Astrocytic outer retinal layer thinning is not a feature in AQP4-IgG seropositive neuromyelitis optica spectrum disorders.

BACKGROUND: Patients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort. METHOD: 197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site. RESULTS: No significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere. CONCLUSION: The results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.

Swept-source optical coherence tomography detects anterior-chamber changes in patients with angle-closure after laser peripheral iridotomy.

PURPOSE: This study aimed to compare an teriorchamber parameters acquired by a swept-source anteriorsegment optical coherence tomography before and after laser peripheral iridotomy. METHODS: This study prospectively evaluated 14 patients with primary-angle closure and six patients with primary-angle closure glaucoma. Gonioscopy and anterior-segment optical coherence tomography using the DRI OCT Triton® were performed before and after laser peripheral iridotomy. Anterior-segment optical coherence tomography parameters were studied using scleral spur as reference: angle opening distance at 250, 500, and 750 µm, trabecular-iris space at 500 µm, trabecular-iris angle, trabecular-iris contact length, and iris curvature. RESULTS: Anterior-segment optical coherence tomography identified 61% of the patients with two or more quadrants closed. Gonioscopy identified more closed angles than anterior-segment optical coherence tomography before laser peripheral iridotomy. In angle parameters, only the angle opening distance of 250 µm at the nasal quadrant was not significantly increased after laser peripheral iridotomy. The iris curvature and trabecular-iris contact length showed a significant reduction induced by the laser procedure. Even in eyes in which gonioscopy did not identify angular widening after laser peripheral iridotomy (n=7), the angle opening distance of 750 µm increased (nasal, 0.15 ± 0.10 mm to 0.27 ± 0.16 mm, p=0.01; temporal, 0.14 ± 0.11 mm to 0.25 ± 0.12 mm, p=0.001) and the iris curvature decreased (nasal, 0.25 ± 0.04 mm vs. 0.11 ± 0.07 mm, p=0.02; temporal, 0.25 ± 0.07 mm vs. 0.14 ± 0.08 mm, p=0.007). CONCLUSIONS: Anterior-chamber changes induced by laser peripheral iridotomy could be quantitatively evaluated and documented by DRI OCT Triton®.

Retinal Optical Coherence Tomography in Neuromyelitis Optica.

BACKGROUND AND OBJECTIVES: To determine optic nerve and retinal damage in aquaporin-4 antibody (AQP4-IgG)-seropositive neuromyelitis optica spectrum disorders (NMOSD) in a large international cohort after previous studies have been limited by small and heterogeneous cohorts. METHODS: The cross-sectional Collaborative Retrospective Study on retinal optical coherence tomography (OCT) in neuromyelitis optica collected retrospective data from 22 centers. Of 653 screened participants, we included 283 AQP4-IgG-seropositive patients with NMOSD and 72 healthy controls (HCs). Participants underwent OCT with central reading including quality control and intraretinal segmentation. The primary outcome was thickness of combined ganglion cell and inner plexiform (GCIP) layer; secondary outcomes were thickness of peripapillary retinal nerve fiber layer (pRNFL) and visual acuity (VA). RESULTS: Eyes with ON (NMOSD-ON, N = 260) or without ON (NMOSD-NON, N = 241) were assessed compared with HCs (N = 136). In NMOSD-ON, GCIP layer (57.4 ± 12.2 µm) was reduced compared with HC (GCIP layer: 81.4 ± 5.7 µm, p < 0.001). GCIP layer loss (-22.7 µm) after the first ON was higher than after the next (-3.5 µm) and subsequent episodes. pRNFL observations were similar. NMOSD-NON exhibited reduced GCIP layer but not pRNFL compared with HC. VA was greatly reduced in NMOSD-ON compared with HC eyes, but did not differ between NMOSD-NON and HC. DISCUSSION: Our results emphasize that attack prevention is key to avoid severe neuroaxonal damage and vision loss caused by ON in NMOSD. Therapies ameliorating attack-related damage, especially during a first attack, are an unmet clinical need. Mild signs of neuroaxonal changes without apparent vision loss in ON-unaffected eyes might be solely due to contralateral ON attacks and do not suggest clinically relevant progression but need further investigation.

Impact of manual correction over automated segmentation of spectral domain optical coherence tomography.

OBJECTIVE: To study the automated segmentation of retinal layers using spectral domain optical coherence tomography (OCT) and the impact of manual correction over segmentation mistakes. METHODS: This was a retrospective, cross-sectional, comparative study that compared the automated segmentation of macular thickness using Spectralis™ OCT technology (Heidelberg Engineering, Heidelberg, Germany) versus manual segmentation in eyes with no macular changes, macular cystoid edema (CME), and choroidal neovascularization (CNV). Automated segmentation of macular thickness was manually corrected by two independent examiners and reanalyzed by them together in case of disagreement. RESULTS: In total, 306 eyes of 254 consecutive patients were evaluated. No statistically significant differences were noted between automated and manual macular thickness measurements in patients with normal maculas, while a statistically significant difference was found in central thickness in patients with CNV and with CME. Segmentation mistakes in macular OCTs were present in 5.3% (5 of 95) in the normal macula group, 16.4% (23 of 140) in the CME group, and 66.2% (47 of 71) in CNV group. The difference between automated and manual macular thickness was higher than 10% in 1.4% (2 of 140) in the CME group and in 28.17% (20 of 71) in the CNV group. Only one case in the normal group had a higher than 10% segmentation error (1 of 95). CONCLUSION: The evaluation of automated segmented OCT images revealed appropriate delimitation of macular thickness in patients with no macular changes or with CME, since the frequency and magnitude of the segmentation mistakes had low impact over clinical evaluation of the images. Conversely, automated macular thickness segmentation in patients with CNV showed a high frequency and magnitude of mistakes, with potential impact on clinical analysis.

Cohort profile: a collaborative multicentre study of retinal optical coherence tomography in 539 patients with neuromyelitis optica spectrum disorders (CROCTINO).

PURPOSE: Optical coherence tomography (OCT) captures retinal damage in neuromyelitis optica spectrum disorders (NMOSD). Previous studies investigating OCT in NMOSD have been limited by the rareness and heterogeneity of the disease. The goal of this study was to establish an image repository platform, which will facilitate neuroimaging studies in NMOSD. Here we summarise the profile of the Collaborative OCT in NMOSD repository as the initial effort in establishing this platform. This repository should prove invaluable for studies using OCT to investigate NMOSD. PARTICIPANTS: The current cohort includes data from 539 patients with NMOSD and 114 healthy controls. These were collected at 22 participating centres from North and South America, Asia and Europe. The dataset consists of demographic details, diagnosis, antibody status, clinical disability, visual function, history of optic neuritis and other NMOSD defining attacks, and OCT source data from three different OCT devices. FINDINGS TO DATE: The cohort informs similar demographic and clinical characteristics as those of previously published NMOSD cohorts. The image repository platform and centre network continue to be available for future prospective neuroimaging studies in NMOSD. For the conduct of the study, we have refined OCT image quality criteria and developed a cross-device intraretinal segmentation pipeline. FUTURE PLANS: We are pursuing several scientific projects based on the repository, such as analysing retinal layer thickness measurements, in this cohort in an attempt to identify differences between distinct disease phenotypes, demographics and ethnicities. The dataset will be available for further projects to interested, qualified parties, such as those using specialised image analysis or artificial intelligence applications.

Swept-source optical coherence tomography detects anterior-chamber changes in patients with angle-closure after laser peripheral iridotomy / Tomografia de coerência óptica swept-source detecta alterações na câmara anterior em pacientes com fechamento angular após iridotomia

ABSTRACT Purpose: This study aimed to compare an teriorchamber parameters acquired by a swept-source anteriorsegment optical coherence tomography before and after laser peripheral iridotomy. Methods: This study prospectively evaluated 14 patients with primary-angle closure and six patients with primary-angle closure glaucoma. Gonioscopy and anterior-segment optical coherence tomography using the DRI OCT Triton® were performed before and after laser peripheral iridotomy. Anterior-segment optical coherence tomography parameters were studied using scleral spur as reference: angle opening distance at 250, 500, and 750 µm, trabecular-iris space at 500 µm, trabecular-iris angle, trabecular-iris contact length, and iris curvature. Results: Anterior-segment optical coherence tomography identified 61% of the patients with two or more quadrants closed. Gonioscopy identified more closed angles than anterior-segment optical coherence tomography before laser peripheral iridotomy. In angle parameters, only the angle opening distance of 250 µm at the nasal quadrant was not significantly increased after laser peripheral iridotomy. The iris curvature and trabecular-iris contact length showed a significant reduction induced by the laser procedure. Even in eyes in which gonioscopy did not identify angular widening after laser peripheral iridotomy (n=7), the angle opening distance of 750 µm increased (nasal, 0.15 ± 0.10 mm to 0.27 ± 0.16 mm, p=0.01; temporal, 0.14 ± 0.11 mm to 0.25 ± 0.12 mm, p=0.001) and the iris curvature decreased (nasal, 0.25 ± 0.04 mm vs. 0.11 ± 0.07 mm, p=0.02; temporal, 0.25 ± 0.07 mm vs. 0.14 ± 0.08 mm, p=0.007). Conclusions: Anterior-chamber changes induced by laser peripheral iridotomy could be quantitatively evaluated and documented by DRI OCT Triton®

RESUMO Objetivo: Comparar os parâmetros de câmara anterior obtidos através da tomografia de coerência óptica de segmento anterior antes e após a iridectomia periférica a laser. Métodos: Quatorze pacientes com fechamento angular primário e seis com glaucoma primário de ângulo fechado foram prospectivamente avaliados neste estudo. Gonioscopia e tomografia de coerência óptica de segmento anterior com DRI OCT Triton® foram realizadas antes e após a iridectomia periférica a laser. Os seguintes parâmetros de tomografia de coerência óptica de segmento anterior, baseados na localização do esporão escleral, foram avaliados: ângulo de abertura angular a 250 µm, 500 µm e 750 µm, área do espaço entre a íris e o trabeculado a 500 µm, ângulo entre a íris e o trabeculado, extensão do contato entre a íris e o trabeculado e curvatura da íris. Resultados: A tomografia de coerência óptica de segmento anterior identificou 61% dos indivíduos com dois ou mais quadrantes fechados. A gonioscopia identificou mais quadrantes com ângulo fechado do que tomografia de coerência óptica de segmento anterior antes da iridectomia periférica a laser. Quanto aos parâmetros angulares, apenas ângulo de abertura angular a 250 µm no quadrante nasal não aumentou significativamente após a iridectomia periférica a laser. A curvatura da íris e a extensão do contato entre a íris e o trabeculado apresentaram redução significativa induzida pelo procedimento a laser. Mesmo nos olhos em que a gonioscopia não identificou aumento da amplitude angular após iridectomia periférica a laser (n=7), ângulo de abertura angular a 750 µm aumentou (nasal: 0,15 ± 0,10 mm para 0,27 ± 0,16 mm, p=0,01; temporal: 0,14 ± 0,11 mm para 0,25 ± 0,12 mm, p=0,001), e ICURVE diminuiu (nasal: 0,25 ± 0,04 mm vs. 0,11 ± 0,07 mm, p=0,02; temporal: 0,25 ± 0,07 mm vs. 0,14 ± 0,08 mm, p=0,007). Conclusões: As alterações na câmara anterior induzidas pelo iridectomia periférica a laser puderam ser avaliadas quantitativamente e documentadas pelo DRI OCT Triton®.

Intraocular pressure and central corneal thickness in full-term newborns.

OBJECTIVE: The aim of this study was to determine the central corneal thickness (CCT) and intraocular pressure (IOP) in full-term newborns and to correlate these values with the following variables: weight, sex, and post-conception age (PCA). METHODS: IOP and CCT were determined in 52 full-term newborns with a mean gestational age of 39.43 ± 1.03 weeks and a mean birth weight of 3,273 ± 558 g. The mean age of the neonates at the time of taking the measurements was 1.15 ± 1.38 days after birth. IOP was determined with a Tono-Pen, and CCT was determined using a handheld ultrasound pachymeter. RESULTS: The mean overall IOP was 14.0 ± 2.91 mmHg, and the mean IOP in male and female newborns was 13.77 ± 2.88 mmHg and 14.32 ± 3.05 mmHg, respectively. The mean overall CCT was 605.87 ± 62.98 µm, and the mean CCT in male and female newborns was 626.70 ± 67.46 µm and 577.45 ± 45.50 µm, respectively; the mean CCT was higher in male newborns than in female newborns. PCA was negatively associated with CCT, IOP, and weight; however, only the correlation with CCT was statistically significant. Comparisons between the sexes showed significant differences for two variables: weight and CCT. CONCLUSIONS: No relationship was found between CCT and IOP; however, we found a positive association between weight and CCT.

Glaucoma e óleo de silicone / Glaucoma and silicone oils

RESUMO O óleo de silicone é um importante tampão utilizado na retinopexia cirúrgica de casos graves de descolamento de retina. O aumento da pressão intraocular e o desenvolvimento de glaucoma secundário são frequentes complicações da sua utilização. A depender do período de aparecimento, diversos mecanismos justificam a ocorrência de tais complicações. Compreender os fatores de riscos e a patogênese do aumento da pressão intraocular associada a aplicação de óleo de silicone em cirurgia retiniana ajuda a orientar o tratamento adequado para cada paciente. O objetivo deste artigo é revisar a literatura sobre a patogenia, a incidência, os fatores de risco e o tratamento desta condição clínica.

ABSTRACT Silicone oil has been an important intraocular tamponade in retinopexy in cases of complicated retinal detachment surgery. The increase of intraocular pressure and development of secondary glaucoma are a known complication of its use. A variety of mechanisms have been proposed for the pathogenesis, depending on the onset. This article aims to review the literature about pathogenesis, the incidence and risk factors, as well as the treatment of this pathology.

The disc damage likelihood scale: Diagnostic accuracy and correlations with cup-to-disc ratio, structural tests and standard automated perimetry.

Our objective was to compare the diagnostic accuracies of and to determine the correlations between the disc damage likelihood scale (DDLS) and anatomical and functional tests used for glaucoma detection. A total of 54 healthy subjects (54 eyes) and 47 primary open-angle glaucoma patients (47 eyes) were included in this cross-sectional observational study. DDLS scores and cup-to-disc (C/D) ratios were evaluated. Subjects underwent standard automated perimetry (SAP), optic disc and retinal nerve fiber layer (RNFL) imaging with time and spectral-domain optical coherence tomography (TD and SD-OCT), Heidelberg Retina Tomograph (HRT II), and scanning laser polarimetry (GDx-VCC). Areas under the receiver operating characteristic curves (AROCs) for DDLS and diagnostic tests parameters were calculated. DDLS correlations (Spearman's rank) among these parameters were analyzed. Fifty-four eyes were healthy and 47 had glaucoma, including 16 preperimetric glaucoma. DDLS, vertical and horizontal C/D ratios had the largest AROCs (0.92, 0.94 and 0.91, respectively). DDLS diagnostic accuracy was better than the accuracies of HRT II parameters, TD and SD-OCT RNFL thicknesses, and SAP mean deviation (MD) index. There were no significant differences between the accuracies of the DDLS and the C/D ratios, TD-OCT vertical (0.89) and horizontal (0.86) C/D ratios, TD-OCT C/D area ratio (0.89), and GDx-VCC NFI (0.81). DDLS showed significant strong correlations with vertical (r = 0.79) and horizontal (0.74) C/D ratios, and with the parameters vertical C/D ratio and C/D area ratio from HRT II (both 0.77) and TD-OCT (0.75 and 0.72, respectively). DDLS had significant moderate correlations with most of the other structural measurements and SAP MD. The optic disc clinical evaluation with DDLS system and C/D ratio demonstrated excellent accuracy in distinguishing glaucomatous from healthy eyes. DDLS had moderate to strong correlations with most structural and functional parameters. These findings stress the importance of optic disc clinical examination to detect glaucoma in a clinical scenario.

Normal-tension glaucoma: an update.

Normal-tension glaucoma (NTG) is a progressive optic neuropathy with intraocular pressure (IOP) within the statistically normal range (≤21 mmHg). The prevalence of NTG varies widely among different population studies, being the most prevalent open-angle glaucoma subtype in some reports. The etiology of NTG possibly is multifactorial and still not well defined. Alternative treatments have been proposed based on pathogenesis details. However, in clinical practice, adequate reduction of IOP remains the keystone of managing patients with NTG. We review the pathogenesis of NTG and the available therapies for this optic neuropathy.