Association of progressive optic disc tilt with development of retinal nerve fibre layer defect in children with large cup-to-disc ratio

Background/aimsWhereas myopic optic disc deformation has been posited as a risk factor for glaucomatous damage, longitudinal studies evaluating their association have been sparse. We investigated whether the optic nerve head (ONH)’s morphological alteration during myopia progression play any role in development of retinal nerve fibre layer defect (RNFLD) in children with a large vertical cup-to-disc ratio (vCDR).MethodsSixty-five normotensive eyes of 65 children aged under 8 years with (1) vCDR ≥0.5 but no additional signs of glaucoma and (2) who could be tracked at young adulthood (18–28 years) were included. Children’s spherical equivalent (SE), intraocular pressure, vCDR and optic disc tilt ratio were recorded. Rare events logistic regression analysis was employed to identify factors associated with RNFLD-development risk.ResultsThe study group’s mean age was 5.4±1.3 years, its average vCDR was 0.62±0.07, and the average SE was −0.3±1.4 dioptres ((D), range −3.15 to 2.75D) at the baseline. After an average follow-up of 16.1±3.0 years, the mean vCDR was 0.64±0.09, and the mean SE, −3.2±2.2D (range −7.25 to 0.00 D). Among the 65 eyes, 12 (18.5%) developed RNFLD. A greater SE change (OR=1.737, p=0.016) and a greater increase in tilt ratio (OR=2.364, p=0.002) were both significantly associated with higher RNFLD-development risk.ConclusionIn this cohort of Korean children with large vCDR, progressive optic disc tilt in the course of myopia progression was associated with higher RNFLD-development risk. This finding suggests that morphological alterations in the ONH during axial elongation might represent an underlying susceptibility to glaucomatous damage in large-vCDR children.

Combined wide-field optical coherence tomography angiography density map for high myopic glaucoma detection

The present study aimed to evaluate the diagnostic ability of wide-field optical coherence tomography angiography (OCTA) density map for detection of glaucomatous damage in high myopic (HM) eyes and to further compare the diagnostic ability of OCTA with that of conventional imaging approaches including red-free photography and swept-source OCT (SS-OCT) wide-field maps. A total of 77 healthy HM eyes and 72 HM eyes with open angle glaucoma (OAG) participated in this retrospective observational study. Patients underwent a comprehensive ocular examination, including wide-field SS-OCT scan and peripapillary area and macular OCTA scans. An integrated OCTA density map thereafter was merged by vascular landmark-guided superimposition of peripapillary and macular superficial vascular density maps onto the red-free photography (resulting in the OCTA-PanoMap). Glaucoma specialists then determined the presence of glaucomatous damage in HM eyes by reading the OCTA-PanoMap and compared its sensitivity and specificity with those of conventional images. Sensitivity and specificity of OCTA-PanoMap for HM-OAG diagnosis was 94.4% and 96.1%, respectively. Compared with other imaging methods, the sensitivity of OCTA-PanoMap was significantly higher than that of red-free photography (P = 0.022) and comparable to that of wide-field SS-OCT maps. Specificity of OCTA-PanoMap was significantly higher than those of other conventional imaging methods (except for wide-field thickness map). The OCTA-PanoMap showed good diagnostic ability for discrimination of HM-OAG eyes from healthy HM eyes. As a complementary method of an alternative imaging modality, OCTA-PanoMap can be a useful tool for detection of HM-OAG.

An Overview of Glaucoma: Bidirectional Translation between Humans and Pre-Clinical Animal Models

Glaucoma is a multifactorial, polygenetic disease with a shared outcome of loss of retinal ganglion cells and their axons, which ultimately results in blindness. The most common risk factor of this disease is elevated intraocular pressure (IOP), although many glaucoma patients have IOPs within the normal physiological range. Throughout disease progression, glial cells in the optic nerve head respond to glaucomatous changes, resulting in glial scar formation as a reaction to injury. This chapter overviews glaucoma as it affects humans and the quest to generate animal models of glaucoma so that we can better understand the pathophysiology of this disease and develop targeted therapies to slow or reverse glaucomatous damage. This chapter then reviews treatment modalities of glaucoma. Revealed herein is the lack of non-IOP-related modalities in the treatment of glaucoma. This finding supports the use of animal models in understanding the development of glaucoma pathophysiology and treatments.

On the protective role of the blood vessels in glaucomatous damage: a transversal study.

Purpose: To corroborate whether vessels on the surface of the optic nerve head can provide protection against the loss of underlying axons in subjects with manifest glaucoma. Methods: In this pilot study, thirty-six glaucomatous eyes with a perimetric defect in the Bjerrum area were included. The retinal nerve fiber layer (RNFL) thickness was measured in each of the sectors of the clock-hour map obtained by Cirrus HD-OCT considering the presence or absence of blood vessels. These sectors were related with their corresponding areas of the retina examined in the visual field using a mathematical model of the retina introduced by Jansonius, in order to determine the values of threshold sensitivity in those areas in the presence or absence of vessels. Results: We corroborated the protective role of the blood vessel for peripapillary RNFL thickness of clock-hour 12 despite obtaining a p-value (p = 0.023; w = 228.5) close to the acceptance zone (p ≥ 0.05). The mean plus-or-minus sign standard deviation with vessel and without vessel were 70.95 plus-or-minus sign 24.35 and 88.46 plus-or-minus sign 23.96, respectively. No differences were found between the mean values of threshold sensitivity to the presence or absence of blood vessels in each of the sectors considered. Conclusions: Our findings do not allow us to affirm that there is an association between the presence of a vessel and protection against glaucomatous damage in subjects with an advanced manifestation of the disease. In the future, more extensive studies are needed to study this relationship in subjects with early glaucoma. Key words: astrocytes, visual field, primary open-angle glaucoma, aqueous humor, blood vessel.

A simplified combined index of structure and function for detecting and staging glaucomatous damage

Glaucomatous damage results in characteristics structural and functional changes on optical coherence tomography (OCT) imaging and standard automated perimetry (SAP) testing. The clinical utility of these measures differs based on disease severity, as they are evaluated along different measurement scales. This study therefore sought to examine if a simplified combined structure–function index (sCSFI) could improve the detection and staging of glaucomatous damage, compared to the use of average retinal nerve fiber layer thickness (RNFL) measurements from OCT and mean deviation (MD) values from SAP alone, and also an estimated retinal ganglion cell counts (eRGC) measure derived using empirical formulas described previously. Examining 577 eyes from 354 participants with perimetric glaucoma and 241 normal eyes from 138 healthy participants, we found that the sCSFI performed significantly better than average RNFL, MD and eRGC count for discriminating between glaucoma and healthy eyes (P ≤ 0.008 for all). The sCSFI also performed significantly better than RNFL and eRGC count at discriminating between different levels of visual field damage in glaucoma eyes (P < 0.001 for both). These findings highlight the clinical utility of combining structural and functional information for detecting and staging glaucomatous damage using the simplified index developed in this study.