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Marie Jeremy B San Pedro,1 George Michael N Sosuan,1,2 Maria Imelda R Yap-Veloso1– 3 1Asian Eye Institute, PHINMA Plaza, Rockwell Center, Makati, Philippines; 2University of the Philippines Manila-Philippine General Hospital, Department of Ophthalmology and Visual Sciences, Metro Manila, Philippines; 3Rizal Medical Center, Department of Ophthalmology, Pasig, PhilippinesCorrespondence: Marie Jeremy B San Pedro, Email mariejeremy.sanpedro@gmail.comPurpose: The study aimed to correlate macular ganglion cell layer + inner plexiform layer (GCL + IPL) thickness and circumpapillary retinal nerve fiber layer (cRNFL) thickness and to determine the validity of GCL + IPL in the evaluation of glaucoma across different stages using the area under the curve (AUC) analysis in comparison to cRNFL.Patients and Methods: The charts of 260 adult glaucoma suspect and glaucoma patients having macular ganglion cell analysis, optical coherence tomography (OCT) of the cRNFL and automated visual field (AVF) were reviewed. GCL + IPL thickness (average, minimum and sectoral) and sectoral cRNFL thickness were obtained. Glaucomatous eyes were further classified into stages based on the Hodapp-Anderson-Parrish Visual Field Criteria of Glaucoma Severity. AUC analysis was used to compare GCL + IPL parameters with cRNFL in glaucoma suspects and glaucoma patients.Results: A total of 122 eyes were included in the study and were grouped into glaucoma suspects (n = 43), early or mild glaucoma (n = 40), and moderate-to-severe glaucoma (n = 39). Both GCL + IPL and cRNFL thickness parameters showed a significant decline with greater glaucoma severity. In the determination of visual field defects across all glaucoma stages, the highest AUC was obtained by minimum GCL + IPL (AUC = 0.859) with cut-off value at ≤ 70 μm. Average GCL + IPL had the highest AUC (0.835) in detecting progression from glaucoma suspect to mild glaucoma, while the inferior sector of the cRNFL had the highest AUC (0.937) in discerning mild from moderate-to-severe glaucoma.Conclusion: The results of this study highlight the significance of macular ganglion cell analysis in the screening, detection and staging of glaucoma. Compared to cRNFL, macular ganglion analysis may be more beneficial in glaucoma screening and detecting progression from glaucoma suspect to mild glaucoma.Keywords: macular ganglion cell analysis, macular ganglion cell layer, inner plexiform layer, retinal nerve fiber layer, GCL + IPL

Purpose: The study aimed to correlate macular ganglion cell layer + inner plexiform layer (GCL + IPL) thickness and circumpapillary retinal nerve fiber layer (cRNFL) thickness and to determine the validity of GCL + IPL in the evaluation of glaucoma across different stages using the area under the curve (AUC) analysis in comparison to cRNFL. Patients and Methods: The charts of 260 adult glaucoma suspect and glaucoma patients having macular ganglion cell analysis, optical coherence tomography (OCT) of the cRNFL and automated visual field (AVF) were reviewed. GCL + IPL thickness (average, minimum and sectoral) and sectoral cRNFL thickness were obtained. Glaucomatous eyes were further classified into stages based on the Hodapp-Anderson-Parrish Visual Field Criteria of Glaucoma Severity. AUC analysis was used to compare GCL + IPL parameters with cRNFL in glaucoma suspects and glaucoma patients. Results: A total of 122 eyes were included in the study and were grouped into glaucoma suspects (n = 43), early or mild glaucoma (n = 40), and moderate-to-severe glaucoma (n = 39). Both GCL + IPL and cRNFL thickness parameters showed a significant decline with greater glaucoma severity. In the determination of visual field defects across all glaucoma stages, the highest AUC was obtained by minimum GCL + IPL (AUC = 0.859) with cut-off value at ≤ 70 μm. Average GCL + IPL had the highest AUC (0.835) in detecting progression from glaucoma suspect to mild glaucoma, while the inferior sector of the cRNFL had the highest AUC (0.937) in discerning mild from moderate-to-severe glaucoma. Conclusion: The results of this study highlight the significance of macular ganglion cell analysis in the screening, detection and staging of glaucoma. Compared to cRNFL, macular ganglion analysis may be more beneficial in glaucoma screening and detecting progression from glaucoma suspect to mild glaucoma. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a non-invasive imaging technique based on the principle of low-coherence interferometry that captures detailed images of ocular structures. Multiple sclerosis (MS) is a neurodegenerative disease that can lead to damage of the optic nerve and retina, which can be depicted by OCT. The purpose of this pilot study is to determine whether macular OCT can be used as a biomarker in the detection of retrochiasmal lesions of the visual pathway in MS patients. We conducted a prospective study in which we included 52 MS patients and 27 healthy controls. All participants underwent brain MRI, visual field testing, and OCT evaluation of the thicknesses of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer (GCL), and macular inner plexiform layer (IPL). OCT measurements were adjusted for optic neuritis (ON). VF demonstrated poor capability to depict a retrochiasmal lesion identified by brain MRI (PPV 0.50). In conclusion, the OCT analysis of the macula appears to excel in identifying retrochiasmal MS lesions compared to VF changes. The alterations in the GCL and IPL demonstrate the most accurate detection of retrochiasmal visual pathway changes in MS patients. [ABSTRACT FROM AUTHOR]

Abstract Background To analyze the morphologic and functional change in traumatic optic neuropathy (TON) divided by the mechanism of optic nerve injury. Methods A retrospective analysis of 58 patients who were diagnosed as monocular TON from February 2015 to August 2021 was conducted at in CHA Bundang Medical Center in Seongnam, South Korea. The patients visited the clinic of the department of ophthalmology for more than 6 months and at least 4 times during this period. Results 44 patients were classified as blunt TON patients, and 14 patients were surgical TON patients. The visual acuity showed significant decrease in traumatic eyes at the first visit after injury compared to fellow eyes and maintained the injured status during the 1-year follow-up period in blunt TON. In surgical TON, the visual acuity slightly improved during 1 month follow-up period. RNFL thickness tended to be decreased at 1 month after first visit blunt TON patients, which was earlier than surgical TON patients. GCIPL thickness showed earlier decreased than RNFL thickness in both blunt and surgical TON patients. Conclusions In both blunt and surgical TON eyes, there was a notable thinning in both RNFL and GCIPL, with particularly remarkable reduction in GCIPL in early phase. Therefore, analyzing each retinal layer thickness using OCT in conjunction with assessing visual function would be necessary. This combined approach is not only crucial for understanding clinical courses of each TON, but also predicting the morphological and functional deteriorations in TON.

ObjectiveTo investigate the confounding effect of nonexudative age-related macular degeneration (AMD), specifically drusen and outer retinal atrophy, on the architecture and automated segmentation of the inner retinal layers as measured with OCT.DesignObservational cross-sectional study.SubjectsTwo hundred sixty-three consecutive eyes with nonexudative AMD were identified through a retrospective chart review. Exclusion criteria were a diagnosis of glaucoma or glaucoma suspect, other retinal pathology affecting the macula, axial length > 26.5 mm or spherical equivalent less than -6 diopters, any other optic nerve or neurologic disorders, or poor image quality.MethodsDrusen were automatically segmented on macular OCT B-scans with a publicly available and validated deep learning approach. Automated segmentation of the inner plexiform layer (IPL)/inner nuclear layer (INL) boundary was carried out with the device's proprietary software.Main outcome measuresQuality of segmentation of the IPL/INL boundary as a function of drusen size and presence of inner retinal layer displacement in the area of macular pathology (drusen or atrophy).ResultsOne hundred twenty-five eyes (65 patients) met the inclusion criteria. Drusen size varied between 16 and 272 μm (mean, 118 μm). Automated segmentation had a 22% chance of failure if the drusen height was between 145 and 185 μm and was most likely to fail with drusen heights above 185 μm. When drusen height was normalized by total retinal thickness, segmentation failed 36% of the time when the drusen to total retinal thickness ratio was 0.45 or above. Images were likely to show displacement of inner retinal layers with drusen heights above 176 μm and a normalized drusen height ratio of 0.5 or higher. Eighty-seven percent of images with outer retinal atrophy displayed incorrect segmentation.ConclusionsOuter retinal diseases can alter the retinal topography and affect the segmentation accuracy of the inner retinal layers. Large drusen may cause segmentation error and compression of the inner macular layers. Geographic atrophy confounds automated segmentation in a high proportion of eyes. Clinicians should be cognizant of the effects of outer retinal disease on the inner retinal layer measurements when interpreting the results of macular OCT imaging in patients with glaucoma.

Copyright of Die Ophthalmologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Multiple factors regulate the differentiation of neuronal morphology during development, including interactions with afferents, targets, and homotypic neighbors, as well as cell-intrinsic transcriptional regulation. Retinal bipolar cells provide an exemplary model system for studying the control of these processes, as there are 15 transcriptionally and morphologically distinct types, each extending their dendritic and axonal arbors in respective strata within the synaptic layers of the retina. Here we have examined the role of the transcription factor Sox5 in the control of the morphological differentiation of one type of cone bipolar cell (CBC), the Type 7 cell. We confirm selective expression of SOX5 in this single bipolar cell type, emerging at the close of the first post-natal week, prior to morphological differentiation. Conditional knockout mice were generated by crossing a bipolar cell-specific cre-expressing line with mice carrying floxed Sox5 alleles, as well as the Gustducin-gfp reporter which labels Type 7 CBCs. Loss of SOX5 was confirmed in the bipolar cell stratum, in GFP+ Type 7 cells. Such SOX5-deficient Type 7 cells differentiate axonal and dendritic arbors that are each reduced in areal extent. The axonal arbors exhibit sprouting in the inner plexiform layer (IPL), thereby extending their overall radial extent, while the dendritic arbors connect with fewer cone pedicles in the outer plexiform layer, showing an increase in the average number of dendritic contacts at each pedicle. SOX5-deficient Type 7 CBCs should therefore exhibit smaller receptive fields derived from fewer if now hyper-innervated pedicles, transmitting their signals across a broader depth through the IPL.

Optical coherence tomography (OCT) is a non-invasive imaging technique based on the principle of low-coherence interferometry that captures detailed images of ocular structures. Multiple sclerosis (MS) is a neurodegenerative disease that can lead to damage of the optic nerve and retina, which can be depicted by OCT. The purpose of this pilot study is to determine whether macular OCT can be used as a biomarker in the detection of retrochiasmal lesions of the visual pathway in MS patients. We conducted a prospective study in which we included 52 MS patients and 27 healthy controls. All participants underwent brain MRI, visual field testing, and OCT evaluation of the thicknesses of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer (GCL), and macular inner plexiform layer (IPL). OCT measurements were adjusted for optic neuritis (ON). VF demonstrated poor capability to depict a retrochiasmal lesion identified by brain MRI (PPV 0.50). In conclusion, the OCT analysis of the macula appears to excel in identifying retrochiasmal MS lesions compared to VF changes. The alterations in the GCL and IPL demonstrate the most accurate detection of retrochiasmal visual pathway changes in MS patients.

Purpose: to assess the tomographic retinal layers' thickness in eyes affected by branch retinal artery occlusion (BRAO) and to compare it to those of patients affected by primary open angle glaucoma (POAG). Methods: retrospective review of 27 patients; 16 with BRAO (16 eyes) and 11 with POAG (20 eyes) were identified among those who received SD-OCT scans, including analysis of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), neuroretinal rim (NRR), circumpapillary RNFL at 3.5 mm and hemisphere asymmetry (HA). Results: the total IPL and INL thinning difference between the two groups was statistically significant (p = 0.0067 and p < 0.0001, respectively). The HA difference for the total macular thinning, mRNFL, GCL, IPL and INL (p < 0.0001) was also statistically significant. The analysis of the average total retinal thinning, total mRNFL and GCL thinning showed no statistically significant difference between the two groups. Conclusions: unilateral inner retinal thinning may represent a sign of temporal BRAO, particularly for INL thinning and HA difference over 17µm in total retinal layer thinning. This information is particularly useful in the diagnosis of previous, undiagnosed BRAO and may help prevent further retinal arterial occlusion and possible cerebrovascular incidents. [ABSTRACT FROM AUTHOR]

INTRODUCTION: We investigated the correlation between retinal thickness and optic tract integrity in subjects with autosomal dominant Alzheimer's disease (ADAD) causing mutations. METHODS: Retinal thicknesses and diffusion tensor images (DTI) were obtained using optical coherence tomography and magnetic resonance imaging, respectively. The association between retinal thickness and DTI measures was adjusted for age, sex, retinotopy, and correlation between eyes. RESULTS: Optic tract mean diffusivity and axial diffusivity were negatively correlated with retinotopically defined ganglion cell inner plexiform thickness (GCIPL). Fractional anisotropy was negatively correlated with retinotopically defined retinal nerve fiber layer thickness. There was no correlation between outer nuclear layer (ONL) thickness and any DTI measure. DISCUSSION: In ADAD, GCIPL thickness is significantly associated with retinotopic optic tract DTI measures even in minimally symptomatic subjects. Similar associations were not present with ONL thickness or when ignoring retinotopy. We provide in vivo evidence for optic tract changes resulting from ganglion cell pathology in ADAD. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between macular nerve fiber layer (mNFL), ganglion cell layer (mGCL), and inner plexiform layer (mIPL) thickness values obtained by spectral domain optical coherence tomography (SD-OCT) segmentation analysis and visual field (VF) mean deviation (MD) values in cases with primary open-angle glaucoma (POAG). Materials and Methods: mNFL, mGCL, and mIPL thickness measurements were performed by SD-OCT in 25 eyes of 25 POAG patients whose intraocular pressures were under medical control. The correlation between the thickness of each segmented layer and VF MD was analyzed by Pearson correlation analysis. Results: The mean age of the patients was 69±9, and the mean VF MD was -8.09±8.21 dB. The mean mNFL thickness was 27.86±4.81 µ, the mean mGCL thickness was 38.12±6.57 µ, and the mean mIPL thickness was 32.09±4.59 µm. Significant positive correlation was found between VF MD and mNFL (r=0.658, p=0.0003), VF MD and mIPL thickness (r=0.718, p=0.00005), and VF MD and mGCL (r=0.789, p<0.00001). Discussion: Strong positive correlations were found between mNFL thickness, mIPL thickness, and mGCL thickness values and VF MD values in the present study. Especially, the changes in IPL that represent dendritic interactions can open new horizons in developing new structural test strategies for early diagnosis of POAG in larger patient populations, when examined longitudinally. [ABSTRACT FROM AUTHOR]

Aim: To assess the thickness of the choroidal layer, inner plexiform layer (IPL), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL) in individuals with attention-deficit/hyperactivity disorder (ADHD). Material and Methods: In this retrospective study, we used a spectral optical coherence tomography (OCT) device. The CPRS-48 was performed to the ADHD group. Results: Both groups consisted of 60 subjects. There were significant differences in NS segment of RNFL (right p=0.039; left p=0.035). The mean right choroidal thickness of ADHD group was significantly lower than the control group (p=0.015). The left GCL and IPL volumes of ADHD group were significantly lower than the control group (p<0.05). In ADHD group, a significant correlation was found between right choroid and opposition (r=0.278, p<0.05) and conduct (r=0.373, p<0.01) subscales of CPRS-48; between age and right choroid (r=0.248, p<0.05). In control group, a significant correlation was found between age and right NS (r=-0.370, p<0.05), right TS (r=-0.381, p<0.05), right mean RNFL (r=-0.352, p<0.05), left NS (r=-0.397, p<0.05), right choroid (r=0.422, p<0.01), left choroid (r=0.443, p<0.01), right GCL (r=0.425, p<0.01), right IPL (r=0.446, p<0.01). Conclusion: This study demonstrated that there is an association between disorder severity, duration of disorder, choroidal layer thickness, GCL, IPL and ADHD. [ABSTRACT FROM AUTHOR]

From the bipolar cells to higher brain visual centers, signals in the vertebrate visual system are transmitted along parallel on and off pathways. These two pathways are spatially segregated along the depth axis of the retina. Yet, to our knowledge, there is no way to directly assess this anatomical stratification in vivo. Here, employing ultrahigh resolution visible light Optical Coherence Tomography (OCT) imaging in humans, we report a stereotyped reflectivity pattern of the inner plexiform layer (IPL) that parallels IPL stratification. We characterize the topography of this reflectivity pattern non-invasively in a cohort of normal, young adult human subjects. This proposed correlate of IPL stratification is accessible through non-invasive ocular imaging in living humans. Topographic variations should be carefully considered when designing studies in development or diseases of the visual system.

IntroductionCongenital X-linked retinoschisis (XLRS) presents as macular retinoschisis/degeneration in almost all patients and as peripheral retinoschisis in half the patients. Although the optical coherence tomography (OCT) findings of macular retinoschisis have been well investigated, those of peripheral retinoschisis have rarely been reported. This study aimed to report the ultra-widefield OCT findings of the peripheral retina in patients with XLRS.MethodsMedical records of 10 Japanese patients (19 eyes) with clinically and/or genetically diagnosed XLRS were retrospectively reviewed. Funduscopic, electroretinographic, and OCT findings were reviewed and evaluated. Some were also genetically evaluated for the RS1 gene.ResultsOCT of the macula revealed schises and/or cystoid changes in the inner nuclear layer (INL) and outer nuclear layer. In contrast, OCT of the peripheral retina revealed schises and/or cystoid changes in the INL in eight eyes (44%), and/or splitting in the ganglion cell layer (GCL) in 10 (56%) of the 18 eyes with clear OCT images. No schisis or cystoid changes were found in the peripheral OCT images of eight eyes (44%). A 16-year-old boy presented with retinal splitting of the GCL and INL of the inferior retina, although he had no ophthalmoscopic peripheral retinoschisis. Genetic examinations were performed on three patients, all of whom had reported missense mutations in the RS1 gene.ConclusionIn XLRS, peripheral bullous retinoschisis results from GCL splitting in the retina. One of the 10 patients with XLRS showed intraretinal retinoschisis in the GCL in the inferior periphery, which was unremarkable on ophthalmoscopy (occult retinoschisis). Although both peripheral bullous retinoschisis and occult retinoschisis showed splitting/cystic changes in the GCL, further studies are needed to determine whether occult retinoschisis progresses to bullous retinoschisis.

Birds have a well‐developed retinopetal system projecting from the midbrain to the contralateral retina. The signal sent to the retina through the retinopetal system facilitates visual responses of the retinal ganglion cells (RGCs), and the retinopetal signals function as attentional signals during visual search. Thus, the retinopetal signal somehow reaches and facilitates visual responses of the RGCs. However, the tertiary neuron of the retinopetal system, the isthmo‐optic target cell (IOTC), is unlikely to contact most RGCs directly, because the IOTCs form axon terminals localized in the outermost sublayer (lamina 1) of the inner plexiform layer (IPL) where few RGC dendrites terminate. Therefore, some other intrinsic retinal neurons must be involved in the centrifugal attentional enhancement of visual responses of the RGCs. We investigated connections of the target cells of the IOTCs in chicken and quail, using light and electron microscopic immunohistochemistry. We show that axon terminals of the IOTC make synaptic contacts with protein kinase Cα (PKCα)‐immunoreactive (ir) bipolar cells (PKCα‐BCs) in lamina 1 of the IPL. Furthermore, with prolonged electrical stimulation of the isthmo‐optic nucleus (ION) on one side, whose neurons send their axons to the contralateral retina and make synaptic contacts there with IOTCs, phosphorylation of cAMP response element‐binding protein was observed in the PKCα‐BCs in the contralateral retina, but not in the ipsilateral retina. This suggests that electrical stimulation of ION activated PKCα‐BCs through synapses from IOTCs to PKCα‐BCs, thus stimulating transcription in PKCα‐BCs. Thus, centrifugal attentional signals may facilitate visual responses of RGCs via the PKCα‐BCs. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the macular spectral domain optical coherence tomography (SD-OCT) measurements of the segmented inner retinal layers in patients with exfoliation syndrome (XFS), exfoliation glaucoma (XFG). Methods: This prospective cross-sectional study included 28 eyes with XFS, 47 eyes with XFG, and 29 healthy controls. Thickness of the inner retinal layers, including retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) was obtained from the horizontal SD-OCT scans. Functional correlation of structural parameters was analyzed using the mean sensitivity (MS) values on 10–2 visual fields. Results: The RNFL, GCL, and IPL were thinnest in eyes with XFG. Among these retinal layers, IPL was significantly thinner in eyes with XFS than healthy controls (p = 0.02) and the IPL thickness was significantly correlated with the corresponding MS scores on 10–2 visual fields (r = 0.492, p = 0.02) in eyes with XFS. Neither GCL nor RNFL thickness values demonstrated significant correlations with functional parameters in eyes with XFS (r = 0.377, p = 0.08; r = 0.212, p = 0.34). In eyes with XFG, the IPL thickness correlated with the visual field MS scores (r = 0.572, p = 0.0007), similar to the correlation of GCL (r = 0.585, p = 0.0005) thickness with visual field scores. Conclusions: Segmented analysis of the macular IPL thickness presented a significant correlation with the 10–2 visual field scores not only in eyes with XFG but also in eyes with XFS. With respect to early dendritic/synaptic alterations in animal models, larger and longitudinal studies are encouraged to determine the predictive value of the IPL thickness for conversion of XFS to XFG. [ABSTRACT FROM AUTHOR]

Abstract Quantifying the smoothness of different layers of the retina can potentially be an important and practical biomarker in various pathologic conditions like diabetic retinopathy. The purpose of this study is to develop an automated machine learning algorithm which uses support vector regression method with wavelet kernel and automatically segments two hyperreflective retinal layers (inner plexiform layer (IPL) and outer plexiform layer (OPL)) in 50 optical coherence tomography (OCT) slabs and calculates the smoothness index (SI). The Bland–Altman plots, mean absolute error, root mean square error and signed error calculations revealed a modest discrepancy between the manual approach, used as the ground truth, and the corresponding automated segmentation of IPL/ OPL, as well as SI measurements in OCT slabs. It was concluded that the constructed algorithm may be employed as a reliable, rapid and convenient approach for segmenting IPL/OPL and calculating SI in the appropriate layers.

The aim of this study was to evaluate the qualitative and quantitative differences between 20 and 85 kHz A-scan rate optical coherence tomography (OCT) images acquired by spectral domain OCT. The study included 60 healthy subjects analyzed with horizontal linear scans with a variable A-scan rate (SHIFT technology, Heidelberg Engineering, Heidelberg, Germany). The retinal thickness measurement of each retinal layer was performed in three different positions (subfoveal, nasal, and temporal). The qualitative assessment was performed by two independent observers who rated every image with a score ranging from 1 ("sufficient") to 3 ("excellent") on the basis of three parameters: visualization of the vitreo-retinal interface, characterization of the retinal layers, and visualization of the sclero-choroidal interface. No statistically significant differences in terms of retinal layer thickness between the two A-scan rate scans were observed (p > 0.05). The coefficient of variation of the retinal thickness values was lower in the 20 kHz group (25.8% versus 30.1% with the 85 kHz). The 20 kHz images showed a higher quality index for both observers. An inner plexiform layer (IPL) multilaminarity was detected in 78.3% of patients from the 20 kHz group and in 40% of patients from the 85 kHz group (p < 0.05). [ABSTRACT FROM AUTHOR]

Quantifying the smoothness of different layers of the retina can potentially be an important and practical biomarker in various pathologic conditions like diabetic retinopathy. The purpose of this study is to develop an automated machine learning algorithm which uses support vector regression method with wavelet kernel and automatically segments two hyperreflective retinal layers (inner plexiform layer (IPL) and outer plexiform layer (OPL)) in 50 optical coherence tomography (OCT) slabs and calculates the smoothness index (SI). The Bland–Altman plots, mean absolute error, root mean square error and signed error calculations revealed a modest discrepancy between the manual approach, used as the ground truth, and the corresponding automated segmentation of IPL/ OPL, as well as SI measurements in OCT slabs. It was concluded that the constructed algorithm may be employed as a reliable, rapid and convenient approach for segmenting IPL/OPL and calculating SI in the appropriate layers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: to assess the tomographic retinal layers’ thickness in eyes affected by branch retinal artery occlusion (BRAO) and to compare it to those of patients affected by primary open angle glaucoma (POAG). Methods: retrospective review of 27 patients; 16 with BRAO (16 eyes) and 11 with POAG (20 eyes) were identified among those who received SD-OCT scans, including analysis of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), neuroretinal rim (NRR), circumpapillary RNFL at 3.5 mm and hemisphere asymmetry (HA). Results: the total IPL and INL thinning difference between the two groups was statistically significant (p = 0.0067 and p < 0.0001, respectively). The HA difference for the total macular thinning, mRNFL, GCL, IPL and INL (p < 0.0001) was also statistically significant. The analysis of the average total retinal thinning, total mRNFL and GCL thinning showed no statistically significant difference between the two groups. Conclusions: unilateral inner retinal thinning may represent a sign of temporal BRAO, particularly for INL thinning and HA difference over 17µm in total retinal layer thinning. This information is particularly useful in the diagnosis of previous, undiagnosed BRAO and may help prevent further retinal arterial occlusion and possible cerebrovascular incidents.

Purpose: Graves' orbitopathy (GO) is an inflammatory process that may involve the ocular surface, orbital fat, extraocular muscles, and optic nerves in patients with Graves' disease (GD). We aimed to compare thicknesses of retinal layers in patients with GD with and without GO. Methods: One hundred seven patients with GD [23 with GO (Group 1), 84 without GO (Group 2)] and eighteen volunteers (Group 3) were enrolled. The spectral-domain optical coherence tomography (SD-OCT) was used for ophthalmologic evaluation. Seven retinal layers including retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium (RPE) were assessed. The thicknesses of layers were compared in groups. Results: The median GCL thickness values in groups 1, 2, and 3 were 14 µm, 15 µm, and 17.5 µm, respectively (p = 0.02). The median IPL thickness was 20 µm in group 1, 21 µm in group 2, and 22 µm in group 3 (p = 0.038). The median RPE thickness values in groups 1, 2, and 3 were 16 µm, 17 µm, and 18.5 µm, respectively (p = 0.001). GCL in group 1 was thinner than in group 3 (p = 0.02), while similar in groups 2 and 3 (p = 0.06). IPL in group 1 was thinner than in group 3 (p = 0.035), while similar in groups 2 and 3 (p = 0.13). RPE in groups 1 and 2 was thinner than in group 3 (p = 0.009, p = 0.001, respectively), while it was similar in groups 1 and 2 (p = 0.93). RNLF, INL, OPL, ONL were similar in all three (p > 0.05 for each). Conclusion: Ganglion cell layer and IPL were thinner in patients with GO than in healthy controls, while both were similar in patients without GO and healthy controls. RPE was thinner in all Graves patients than in healthy controls. Early detection of changes in retinal layers of GD may guide the physician to prevent significant vision problems. [ABSTRACT FROM AUTHOR]

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Purpose: To compare the thickness of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and choroid in healthy electronic cigarette smokers and non-smokers using spectral domain optical coherence tomography (SD-OCT)., Material and Method: 25 healthy electronic cigarette smokers and 25 age- and gender-matched healthy non-smokers were included in the study. RNFL, GCL, IPL and choroidal thickness were measured by SD-OCT using an automated programme. After normality tests, an independent sample t -test was used to analyse the differences in RNFL, GCL, IPL, and choroidal thickness values between the groups., Results: The mean age of electronic cigarette smokers and non-smokers was 33.68 and 33.64 years, respectively. The mean smoking history was 6.6 years (range 5-8 years). Most of the participants smoked 2-5 ml of e-liquid per day (52%), while 36% smoked more than 5 ml and 12% smoked less than 2 ml per day. The mean intraocular pressure in the electronic cigarette smoker group was 15.0 mmHg, while the non-smoker group was 15.32 mmHg. The mean axial length in the electronic cigarette smoker group and non-smoker group was 23.36 and 23.63 mm, respectively. No significant difference was observed regarding RNFL, GCL, IPL or choroidal thickness between both groups., Conclusion: The thickness of the RNFL, GCL, IPL, and choroid was found to be similar in both the healthy electronic cigarette smokers and non-smokers groups.

Background/objectivesCo-existing idiopathic epiretinal membrane (ERM) and glaucoma complicate the estimation of glaucoma severity via optical coherence tomography (OCT). We investigated the effect of ERM and a new associated parameter, SUKIMA (space between the ERM and retinal surface), on ganglion cell complex (GCC) thickness in eyes with glaucoma, based on a matched comparison of visual field defects.Subjects/methodsWe retrospectively recruited 41 eyes from 34 glaucoma patients with idiopathic ERM and 41 eyes from 41 glaucoma patients without ERM as controls (matched by age, axial length, and mean visual field deviation). The thicknesses of GCC layers [retinal nerve fiber layer (RNFL), ganglion cell layer + inner plexiform layer (GCIPL), and GCC (RNFL + GCIPL)] were measured with swept-source OCT. We investigated the presence of SUKIMA and its effect on GCC measurements.ResultsRNFL, GCIPL, and GCC were thicker in ERM (+) eyes than in control eyes (31.0 ± 12.3 μm vs. 22.7 ± 10.8 μm, 62.6 ± 12.2 μm vs. 53.8 ± 5.9 μm, and 91.8 ± 16.6 μm vs. 76.8 ± 13.3 μm, respectively; P < 0.01). Eyes in the ERM-associated SUKIMA (+) group had thicker GCIPL and GCC than those in the ERM-associated SUKIMA (−) and control groups (P < 0.01).ConclusionERM-associated SUKIMA affects GCC thickness and can result in underestimations of glaucoma severity. We should check for the presence of ERM using a B mode scan as well as check for the SKIMA sign.

Multiple factors regulate the differentiation of neuronal morphology during development, including interactions with afferents, targets, and homotypic neighbors, as well as cell-intrinsic transcriptional regulation. Retinal bipolar cells provide an exemplary model system for studying the control of these processes, as there are 15 transcriptionally and morphologically distinct types, each extending their dendritic and axonal arbors in respective strata within the synaptic layers of the retina. Here we have examined the role of the transcription factor Sox5 in the control of the morphological differentiation of one type of cone bipolar cell (CBC), the Type 7 cell. We confirm selective expression of SOX5 in this single bipolar cell type, emerging at the close of the first post-natal week, prior to morphological differentiation. Conditional knockout mice were generated by crossing a bipolar cell-specific cre-expressing line with mice carrying floxed Sox5 alleles, as well as the Gustducin-gfp reporter which labels Type 7 CBCs. Loss of SOX5 was confirmed in the bipolar cell stratum, in GFP+ Type 7 cells. Such SOX5-deficient Type 7 cells differentiate axonal and dendritic arbors that are each reduced in areal extent. The axonal arbors exhibit sprouting in the inner plexiform layer (IPL), thereby extending their overall radial extent, while the dendritic arbors connect with fewer cone pedicles in the outer plexiform layer, showing an increase in the average number of dendritic contacts at each pedicle. SOX5-deficient Type 7 CBCs should therefore exhibit smaller receptive fields derived from fewer if now hyper-innervated pedicles, transmitting their signals across a broader depth through the IPL.

Non-invasive spatially resolved functional imaging in the human retina has recently attracted considerable attention. Particularly functional imaging of bipolar and ganglion cells could aid in studying neuronal activity in humans, including an investigation of processes of the central nervous system. Recently, we imaged the activity of the inner neuronal layers by measuring nanometer-size changes of the cells within the inner plexiform layer (IPL) using phase-sensitive optical coherence tomography (OCT). In the IPL, there are connections between the neuronal cells that are dedicated to the processing of different aspects of the visual information, such as edges in the image or temporal changes. Still, so far, it was not possible to assign functional changes to single cells or cell classes in living humans, which is essential for studying the vision process. One characteristic of signal processing in the IPL is that different aspects of the visual impression are only processed in specific sub-layers (strata). Here, we present an investigation of these functional signals for three different sub-layers in the IPL with the aim to separate different properties of the visual signal processing. Whereas the inner depth-layer, closest to the ganglion cells, exhibits an increase in the optical path length, the outer depth-layer, closest to the bipolar cell layer, exhibits a decrease in the optical path length. Additionally, we found that the central depth is sensitive to temporal changes, showing a maximum response at a stimulation frequency of around 12.5 Hz. The results demonstrate that the signals from different cell types can be distinguished by phase-sensitive OCT.

Mouna Al Saad, Amin Shehadeh, Jehad Meqbil, Khaled Elubous, Mohammed Qablawi, Nakhleh Abu-Yaghi Department of Special Surgery/Ophthalmology Division, School of Medicine, The University of Jordan, Amman, JordanCorrespondence: Mouna Al SaadDepartment of Special Surgery/Ophthalmology Division, School of Medicine, The University of Jordan, Queen Rania Street, P.O Box 113301, Amman, 11942, JordanTel +962 797793018Email eye_maas@yahoo.comPurpose: To determine the relationship between central corneal thickness (CCT), ganglionic cell-inner plexiform layer thickness and macular nerve fibre layer (RNFL) thickness as measured by optical coherence tomography in a cohort of healthy subjects.Methods: Sixty healthy eyes from 60 subjects were included in this study. All subjects had a standard slit-lamp examination and optical coherence tomography. Central corneal thickness was measured using the Optopol spectral domain optical coherence tomography (SD OCT) machine (version 7.2.0). A linear mixed effects model was used to assess the relationship between central corneal thickness (CCT) and ganglionic cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness (RNFL).Results: Sixty healthy eyes from 60 subjects were included in this study. The average age was 41.8 years (± 20.6 years). There were 22 males (37%) and 38 females (63%). The average central corneal thickness was 525.2 ± 35.1 μm (451– 601) μm. The average macular retinal nerve fiber layer thickness was 28.9 ± 2.5 μm (23– 38μm), and the average ganglionic cell-inner plexiform layer thickness was 88.6 ± 6.3 μm (75– 110 μm). We found no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness (p=0.983) nor with macular RNFL (p =0.285).Conclusion: In this cohort of healthy subjects, there was no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness or with macular retinal nerve fibre layer thickness.Keywords: central corneal thickness, ganglion cell layer, inner plexiform layer, optical coherence tomography

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.

Purpose: To examine retinal and choroidal thicknesses in individuals with obstructive sleep apnea (OSA) and determine the impacts of continuous positive airway pressure (CPAP) treatment. Methods: Prospective follow-up study conducted at a university hospital. 40 patients with OSA, 28 treated with CPAP, and 12 untreated, were enrolled immediately after diagnosis and graded according to the apnea hypopnea index (AHI) determined in an overnight polysomnography. Inclusion criteria were a new diagnosis of OSA and CPAP indicated. Participants underwent a full ophthalmologic examination including optical coherence tomography (OCT) at the peripapillary, macular, and choroidal levels and the same examination 3 months later. Outcome measures were peripapillary retinal nerve fiber layer (RNFL), total retinal (TRT), retinal ganglion cell layer (RGCL), inner plexiform layer (IPL), photoreceptor layer (PL), and choroidal thicknesses. Results: At 3 months, RGCL thickness was reduced at the inner nasal macula segment in the no-CPAP group (P = 0.016). In + CPAP, increases were produced in RNFL thickness (5/6 segments) and TRT (7/ 9 segments), while choroidal thinning was observed temporally (P = 0.003). At baseline, positive correlation was detected between choroidal thickness and AHI (r = 0.352, P = 0.005) and between IPL thickness (7/9 segments) and AHI (r = 0.414, P < 0.001). Conclusions: Initial retinal and choroidal thickening was followed by RGCL thinning over 3 months. In patients receiving CPAP, we observed no thinning of any retinal layer and normalization of choroidal thickness. [ABSTRACT FROM AUTHOR]

Introduction: Retinal nerve fiber layer thickness has been used for monitoring of disease activity in patients with multiple sclerosis (MS). Macular ganglion cell complex (GCC) layer of retina also can be measured by OCT and has been suggested as a potential biomarker in MS. In this study we investigated the macular GCC and its role as a potential biomarker in patients with Multiple Sclerosis (MS). Methods: A prospective cohort-study, subjects consisted of Relapsing-Remitting MS patients (n=62) and healthy controls (n=60). Eyes of MS patients were divided into two subgroups according to the history of the optic neuritis (ON). Standard peripapillary-RNFL and macular scan protocol, and retinal auto-segmentation of spectral-domain OCT were performed. Macular RNFL (mRNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL), and GCC (the sum of these former three layers) were recorded. The macula was divided into nine sectors using the ETDRS grid (4x9=36 variables). Results: In total, 50 eyes of 36 patients had previous ON attacks. 35/36 GCC parameters were thinner in MS patients and subgroups compared to the control group (p<0.05). When the eyes with and without a history of optic neuritis were compared, 25 of 36 parameters were thinner in those with ON. There were strong correlations between visual acuity-GCC parameters and EDSS scores in patients with a history of optic neuritis. However, no such relationship was found in those without an ON story. Conclusion: Ganglion cell complex gets thinner in patients with MS with a decreasing order of GCL, IPL, and mRNFL. The examination of GCC in detail could be a beneficial biomarker for MS. [ABSTRACT FROM AUTHOR]

From the bipolar cells to higher brain visual centers, signals in the vertebrate visual system are transmitted along parallel on and off pathways. These two pathways are spatially segregated along the depth axis of the retina. Yet, to our knowledge, there is no way to directly assess this anatomical stratification in vivo. Here, employing ultrahigh resolution visible light Optical Coherence Tomography (OCT) imaging in humans, we report a stereotyped reflectivity pattern of the inner plexiform layer (IPL) that parallels IPL stratification. We characterize the topography of this reflectivity pattern non-invasively in a cohort of normal, young adult human subjects. This proposed correlate of IPL stratification is accessible through non-invasive ocular imaging in living humans. Topographic variations should be carefully considered when designing studies in development or diseases of the visual system.

Purpose: To determine the relationship between central corneal thickness (CCT), ganglionic cell-inner plexiform layer thickness and macular nerve fibre layer (RNFL) thickness as measured by optical coherence tomography in a cohort of healthy subjects. Methods: Sixty healthy eyes from 60 subjects were included in this study. All subjects had a standard slit-lamp examination and optical coherence tomography. Central corneal thickness was measured using the Optopol spectral domain optical coherence tomography (SD OCT) machine (version 7.2.0). A linear mixed effects model was used to assess the relationship between central corneal thickness (CCT) and ganglionic cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness (RNFL). Results: Sixty healthy eyes from 60 subjects were included in this study. The average age was 41.8 years (± 20.6 years). There were 22 males (37%) and 38 females (63%). The average central corneal thickness was 525.2 ± 35.1 μm (451– 601) μm. The average macular retinal nerve fiber layer thickness was 28.9 ± 2.5 μm (23– 38μm), and the average ganglionic cell-inner plexiform layer thickness was 88.6 ± 6.3 μm (75– 110 μm). We found no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness (p=0.983) nor with macular RNFL (p =0.285). Conclusion: In this cohort of healthy subjects, there was no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness or with macular retinal nerve fibre layer thickness. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare all retinal layers' thickness in full-term and preterm children without retinopathy of prematurity (ROP). Methods: Cross-sectional study including two groups of patients: group 1 children with history of preterm gestation without ROP (gestational age < 37 weeks) and group 2 healthy children with history of full-term gestation. All subjects underwent an ophthalmic examination including spectral domain-optical coherence tomography. After automatic retinal segmentation, each retinal layer thickness (eight separate layers and overall thickness) was calculated in all nine Early Treatment Diabetic Retinopathy Study areas. Demographic, systemic, gestational, and birth data were collected. Generalized additive regression models were used to analyze the data. Results: Fifty-one children (51 eyes) were recruited, 19 full-term and 32 preterm children, mean age at ophthalmic examination of 10.58 (4.21) and 14.13 (3.16), respectively. In multivariable analysis, the preterm group's retinal thickness was significantly decreased in total retina nasal outer sector, ganglion cell layer (GCL), and inner plexiform layer (IPL), specifically GCL temporal outer (p = 0.010), GCL superior outer (p = 0.009), IPL temporal outer (p = 0.022), and IPL superior outer (p = 0.004), when compared with full-term group. From the variables compared only with birth head circumference that influenced the models, a non-linear association was identified and consequently modeled with splines through a generalized additive model. Conclusion: This study suggests that preterm children without ROP have structural retinal alterations, mostly in GCL and IPL in outer areas of the macula. Therefore, it is crucial to question gestational history since these retinal changes may be found later in life leading to useless investigation. [ABSTRACT FROM AUTHOR]

Retinal ganglion cells (RGCs) convey visual signals to 50 regions of the brain. For reasons of interest and convenience, they constitute an excellent system for the study of brain structure and function. There is general agreement that, absent a complete "parts list," understanding how the nervous system processes information will remain an elusive goal. Recent studies indicate that there are 30–50 types of ganglion cell in mouse retina, whereas only a few years ago it was still written that mice and the more visually oriented lagomorphs had less than 20 types of RGC. More than 30 years ago, I estimated that rabbits have about 40 types of RGC. The present study indicates that this number is much too low. I have employed the old but powerful method of Golgi‐impregnation to rabbit retina, studying the range of component neurons in this already well‐studied retinal system. Close quantitative and qualitative analyses of 1,142 RGCs in 26 retinas take into account cell body and dendritic field size, level(s) of dendritic stratification in the retina's inner plexiform layer, and details of dendritic branching. Ninety‐one morphologies are recognized. Of these, at least 32 can be correlated with physiologically studied RGCs, dye‐injected for morphological analysis. It is unlikely that rabbits have 91 types of RGC, but is argued here that this number lies between 60 and 70. The present study provides a "yardstick" for measuring the output of future molecular studies that may be more definitive in fixing the number of RGC types in rabbit retina. [ABSTRACT FROM AUTHOR]

Retinal ganglion cells (RGCs) are the only output neurons of the vertebrate retina, integrating signals from other retinal neurons and transmitting information to the visual centers of the brain. The death of RGCs is a common outcome in many optic neuropathies, such as glaucoma, demyelinating optic neuritis and ischemic optic neuropathy, resulting in visual defects and blindness. There are currently no therapies in clinical use which can prevent RGC death in optic neuropathies; therefore, the identification of new targets for supporting RGC survival is crucial in the development of novel treatments for eye diseases. In this study we identify that the receptor tyrosine kinase, Tyro3, is critical for normal neuronal function in the adult mouse retina. The loss of Tyro3 results in a reduction in photoreceptor and RGC function as measured using electroretinography. The reduction in RGC function was associated with a thinner retinal nerve fiber layer and fewer RGCs. In the central retina, independent of the loss of RGCs, Tyro3 deficiency resulted in a dramatic reduction in the number of RGC dendrites in the inner plexiform layer. Our results show that Tyro3 has a novel, previously unidentified role in retinal function, RGC survival and RGC morphology. The Tyro3 pathway could therefore provide an alternative, targetable pathway for RGC protective therapeutics.

Retinal ganglion cells (RGCs) encrypt stimulus features of the visual scene in action potentials and convey them toward higher visual centers in the brain. Although there are many visual features to encode, our recent understanding is that the ~46 different functional subtypes of RGCs in the retina share this task. In this scheme, each RGC subtype establishes a separate, parallel signaling route for a specific visual feature (e.g., contrast, the direction of motion, luminosity), through which information is conveyed. The efficiency of encoding depends on several factors, including signal strength, adaptational levels, and the actual efficacy of the underlying retinal microcircuits. Upon collecting inputs across their respective receptive field, RGCs perform further analysis (e.g., summation, subtraction, weighting) before they generate the final output spike train, which itself is characterized by multiple different features, such as the number of spikes, the inter-spike intervals, response delay, and the rundown time (transience) of the response. These specific kinetic features are essential for target postsynaptic neurons in the brain in order to effectively decode and interpret signals, thereby forming visual perception. We review recent knowledge regarding circuit elements of the mammalian retina that participate in shaping RGC response transience for optimal visual signaling.

Purpose. Investigation of the influence of the axial length of the eye on the thickness of the ganglion cell-inner plexiform layer (GCIPL) and the development of methods for its evaluation in patients with myopia in the age of over 40 years.Material and methods. The study involved 53 patients (53 eyes) over the age of 40 years, with medium- and high-degree myopia, as well as 80 healthy subjects (80 eyes) of the same sex and age with emmetropia (control group). OCT was performed on a Cirrus HD-OCT device (Carl Zeiss Meditec).Results. To assess the influence of the optical magnification effect on the average thickness of the GCIPL, the authors and the programmer A.A. Evsukov created a computer program. The average thickness of the GCIPL in the control group was 79.0±5.3 (68-90) μm. In the group of patients with myopia, the GCIPL thickness was lower by an average of 5.1 μm (73.9±5.2, 64 to 86 μm, P

AIM: To detect the relationship between infusion pressure and postoperative ganglion cells function. METHODS: This prospective observational cohort study included sixty-one eyes that underwent uncomplicated cataract surgery. Patients were divided into two groups according to infusion time (IT) recorded using surgery equipment [Group A: IT>ITmean (27 eyes); Group B: IT

Background: Alzheimer's disease (AD) pathological hallmarks were found in retinas of AD patients. Several studies showed a significant reduction of neuro-retina thickness measured through optical coherence tomography (OCT) in AD patients, but possible correlations between retina morphology, cognition, and cerebrospinal fluid (CSF) AD biomarkers (Aβ42, t-tau, and p-tau) have been poorly investigated so far.Objective: In the present cross-sectional study, we measured the thickness of neuro-retinal layers through OCT searching for possible correlations with patients' cognitive performances and CSF AD biomarkers.Methods: 137 consecutive subjects [43 with AD, 37 with mild cognitive impairment (MCI), and 57 healthy controls (HC)], received an OCT scan acquisition to measure the peripapillary retinal nerve fiber layer (RNFL) thickness. In a subsample of 21 AD, 18 MCI, and 18 HC, the macular volume of ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer was computed. A comprehensive neuropsychological assessment and CSF AD biomarkers' concentrations were available in AD and MCI patients.Results: Peripapillary RNFL, global, and in superior quadrant was significantly thinner in AD and MCI patients when compared to HC, while macular GCL volume was significantly reduced only in AD. RNFL thickness in nasal and inferior quadrants was correlated with single CSF AD biomarker concentrations, but no differences were found in retina morphology depending on the presence of a CSF profile typical for AD. Memory performances were positively associated with GCL and IPL volume.Conclusion: Our findings might propose OCT as a reliable and easy to handle tool able to detect neuro-retinal atrophy in AD in relation with cognitive performances. [ABSTRACT FROM AUTHOR]

Alcohol and illicit drugs affect neurons through various mechanisms and are detected by neuroimaging techniques. The optical coherence tomography device has just been used in research on substance use disorders. In this study, we compared the retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL), the inner plexiform layer (IPL), and choroid layer of alcohol use disorder (AUD) and healthy subjects. We included 38 male patients and 38 male healthy controls of similar age (p =.714) in the study, prospectively. Monthly income (p =.001) and stable employment (p =.001) were lower in the patient group. There was a significant difference between patient and control groups in terms of RNFL sectors, choroid, GCL, IPL values of both eyes were significantly different (p <.05). When the effect of age and liver damage was controlled in the patient group, a correlation was found between alcohol unit/year and nasal superior (r = –0.474, p =.004), temporal (r = –0.402, p =.015) sectors of the RNFL. The regression analysis indicated that the sensitivity and specificity of mean N (p =.060), mean choroidal thickness (p <.001), mean GCL (p =.013), and mean IPL (p =.017) related to the diagnosis of AUD were 78.9% and 81.6% (-2 Log likelihood = 57.57, Nagelkerke R2=0.622), respectively. Alcohol has neurotoxic effects, either directly or indirectly, with withdrawal. Our study results suggest that RNFL, the non-myelinated white matter tissue, can be a follow-up marker of neuronal damage due to cumulative alcohol intake. [ABSTRACT FROM AUTHOR]

Retinal ganglion cells (RGCs) are the only output neurons of the vertebrate retina, integrating signals from other retinal neurons and transmitting information to the visual centers of the brain. The death of RGCs is a common outcome in many optic neuropathies, such as glaucoma, demyelinating optic neuritis and ischemic optic neuropathy, resulting in visual defects and blindness. There are currently no therapies in clinical use which can prevent RGC death in optic neuropathies; therefore, the identification of new targets for supporting RGC survival is crucial in the development of novel treatments for eye diseases. In this study we identify that the receptor tyrosine kinase, Tyro3, is critical for normal neuronal function in the adult mouse retina. The loss of Tyro3 results in a reduction in photoreceptor and RGC function as measured using electroretinography. The reduction in RGC function was associated with a thinner retinal nerve fiber layer and fewer RGCs. In the central retina, independent of the loss of RGCs, Tyro3 deficiency resulted in a dramatic reduction in the number of RGC dendrites in the inner plexiform layer. Our results show that Tyro3 has a novel, previously unidentified role in retinal function, RGC survival and RGC morphology. The Tyro3 pathway could therefore provide an alternative, targetable pathway for RGC protective therapeutics. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of vitrectomy, epiretinal membrane and internal limiting membrane peeling surgery on macular and ganglion cell/inner plexiform layer (GC/IPL) thicknesses in patients with unilateral epiretinal membrane (ERM). Materials and methods: The records of patients who underwent ERM surgery between November 2017 and September 2018 were retrospectively reviewed. The preoperative (pre-op) and postoperative (post-op) 6th month macula and GC/IPL thicknesses of the patients undergoing ERM surgery were used for analysis in the study. The pre-op and post-op macular and GC/IPL thicknesses of the patients were also compared with the fellow eyes of the patients. Results: Pre-op (48,76±19,81μ) and post-op (53,05±13,08μ) mean GC/IPL thicknesses were lower (p<0,001) than fellow eye (82,71±12,30μ). Pre-op and post-op mean GC/IPL thicknesses were similar (p=0,304). Pre-op (416,76±77,36μ) foveal thicknesses were measured higher than post-op (360±73,89μ) foveal thicknesses (p=0,030). Pre-op foveal thicknesses were found to be higher than fellow eye (274,71±48,73μ) foveal thicknesses (p<0,001). Post-op foveal thicknesses were also higher than fellow eye foveal thicknesses (p<0,001). There was no relationship 375 between pre-op (r=-0,459;p=0,064), post-op (r=-0,305;p=0,233), fellow eye (r=0,396; p=0,116) mean GC/IPL thicknesses and visual acuity. There was no relationship between pre-op (r=-0,027; p=0,919) and fellow eyes (r=-0,079; p=0,752) foveal thicknesses and visual acuity, too. There was a partial relationship between post-op (r=0,525; p=0,030) foveal thicknesses and visual acuity. Conclusion: Epiretinal membrane causes changes in central macular thickness and GC/IPL. After the surgery, these changes cannot return to levels of fellow eyes. [ABSTRACT FROM AUTHOR]