Ganglion Cell Layer Thinning Research Articles

Lifestyle modifications and environmental risk factors for glaucoma

Purpose of review To summarize recent evidence about the association between different lifestyle modifications and environmental risk factors and glaucoma. Recent findings Incorporating moderate exercise into the routine of glaucoma patients may help slow the progression of the condition. However, caution should be taken when using swim goggles, and it may be advisable to avoid certain yoga positions and heavy weight-lifting exercises, as they have been linked to intraocular pressure (IOP) spikes and potential risks for glaucoma patients. Various relaxation techniques may lower IOP. The evidence remains inconclusive about the association between vitamins intake and glaucoma. Dietary nitric oxide has been associated with a lower risk of glaucoma. Higher smoking intensity has been linked to faster visual field decline and retinal nerve fiber layer thinning. Additionally, there is currently insufficient evidence to support the use of marijuana in managing glaucoma, with side effects outweighing the proposed benefits. A significant association has been found between air pollutants and ganglion cell layer thinning, as well as a greater burden of glaucoma. Summary Lifestyle and environmental factors are increasingly recognized as significant contributors to glaucoma development and progression. These modifications should be integrated into a comprehensive treatment approach alongside medications or surgical interventions.

Maculopapillary Bundle Degeneration in Optic Neuropathies.

Degeneration of the maculopapillary bundle (MPB) is a prominent feature in a spectrum of optic neuropathies. MPB-selective degeneration is seen in specific conditions, such as nutritional and toxic optic neuropathies, Leber hereditary optic neuropathy (LHON), and dominant optic atrophy (DOA). Despite their distinct etiologies and clinical presentations, which encompass variations in age of incidence and monocular or binocular onset, these disorders share a core molecular mechanism: compromised mitochondrial homeostasis. This disruption is characterized by dysfunctions in mitochondrial metabolism, biogenesis, and protein synthesis. This article provides a comprehensive understanding of the MPB's role in optic neuropathies, emphasizing the importance of mitochondrial mechanisms in the pathogenesis of these conditions. Optical coherence tomography studies have characterized the retinal nerve fiber layer changes accompanying mitochondrial-affiliated optic neuropathies. Selective thinning of the temporal optic nerve head is preceded by thickening in early stages of these disorders which correlates with reductions in macular ganglion cell layer thinning and vascular atrophy. A recently proposed mechanism underpinning the selective atrophy of the MPB involves the positive feedback of reactive oxygen species generation as a common consequence of mitochondrial dysfunction. Additionally, new research has revealed that the MPB can undergo degeneration in the early stages of glaucoma, challenging the historically held belief that this area was not involved in this common optic neuropathy. A variety of anatomical risk factors influence the propensity of glaucomatous MPB degeneration, and cases present distinct patterns of ganglion cell degeneration that are distinct from those observed in mitochondria-associated diseases. This review synthesizes clinical and molecular research on primary MPB disorders, highlighting the commonalities and differences in their pathogenesis. 1.Temporal degeneration of optic nerve fibers accompanied by cecocentral scotoma is a hallmark of maculopapillary bundle (MPB) degeneration. 2.Mechanisms of MPB degeneration commonly implicate mitochondrial dysfunction. 3.Recent research challenges the traditional belief that the MPB is uninvolved in glaucoma by showing degeneration in the early stages of this common optic neuropathy, yet with features distinct from other MPB-selective neuropathies. 4.Reactive oxygen species generation is a mechanism linking mitochondrial mechanisms of MPB-selective optic neuropathies, but in-vivo and in-vitro studies are needed to validate this hypothesis.

THE EFFECT OF INTERNAL LIMITING MEMBRANE PEELING ON THE INNER RETINAL LAYERS IN PATIENTS WITHOUT MACULAR PATHOLOGIC CONDITION.

To examine the effect of internal limiting membrane peeling on the inner retinal layers in patients without macular pathological condition. A prospective nonrandomized trial of patients undergoing pars plana vitrectomy with internal limiting membrane peeling for pathologic condition outside the macula was performed. Optical coherence tomography including macular ganglion cell layer, inner plexiform layer, and peripapillary retinal nerve fiber layer imaging was performed before surgery, 1, 3, and 6 months postoperatively, and at the end of follow-up (ranges between 4 and 17 months). Patients with any macular pathological condition on optical coherence tomography before surgery were excluded. The main outcome measure was change in thickness of the ganglion cell layer and inner plexiform layer. Ten patients who underwent pars plana vitrectomy with internal limiting membrane peeling for macula-on retinal detachment were included in the analysis. The mean age was 55 years, and the mean follow up was 10.8 months. All patients completed at least two postoperative follow-up visits that included an optical coherence tomography as per the protocol (range 2-6 months). There was an immediate reduction in the global (G), inferotemporal, superotemporal, and superior (S) ganglion cell layer thickness at the first follow up as compared with the preoperative state ( P = 0.028, P = 0.027, P = 0.026, and P = 0.027 respectively). From the first follow-up visit onward until the final follow-up, the thinning persisted, although there was no further statistically significant thinning. Peeling of the internal limiting membrane causes significant ganglion cell layer thinning in maculae without pathologic condition before surgery. At up to 17 months of follow-up, this effect seems to be immediate and nonprogressive.

An analytical longitudinal observational study on the association of Vitamin D insufficiency in subjects with primary (idiopathic) demyelinating optic neuritis using visual evoked potential and optical coherence tomography

Background: Optic neuritis (ON) is an acute and often immune-mediated inflammatory condition of the optic nerve. Vitamin D acts as an anti-inflammatory agent and may confer neuroprotection. Visual evoked potential (VEP) and optical coherence tomography (OCT) are emerging tools for demyelinating diseases. Aims and Objectives: We tried to correlate between Vitamin D insufficiency and acute demyelinating ON using different parameters such as VEP, ganglion cell layer (GCL) thickness, and retinal nerve fiber layer (RNFL) thickness. Materials and Methods: This observational longitudinal analytical study included thirty non-consecutive patients with primary ON and 30 healthy controls. All patients with ON underwent detailed clinical and ophthalmological examination, and detailed blood workup, including serum 25 (OH) Vitamin D. VEP P100 latency, amplitude, OCT, RNFL thickness, and GCL thickness at presentation and after 3 months from May 2019 to November 2020. Results: Vitamin D insufficiency (below 30 ng/mL) was present in 60% of cases of ON. The baseline VEP showed significantly prolonged P100 latency in affected eyes in the Vitamin D insufficient group (mean 129.78±7.97 ms vs. 121.0±4.99 ms) whereas the P100 amplitude was not significantly altered between the two groups (5.5±3.13 μV vs. 7.08±3.01 μV). The baseline RNFL thickness (132.21±10.69 μm vs. 118.01±10.4 μm) and GCL thickness (76.82±2.04 μm vs. 73.06±3.2 μm) were greater in affected eyes of vitamin D insufficiency ON. There was greater RNFL thinning (79.93±3.42 μm vs. 74.80±3.5 μm) and GCL thinning (64.78±1.9μm vs. 69.02±2.22 μm) in affected eyes of ON with Vitamin D insufficiency at 3 months. Conclusion: Vitamin D insufficiency was found in most cases of ON. Insufficient Vitamin D positively correlated with optic nerve affection severity as evidenced by significantly increased baseline thickness of RNFL and GCL and more thinning of RNFL and GCL at the end of 3 months of follow-up.

Inner Retinal Thinning Comparison between Branch Retinal Artery Occlusion and Primary Open-Angle Glaucoma.

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.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY BIOMARKERS AND MICROPERIMETRY FEATURES IN BEHÇET'S UVEITIS.

To evaluate the parafoveal macular microvasculature and the macular function in patients with retinal vasculitis associated with Behçet's uveitis. In 14 patients with inactive Behçet's uveitis and 26 control individuals (13 with nonocular Behçet's syndrome and 13 healthy subjects), we analyzed the retinal nerve fiber layer, ganglion cell layer, full retinal thickness, foveal avascular zone area and sectorial parafoveal vascular density in the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus using SPECTRALIS optical coherence tomography (OCT) 2 and OCT angiography. Macular sensitivity was analyzed using an MP-3 microperimeter. Eighteen eyes (78%) had a best-corrected visual acuity ≥ 20/25. Significant differences were found in Behçet's uveitis in comparison with the controls on the OCT and OCT angiography: 14.8%, 22.4%, and 14.9% ganglion cell layer thinning in the global, nasal, and inferior sectors, respectively; 6%, 13.2%, and 7.5% full retinal thickness thinning in the superior, nasal, and inferior sectors; and 16.8%, 14.9%, 23.6%, 15.8%, and 12.6% mean deep capillary plexus density reduction in the global, superior, nasal, inferior, and temporal sectors. Microperimetry data demonstrated significant mean reductions of 21% and 23.6% in central and average macular sensitivities and 28.8%, 40.4%, 27.7%, and 24.2% in the superior, nasal, inferior, and temporal sectors, respectively. Outer plexiform layer elevations were observed in Behçet's uveitis (69.6%). Behçet's uveitis presented structural and functional macular damage despite good best-corrected visual acuity, mainly affecting the nasal sector and the deep capillary plexus. On OCT and OCT angiography, quantitative and qualitative changes can be valuable biomarkers of ocular involvement in Behçet's syndrome.

Unexplained Vision Loss Associated With Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment Repair.

Purpose: To evaluate the visual outcomes with unexplained vision loss during or after silicone oil (SO) tamponade. Methods: This multicenter retrospective case series comprised patients with unexplained vision loss associated with SO tamponade or its removal. Eyes with other clear secondary identifiable causes of vision loss were excluded. Results: Twenty-nine eyes of 28 patients (64% male) were identified. The mean age was 50 ± 13 years (range, 13-78 years). The mean duration of SO tamponade was 148 ± 38 days. Eighteen eyes (62%) developed unexplained vision loss while under SO; 11 (38%) had vision loss after SO removal. The most common optical coherence tomography (OCT) finding was ganglion cell layer (GCL) thinning (55%). Eyes with vision loss after SO removal had a mean logMAR best-corrected visual acuity (BCVA) of 0.6 ± 0.7 (Snellen 20/85) before SO tamponade and 1.2 ± 0.4 (20/340) before SO removal. By the last follow-up after SO removal, the BCVA had improved to 1.1 ± 0.4 (20/235). In eyes with vision loss after SO removal, the BCVA before SO removal was 0.7 ± 0.7 (20/104), which deteriorated to 1.4 ± 0.4 (20/458) 1 month after SO removal. By the last follow-up, the BCVA had improved to 1.0 ± 0.5 (20/219). Conclusions: Unexplained vision loss can occur during SO tamponade or after SO removal. Vision loss was associated with 1000-centistoke and 5000-centistoke oil and occurred in macula-off and macula-on retinal detachments. The duration of tamponade was 3 months or longer in the majority of eyes. Most eyes had GCL thinning on OCT. Gradual visual recovery can occur yet is often incomplete.

Regional Analysis of Inner Retinal Layer Changes in Multiple Sclerosis with and without Optic Neuritis.

The study aimed to investigate inner retinal changes in multiple sclerosis (MS) patients by comparing them with healthy controls. The study also aimed to assess regional differences of inner retinal layer involvement in eyes with and without optic neuritis (ON). This retrospective, cross-sectional study consisted of 141 eyes of 74 relapsing-remitting MS patients and 80 eyes of 40 healthy controls. The study group was separated into two subgroups according to the presence of ON history. Peripapillary retinal nerve fiber layer (pRNFL) thickness, total macular thickness, and thicknesses of the macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer were compared between the MS and healthy control groups and between eyes with and without ON history. Mean pRNFL, total macular, mRNFL, GCL, and IPL thicknesses were significantly thinner in the MS group than in the control group (p<0.001) and in eyes with ON compared to those without ON (p<0.05). Comparison of inner retinal layer thicknesses in the inner 3-mm ring subfields of the ETDRS grid revealed significant thinning in all subfields of the GCL and IPL of eyes with ON (p<0.05). The inferior subfield demonstrated the highest difference. The study demonstrated that GCL and IPL thinning is a robust and reliable biomarker in all MS patients. The thinning was significantly greater in eyes with ON than in eyes without ON. The study also documented that the inferior region showed significantly greater GCL and IPL thinning in eyes with previous ON attacks.

Leber's hereditary optic neuropathy: Update on current diagnosis and treatment.

Leber's hereditary optic neuropathy (LHON) is a fairly prevalent mitochondrial disorder (1:50,000) arising from the dysfunction of the mitochondrial respiratory chain, which eventually leads to apoptosis of retinal ganglion cells. The usual presentation is that of a young male with a sequential reduction in visual acuity. OCT has been used to study the pattern of optic nerve involvement in LHON, showing early thickening of the inferior and superior retinal nerve fibre layer and ganglion cell layer thinning corresponding with the onset of symptoms. Of the three primary mutations for LHON, the m.14484T>C mutation has the best visual prognosis. Recent emerging therapeutic options for LHON include idebenone and the introduction of genetic vector therapy, which is currently in phase III clinical trials. Screening of family members and adequate advice to avoid environmental triggers, such as smoking and alcohol consumption, are also cornerstones in the management of LHON.

Patients with septo-optic dysplasia: General ophthalmologic assessment and retinal imaging.

To evaluate the functional development and, retinal and optic disc morphology using OCT in patients with septo-optic dysplasia (SOD). This retrospective case series included patients diagnosed with SOD between 2007 and 2020. Ophthalmologic assessment included visual acuity (VA) and funduscopy at the initial and last presentation. Retinal imaging included OCT of the macula analyzing the retinal morphology, central retinal thickness volume (CRT) and ganglion cell layer (GCL). Also, scans of the optic nerve head were taken to evaluate the retinal nerve fiber layer (RNFL) and global value. 38 eyes of 19 children with a mean age 6.3 ± 5.3 years were included. 31.6% showed all 3 characteristics of SOD, whereof ONH, midline defects and endocrine dysfunctions were found in 94.7%, 89.5% and 47.4% respectively. The mean VA was 0.70 ± 0.66logMar in the right eye (RE) and 0.40 ± 0.55logMar in the left eye (LE) at the initial presentation. No change of vision (RE: 0.69 ± 0.71logMar; LE: 0.31 ± 0.57logMar) was found after a follow-up period of 6.3 ± 4.5years. Funduscopy showed an ONH in 79% (n = 30/38), tortuous retinal vessels in 36.8% (n = 14/38) and a double-ring sign in 15.8% (n = 6/38). Retinal imaging showed variable morphology. 6 eyes of 4 patients showed temporal retinal thinning with corresponding GCL attenuation. The optic nerve head appearance varied between no changes, sectoral and hemispherical reduction. Patients suffering from SOD show diverse expression of retinal changes such as retinal, GCL and RNFL thinning in OCT. Furthermore, visual function remained stable during follow-up examinations, indicating no further alteration due to underlying pathology.

Short-term progression of optic disc and macular changes in optic nerve head drusen

PurposeTo quantify in patients with optic nerve head drusen (ONHD)changes after 1-year observation in: (i) optic disc and (ii) macular optical coherence tomography (OCT) parameters and (iii) the effect of age at enrolment in the study.DesignProspective, cross-sectional observational study using Spectral Domain-OCT (Copernicus; OPTOPOL Technology S.A., Zawiercie, Poland) imaging was carried out in 35 patients with ONHD (age–42.8 ± 19.9 years; males = 15; females = 20) at baseline and after 12 months follow-up.ResultsPatients with ONHD had significant thinning of the surface nerve fibre layer in the central (p = 0.03), superior (p = 0.05) and inferior (p = 0.04) areas; mean ppRNFL thinning (p = 0.0 4) and ppRNFL thinning in the nasal segment (p = 0.028). Retinal thinning in the central (p = 0.001), inner (p = 0.01) and outer (p = 0.002) temporal, outer superior (p = 0.03) and inferior (p = 0.02) areas; borderline ganglion cell layer thinning (p = 0.051) and outer nuclear layer (p = 0.03) thinning in the central retina and outer segment layer thinning nasally (p = 0.01) between the first and the second visit in macula. Correlation of the difference in optic disc and macular parameters with the age at enrolment did not reveal any significance.ConclusionsStatistically detectable thinning of the optic nerve and macula structures occurred already after 12 months. The proximity of optic nerve changes to the vascular arcades can possibly be explained by involvement of retinal vessels in the pathophysiology of ONHD.

A Pediatric COVID-19 Study: Retinal Nerve Fiber Layer, Ganglion Cell Layer, and Alterations in Choroidal Thickness in Swept-Source OCT Measurements.

To investigate early covid measurements of central macular thickness (CMT), retinal nerve fiber layer (RNFL), ganglion cell layer (GCL) thickness, and choroidal thickness (ChT) in children recovered from coronavirus disease 2019 (COVID-19). This cross-sectional study was carried out 4 weeks after completed COVID-19 treatment. The diagnosis of the Alpha variant COVID-19 was made by the polymerase chain reaction test after prediagnosis with clinical, laboratory, and radiological findings. A total of 46 children were included in the study. Pediatric patients who received COVID-19 treatment comprised the COVID-19 group (24 children), and healthy children were enrolled in the control group (22 children). Only the right eyes of the participants were enrolled in the study. All pediatric patients in the COVID-19 group required hospitalization without the need for intubation. Swept-source optical coherence tomography (SS-OCT) was used to measure CMT, RNFL, and GCL thickness, and ChT measurements. The COVID-19 and control groups had similar mean values of visual acuity, intraocular pressure, spherical equivalent, axial length, and CMT (p > 0.05 for all). RNFL thickening, GCL, and choroidal thinning were observed in all SS-OCT measurements of COVID-19 children. However, RNFL thickening was significant only in the global and nasal peripapillary quadrants. GCL thinning was significant in the nasal/inferior sector (p < 0.002 for all). Some significant correlations were observed between the mean levels of inflammatory markers and OCT measurements (p < 0.002). This study may be among the first reports of SS-OCT examination of COVID-19 children. OCT measurements showed changes in retinal and ChT in the COVID-19 children as in adult patients.

Retinal nerve fibre layer and ganglion cell layer thickness changes following intravitreal aflibercept for age-related macular degeneration

Purpose To evaluate the effect of intravitreal aflibercept (IVA) injections on peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) in neovascular age-related macular degeneration (nAMD) patients during a 1-year follow-up. Methods This is a prospective study including 34 patients who were treated with aflibercept for treatment-naive nAMD. Following a loading phase of 3-monthly aflibercept, re-injections were performed on a pro re nata regimen for 12 months. Best-corrected visual acuity, intraocular pressure, and spectral-domain-optical coherence tomography analysis were performed at baseline and 1 month, 3 months, 6 months, and 12 months following treatment. Peripapillary RNFLT and macular GCLT along with the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) were evaluated at each visit. Results Mean number of aflibercept injections was 6.0 ± 1.8. Significant thinning was observed at the central macular ganglion cell layer and at 1 mm superior, temporal, and nasal ganglion cell layer compared to baseline at 1-year (p < 0.05). No significant change of RNFLT was shown (p > 0.05). Mean CMT and SFCT were significantly reduced after IVA therapy (p < 0.05, for both). No correlation was found between injection number and GCLT change. Conclusions Intravitreal aflibercept caused significant ganglion cell layer thinning during a 1-year follow-up without any changes in RNFLT. Intravitreal aflibercept itself may have a chance to induce decreased GCLT in nAMD patients.

Inner retinal degeneration associated with optic nerve head drusen in pseudoxanthoma elasticum

Background/aimsTo determine the association of age, presence of optic nerve head drusen (ONHD) and number of previous intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections with inner retinal layer thicknesses in...

Functional and anatomic changes between early postoperative recovery and long-term follow-up after combined epiretinal and internal limiting membrane peeling

ObjectiveTo evaluate short- and long-term changes in best-corrected visual acuity (BCVA) and retinal layer thicknesses after combined epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling for macular holes and symptomatic ERMs. DesignRetrospective observational case series. ParticipantsPatients with ERMs or with macular holes and ERMs treated with combined ERM and ILM peeling. MethodsStudy eyes (n = 36) and healthy fellow eyes (n = 17) were evaluated using the automated segmentation of retinal layers performed by SPECTRALIS software that automatically calculated the average central retinal thickness and the average thickness in each of the individual retinal layers. The analysis was performed at 6–18 months after surgery and after 60 months. Main Outcome MeasuresChanges in BCVA and retinal layer thicknesses determined by automated segmentation at the first and last follow-up visits. ResultsBCVA improved from a baseline 0.48 ± 0.25 logMAR (20/60 Snellen) to 0.18 ± 0.18 logMAR (20/30 Snellen) at the short-term postoperative examination (p < 0.0001). Between first and last follow-up visit, 5 eyes (14%) were classified as better, 28 (78%) as stable, and 3 (8%) as worse. BCVA of the control fellow eyes remained stable during the follow-up. The thicknesses of retinal layers decreased significantly (p < 0.009). At the last follow-up, the ganglion cell layer was thinner and the inner nuclear layer was thicker in the operated eyes compared with the healthy fellow eyes. ConclusionCombined ERM and ILM peeling may improve BCVA in some patients. However, over a long follow-up period, it can be associated with progressive ganglion cell layer thinning that could affect BCVA stability.

Association of serum apolipoprotein B with retinal neurovascular structural alterations in patients with type 2 diabetes: an optical coherence tomography angiography study.

To investigate the association of serum apoB concentrations with retinal neurovascular structural alterations in type 2 diabetes patients without clinically visible retinopathy. Eyes with no clinically visible diabetic retinopathy (DR) from diabetic patients with or without dyslipidemia were included. Changes in retinal neural structures, including the ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (RNFL) thicknesses, and microvascular metrics, including macular vessel density (VD) and perfusion density (PD) of the superficial capillary plexus, were measured with optical coherence tomography angiography (OCTA). Correlations between inner retinal layer thickness and OCTA metrics were analyzed. The association of serum apoB and diabetic retinal neurovascular structures was identified with regression analysis. A total of 148 eyes in the diabetes group (n = 74) and dyslipidemia group (n = 74) were enrolled. GCL and RNFL thicknesses in patients in the dyslipidemia group were significantly thinner than those in the diabetes group (all p < 0.025). The total area of the VD and PD in the dyslipidemia group was also decreased compared to that of the diabetes group (p < 0.05) and was found to correlate with GCL and RNFL (all p < 0.01) thicknesses in all diabetic patients. Serum apoB levels were positively related to low-density lipoprotein (LDL) and total cholesterol (TC). Moreover, the average GCL thickness was significantly associated with serum apoB levels (all p < 0.05). GCL and RNFL thinning was significantly correlated with decreased retinal blood flow in diabetic patients with dyslipidemia. Strictly controlling serum lipids, especially apoB levels, might be an effective strategy for DR treatment.

Optical coherence tomography angiography in the multimodal assessment of the retinal posterior pole in autosomal dominant optic atrophy.

To assess retinal vascular involvement in patients with autosomal dominant optic atrophy (ADOA) genetically confirmed by the presence of the OPA1 (Optic Atrophy 1) gene mutation using a multimodal protocol of investigation of retinal posterior pole. In this cross-sectional, case-control, observational study, both eyes of 13 patients with a genetic diagnosis of ADOA were compared with both eyes of 13 healthy controls (HCs). All subjects underwent full ophthalmological examination, spectral domain-optical coherence tomography (SD-OCT), fundus perimetry (FP) and OCT angiography (OCTA). Vessel density (VD) of the superficial and deep macular vascular plexi and of the radial peripapillary capillary plexus were significantly decreased (p ≤ 0.001) in ADOA patients compared with HCs. The area under the receiver operating characteristics analysis also revealed high values of sensitivity and specificity of OCTA parameters in distinguish between patients and HCs. A strong correlation (Pearson Coefficient, r = 0.91) emerged between OCTA VD of the superficial retinal plexus and the average Ganglion Cell Layer (GCL) thickness as measured by SD-OCT; a slightly lower correlation (Pearson Coefficient, r = 0.89) was also found between VD of the deep plexus and the average GCL thickness of the same eyes in patients with ADOA. The correlation among values of differential light sensitivity (DLS) measured by FP with VD and GCL thickness parameters was also investigated. The correlation analysis among DLS and the VD parameters showed from low-to-moderate correlation (ranging from r = 0.29 for the deep fovea VD to r = 0.59 for the deep whole image VD). The correlation coefficient between the mean DLS and the average thickness of GCL was more significant (Pearson Coefficient, r = 0.75). A significant correlation emerged also between the VD and the visual acuity, in terms of LogMAR BCVA (best-corrected visual acuity), especially for the VD of the deep capillary plexus (Pearson Coefficient for the Deep whole Image VD and LogMAR BCVA r = -0.75; for the Deep parafovea VD and LogMAR BCVA r = -0.78). Retinal microvascular assessment by OCTA angiography can provide relevant clinical information on retinal involvement in ADOA patients. In patients with genetically confirmed OPA1-related ADOA, there is a decrease in retinal vessel density associated with GCL thinning and DLS reduction.

Teaching NeuroImage: Ganglion Cell Patterns Localize Anterior Visual Pathway Lesions.

Measurement of retinal ganglion cell layer thickness by optical coherence tomography provides an objective and reliable evaluation of anterior visual pathway lesions to complement visual field testing in the management of optic chiasm compression from pituitary tumors.1,2 We demonstrated 3 differing patterns of ganglion cell layer thinning—junctional (figure 1, A and D), binasal (figure 1, B and E), and homonymous (figure 1, C and F)—and illustrated how these patterns correspond to the location of chiasmal compression by pituitary adenomas, anteriorly (figure 2A), centrally (figure 2B), or posteriorly (figure 2C). Consideration of the pattern of ganglion cell layer thinning in conjunction with visual field testing is useful for predicting the location of anterior visual pathway lesions.

Subclinical anterior optic pathway involvement in early multiple sclerosis and clinically isolated syndromes.

Optical coherence tomography (OCT) is gaining increasing relevance in the assessment of patients with multiple sclerosis. Converging evidence point to the view that neuro-retinal changes, in eyes without acute optic neuritis, reflect inflammatory and neurodegenerative processes taking place throughout the CNS. The present study aims at exploring the usefulness of OCT as a marker of inflammation and disease burden in the earliest phases of the disease. Thus, a cohort of 150 consecutive patients underwent clinical, neurophysiological and brain MRI assessment as well as lumbar puncture as part of their diagnostic workup for a neurological episode suggestive of inflammatory CNS disorder; among those 32 patients had another previous misdiagnosed episode. For the present study, patients also received a visual pathway assessment (OCT, visual evoked potentials, visual acuity), measurement of CSF inflammatory markers (17 cytokines-chemokines, extracellular vesicles of myeloid origin), and dosage of plasma neurofilaments. Subclinical optic nerve involvement is frequently found in clinically isolated syndromes by visual evoked potentials (19.2%). OCT reveals ganglion cell layer asymmetries in 6.8% of patients; retinal fibre layer asymmetries, despite being more frequent (17.8%), display poor specificity. The presence of subclinical involvement is associated with a greater disease burden. Second, ganglion cell layer thinning reflects the severity of disease involvement even beyond the anterior optic pathway. In fact, the ganglion cell layer in eyes without evidence of subclinical optic involvement is correlated with Expanded Disability Status Scale, low contrast visual acuity, disease duration, brain lesion load, presence of gadolinium enhancing lesions, abnormalities along motor and somatosensory evoked potentials, and frequency of CSF-specific oligoclonal bands. Third, the inner nuclear layer thickens in a post-acute (1.1-3.7 months) phase after a relapse, and this phenomenon is counteracted by steroid treatment. Likewise, a longitudinal analysis on 65 patients shows that this swelling is transient and returns to normal values after 1 year follow-up. Notwithstanding, the clinical, MRI, serological and CSF markers of disease activity considered in the study are strictly associated with one another, but none of them are associated with the inner nuclear layer. Our findings challenge the current hypothesis that the inner nuclear layer is an acute phase marker of inflammatory activity. The present study suggests that instrumental evidence of subclinical optic nerve involvement is associated with a greater disease burden in clinically isolated syndrome. Neuro-retinal changes are present since the earliest phases of the disease and yield important information regarding the neurodegenerative and inflammatory processes occurring in the CNS.

Correlations between Retinal Arterial Morphometric Parameters and Neurodegeneration in Patients with Type 2 Diabetes Mellitus with No or Mild Diabetic Retinopathy.

Background and Objectives: In patients with diabetes mellitus (DM), the neural retina is starting to degenerate before the development of vascular lesions. Our purpose was to investigate the correlation between the retinal arterial morphometric parameters and structural neurodegeneration in patients with type 2 DM with no or mild diabetic retinopathy (DR). Materials and Methods: This is a prospective study including 53 eyes of patients with type 2 DM and 32 eyes of healthy controls. Based on SD-OCT (spectral domain—optical coherence tomography) images, using a micro-densitometry method, we measured the outer and luminal diameter of retinal arteries and calculated the AWT (arterial wall thickness), WLR (wall-to-lumen ratio), and WCSA (wall cross-sectional area). GCL (ganglion cell layer) and RNFL (retinal nerve fiber layer) thickness were analyzed in correlation with the retinal arterial morphometric parameters mentioned above. Results: GCL was thinner in the inner quadrants in the NDR (no DR) group compared to controls (p < 0.05). RAOD (retinal artery outer diameter), RALD (retinal artery lumen diameter), AWT, WLR, and WCSA were similar between groups. A regression model considering age, gender, duration of DM, and HbA1C was carried out. Central GCL thickness was correlated positively with RAOD (coefficient 0.360 per µm, p = 0.011), RALD (coefficient 0.283 per µm, p = 0.050), AWT (coefficient 0.304 per µm, p = 0.029), and WCSA (coefficient 3.90 per µm, p = 0.005). Duration of DM was positively correlated with WCSA (coefficient 0.311 per one year duration of diabetes, p = 0.043). Conclusions: Significant GCL thinning in the inner quadrants preceded the morphological retinal arterial morphometric changes, supporting the neurodegeneration as primary pathogenic mechanism in DR.