes of 20 patients), and control (20 eyes of 20 patients) groups. All subjects underwent standard 24-2 humphrey visual field test. An MP-3 microperimeter with a new custom-made pattern (28 testing points distributed in four quadrants, covering the central 10° of the retina) was used to evaluate macular sensitivity. Ganglion cell complex (GCC) thicknesses were examined using an RS-3000 Advance OCT system. The features of structure and function were analysed per quadrant. The pre-perimetric glaucoma group had significantly lower inferior hemifield macular sensitivity compared to controls (P<0.05). The early-stage POAG group had significantly lower average, inferior hemifield, inferonasal, and inferotemporal mean sensitivities compared to the pre-perimetric glaucoma group (P<0.05), and lower macular sensitivity in all sectors compared to controls (P<0.05). Regarding GCC thickness, all sectors in the early-stage POAG group became thinner compared to those in controls (P<0.05); whereas all sectors in the early-stage POAG group, except the superonasal quadrant, became thinner compared to those in the pre-perimetric glaucoma group (P<0.05). Macular sensitivity and GCC thickness were significantly associated in each sector. The inferotemporal quadrant had the highest correlation coefficients (0.840). The structure-function relationship for the inferonasal and inferotemporal sectors was stronger compared to the corresponding superior sectors. Microperimetry reveals variations in macular sensitivity in patients with early glaucoma earlier than conventional perimetry, particularly in pre-perimetric glaucoma cases in which it might be undetectable by conventional methods. The new custom-made pattern may improve the accuracy of microperimetry by enhancing point arrangement and reducing fatigue effects. Macular sensitivity measured by MP-3 with this pattern shows statistically significant structural and functional associations with the thicknesses of the GCC.

Retinal Vascular Abnormalities and Clinical Parameters in Systemic Sclerosis.

Background: Systemic sclerosis is a complex autoimmune disease characterized by vasculopathy, fibrosis, and immune dysregulation. Ocular manifestations in these patients are increasingly recognized, suggesting potential correlations between systemic vascular abnormalities and ocular microvascular changes. Advancements in molecular immunology and imaging technology using ocular coherence tomography (OCT) have unveiled intricate pathways underlying possible disease pathogenesis. Understanding the interplay between retinal vascular abnormalities and molecular immunology parameters could provide insights into disease mechanisms and potential biomarkers. Purpose: The aim of this study was to investigate vascular abnormalities, detected with optical coherence tomography angiography (OCT-A), in systemic sclerosis patients and to find correlations between the severity of the disease detected with molecular immunology findings and OCT-A parameters. Methods: A group of 32 systemic sclerosis patients were compared with 9 healthy controls. Ganglion cell complex thickness (GCC), retina thickness of the fovea and parafovea, nerve fiber layer thickness (RNFL) and cup/disc area ratio were investigated using OCT. Vessel density (VD) of the superficial (SCP) and deep capillary plexus (DCP) of the whole macular area and ETDRS grid, size of the foveal avascular zone (FAZ) and vessel density of the radial peripapillary capillary plexus (RPCP) were evaluated using OCT-A. Modified Rodnan skin score (mRSS), capillaroscopy and disease duration were used to stage disease severity. Results: There was a statistically significant reduction in retina thickness of the fovea and parafovea, VD of the whole DCP, VD of the SCP and DCP in ETDRS grid in the patient group compared to controls (p < 0.001). The patients presented a significant enlargement of the FAZ (p 0.005). No significant correlation between OCT and OCT-A parameters and disease severity scores was found. Conclusions: OCT-A could represent a non-invasive tool to detect retinal microvascular damage in systemic sclerosis.

Symptomatic Presbyopia may Develop Earlier in Patients With Glaucoma-A Cross-Sectional Retrospective Cohort Study.

The purpose of this study was to explore risk factors for symptomatic presbyopia, defined as near add power ≥1.50 diopters, in patients with glaucoma. Treated glaucoma (n = 56), untreated glaucoma (n = 21), and control individuals (n = 376), aged 40 to 55 years at first visit, were enrolled in the study, and near add power, retinal thickness, and visual field were examined. The association between near add power and ocular parameters and the odds ratios (ORs) for symptomatic presbyopia were investigated. Survival analysis for symptomatic presbyopia was conducted. Age, astigmatic power, mean deviation, and ganglion cell complex thickness were associated with near add power. The OR for symptomatic presbyopia was significant for age (OR = 1.51), astigmatism (OR = 1.01), mean deviation (OR = 0.72), ganglion cell complex thickness (OR = 0.98), treated and untreated glaucoma (OR = 2.09), and use of glaucoma eye drops (OR = 3.33). Survival analysis showed that the treated glaucoma group reached the near add power endpoint of ≥1.50 D (symptomatic presbyopia) significantly earlier than the other two groups, and there was no difference between the control and untreated glaucoma groups. Glaucoma patients treated with eye drops may start near correction earlier. Symptomatic presbyopia may develop earlier in patients with glaucoma, and our findings could further contribute to better management and understanding of presbyopia with glaucoma.

Longitudinal optical coherence tomography indices in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) may result in optic nerve fiber loss and even atrophy. The timing of the optical coherence tomography (OCT) indices reaching the lowest point (nadir) and the factors that predict the patient's anatomical outcome are not known. We aimed to determine the timing and the factors that affect nadir retinal nerve fiber layer (RNFL) thickness. The medical records of 99 IIH patients who were treated from December 2009 to January 2020 were retrospectively reviewed. The mean RNFL thickness at presentation was 263.5 ± 106.4 µm. The mean time to nadir was 7.9 ± 6.3 months. The average RNFL and ganglion cell complex (GCC) thickness at the nadir were 92.6 ± 14.5 µm (47% showed thinning) and 77.9 ± 27.8 µm (70% showed thinning), respectively. The Frisén disc edema stage and average RNFL thickness at baseline correlated with a longer time to nadir, (r = 0.28 P = 0.003 and r = 0.24, P = 0.012, respectively). The nadir average RNFL thickness and the nadir average GCC thickness (r = 0.32, P = 0.001, r = 0.29, P = 0.002, respectively) correlated with the baseline visual field mean deviation. The final anatomical outcome of IIH episodes in this study resulted in RNFL and GCC thinning. The time to RNFL nadir and its values correlated with IIH severity at presentation.

Alterations of the Ganglion Cell Complex in Age-Related Macular Degeneration: An Amish Eye Study Analysis

To compare the ganglion cell complex (GCC) thickness in eyes with age-related macular degeneration (AMD) vs healthy controls in an elderly Amish population. Prospective cross-sectional study. This is a post hoc analysis of the family-based prospective study of Amish subjects. Study subjects underwent imaging with the Cirrus HD-OCT (Carl Zeiss Meditec Inc) using a macular cube protocol of 512 × 128 scans (128 horizontal B-scans, each comprising 512 A-scans) over a 6 mm × 6 mm region centered on the fovea. The ganglion cell analysis algorithm calculated the GCC thickness by segmenting the outer boundaries of the retinal nerve fiber layer (RNFL) and inner plexiform layer (IPL) in all B-scans of the volume, with the region between these boundaries representing the combined thickness of the ganglion cell layer (GCL) and the IPL. A number of parameters were used to evaluate the GCC thickness: the average GCC thickness, minimum (lowest GCC thickness at a single meridian crossing the elliptical annulus), and sectoral (within each of 6 sectoral areas: superior, superotemporal, superonasal, inferior, inferonasal, and inferotemporal). The stage of AMD was graded on color fundus photographs in accordance with the Beckman Initiative for Macular Research classification system. Of 1339 subjects enrolled in the Amish eye study, a total of 1294 eyes of 1294 subjects had all required imaging studies of sufficient quality and were included in the final analysis. Of these, 798 (62%) were female. Following age adjustment, the average GCC thickness was significantly (P < .001) thinner in AMD subjects (73.71 ± SD; 13.77 µm) compared to normals (77.97 ± 10.42 µm). An independent t test showed that the early AMD (75.03 ± 12.45 µm) and late AMD (61.64 ± 21.18 µm) groups (among which eyes with geographic atrophy [GA] had the lowest thickness, of 58.10 ± 20.27 µm) had a statistically significant lower GCC thickness compared to eyes without AMD. There was no significant differences in average GCC thickness between early AMD and intermediate AMD (76.36 ± 9.25 µm) eyes. The GCC thickness in AMD eyes is reduced compared to normal eyes; however, the relationship is complex, with the greatest reduction in late AMD eyes (particularly eyes with GA) but no difference between early and intermediate AMD eyes.

Association of Retinal Neurovascular Impairment with Disease Severity in Patients with Major Depressive Disorder: An Optical Coherence Tomography Angiography Study.

Identifying the fundus objective biomarkers for the major depressive disorders (MDD) may help promote mental health. The aim of this study was to evaluate retinal neurovascular changes and further investigate their association with disease severity in MDD. This cross-sectional study conducted in the hospital enrolled patients with MDD and healthy controls.The retinal neurovascular parameters for all subjects, including vessel density (VD), thickness of ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL), and optic nerve head (ONH) eg are automatically calculated by the software in optical coherence tomography angiography (OCTA). The severity of MDD including depressive symptoms, anxiety, cognition, and insomnia was assessed by Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), Montreal Cognitive Assessment (MoCA), and Insomnia Severity Index (ISI) respectively. This study included 74 MDD patients (n=74 eyes) and 60 healthy controls (HCs) (n=60 eyes). MDD patients showed significantly decreased VD of superficial and deep capillary plexus, thickness of GCC and RNFL, and volume of ONH (all p<0.05) and increased vertical cup-to-disc ratio and global loss volume (GLV) (all p<0.05) compared to HCs. Positive associations were found between HAMD scores and cup area (r=0.30, p=0.035), cup volume (r=0.31, p=0.029), and disc area (r=0.33, p=0.020) as well as ISI scores and RNFL thickness (r=0.34, p=0.047). We found the retinal neurovascular impairment and its association with disease severity in MDD patients. OCTA showed promise as a potential complementary assessment tool for MDD.

Visual Field and Optical Coherence Tomography Parameters With and Without Positive Family History of Glaucoma.

To evaluate the Retinal Nerve Fiber Layer and Ganglion Cell Complex thickness using Spectral Domain Optical Coherence Tomography with and without positive family history of Primary Open Angle Glaucoma and its relation to visual field. Total 120 eyes with each subjects with positive family history of Primary Open Angle Glaucoma (Group I, n=30) and healthy subjects without positive family history of Primary Open Angle Glaucoma (Group II, n=30) undergone complete ophthalmic evaluation with Retinal Nerve Fiber Layer, Ganglion Cell Complex and VF obtained from Spectral Domain Optical Coherence Tomography RTVue-100 and Humphrey visual field respectively .The measurements were analyzed and compared among two groups using independent-t test by using SPSS version 23.The relationship of Retinal Nerve Fiber Layer with visual field were evaluated with correlation analysis. There were 75 patients included in the study.nasal, temporal RNFL and average Ganglion Cell Complex was significantly lower and thinner in Group I with mean difference of -8.53±2.30 µm (p<0.001), -7.35±3.34 µm (p<0.001), -8.52±3.58µm (p<0.001),-11.87±2.24µm (p<0.001), -5.31±1.95µm (p<0.001) and -8.05±1.52µm (p<0.001) respectively. Correlation plot with Retinal Nerve Fiber Layer thickness as predictor of Mean Deviation and Pattern Standard Deviation indicated statistically significant degree of determination in Group I (r=0.455 and r=0.623, p<0.001 and p<0.001). The Optical Coherence Tomography and visual field Parameters are lower in group I and used as an early predictor, diagnosis, monitoring and management.

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.