Ganglion Cell-inner Plexiform Layer Research Articles

Retinal structural and microvascular changes in myelin oligodendrocyte glycoprotein antibody disease and neuromyelitis optica spectrum disorder: An OCT/OCTA study.

To compare the optical coherence tomography (OCT)/OCT angiography (OCTA) measures in patients with neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD). Twenty-one MOG, 21 NMOSD, and 22 controls were enrolled in our study. The retinal structure [retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL)] was imaged and assessed with the OCT; OCTA was used to image the macula microvasculature [superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP)]. Clinical information such as disease duration, visual acuity, and frequency of optic neuritis and disability was recorded for all patients. Compared with NMOSD patients, MOGAD patients showed significantly reduced SVP density (P = 0.023). No significant difference (P > 0.05) was seen in the microvasculature and structure when NMOSD-ON was compared with MOG-ON. In NMOSD patients, EDSS, disease duration, reduced visual acuity, and frequency of ON significantly correlated (P < 0.05) with SVP and ICP densities; in MOGAD patients, SVP correlated with EDSS, duration, reduced visual acuity, and frequency of ON (P < 0.05), while DCP density correlated with disease duration, visual acuity, and frequency of ON. Distinct structural and microvascular changes were identified in MOGAD patients compared with NMOSD patients suggesting that the pathological mechanisms are different in NMOSD and MOGAD. Retinal imaging via the SS-OCT/OCTA might have the potential to be used as a clinical tool to evaluate the clinical features associated with NMOSD and MOGAD.

Structural and vascular changes in glaucoma with single-hemifield defect: predictors of opposite hemifield visual field progression.

To investigate longitudinal changes in optic nerve head (ONH) superficial vessel density (VD), macular VD, circumpapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell-inner plexiform layer (GCIPL) thickness, and their associations with future VF defects in unaffected hemifields of primary open angle glaucoma (POAG) eyes with baseline VF defect confined to a single hemifield. This retrospective observational study included 61 POAG eyes with VF defect confined to a single hemifield monitored over a mean follow-up time of 2.7years. Development of VF defect in opposite hemifield was defined based the Early Manifest Glaucoma Trail criteria. Each eye was classified into either "conversion" or "no conversion" groups according to development of VF defect in the unaffected hemifield. The rates of longitudinal changes in VD and structure parameters in each hemiretina were compared between the two groups. A Cox proportional hazard model was used to identify potential risk factors for VF conversion in the unaffected hemifield. Among 61 eyes, 17 eyes (27.9%) were classified as "conversion" and 44 eyes (72.1%) were classified as "non-conversion" groups. The conversion group exhibited significantly greater rates of both VD and structural changes in both hemiretinas. In Cox proportional hazard model, greater rate of change in GCIPL thickness, ONH superficial VD, and macular VD of both hemiretinas and greater rate of change in RNFL thickness of the unaffected hemiretina were identified as risk factors for VF conversion in the unaffected hemifield. Monitoring progressive changes in VD and structural parameters effectively predict future VF defect in the opposite hemifields of POAG eyes with single-hemifield defects.

A prospective study of disease modifying therapy and retinal atrophy in relapsing-remitting multiple sclerosis

BackgroundTo compare the rate of retinal atrophy over time in patients with relapsing-remitting multiple sclerosis (RRMS) treated with various disease-modifying therapies (DMT). MethodsPatients with RRMS on various DMT and those observed without treatment were prospectively enrolled into the study between September 2015 and June 2018. All subjects with follow-up of 1–4 years were included and categorized into groups as “no drug”, “low efficacy drug”, “high efficacy drug”, or “dimethyl fumarate” (DMF), based on treatment modality used for the longest duration of their follow-up. Ocular coherence tomography (OCT) was used to measure peripapillary retinal nerve fiber layer thickness (RNFL) and ganglion cell/inner plexiform layer (GC-IPL) thickness at baseline and every 6 months. A linear mixed effects regression model was performed to compare rates of retinal atrophy across treatment groups. ResultsOut of 67 participants who met inclusion criteria (mean age = 37; 76% female), 13 were untreated, 12 on low efficacy therapy, 18 on DMF, and 24 on high efficacy therapy. History of optic neuritis was associated with lower baseline GC-IPL thickness (p = 0.003). Higher baseline GC-IPL thickness was associated with increased rate of GC-IPL thinning (p = 0.009). Age, disease duration, and ethnicity were not predictors of baseline RNFL or GC-IPL thickness, or rate of atrophy of these layers. ConclusionsThere were no differences in rate of GC-IPL atrophy between patients with RRMS on different treatments in this cohort. Age, disease duration, and ethnicity also did not predict retinal atrophy. History of ON was associated with reduced GC-IPL thickness at baseline, consistent with previous research. Rate of GC-IPL thinning was higher for subjects with higher baseline GC-IPL thickness, suggesting a plateau effect.

Changes in and the association of retinal blood perfusion and retinal nerves in diabetic patients without retinopathy.

To explore intraretinal blood flow perfusion and nerve changes, as well as the correlation between them, in diabetic patients without diabetic retinopathy (NDR). Eighty-six NDR patients (86 eyes) who attended the ophthalmology clinic between December 2019 and December 2021 were included. Sixty-four eyes of 64 healthy examined controls in the same period were selected as the control group. The patients underwent routine ophthalmological examination, optical coherence tomography (OCT) and OCT angiography. The average thickness, minimum thickness and thickness of each quadrant except for the superior temporal quadrant of the ganglion cell-inner plexiform layer (GCIPL) in the macular area of the affected eyes in the NDR group were lower than that of the tested eyes in the control group (P < 0.05). The average retinal nerve fibre layer (RNFL) thickness of the NDR group and the superior, inferior and nasal quadrants around the optic disc of the affected eyes in the NDR group were lower compared with the tested eyes in the control group (P < 0.001, P = 0.003, P = 0.001, P = 0.009). The mean vessel length density in the parafoveal and perifoveal areas in the NDR group was positively associated with the mean GCIPL thickness in the macular area (ρ = 0.265, ρ = 0.257 and P < 0.001). No blood flow perfusion parameters in the NDR group were correlated with the RNFL thickness of the corresponding quadrant around the optic disc (P > 0.05). In diabetic patients without diabetic retinopathy, the superficial retinal vessel density in the macular area positively correlated with GCIPL thickness, and the superficial retinal vessel density around the optic disc was not correlated with RNFL thickness.

Ganglion Cell Complex Analysis: Correlations with Retinal Nerve Fiber Layer on Optical Coherence Tomography.

The aim of this review is to analyze the correlations between the changes in the ganglion cell complex (GCC) and the retinal nerve fiber layer (RNFL) on optical coherence tomography in different possible situations, especially in eyes with glaucoma. For glaucoma evaluation, several studies have suggested that in the early stages, GCC analysis, especially the thickness of the infero and that of the inferotemporal GCC layers, is a more sensitive examination than circumpapillary RNFL (pRNFL). In the moderate stages of glaucoma, inferior pRNFL thinning is better correlated with the disease than in advanced cases. Another strategy for glaucoma detection is to find any asymmetry of the ganglion cell-inner plexiform layers (GCIPL) between the two macular hemifields, because this finding is a valuable indicator for preperimetric glaucoma, better than the RNFL thickness or the absolute thickness parameters of GCIPL. In preperimetric and suspected glaucoma, GCC and pRNFL have better specificity and are superior to the visual field. In advanced stages, pRNFL and later, GCC reach the floor effect. Therefore, in this stage, it is more useful to evaluate the visual field for monitoring the progression of glaucoma. In conclusion, GCC and pRNFL are parameters that can be used for glaucoma diagnosis and monitoring of the progression of the disease, with each having a higher accuracy depending on the stage of the disease.

Optical coherence tomography reflects clinically relevant gray matter damage in patients with multiple sclerosis

BackgroundRetinal degeneration leading to optical coherence tomography (OCT) changes is frequent in patients with multiple sclerosis (PwMS).ObjectiveTo investigate associations among OCT changes, MRI measurements of global and regional brain volume loss, and physical and cognitive impairment in PwMS.Methods95 PwMS and 52 healthy controls underwent OCT and MRI examinations. Mean peripapillary retinal nerve fiber layer (pRNFL) thickness and ganglion cell/inner plexiform layer (GCIPL) volume were measured. In PwMS disability was quantified with the Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT). Associations between OCT, MRI, and clinical measures were investigated with multivariable regression models.ResultsIn PwMS, pRNFL and GCIPL were associated with the volume of whole brain (p < 0.04), total gray matter (p < 0.002), thalamus (p ≤ 0.04), and cerebral cortex (p ≤ 0.003) –both globally and regionally–, but not white matter. pRNFL and GCIPL were also inversely associated with T2-lesion volume (T2LV), especially in the optic radiations (p < 0.0001). The brain volumes associated with EDSS and SDMT significantly overlapped with those correlating with pRNFL and GCIPL.ConclusionsIn PwMS, pRNFL and GCIPL reflect the integrity of clinically-relevant gray matter structures, underling the value of OCT measures as markers of neurodegeneration and disability in multiple sclerosis.

Influence of Multiple Anti-VEGF Injections on Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer Thickness in Patients with Exudative Age-Related Macular Degeneration.

Backgrounds and Objectives: To analyze the influence of multiple anti-VEGF intravitreal injections for exudative age-related macular degeneration on the thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC + IPL) using spectral domain optical coherence tomography (SD-OCT). Materials and Methods: A prospective interventional study of consecutive patients treated with intravitreal bevacizumab (IVB) was performed. Average and sectorial values of RNFL and GC + IPL thickness were recorded using Cirrus SD-OCT at 0, 6, 12, and 24 months. Patients suffering from any ocular disease that could affect RNFL or GC + IPL thickness were excluded. Results: A total of 135 patients (70 women and 65 men, aged 65 ± 15 years) were included. The average number of injections per patient was 12.4 ± 2.4. Average RNFL and GC + IPL thickness prior to the first injection (87.6 ± 12.2 and 47.2 ± 15.5 respectively), and after 24-month follow-up (86.2 ± 12.6 and 46.7 ± 11.9 respectively) did not differ significantly (p &gt; 0.05). There was a significant decrease in GC2, GC5 segments, and minimum GC + IPL thickness. Conclusion: Repeated anti-VEGF treatment did not cause significant changes in the thickness of RNFL and GC + IPL layers over a period of 24 months. The detected decrease in GC2 and GC5 sectors, as well as in minimum GC + IPL thickness, could be a sign of ganglion cell damage induced by the treatment or could occur during the natural course of the disease.

Effects of Blood Pressure and Arterial Stiffness on Retinal Neurodegeneration: Cross-Sectional and Longitudinal Evidence From UK Biobank and Chinese Cohorts.

Hypertension might be a modifiable risk factor for neurodegeneration diseases. However, the associations between blood pressure (BP), arterial stiffness index and retinal neurodegeneration remain unclear. This study used cross-sectional data from the United Kingdom BioBank (UKB) and longitudinal data from the Chinese Ocular Imaging Project (COIP). The macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and macular retinal nerve fiber layer thickness were measured using spectral domain optical coherence tomography imaging. Swept-source optical coherence tomography was performed to obtain the longitudinal trajectory of the mGCIPLT and peripapillary retinal nerve fiber layer thickness in the COIP cohort. Multivariable linear models were used to analyze the associations between BP and retinal measurements. In a cross-sectional analysis of 22 801 participants from UKB, thinner mGCIPLT was related to higher systolic BP (β: -0.103 [-0.146 to -0.061]; P<0.001), and higher diastolic BP (β: -0.191 [-0.265 to -0.117]; P<0.001), and was significantly associated with higher mean arterial pressure (β: -0.174 [-0.238 to -0.109]; P<0.001) and higher mean pulse pressure (β: -0.080 [-0.139 to -0.020]; P=009). In a longitudinal analysis of 2012 eligible COIP participants, higher levels of baseline systolic BP, diastolic BP, mean arterial pressure, and mean pulse pressure were associated with faster thinning in mGCIPLT and peripapillary retinal nerve fiber layer thickness (all P<0.001). The strongest association was the effect of mean arterial pressure on mGCIPLT (β: -0.118 [-0.175 to -0.061]; P<0.001). The results of the analysis of macular retinal nerve fiber layer thickness and peripapillary retinal nerve fiber layer thickness were consistent with those of mGCIPLT. BP levels were independently and consistently associated with various retinal neurodegenerative exacerbations.

Quantitatively Evaluating the Relationships between Insulin Resistance and Retinal Neurodegeneration with Optical Coherence Tomography in Early Type 2 Diabetes Mellitus

Introduction: The aim of this study was to quantitatively assess retinal neurodegenerative changes with optical coherence tomography (Cirrus HD-OCT) in type 2 diabetes mellitus (T2DM) patients without diabetic retinopathy (DR) and evaluate their relationships with insulin resistance (IR) and associated systemic indicators. Methods: 102 T2DM patients without DR and 48 healthy controls were included in this observational cross-sectional study. The OCT parameters of macular retinal thickness (MRT) and ganglion cell-inner plexiform layer (GCIPL) thicknesses were evaluated between diabetic and normal eyes. The receiver operating characteristics (ROC) curve was generated to evaluate the discrimination power of early diabetes. Correlation and multiple regression analysis were performed between ophthalmological parameters and T2DM-related demographic and anthropometric variables, and serum biomarkers and homeostasis model assessment of insulin resistance (HOMA-IR) scores. Results: MRT and GCIPL thicknesses showed significant thinning in patients, especially in inferotemporal area. High body mass index (BMI) correlated with decreased GCIPL thicknesses and elevated intraocular pressure (IOP). A negative correlation between waist-to-hip circumference ratio (WHR) and GCIPL thicknesses was also found. High-density lipoprotein (HDL) and fasting C-peptide (CP0) were associated with GCIPL thickness but only in inferotemporal region (r = 0.20, p = 0.04; r = −0.20, p = 0.05, respectively). Multiple regression analysis showed that increased HOMA-IR scores independently predicted both average (β = −0.30, p = 0.05) and inferotemporal (β = −0.34, p = 0.03) GCIPL thinning. Conclusion: Retinal thinning in early T2DM was associated with obesity-related metabolic disorders. IR as an independent risk factor for retinal neurodegeneration may increase the risk of developing glaucoma.

Microstructural Changes in Intraretinal Layers and Macular Structures of People with Epilepsy Measured Using Optical Coherence Tomography.

Epilepsy is a network disorder that can cause alterations in retinal morphology due to microstructural changes in the brain. The aim of our study was to use spectral optical coherence tomography (OCT) to assess the possible effects of neuronal degeneration on the intraretinal layers and macular structures of people with epilepsy and epilepsy subgroups. We enrolled 52 consecutive people with epilepsy (37 females, 15 males; mean age 29.8±9.9 years; range, 17-48 years) and 40 healthy volunteers (27 females, 13 males; mean age 33.3±10.2 years; range, 19-49 years) in this study. Both eyes of all participants were assessed by using spectral-domain OCT. Optical coherence tomography was used to assess the thickness of the peripapillary retinal nerve fiber layer (RNFL), ganglion cell layer-inner plexiform layer (GCC-IPL), central macula, and central macular volume. In comparison to healthy controls, people with epilepsy showed a thinner GCC-IPL in the superior and superior-nasal quadrants, as well as reduced macular thickness and macular volume (p<0.05). The thickness of the GCC-IPL layer in the superior and inferior subquadrants was negatively affected by frequent seizures (>5 seizures/year), polytherapy, and long-duration of epilepsy (≥10 years) (p<0.05). However, we did not find any other statistically significant associations between OCT measurements, age, sex, and epilepsy type (focal and generalized onset epilepsy). Individuals with epilepsy exhibited microstructural alterations in the retinal layers, primarily in the superior and inferior quadrants. Frequent seizures, polytherapy, and long-duration of epilepsy may result in neuronal damage in the afferent visual system.

Topographic Differences in Superficial Macular Vessel Density in Eyes with Early Primary Open-Angle Glaucoma and Normal Tension Glaucoma

Introduction: The aim of the study was to compare macular vascular microcirculation in early primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and normal subjects. Methods: 99 patients with early glaucoma (99 eyes: 60 POAG and 39 NTG) and 78 normal subjects were included. All subjects underwent optical coherence tomography angiography scan at 6 × 6 mm macular area. Macular vessel density (VD) and perfusion density (PD) and 9 sectors were compared between the controls, POAG, and NTG groups. Linear regression analysis was used to investigate the relationship between VD and other variables including macular PD, signal strength (SS), and mean macular ganglion cell-inner plexiform layer (mGCIPL) thickness. Results: Significant losses in total area of VD and PD were detected in POAG and NTG groups compared to the controls (all p < 0.01). There were no significant differences in all inner sectors of macular VD and PD between POAG and controls (all p > 0.05). Except for outer-nasal sector, all other outer sectors of macular VD and PD were significantly lower in POAG than in the controls (all p < 0.01). The inferior-inner sector and all outer sectors of VD and PD were significantly lower in NTG than in the controls (all p < 0.01). Macular VD was significantly correlated with macular PD (r = 0.99, p < 0.001), SS (r = 0.60, p < 0.001), and mGCIPL thickness (r = 0.51, p < 0.001). Conclusions: Macular microcirculation declined significantly in early POAG and NTG patients. Macular microcirculation loss in the NTG group was more central and nasal compared with that in the POAG group. A decrease in macular VD was correlated with lower macular PD, lower SS, and thinner mGCIPL thickness.

Prediction of Retinal Loss Based on Lesion of the Optic Nerve in Acute Stage of Optic-Neuritis

Aim: To assess the predictive features of optic neuritis in retinal loss through optic nerve lesion identification. Study design: Prospectively longitudinal study Place and duration of study: Ghulam Muhammad Mahar Medical College Sukkur and Shaheed Mohtarma Benazir Bhutto Medical University Larkana from 1st January 2021 to 30th June 2022. Methodology: One hundred and ten patients suffering from acute optic neuritis ≤8 weeks were enrolled. Retinal optical-coherence tomography was performed in all patients. Fifty five patients in the whole cohort while clinically isolated syndrome (CIS) 25 patients and relapsing remitting multiple sclerosis (RRMS) as well as neuromyelitis-optica spectrum disorders (NMOSD) and isolated optic neuritis as 20, 3 and 7 respectively. Brain optic nerve magnetic resonance imaging which included three-dimensional double inversion recovery sequence was also conducted at acute phase (M0) and then post 12 months (M12). Results: The mean age of the cases was 30.85±8.9 years. There was a higher frequency of males then females. The duration of the disease was found highest in RRMS cases with 50.31±77.45 months. The variance in estimated and standard error of the ganglion cell-inner plexiform layer volume change was significantly different in whole acute optic neuritis cases as well as the one with CIS and multiple sclerosisat cohort. Conclusion: Optic nerve-lesion length in prediction of retinal-neuroaxonal loss in cases of optic neuritis. The optic-nerve lesion length can also be considered as a biomarker for the process of retinal remodeling as well as visual impairment. Key words: Optic nerve lesion, Acute phase, Optic neuritis (ON), Retinal neuronal loss

Assessment of early and long-COVID related retinal neurodegeneration with optical coherence tomography.

The aim of this study is to investigate short-term and long-term effects of coronovirus 19 disease (COVID-19) at inner and outer retinal layers of patients recovered from COVID-19 with Spectral Domain Optical Coherence Tomography (SD-OCT) and compare these to healthy subjects. Twenty-seven patients recovered from COVID-19, and age- and gender-matched 27 healthy controls were included in this study. Macular and peripapillary retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL), outer plexiform layer (OPL) and outer nuclear layer (ONL) were analyzed with SD-OCT 1 month (V1 visit) and 12 months (V2 visit) after negative result of reverse transcriptase-polymerase chain reaction test. Macular RNFL thickness in outer ring was thinner at V1 and V2 visits than healthy control (p = 0.049 and p = 0.005). Central and inferonasal quadrants of peripapillary RNFL thicknesses were reduced at V1 and V2 visits compared to controls (p = 0.001 and p = 0.024 for V1 visit; p = 0.001 and p = 0.006 for V2 visit). Thinning in ONL thickness in inner ring was observed at V1 and V2 visits than healthy subjects (p = 0.006 and p = 0.001). Subclinical localized changes in macular and peripapillary RNFL and outer nuclear layer were demonstrated in early and 12-months follow-up after COVID-19 recovery.

The age-related pattern of inner retinal thickening is affected by myopia development and progression

The longitudinal effect of myopic eye growth on each individual retinal layer has not been described to date on an established non-human primate (NHP) model of myopia. We evaluated the changes experienced by the overall and individual central and mid-peripheral retinal thickness profiles in marmosets (Callithrix jacchus) induced with myopia continuously for 5.5 months compared to controls using spectral-domain optical coherence tomography. Cycloplegic refractive state (Rx), vitreous chamber depth (VCD) and retinal thickness were measured at baseline and after 3 and 5.5 months on thirteen marmosets: eight animals with lens-induced myopia and five untreated controls. The overall and individual retinal layer thickness in the central and mid-peripheral retina were obtained and compared between groups. Regression models were used to explore the extent to which VCD or Rx changes could predict the thickness changes observed. While the retinas of control marmosets thickened significantly over 5.5 months, marmosets with lens-induced myopia experienced less retinal thickening and thinning at times, mostly in the inner neuroretinal layers and the ganglion cell-inner plexiform layer. The regression models suggest that 90% of the growth and refractive changes observed could be predicted by the thickness changes in the near to mid peripheral retina. This study confirms the longitudinal effect that myopia has on the inner retina of a NHP model during the early stages of myopia development. The observed myopia-driven differences in inner retina thickness templates might represent early biomarkers of myopia progression and associated complications.

Evaluation of Macular Ganglion Cell-Inner Plexiform Layer in Children with Deprivational Amblyopia Who Underwent Unilateral Cataract Surgery.

Background and Objectives: The aim of the study is to assess macular ganglion cell and inner plexiform layer (mGCIPL) thickness in deprivational amblyopic eyes (AE), fellow non-amblyopic eyes (FE) and normal eyes (NE) using spectral. domain optical coherence tomography (SD-OCT). Materials and Methods: Twenty two children (64% boys) who underwent surgical removal of unilateral congenital or developmental cataracts and exhibited visual impairment despite postoperative visual rehabilitation were included in the study. Cataract surgery was performed in patients aged 55.82 ± 35.85 months (range 6 to 114 months). The mean age of the study group was 9.73 ± 2.85 years (range 5 to 15 years). The comparison group consisted of 22 healthy age- and gender-matched children. The best corrected visual acuity (BCVA) after surgery was: 0.75 ± 0.27 (range 0.3 to 1.3) in AE, 0.1 ± 0.13 (range 0 to 0.5) in FE and 0.04 ± 0.07 (range 0 to 0.2) in NE. OCT scans were performed in all patients and subsequently corrected for axial length related magnification errors. Results: The average thickness of mGCIPL was 70.6 ± 11.28 μm in AE; 77.50 ± 6.72 μm in FE and 81.73 ± 5.18 μm in NE. We found that mGCIPL was statistically significantly thinner in deprivation AE compared to FE (p = 0.038) and NE (p = 0.0005). The minimum thickness of mGCIPL was respectively: 62.68 ± 13.2 μm, 70.3 ± 7.61 μm, and 74.5 ± 5.47, and also differed between AE and FE (p = 0.023) and AE and NE (p = 0.0004). Also, measurements in the inferior, inferotemporal, and superotemporal sectors showed thinning of mGCIPL in AE compared to NE. Conclusions: This analysis may suggest that deprivational amblyopia caused by unilateral congenital or developmental cataract in children may be associated with mGCIPL thinning.

Association of paramagnetic rim lesions and retinal layer thickness in patients with multiple sclerosis

Background: Paramagnetic rim lesions (PRLs) are chronic active lesions associated with a more severe disease course in multiple sclerosis (MS). Retinal layer thinning measured by optical coherence tomography (OCT) is a biomarker of neuroaxonal damage associated with disability progression in MS. Objective: We aimed to determine a potential association between OCT parameters (peripapillary retinal nerve fiber layer (pRNFL) ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL) thickness), and PRLs in patients with MS (pwMS). Methods: In this cross-sectional retrospective study, we included pwMS with both 3T brain MRI and an OCT scan. Regression models were calculated with OCT parameters (pRNFL, GCIPL, INL) as dependent variables, and the number of PRLs as an independent variable adjusted for covariates. Results: We analyzed data from 107 pwMS (mean age 34.7 years (SD 10.9), 64.5% female, median disease duration 6 years (IQR 1–13), median EDSS 1.5 (range 0–6.5)). Higher number of PRLs was associated with lower pRNFL (β = −0.18; 95% CI −0.98, −0.03; p = 0.038) and GCIPL thickness (β = −0.21; 95% CI −0.58, −0.02; p = 0.039). Conclusion: The association between higher number of PRLs and lower pRNFL and GCIPL thicknesses provides additional evidence that pwMS with PRLs are affected by a more pronounced neurodegenerative process.

Border tissue morphology is associated with macular ganglion cell thickness in open-angle glaucoma

Externally oblique border tissue (EOBT) configuration is topographically associated with glaucomatous damage in the optic nerve head. We investigated the relationship between the EOBT characteristics and macular retinal ganglion cell (RGC) thickness in patients with open-angle glaucoma (OAG). A total of 149 eyes with OAG that had an EOBT observed on optical coherence tomography exams were included. After determining the maximum EOBT length and angular location of the maximal EOBT length, we analyzed their correlation with macular ganglion cell inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thickness. The macular GCIPL and pRNFL thickness were compared based on the angular location of the longest EOBT, and their association was assessed using multivariable regression analysis. Maximum EOBT length was significantly correlated with macular GCIPL thickness, but not with pRNFL thickness. Macular GCIPL was thinnest in eyes with EOBT located in a temporal direction to the optic disc. Longer maximum EOBT and temporally elongated EOBT were independently associated with a thinner macular GCIPL in the multivariable regression analysis. These suggest that temporal elongation of the EOBT may increase the stress and strain on the RGCs derived from the macula and make RGCs more susceptible to glaucoma-inducing damage.

Spatial characterization of the effect of age and sex on macular layer thicknesses and foveal pit morphology.

Characterizing the effect of age and sex on macular retinal layer thicknesses and foveal pit morphology is crucial to differentiating between natural and disease-related changes. We applied advanced image analysis techniques to optical coherence tomography (OCT) to: 1) enhance the spatial description of age and sex effects, and 2) create a detailed open database of normative retinal layer thickness maps and foveal pit shapes. The maculae of 444 healthy subjects (age range 21-88) were imaged with OCT. Using computational spatial data analysis, thickness maps were obtained for retinal layers and averaged into 400 (20 x 20) sectors. Additionally, the geometry of the foveal pit was radially analyzed by computing the central foveal thickness, rim height, rim radius, and mean slope. The effect of age and sex on these parameters was analyzed with multiple regression mixed-effects models. We observed that the overall age-related decrease of the total retinal thickness (TRT) (-1.1% per 10 years) was mainly driven by the ganglion cell-inner plexiform layer (GCIPL) (-2.4% per 10 years). Both TRT and GCIPL thinning patterns were homogeneous across the macula when using percentual measurements. Although the male retina was 4.1 μm thicker on average, the greatest differences were mainly present for the inner retinal layers in the inner macular ring (up to 4% higher TRT than in the central macula). There was an age-related decrease in the rim height (1.0% per 10 years) and males had a higher rim height, shorter rim radius, and steeper mean slope. Importantly, the radial analysis revealed that these changes are present and relatively uniform across angular directions. These findings demonstrate the capacity of advanced analysis of OCT images to enhance the description of the macula. This, together with the created dataset, could aid the development of more accurate diagnosis models for macular pathologies.

Brain-derived neurotrophic factor levels and macular ganglion cell-inner plexiform layer thickness in macular telangiectasia type 2.

To determine brain-derived neurotrophic factor (BDNF) levels in the serum and aqueous humor (AH) and assess the relationship between BDNF levels and the thickness of the macular ganglion cell-inner plexiform layer (GCIPL) in macular telangiectasia type 2 (MacTel). This study included 25 patients with MacTel (MacTel group) and 25 control subjects (control group). The levels of BDNF in the serum and AH were tested using an enzyme-binding immunosorbent assay. GCIPL thickness was measured by segmentation analysis using optical coherence tomography (OCT). There was no significant difference in the mean serum BDNF levels between the MacTel and control groups (p = 0.145). The average BDNF level in the AH was significantly lower than that in the control group (p = 0.026). OCT segmentation analyses revealed that the minimum GCIPL thickness was significantly lower in the MacTel group than in the control group (p = 0.039). In the correlation analysis of BDNF levels with GCIPL thickness, significant correlations existed between the BDNF level of the AH and minimum GCIPL thickness in the MacTel group. The concentration of BDNF in the AH was decreased in the MacTel group, and this reduction was related to the minimum GCIPL thickness. The low BDNF levels detected in the MacTel group may have resulted in thinning of the GCIPL due to the loss of retinal ganglion cells.

DESCRIBING THE EFFECTS OF PRIMARY OPEN ANGLE GLAUCOMA ON MACULA USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY IN CENTRAL INDIA

Introduction: Primary open-angle glaucoma is a silent predator of sight, killing retinal ganglion cells (RGCs), and leads to characteristic optic nerve head (ONH) changes and visual field (VF) defects. The conventional methods of diagnosis include clinical examination and perimetry. However, by these at the time of diagnosis, a substantial loss of RGCs has already occurred. Spectral domain optical coherence tomography (SD-OCT) allows quantitative measurements of various parameters of the retina. This tool may be utilized for selective measurement of macular parameters to make an early diagnosis of primary open angle glaucoma (POAG). Methods: In 6 months of study, a total of 81 eyes of 51 subjects underwent SD-OCT measurements, that is, 49 eyes of 35 POAG subjects and 32 eyes of 16 age-matched healthy subjects, to record all measurable macular parameters, namely, macular thickness (MT)-central, average, in all sectors of the inner and outer circle of early treatment of diabetic retinopathy study (ETDRS) macular map; macular volume, ganglion cell-inner plexiform layer (GC-IPL) thickness-in all sectors; succeeded by statistical calculations using the unpaired t-test to calculate two-tailed p-value which is significant when its value is &lt;0.05. Results: As an observation the average MT, MT in the inferior and temporal sector of the inner circle of the ETDRS macular map, that in the inferior sector of the outer circle, minimum GC-IPL thickness, and GC-IPL thickness in all sectors were all significantly reduced in POAG eyes than healthy eyes. Whereas central MT, average GC-IPL thickness, macular volume, and MT in few sectors of the inner and outer circle of the ETDRS macular map proved to bear an insignificant change of POAG. Conclusion: In this study, the greatest impact of POAG on macula was discovered in the GC-IPL layer and MT in the inferior sector of inner and outer ring which might serve the purpose of diagnosis of POAG apart from the established parameters of RNFL and ONH.