Relationship of macular ganglion cell complex thickness to choroidal microvasculature drop-out in primary open-angle glaucoma

Background/aimsTo investigate the rate of ganglion cell complex (GCC) thinning in primary open-angle glaucoma (POAG) patients with and without deep-layer microvasculature drop-out (MvD).MethodsPOAG patients who had at least 1.5 years of follow-up and a minimum of three visits were included from the Diagnostic Innovations in Glaucoma Study. MvD was detected at baseline by optical coherence tomography angiography (OCT-A). Area and angular circumference of MvD were evaluated on en face choroidal vessel density images and horizontal B-scans. Rates of global and hemisphere GCC thinning were compared in MvD and non-MvD eyes using linear mixed-effects models.ResultsThirty-six eyes with MvD and 37 eyes without MvD of 63 patients were followed for a mean of 3.3 years. In 30 out of 36 eyes, MvD was localised in the inferotemporal region. While mean baseline visual field mean deviation was similar between the two groups (p=0.128), global GCC thinning was significantly faster in eyes with MvD than in those without MvD (mean differences: −0.50 (95% CI −0.83 to –0.17) µm/year; p=0.003)). Presence of MvD, area and angular circumference of MvD were independently associated with a faster rate of thinning (p=0.002, p=0.031 and p=0.013, respectively).ConclusionIn POAG eyes, GCC thinning is faster in eyes with MvD. Detection of MvD in OCT-A images can assist clinicians to identify patients who are at higher risk for central macula thinning and glaucomatous progression and may require more intensive management.

Strong Euler well-composedness

In this paper, we define a new flavour of well-composedness, called strong Euler well-composedness. In the general setting of regular cell complexes, a regular cell complex of dimension n is strongly Euler well-composed if the Euler characteristic of the link of each boundary cell is 1, which is the Euler characteristic of an $$(n-1)$$ ( n - 1 ) -dimensional ball. Working in the particular setting of cubical complexes canonically associated with $$n$$ n D pictures, we formally prove in this paper that strong Euler well-composedness implies digital well-composedness in any dimension $$n\ge 2$$ n ≥ 2 and that the converse is not true when $$n\ge 4$$ n ≥ 4 .

Changes in retinal structures as markers of multiple sclerosis progression

The involvement of the visual pathway in multiple sclerosis (MS) pathology determines the importance of studying the structures of the retina for earlier diagnosis and monitoring the severity of the neurodegeneration. The introduction of the reference method of optical coherence tomography (OCT) allows high resolution in vivo visualization of the retinal structures.Objective: to identify changes in various retinal structures in remitting (RMS) and secondary-progressive (SPMS) MS phenotypes.Patients and methods. The study included 80 patients with RMS (n=48) and SPMS (n=32); the control group included 20 age- and sex-adjusted healthy individuals. Clinical assessment was carried out using the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS). All patients were examined by an ophthalmologist. To assess changes in the retina, OCT was performed using the RTVue XR Avanti apparatus (Optovue, USA).Results and discussion. We found a significant (p<0.001) decrease in the thickness of the retina of the foveal and parafoveal regions, the thickness of the ganglionic cell complex when comparing the parameters of the retina of the control group and patients with RMS. There was also a significant (p<0.01) decrease in the retinal thickness in the perifoveal region, the thickness of the layer of retinal nerve fibers, the magnitude of focal and global losses. During comparation of the retinal OCT data between patients with RMS and SPMS, we revealed significant differences (p<0.001) in the thickness of the retinal nerve fiber layer, the retinal thickness in the parafoveal and foveal regions, and a significant (p<0.01) decrease in the thickness of the peripheral region, the thickness of the ganglionic cell complex, the volume of focal and global losses. Assessment of the correlations of OCT parameters with the EDSS and MSSS scales in both phenotypes showed a single significant (p<0.05) strong negative correlation (r=-0.70) of the EDSS score and retinal thickness in the foveal region in patients with SPMS.Conclusion. As a domain of criteria for the MS course without signs of disease activity (No Evidence of Disease Activity, NEDA), it is advisable to use retinal OCT with analysis of the retinal thickness in the foveal region, the thickness of the retinal nerve fiber layer, the ganglion cell complex for dynamic monitoring of the inflammatory process activity in patients with RMS and assessment of its progression in patients with SPMS.

Retinal nerve fiber layer and ganglion cell complex thickness as a diagnostic tool in early stage dysthyroid optic neuropathy

Purpose To compare the diagnostic accuracy of peripapillary retinal nerve fiber layer with macular ganglion cell complex thickness as an auxiliary tool for the early diagnosis of dysthyroid optic neuropathy and help assess the effectiveness of the treatment. Methods In this retrospective case–control study, a total of 58 thyroid-associated opthalmopathy patients and 58 healthy participants were enrolled in the study. Thyroid-associated opthalmopathy patients were divided according to the European Group Graves’ Orbitopathy severity classification. The thicknesses of peripapillary nerve fiber layer and macular ganglion cell complex were measured using optical coherence tomography and their correlation with the severity of the disease as well as the effect of the treatment was investigated. Results No statistically significant differences were found between the mild thyroid-associated opthalmopathy group and the control group in both peripapillary nerve fiber layer and macular ganglion cell complex thickness. In the moderate-to-severe thyroid-associated opthalmopathy group, however, Temporal and Nasal peripapillary nerve fiber layer thicknesses were lower compared to the control group ( p = 0.041, p = 0.012), whereas in the sight-threatening thyroid-associated opthalmopathy group Temporal Inferior, Nasal Superior, and mean (G) peripapillary nerve fiber layer thicknesses were larger ( p = 0.000, p = 0.004, p = 0.000). No significant differences were observed in the macular ganglion cell complex thickness among the different severity groups and the control groups ( p > 0.05). After treatment, the mean peripapillary nerve fiber layer thickness decreased whereas mean macular ganglion cell complex thickness showed no significant change in the sight-threatening group. A correlation was established between exophthalmos, best corrected visual acuity, clinical activity score, disease course, and the mean peripapillary nerve fiber layer thickness. The area under curve analysis indicated that mean peripapillary nerve fiber layer thickness can be used as a powerful diagnostic tool in early stage dysthyroid optic neuropathy in thyroid-associated opthalmopathy patients. Conclusion Our study indicates that peripapillary nerve fiber layer act as an auxiliary tool for the early diagnosis of dysthyroid optic neuropathy and helps assess the effectiveness of the treatment.