Retinal Ganglion Cell Layer Thickness Research Articles

Study of peripapillary vascular flow using optical coherence tomography angiography in optic nerve head drusen.

To evaluate peripapillary vascular flow using optical coherence tomography angiography (angio-OCT) in patients with optic nerve head drusen (ONHD). Angio-OCT allows non-invasive visualization and quantification peripapillary vascular flow. Cross-sectional study. Seventy-six eyes of 40 patients. Between January 2018 and May 2019, consecutive patients with ONHD and healthy controls underwent a complete ocular assessment, including visual acuity testing, biomicroscopy, tonometry, funduscopy, automated perimetry, retinography and autofluorescence, spectral-domain OCT and peripapillary angio-OCT. Peripapillary vascular flow, vascular density, retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thicknesses. We included 23 patients with ONHD (42 eyes, 32 with visible drusen; mean age 50.96 years, 12 men) and 17 control patients (34 eyes; mean age 47.12 years, 7 men), without significant differences in age or sex. Vascular flow and density were significantly lower in patients with ONHD (0.409% and 40.18%, respectively) than in normal eyes (0.438% and 43.30%, respectively) (P = .006 and P < .001). RNFL and GCL thicknesses were significantly lower in patients with ONHD (81.81 and 77.43 μm, respectively) than in controls (91.38 and 81.97 μm, respectively) (P = .001 and P = .032). We obtained high correlation indexes between RNFL and GCL and vascular flow and density (RNFL = 0.702 and 0.744, respectively, and GCL = 0.808 and 0.857, respectively). Angio-OCT demonstrated significant reductions in peripapillary vascular flow and vascular density in patients with ONHD, with strong correlations with RNFL and GCL thicknesses.

Serum neurofilament light chain and optical coherence tomography measures in MS: A longitudinal study.

ObjectiveTo study the association between serum neurofilament light chain (sNfL) and multiple optical coherence tomography (OCT) measures in patients with MS and healthy controls (HCs).MethodsIn this prospective study, 110 patients with MS were recruited, together with 52 age- and sex-matched HCs. Clinical evaluation and spectral domain OCT and sNfL were obtained at baseline and after 5.5 years of follow-up. Nested linear mixed models were used to assess differences between MS vs HC and associations between sNfL and OCT measures. Partial correlation coefficients are reported, and p values were adjusted for the false discovery rate.ResultsAt baseline, peripapillary retinal nerve fiber layer thickness (pRNFLT) and macular ganglion cell and inner plexiform layer thickness (mGCIP) were significantly lower in MS than HC both in MS-associated optic neuritis (MSON) (p = 0.007, p = 0.001) and nonaffected MSON (n-MSON) eyes (p = 0.003, p = 0.018), along with total macular volume (TMV) in n-MSON eyes (p = 0.011). At follow-up, MS showed significantly lower pRNFLT, mGCIP, and TMV both in MSON and n-MSON eyes (p < 0.001) compared with HC. In MS n-MSON eyes, sNfL was significantly associated with baseline pRNFLT and mGCIP (q = 0.019). No significant associations were found in MSON eyes.ConclusionsThis study confirms the ability of sNfL to detect neurodegeneration in MS and advocates for the inclusion of sNfL and OCT measures in clinical trials.Classification of evidenceThis study provides Class III evidence that sNfL levels were associated with MS neurodegeneration measured by OCT.

Long-term Kinetic Papilledema Improvement After Venous Sinus Stenting in Idiopathic Intracranial Hypertension

The aim of this study was to assess the safety and effectiveness of lateral sinus stenosis (LSS) stenting in patients with idiopathic intracranial hypertension (IIH) who are refractory to medical treatment, particularly focusing on visual outcomes including papilledema. Retrospective study of consecutive patients with IIH refractory to medical treatment who underwent LSS stenting. Clinical features, visual fields and optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thicknesses were assessed before stenting, at 1 month poststenting and at last follow-up. Complications were also recorded. A total of 16women were included, with amean age of 39 ± 11years. All patients had papilledema while 15/16 (94%) had headaches. Mean visual acuity was 0.036 logMAR, range (+0.4 to +0.0 logMAR). The mean RNFL thickness prior to stenting was 121.7 µm (±34.7 µm) and mean GCL thickness was 80.2 µm (±8.9 µm). Mean follow-up was 19.7months (±11.8 months). After stenting, acetazolamide was discontinued in 15/16 (94%) patients. Papilledema improved in 14/16 (88%) of patients. The mean RNFL thickness was significantly decreased 1 month after stenting (96.3 ± 15.6 µm; p < 0.001) and at last visit (93.4 ± 15.3 µm; p < 0.001). The GCL thickness after LSS stenting was moderately decreased at the last visit examination: 80.2 ± 8.9 µm vs. 78.0 ± 10.7 µm; (p < 0.01). No stent-related complication occurred, while there was one case of restenosis. Improvement of papilledema appears to occur relatively rapidly after the LSS stenting. The results further support the role of LSS stenting in the treatment of IIH, especially with respect to visual symptoms.

The Detection of Retina Microvascular Density in Subclinical Aquaporin-4 Antibody Seropositive Neuromyelitis Optica Spectrum Disorders

Purpose: To use optical coherence tomography (OCT) and OCT angiography (OCT-A) to measure changes in the retinal structure and microvasculature of patients with aquaporin-4 antibody-positive, neuromyelitis optica spectrum disorder (NMOSD) with a history of optic neuritis (NMOSD+ON) and those without it (NMOSD–ON).Methods: A total of 27 aquaporin-4 antibody-positive NMOSD patients and 31 age- and gender-matched healthy control (HC) participants were included. In 27 NMOSD patients, 19 of them had a history of optic neuritis (ON) and 8 of them had no history of ON. Peripapillary retinal nerve fiber layer (pRNFL) thickness and macular ganglion cell and inner plexiform layer (GCIPL) thickness were measured by OCT. Radial peripapillary capillary density (RPCD) and macular superficial vessel density (MSVD) were measured by OCT-A. Comparisons of retinal structural and microvascular parameters between the cohorts were performed using generalized estimating equation (GEE) models. Diagnostic accuracy was evaluated by the area under the receiver operating characteristics curve (AROC).Results: In NMOSD+ON eyes, the GCIPL and pRNFL thicknesses, 48.6 ± 7.1 and 61.7 ± 25.1 μm, respectively, were significantly thinner than in HC eyes (P < 0.001 for both). However, in NMOSD–ON eyes, the GCIPL and pRNFL thicknesses were not significantly thinner than in HC eyes (P > 0.05 for both). In NMOSD+ON eyes, the RPCD and MSVD, 37.8 ± 7.1 and 36.7 ± 5.0%, respectively, were significantly less dense than HC eyes (P < 0.001 for both). Similarly, the RPCD and MSVD in NMOSD–ON eyes, 49.0 ± 2.8 and 43.9 ± 4.2%, respectively, were also less dense than in HC eyes (P < 0.029 for RPCD, P < 0.023 for MSVD). The highest AROC, 0.845 (sensitivity = 88.5%, specificity = 78.0%), was achieved by the logistic regression combination of all of the variables, i.e., pRNFL, GCIPL, RPCD, and MSVD.Conclusions: Retinal microvascular changes were present in NMOSD–ON eyes. The combination of retinal structural and microvascular parameters might be helpful to discriminate NMOSD–ON eyes from HC eyes.

Retinal Fiber Layer and Macular Ganglion Cell Layer Thickness in Diabetic Patients

Background: To compare the ganglion cell-inner plexiform layer (GCIPL) thickness and the retinal nerve fibre layer (RNFL) thickness between type 2 diabetic patient's eyes with and without diabetic retinopathy (DR) and normal eyes. Methods: In this comparative case-control study two groups of 58 eyes were examined by SD-OCT with peripapillary RNFL, and macular GCIPL assessment. The first group includes 58 eyes of type 2 diabetic patients (33 eyes without DR, 25 eyes with moderate DR, without diabetic macular edema), the second group included 58 eyes of non-diabetic, non-glaucomatous patients. We compared RNFL and GCIPL thicknesses among different groups. We evaluated the potential systemic risk factors for RNFL and GCIPL loss (HBA1C, the presence of DR, other vascular diseases). Results: The two groups were matched concerning the age, gender and the intra-ocular pressure (IOP) level. A significant differences between the two groups was found for the average, superior and inferior RNFL thickness (p<0.001, p=0.005 and p=0.01 respectively). Concerning the GCIPL thickness, it was significantly less in the diabetic eyes (p<0.001), but no significant difference was noted between the diabetic patient's eyes without DR and the healthy controls in all quadrants for the RNFL and the GCIPL. Multivariate linear regression analysis concluded that the diabetic duration, the HbA1c were correlated to RNFL and GCIPL loss in diabetic patient's eyes and the presence of arterial hypertension as well as lipid disorders were found as risk factors in the non-diabetic group. Conclusion: RNFL and GCIPL loss seems to be the earliest retinal changes in diabetic patients, and associated with diabetic duration and poor control. These results can explain the higher risk of primitive angle closure glaucoma in diabetic patients and confirm the neurodegeneration theory in DR's physiopathology.

Quantitative analysis of metabolites in glucose metabolism in the aqueous humor of patients with central retinal vein occlusion

Quantitative analysis of aqueous humor (AH) was performed to investigate glucose metabolism in patients with central retinal vein occlusion (CRVO), and to explore metabolic changes after anti-vascular endothelial growth factor (VEGF) treatment. AH samples were collected from 35 patients. Participants diagnosed with CRVO (n = 15) were compared to participants who underwent cataract surgery (n = 20). Thirteen of the participants with CRVO received second-round anti-VEGF treatments. Ultra-high performance liquid chromatography tandem-mass spectrometry (UHPLC-MS/MS) was used to quantify metabolites of the AH. Central macular thickness (CMT) and retinal ganglion cell layer (RGC) thickness were measured using spectral-domain optical coherence tomography. Thirteen metabolites involved in glucose metabolism were identified. Among these metabolites, succinate, glutamate, and glutamine were significantly decreased for the CRVO group (p = 0.028, 0.009, and 0.017, respectively). The α-ketoglutarate/citrate (K/C) ratio had a significant positive correlation with glutamine levels for both control (r = 0.922, p < 0.001) and CRVO groups (r = 0.674, p = 0.006). A significant increase in lactate was observed after intravitreal anti-VEGF administration (t = 2.273, p = 0.045); the change in CMT was negatively correlated with this increase (r = −0.745, p = 0.003). The alteration of RGC thickness was negatively correlated with increases in both glutamine (r = −0.619, p = 0.024) and glucose (r = −0.754, p = 0.003). These results indicate that, compared to glucose metabolism, glutamine was significantly decreased in the AH of patients with CRVO, and may therefore serve as a potential target for CRVO therapy. The glycolytic pathway might be enhanced after intravitreal anti-VEGF injection, which is an important insight into CRVO pathophysiology.

Differences in macular pigment optical density across four ethnicities: a comparative study.

Objective:The aim of this study is to compare macular pigment optical density levels across four different ethnicities and study its influence on ganglion cell layer and retinal nerve fibre layer thickness across these ethnicities.Methods:Consenting adults visiting the ophthalmology and optometry clinics for a routine eye examination without any ocular comorbidity were enrolled. Participants underwent optical coherence tomography for macular thickness, retinal nerve fibre layer thickness and ganglion cell layer thickness. The macular pigment optical density levels were determined in the dominant eye using the QuantifEye device by trained observers.Results:In total, 336 eyes of 336 participants with a mean age of 39.2 ± 14.4 years were included of which 103 (30%) were Caucasians, 111 (33%) were African Americans, 29 (9%) were South Asian Indians and 94 (28%) were Hispanics. The mean macular pigment optical density value across the entire study population was 0.47 ± 0.15. South Asian Indians (0.58 ± 0.16) and Hispanics (0.52 ± 0.15) had significantly higher mean macular pigment optical density values compared with Caucasians (0.41 ± 0.16) and African Americans (0.38 ± 0.15). Linear regression analysis showed that there was a significant association between ethnicities and macular pigment optical density values when adjusted for age (β coefficient = 0.31, 95% confidence interval = 0.029–0.58, p < 0.001 for South Asian Indian and Hispanic ethnic groups compared with African Americans). There were no differences in the retinal nerve fibre layer and ganglion cell layer thickness across ethnic groups. Linear regression analysis also did not reveal any significant association between macular pigment optical density levels and retinal nerve fibre layer or ganglion cell layer thickness.Conclusion:Caucasians and African Americans have lower macular pigment optical density compared with South Asian Indians and Hispanics. There is no clinically significant association between macular pigment optical density levels and retinal nerve fibre layer and ganglion cell layer thickness in healthy individuals across races.

Retinal Ganglion Cell Layer Thicknesses and Visual Functions in Patients with Bilateral Temporal Optic Atrophy

Retinal Ganglion Cell Layer Thicknesses and Visual Functions in Patients with Bilateral Temporal Optic Atrophy

Assessments of vessel density and foveal avascular zone metrics in multiple sclerosis: an optical coherence tomography angiography study.

To investigate optical coherence tomography angiography (OCT-A) findings of foveal avascular zone (FAZ) metrics and macular & peripapillary vessel densities (VD) in subjects with multiple sclerosis (MS). The study design was prospective and cross-sectional. FAZ metrics and VDs of the superficial capillary plexus (SCP), deep capillary plexus (DCP), retinal peripapillary capillary plexus (RPCP) along with the structural OCT measurements were scanned by using the Nidek's RS-3000 Advance in MS patients and healthy controls. All subject also underwent an assessment of visual evoked potentials (VEPs). The relationships between the OCT-A parameters with other clinical findings were analysed. Forty-seven MS patients (94 eyes) and 61 healthy volunteers (122 eyes) were included in this study. Thirty-five eyes of the MS patients had an ON history. The structural OCT measurements were significantly differed between the groups (P < 0.001). All FAZ metrics were inversely correlated with central foveal thickness (CFT) (P < 0.001). The FAZ area and perimeter were inversely correlated with the VD of both SCP and DCP (P < 0.05). The VDs of SCP and DCP were significantly differed between the study groups (P < 0.001). The VEP latency was inversely correlated with the retinal nerve fibre layer, macular and ganglion cell layer thicknesses, the VD of SCP, and the VD of the DCP (P < 0.001). Based on OCT angiography, VDs of macular and peripapillary area may be useful in detecting damage from ON in patients with MS.

Negative correlation between retinal displacement and ganglion cell layer thickness changes in eyes with epiretinal membrane.

To examine retinal displacement after vitrectomy with internal limiting membrane peeling for epiretinal membrane treatment, and to determine the correlation between the extent of displacement and the ganglion cell layer thickness changes. Thirty-nine consecutive patients were evaluated. Optical coherence tomography was performed preoperatively, and 2 and 6 months postoperatively. The distance between the fovea, the vessel intersection in the superior nasal, superior temporal, inferior nasal, and inferior temporal macular regions, and the optic disk were measured. Ganglion cell layer thickness was recorded. The distance from the optic disk to the fovea and the superior nasal and inferior nasal vessel intersections significantly reduced at 2 and 6 months. Ganglion cell layer thickness significantly decreased in all the subfields (except nasal) at 6 months. A significant negative correlation was found between the change in the ganglion cell layer thickness and the movement of the fovea toward the optic disk. The ganglion cell layer thickness changes significantly correlated with retinal displacement. Retinal displacement toward the optic disk was detected after vitrectomy with internal limiting membrane peeling in eyes with epiretinal membrane. Ganglion cell layer thickness significantly reduced in all the subfields (except nasal). The extent of the displacement and the ganglion cell layer thickness changes showed significant negative correlation.

Longitudinal morphological assessment of macular changes in glaucoma

AbstractPurposeTo investigate the role of longitudinal analysis of macular Optical Coherence Tomography (OCT) scans in identification of glaucoma progression.Methods40 eyes of 20 patients diagnosed with glaucoma were retrospectively assessed over a period of 3 years with visits intervals of 4–6 months. Data were acquired at each time point with Posterior Pole (PPole) and Peripapillary RNFL protocols. Following automatic layer segmentation and macular regional subdivision, measurements of total retinal, Retinal Nerve Fiber Layer (RNFL) and Ganglion cell layer (GCL) thickness were recorded. Thickness gradients and linear regression analyses were calculated for each macular region in each eye longitudinally over time using “R” software (https://www.R-project.org). All data are expressed as mean ± SD. p &lt; 0.05 was considered as significant.ResultsLinear regression analysis of each individual region showed that macular morphological analysis detected progression significantly earlier than RNFL peripapillary scan in 90.4% (total retina: 3.8 ± 0.8 visits versus 6 ± 0.9 visits, p &lt;0.0001), 96% (RNFL:3.7 ± 0.6 visits versus 5.6 ± 0.6 visits, p &lt; 0.0001) and 83% (GCL: 4 ± 0.8 visits versus 5.6 ± 0.7 visits, p &lt; 0.01) of eyes. Interestingly, in 78% of progressing glaucomatous eyes, a supero‐temporal thinning of whole retina, RNFL and GCL could be detected.ConclusionIn this study we have shown that longitudinal analysis of macular morphology is able to detect and quantify glaucoma progression. Macular thickness changes represent a potential biomarker for glaucoma diagnosis and detection of early disease progression.

Optical Coherence Tomography Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness before and after Argon Laser in Treatment of Diabetic Retinopathy

Background: Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes with the potential to cause severe vision loss and blindness and a devastating effect on quality of life. Objective: Discuss the macular ganglion cell and retinal nerve fiber layer (RNFL) changes after laser treatment as a management of diabetic retinopathy. Patients and Methods: This study was carried out on 55 eyes of 35 patients designed as a prospective, interventional case series at Sohag Ophthalmic Diagnostic Laser Unit between January 2016 and March 2017. A complete ophthalmologic examination was performed, including best-corrected visual acuity (BCVA) using the ETDRS charts, intraocular pressure (IOP) measurement, slit-lamp biomicroscopic examination, fundus examination, fluorescein angiography, and 3D optical coherence tomography (OCT) 2000. Results: The value of RNFL (superior and total) in the GRID group is more than in the pan-retinal photocoagulation (PRP) group which increased at 1 month post laser (not significant) then significantly decreased at 6 month follow up. The value of RNFL (inferior) in the GRID group is more than in the PRP group which significantly increased at 1 month post laser then decreased at 6 month follow up table 4. Conclusion: Significant ganglion cell (GC) and RNLF decrease at the sixth month of follow-up can be attributed to axonal loss secondary to direct or indirect effects of PRP treatment. SD OCT is a very valuable tool to document the RNFL thickness changes following the argon laser photocoagulation.

Optical Coherence Tomography Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness before and after Argon Laser in Treatment of Diabetic Retinopathy

Background: Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes with the potential to cause severe vision loss and blindness and a devastating effect on quality of life. Objective: Discuss the macular ganglion cell and retinal nerve fiber layer (RNFL) changes after laser treatment as a management of diabetic retinopathy. Patients and Methods: This study was carried out on 55 eyes of 35 patients designed as a prospective, interventional case series at Sohag Ophthalmic Diagnostic Laser Unit between January 2016 and March 2017. A complete ophthalmologic examination was performed, including best-corrected visual acuity (BCVA) using the ETDRS charts, intraocular pressure (IOP) measurement, slit-lamp biomicroscopic examination, fundus examination, fluorescein angiography, and 3D optical coherence tomography (OCT) 2000. Results: The value of RNFL (superior and total) in the GRID group is more than in the pan-retinal photocoagulation (PRP) group which increased at 1 month post laser (not significant) then significantly decreased at 6 month follow up. The value of RNFL (inferior) in the GRID group is more than in the PRP group which significantly increased at 1 month post laser then decreased at 6 month follow up table 4. Conclusion: Significant ganglion cell (GC) and RNLF decrease at the sixth month of follow-up can be attributed to axonal loss secondary to direct or indirect effects of PRP treatment. SD OCT is a very valuable tool to document the RNFL thickness changes following the argon laser photocoagulation.

The relation of individual variation in total retinal ganglion cell layer thickness to post-retinal anatomy

The relation of individual variation in total retinal ganglion cell layer thickness to post-retinal anatomy

Establishment of an adult zebrafish model of retinal neurodegeneration induced by NMDA.

To establish a model of retinal neurodegeneration induced by N-Methyl-D-aspartic acid (NMDA) in adult zebrafish. We compared the effects of three different NMDA delivery methods on retinal neurodegeneration in adult zebrafish: immersion (I.M.), intravitreal injection (I.V.), and intraperitoneal injection (I.P.), and examined retinal pathology and degeneration by hematoxylin and eosin and TUNEL staining in the treated zebrafish. Effects of the NMDA receptor antagonist MK-801 and the natural product resveratrol on NMDA-induced retinal neurodegeneration were also assessed. The thickened inner retina was seen in histology with 100 µmol/L NMDA by I.M. administration. Significant apoptosis in the retinal ganglion cell layer and retinal thickness reduction occurred in 0.5 mol/L NMDA I.P. administration group.Seizure-like behavioral changes, but no retinal histological alteration occurred in 16 mg/kg NMDA I.P. administration group. Resveratrol and MK-801 prevented NMDA-induced retinal neurodegeneration in the zebrafish. Among the three drug administration methods, I.V. injection of NMDA is the most suitable for establishment of an acute retinal damage model in zebrafish. I.M. with NMDA is likely the best for use as a chronic retinal damage model. I.P. treatment with NMDA causes brain damage. Resveratrol and MK801 may be a clinically valuable treatment for retinal neurodegeneration.

Short-Term Changes in Retinal Vasculature and Layer Thickness after Phacoemulsification Surgery

ABSTRACT Purpose To evaluate the short-term influence of uncomplicated phacoemulsification on fundus structure and vasculature change. Methods A total of 51 eyes from 51 patients with mild-to-moderate cataracts were included. Retinal vessel density, perfusion density, and layer thickness in both macular and peripapillary areas were scanned by OCT at baseline and at 1 day, 1 week, and 1 month after cataract surgery. Cumulative dissipated energy (CDE), U/S total time (USTT) and total aspiration time (TAT) were recorded as parameters of surgical injury to analyze the surgical influence on fundus change. Results There was a significant increase up in retinal vasculature parameters in both macular and optic nerve area after the surgery. The retinal layer thickness had pronounced increase from 1 week after the surgery (all p < .05, repeated-measures analysis of variance). Retinal nerve fiber layer (RNFL) thickness and ganglion cell layer (GCL) thickness increased more rapidly than other layers. There was a positive correlation between CDE and vasculature changes from 1 week to 1 month (Vessel density in macular to CDE: standardized β = 0.448, p = .005; Perfusion density in peripapillary area to CDE: standardized β = 0.382, p = .015). Conclusions Retinal vasculature and layer thickness increased in short-term follow-up after cataract surgery. Whether these changes would persist over a longer period needs to be verified.

Vascular Changes in Intermediate Age-Related Macular Degeneration Quantified Using Optical Coherence Tomography Angiography.

PurposeTo examine changes in retinal vasculature and ganglion cell layer (GCL) thickness in intermediate age-related macular degeneration (AMD) using optical coherence tomography angiography (OCTA).MethodsZeiss Cirrus Angioplex OCTA 6 × 6 mm scans and a macula 512 × 128 cube scans of the central retina were taken of 63 eyes with intermediate AMD and 51 control eyes. For OCTA scans, the superficial and deep capillary plexus were automatically segmented and vascular density quantified as total number of pixels contributing to the blood flow signal detectable by OCTA. Images were then skeletonized and vessel length, diameter index, morphology, and branching complexity determined. Foveal avascular zone (FAZ) characteristics and GCL thickness were extracted from in-built Angioplex software.ResultsVascular density was significantly reduced in the superficial capillary plexus of AMD eyes compared with normal eyes, particularly in the superior quadrant (42.4% ± 1.6% vs. 43.2% ± 1.4%; P < 0.05). A nonsignificant reduction was also seen in the deep capillary plexus (P = 0.06). Total vessel length and average vessel diameter were all significantly decreased in AMD eyes suggesting density changes were related to decreased vessel number and caliber. Vascular complexity and number of branch points was significantly decreased in the deep capillary plexus (P < 0.05) suggesting loss or significantly reduced flow of vessels. Average GCL thickness was also significantly reduced in the AMD eyes (P < 0.05). No significant changes in FAZ parameters were observed in AMD eyes.ConclusionsThis study suggests intermediate AMD affects both the quantity and morphology of inner retinal vasculature and may be associated with changes in inner retinal structure. This work builds upon the notion that AMD pathogenesis may extends beyond the outer retina.Translational RelevanceBetter understanding of retinal vascular changes in AMD can provide insights in the development of treatment and prevention protocols for these diseases.

Ocular changes in traumatic brain injury: A review.

Traumatic brain injury is represented by a penetrating or non-penetrating head injury, which causes disruption in the normal functioning of the brain. Traumatic brain injury has been an ardently debated topic of discussion due to its prevalence in media centric persons such as military personnel and athletes. Current assessments for traumatic brain injury have looked at vestibulo-ocular and vascular parameters to aid in diagnosis. Innovations in non-invasive ophthalmic imaging have allowed for the visualization of specific tissue structure/function relationships in a variety of ophthalmic and neurodegenerative diseases. As the eye and brain share significant embryological and physiological pathways, ocular imaging modalities may provide a novel and impactful tool in advancing assessment of traumatic brain injury. Herein, we examined the available literature and data on visual fields, mean retinal nerve fiber layer thickness, retinal ganglion cell layer thickness, and cerebral blood flow following traumatic brain injury. This review of published individual and population-based studies was performed in order to explore the feasibility and importance of considering ocular imaging biomarkers following traumatic brain injury.

A New Approach for the Segmentation of Three Distinct Retinal Capillary Plexuses Using Optical Coherence Tomography Angiography.

PurposeTo segment three distinct retinal capillary plexuses by using optical coherence tomography angiography (OCTA).MethodsThis prospective study included 30 eyes of 15 healthy subjects. En face OCTA images generated by the AngioPlex platform were manually segmented by the “progressive matching” method to the superficial, middle, and deep capillary plexuses (SCP, MCP, and DCP, respectively). The estimated position of each plexus relative to the reference line was calculated. Vascular density (VD) and skeleton density (SD) analyses, as well as the interclass correlation coefficient and relative standard deviation, were performed on each capillary plexus. We also measured central retinal thickness (CRT) and ganglion cell layer thickness (GCT).ResultsThirty eyes of 15 healthy subjects (9 females; average age of 28.33 ± 3.07 years) were included in the analysis. We defined the relative estimated positions of the outer boundary MCP to the RPEfit as MCP = 14.491 − 0.307 CRT − 1.443 GCT, while the outer boundary of DCP was 37.63 ± 7.04 μm below the IPL. The VDs of SCP, MCP, and DCP were 32.97% ± 3.90%, 45.05% ± 5.34%, and 37.34% ± 4.96%, respectively, while the SDs of SCP, MCP, and DCP were 14.45 ± 1.51 mm−1, 19.80 ± 1.92 mm−1, and 17.38 ± 1.97 mm−1, respectively.ConclusionsWith the progressive matching method, we segmented three capillary plexuses and defined the relative estimated positions of each capillary plexus to the reference line and calculated the VD and SD of three capillary plexuses in healthy subjects, providing controls for future studies.Translational RelevanceOur study provides a visual method for OCTA image vascular segmentation and provides reference and control for future studies on retinal three capillary plexuses.

Normal Visual Recovery after Optic Neuritis Despite Significant Loss of Retinal Ganglion Cells in Patients with Multiple Sclerosis.

Optic neuritis (ON) is a frequent manifestation of demyelinating attack in multiple sclerosis (MS). Initial visual loss can vary from minimal to complete. Visual improvement occurs in about 95% of patients, some of them recovering to normal [visual acuity (VA), color vision, visual field (VF)]. We analyzed retinal ganglion cell layer (RGCL) thickness in MS patients who recovered their normal vision after ON to determine whether a relative preservation of RGCL existed in these patients. We conducted a retrospective study of all patients with MS and ON examined by one of us (F. X. B.) between 2013 and 2018. Inclusion criteria were strictly unilateral ON, full recovery of vision, computerized visual field, and OCT examinations. Full recovery of vision was defined as VA ≥ 10/10, Ishihara ≥ 11/13, and VF mean defect (MD) ≤ 2.6 dB. Evaluation of RGCL was obtained with spectral domain optical coherence tomography (SD-OCT). The normal fellow eye of all patients served as the control group. Relative thinning of RGCL, expressed as percentage, was calculated by comparing results from the affected eye to the fellow eye of the same patient. Twenty-one patients (21 affected eyes - Group 1, 21 normal fellow eyes - Group 2) satisfying the inclusion criteria were retrieved from our database. All patients exhibited the relapsing-remitting form of MS. There were 16 women and 5men. Mean age was 39.3 years old. There were no statistically significant differences between Group 1 and Group 2 for either VA (p = 0.3934) or Ishihara (p = 0.140), but a significant difference was found for VF MD (p = 0.0405). A markedly significant difference for RGCL thickness (p = 0.0001) was found, without any correlation with the degree of visual recovery. A subgroup of patients (n = 14) was examined at the time of initial visual loss. We correlated their results of visual function to the final RGCL thickness, and a correlation was found between either the initial VA loss or the initial VF loss and the final loss of RGCL (R2 = 0.4075 and R2 = 0.00739, respectively). In our study, all patients with ON lost a significant amount of RGCL despite a full recovery of vision, as defined by our criteria. The percentage of RGCL loss varied from 5 - 27% and could not be correlated with any final visual indices. However, a correlation was found with the degree of initial visual loss. Despite sometimes marked RGCL loss after ON, patients with MS can recover normal visual function, according to standard clinical tests.