Ganglion cell complex analysis in glaucoma patients: what can it tell us?

Glaucoma is a group of optic neuropathies characterized by a progressive degeneration of retina ganglion cells (RGCs) and their axons that precedes functional changes detected on the visual field. The macular ganglion cell complex (GCC), available in commercial Fourier-domain optical coherence tomography, allows the quantification of the innermost retinal layers that are potentially involved in the glaucomatous damage, including the retinal nerve fiber (RNFL), ganglion cell and inner plexiform layers. The average GCC thickness and its related parameters represent a reliable biomarker in detecting preperimetric glaucomatous damage. The most accurate GCC parameters are represented by average and inferior GCC thicknesses, and they can be associated with progressive visual field loss. Although the diagnostic accuracy increases with more severe glaucomatous damage and higher signal strength values, it is not affected by increasing axial length, resulting in a more accurate discrimination of glaucomatous damage in myopic eyes with respect to the traditional RNFL thickness. The analysis of the structure-function relationship revealed a good agreement between the loss in retinal sensitivity and GCC thickness. The use of a 10-2° visual field grid, adjusted for the anatomical RGCs displacement, describes more accurately the relationship between RGCs thickness and visual field sensitivity loss

Near-infrared reflectance imaging in retinal diseases affecting young patients

Near-infrared reflectance (NIR) is a noninvasive, contactless, and rapid in vivo imaging technique for visualizing subretinal alterations in the photoreceptor layer, retinal pigment epithelium, and choroid. The present report describes the application of this imaging method in retinal and choroidal pathologies affecting young patients where scarce cooperation, poor fixation, and intense glare sensation can result in a challenging clinical examination. A literature search of the MEDLINE database was performed using the terms "near-infrared reflectance"and "spectral-domain optical coherence tomography."Articles were selected if they described the diagnostic use of NIR in children or young adults. Of 700 publications, 42 manuscripts published between 2005 and 2020 were inherent to children or young adults and were considered in this narrative literature review. The first disease category is the phakomatoses where NIR is essential in visualizing choroidal alterations recognized as cardinal biomarkers in neurofibromatosis type 1, microvascular retinal alterations, and retinal astrocytic hamartomas. Another diagnostic application is the accurate visualization of crystals of various nature, including the glistening crystals that characterize Bietti crystalline dystrophy. Acute macular neuropathy and paracentral acute middle maculopathy represent a further disease category with young adulthood onset where NIR is not only diagnostic but also essential to monitor disease progression. A further interesting clinical application is to facilitate the detection of laser-induced maculopathy where funduscopic examination can be normal or subnormal. In conclusion, NIR imaging has a noninterchangeable role in diagnosing certain retinal diseases, especially in children and young adults where there is scarce collaboration and a lack of evident clinical findings. Moreover, this technique can reveal unique retinal and choroidal biomarkers highly specific to rare conditions

Clinical manifestations of cuticular drusen. Current perspectives

Cuticular drusen are part of the spectrum of age-related macular degeneration (AMD) with particular clinical and multimodal imaging characteristics. This drusen sub-population shares several high-risk single nucleotide polymorphisms with AMD. Despite this feature, they can manifest at a relatively young age, presenting with a female preponderance. Multimodal imaging is essential for characterizing such lesions, using a combination of color fundus photographs, optical coherence tomography (OCT), fluorescein angiography (FA), and fundus autofluorescence (FAF). The classic starry-sky pattern visible on FA and the typical central hypoautofluorescent lesion with hyperautofluorescent rim on FAF is consid-ered the result of a central retinal pigment epithelium (RPE) erosion from these triangular elevations of the RPE-basal lamina. This finding may also be responsible for the typical choroidal hypertransmission appreciated through OCT. The clinical course of cuticular drusen may be relatively benign at early stages, with small drusen presenting at a young age. However, the presence of clinical phenotypes characterized by diffuse involvement and/ or accompanying large drusen in patients older than 60 years may confer a significant risk for either macular neovascularization or geographic atrophy

Diagnostic and Therapeutic Challenges

No abstract availabl

Current concepts on ocular vascular abnormalities in the phakomatoses

Background: Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors. Purpose: Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses. Conclusion: Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area

Choroidal vascularity index in adult-onset foveomacular vitelliform dystrophy: a pilot study

This pilot study aims to investigate choroidal vascular status in eyes with adult-onset foveomacular vitelliform dystrophy (AOFVD), early age-related macular degeneration (AMD), and age-matched controls. In this retrospective study, choroidal thickness (CT) was measured manually using spectral domain optical coherence tomography images of the fovea, and 500 and 1500 µm from the nasal and temporal regions in the fovea. The horizontal B-scan was imported into Fiji software. Choroidal vascularity index (CVI) and luminal and stromal areas were calculated. A total of 36 eyes from 36 patients, including 18 eyes with AOFVD and 18 eyes with CD, and 16 eyes of healthy subjects were included. CVI was significantly different among subgroups (ANOVA, p = 0.004). Eyes with AOFVD presented a higher CVI (+0.03 ± 0.01, p = 0.001) than eyes with CD and controls (p = 0.03). No differences in CVI were detected between controls and eyes with CD (p = 0.25). AOFVD eyes accounted for the greatest luminal area, particularly significant in comparison with healthy controls (+0.27 ± 0.11, p = 0.02). AOFVD eyes present a greater CVI than eyes with CD and controls. The major choroidal involvement is on the luminal component, further corroborating a possible role of the choroidal vasculature in the pathological manifestations of AOFVD disease

Nab-Paclitaxel related cystoid macular edema

Nab-paclitaxel is a chemotherapeutic drug used to treat various solid malignant tumors. It was conceived with a solvent free formulation to overcome toxicity events and hypersensitivity reactions associated with paclitaxel. However, it still carries ocular adverse effects. The present review examines nab-paclitaxel related cystoid macular edema (CME) and the available therapeutic options

Volume rendering of angiographic optical coherence tomography angiography in fovea plana and normal foveal pit

This paper aims to study adaptative vascular arrangements in idiopathic fovea plana with volume-rendered optical coherence tomography angiography (OCTA). A retrospective review of two cases of idiopathic fovea plana (mean age: 26.5 years) and two age-matched controls imaged with OCTA was conducted using spectral-domain OCTA (RTVue XR Avanti, Optovue, Inc., Fremont, CA) equipped with the AngioVue software. Both en face OCTA slabs and OCTA b scans were processed through Fiji software (http://fiji.sc; software version 2.0.0-rc-68/1.52e), and then extracted as image sequences for volume rendering reconstructions using the ImageVis3D volume rendering system (3.1.0 release). Eyes with idiopathic fovea plana demonstrated a regular superficial vascular plexus connecting to a single vascular monolayer representing the deeper vascular plexuses. At this location, several vertical short path connections were demonstrated, in contraposition with normal eyes where short path connections were infrequently observed. Advances in three-dimensional OCTA reconstruction increase the understanding of vascular connections and arrangement in retinal plexuses and possible anatomical variations that cannot be detected with conventional two-dimensional b scans

Postural changes revealing orbital venous malformation using ultrasound in blue rubber bleb nevus syndrome

A 62-year-old white woman presented with a diagnosis of blue rubber bleb nevus syndrome (BRBNS). The right eye appeared enophthalmic, yet the patient complained of episodes of right proptosis on bending forward. The remainder of the examination was unremarkable. Orbital ultrasound (US) in an upright posture revealed a single low reflectivity cavity (4.27 mm x 2.82 mm) of uncertain interpretation. In a forward-leaning posture the lesion increased in size (maximum thickness of 13.72 mm), demonstrating multiple low reflectivity spaces with highly reflective septae. This case first reports the use of US with postural changes to assess the presence of orbital venous malformation in BRBNS. The expansile nature upon postural changes supports the venous origin of the orbital lesion

Significance of hyperreflective foci as an optical coherence tomography biomarker in retinal diseases: characterization and clinical implications

Hyperreflective foci (HRF) is a term coined to depict hyperreflective dots or roundish lesions within retinal layers visualized through optical coherence tomography (OCT). Histopathological correlates of HRF are not univocal, spacing from migrating retinal pigment epithelium cells, lipid-laden macrophages, microglial cells, and extravasated proteinaceous or lipid material. Despite this, HRF can be considered OCT biomarkers for disease progression, treatment response, and prognosis in several retinal diseases, including diabetic macular edema, age-related macular degeneration (AMD), retinal vascular occlusions, and inherited retinal dystrophies. The structural features and topographic location of HRF guide the interpretation of their significance in different pathological conditions. The presence of HRF less than 30 μm with reflectivity comparable to the retinal nerve fiber layer in the absence of posterior shadowing in diabetic macular edema indicates an inflammatory phenotype with a better response to steroidal treatment. In AMD, HRF overlying drusen are associated with the development of macular neovascularization, while parafoveal drusen and HRF predispose to macular atrophy. Thus, HRF can be considered a key biomarker in several common retinal diseases. Their recognition and critical interpretation via multimodal imaging are vital to support clinical strategies and management