Retinal pigment epithelial cells reduce vascular leak and proliferation in retinal neovessels.

In multiple neurodegenerative diseases, including age-related macular degeneration, retinitis pigmentosa, and macular telangiectasia type 2 (MacTel), retinal pigment epithelial (RPE)-cells proliferate and migrate into the neuroretina, forming intraretinal pigment plaques. Though these pigmentary changes are hallmarks of disease progression, it is unknown if their presence is protective or detrimental.Here, we first evaluated the impact of pigment plaques on vascular changes and disease progression in MacTel.

Developing a 10-Layer Retinal Segmentation for MacTel Using Semi-Supervised Learning.

Purpose: Automated segmentation software in optical coherence tomography (OCT) devices is usually developed for and primarily tested on common diseases. Therefore segmentation accuracy of automated software can be limited in eyes with rare pathologies.

Methods: We sought to develop a semisupervised deep learning segmentation model that segments 10 retinal layers and four retinal features in eyes with Macular Telangiectasia Type II (MacTel) using a small labeled dataset by leveraging unlabeled images.

Relative Ellipsoid Zone Reflectivity in Macular Telangiectasia Type 2.

Purpose: The relative ellipsoid zone reflectivity (rEZR) has been proposed as an innovative biomarker for photoreceptor integrity. This study evaluates the rEZR in macular telangiectasia type 2 (MacTel) eyes of different disease stages.

Methods: The mean rEZR (ratio ellipsoid zone [EZ]/external limiting membrane [ELM] reflectivity [arbitrary units {AUs}], grey level range = 0-1) was analyzed for an entire spectral domain optical coherence tomography volume scan (global) and for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid (topographic) in patients with MacTel and controls.

iPSC-derived retinal pigmented epithelial cells from patients with macular telangiectasia show decreased mitochondrial function.

Patient-derived induced pluripotent stem cells (iPSCs) provide a powerful tool for identifying cellular and molecular mechanisms of disease. Macular telangiectasia type 2 (MacTel) is a rare, late-onset degenerative retinal disease with an extremely heterogeneous genetic architecture, lending itself to the use of iPSCs. Whole-exome sequencing screens and pedigree analyses have identified rare causative mutations that account for less than 5% of cases.

Divergent amino acid and sphingolipid metabolism in patients with inherited neuro-retinal disease.

Objectives: The non-essential amino acids serine, glycine, and alanine, as well as diverse sphingolipid species, are implicated in inherited neuro-retinal disorders and are metabolically linked by serine palmitoyltransferase (SPT), a key enzyme in membrane lipid biogenesis. To gain insight into the pathophysiological mechanisms linking these pathways to neuro-retinal diseases we compared patients diagnosed with two metabolically intertwined diseases: macular telangiectasia type II (MacTel), hereditary sensory autonomic neuropathy type 1 (HSAN1), or both.

Methods: We performed targeted metabolomic analyses of amino acids and broad sphingolipids in sera from a cohort of MacTel (205), HSAN1 (25) and Control (151) participants.

Tamoxifen Retinopathy and Macular Telangiectasia Type 2: Similarities and Differences on Multimodal Retinal Imaging.

Purpose: Tamoxifen-induced retinopathy (TR) and macular telangiectasia type 2 (MacTel) share a highly similar retinal phenotype. In this study, we aimed to evaluate differences and similarities that may point toward underlying mechanisms linking both disease entities.

Design: Retrospective, cross sectional study.

Morphological characteristics preceding exudative neovascularisation secondary to macular telangiectasia type 2.

Aims: To identify morphological characteristics preceding the development of exudative neovascularisation secondary to Macular Telangiectasia type 2 (MacTel) using multimodal retinal imaging.

Methods: In this retrospective study, eyes with a minimum observation period of 6 months prior to the de novo diagnosis of an exudative neovascularisation secondary to MacTel were analysed. Morphological changes preceding the formation of neovascularisation were evaluated using colour fundus photography, infrared imaging, fluorescein angiography, macular pigment measurement and optical coherence tomography (OCT).

Functional Relevance of Hyper-Reflectivity in Macular Telangiectasia Type 2.

Purpose: The purpose of this study was to quantify hyper-reflective lesions on en face optical coherence tomography (OCT) and study its functional relevance in macular telangiectasia type 2 (MacTel).

Design: This was a retrospective, cross-sectional cohort study.

Methods: Baseline image and functional data from participants of a phase II clinical trial (NCT01949324) that studied the effect of Ciliary Neurotrophic Factor in patients with MacTel were analyzed.

HYPERREFLECTIVITY ON OPTICAL COHERENCE TOMOGRAPHY IN MACULAR TELANGIECTASIA TYPE 2.

Purpose: To define, characterize, and classify hyperreflectivity on optical coherence tomography and report its prevalence in macular telangiectasia Type 2.

Methods: In a primary cross-sectional analysis, multimodal imaging data were retrospectively analyzed. The definition of hyperreflectivity and neovascularization on optical coherence tomography followed optical coherence tomography angiography-based criteria.

WITHDRAWN: Hyper-reflectivity on optical coherence tomography in macular telangiectasia type 2.

Ahead of Print article withdrawn by publisher.

Optical coherence tomography-angiography for monitoring neovascularisations in macular telangiectasia type 2.

Purpose: To evaluate the utility of optical coherence tomography-angiography (OCT-A) for monitoring activity, progression and response to therapy of neovascularisations (NVs) secondary to macular telangiectasia type 2 (MacTel).

Methods: In a retrospective analysis, eyes with NVs secondary to MacTel were reviewed over a period of ≥8 months. Examinations at monthly intervals included visual acuity testing, dilated funduscopy, spectral domain-OCT and OCT-A.

DARK ADAPTATION IN MACULAR TELANGIECTASIA TYPE 2.

Purpose: To evaluate dark adaptation (DA) in patients with macular telangiectasia Type 2 (MacTel).

Methods: After a local photobleach (4 × 4° size, 83% bleach), DA was measured using a test stimulus (2° diameter) projected at 5° eccentricity horizontal from the foveal center within the temporal parafovea. Cone plateau, rod intercept time, and rod recovery rate (S2) were calculated from the resulting DA curves.

Binocular Inhibition of Reading in Macular Telangiectasia Type 2.

Purpose: To assess the presence of binocular gain in macular telangiectasia type 2 (MacTel) and its correlation to paracentral scotomas.

Methods: Sixty-eight patients with MacTel were consecutively recruited for a cross-sectional analysis. Best-corrected visual acuity (BCVA), reading acuity, and reading speed were tested monocularly and binocularly.

Quantification of Retinal and Choriocapillaris Perfusion in Different Stages of Macular Telangiectasia Type 2.

Purpose: To quantify the retinal and choriocapillaris perfusion in different disease stages of macular telangiectasia type 2 (MacTel) using optical coherence tomography-angiography (OCT-A).

Methods: We examined 76 eyes of 76 patients and 24 eyes of 24 age-related controls. Participants underwent multimodal imaging, including OCT and OCT-A.

Dark-Adapted Two-Color Fundus-Controlled Perimetry in Macular Telangiectasia Type 2.

Purpose: Macular telangiectasia type 2 (MacTel) is a bilateral neurodegenerative disorder of the central macula. Previous findings indicated more functional impairment in low light conditions. We sought to further characterize retinal dysfunction using dark-adapted two-color fundus-controlled perimetry ("scotopic microperimetry").

Right-angled vessels in macular telangiectasia type 2.

Purpose: To evaluate the role of right-angled vessels (RAVs) during disease progression in macular telangiectasia type 2 (MacTel).

Methods: In this study, 100 eyes of 52 patients and 52 eyes of 26 age-related controls were examined using fundus photography, spectral-domain optical coherence tomography (SD-OCT), OCT angiography (OCT-A) and fundus fluorescein angiography (FFA). Two masked readers graded fundus photographs of patients' eyes into five disease stages according to Gass and Blodi, and evaluated all eyes for the presence of RAVs.

Estimating Retinal Sensitivity Using Optical Coherence Tomography With Deep-Learning Algorithms in Macular Telangiectasia Type 2.

Importance: As currently used, microperimetry is a burdensome clinical testing modality for testing retinal sensitivity requiring long testing times and trained technicians.

Objective: To create a deep-learning network that could directly estimate function from structure de novo to provide an en face high-resolution map of estimated retinal sensitivity.

Design, Setting, And Participants: A cross-sectional imaging study using data collected between January 1, 2016, and November 30, 2017, from the Natural History Observation and Registry of macular telangiectasia type 2 (MacTel) evaluated 38 participants with confirmed MacTel from 2 centers.