Postretinal Detachment Retinal Displacement: How Best to Detect It?

PURPOSE: The reported incidence of postretinal detachment (RD) macular displacement varies markedly (14-72%). This may in part be due to the imaging modalities used. We compared the ability of 2 types of fundus autofluorescence (FAF) imaging modalities to detect this phenomenon. METHODS: Prospective study of 70 eyes with macula-involving RDs. 8 weeks postoperatively, patients underwent FAF imaging with 2 machines: a confocal scanning laser ophthalmoscope (cSLO) and a digital fundus camera (FC). Images were graded for the presence of hyperautofluorescent RPE (retinal pigment epithelium) ghost vessels, indicative of retinal displacement, by 2 masked, independent graders. RESULTS: In total, 87.1% of FC images were gradable versus 88.6% of cSLO images. Retinal displacement was detectable in 61.4% of FC images versus 52.8% of cSLO images. Vessel shift often appeared more autofluorescent on FC imaging, but choroidal vessels were more visible. Cohen's agreement between the imaging modalities was 0.50, rated as moderate agreement. For both imaging modalities, the inter- and intragrader agreement was substantial, representing good test-retest reliability. CONCLUSIONS: Detection of post-RD retinal displacement was similar between FC and cSLO FAF imaging, with only moderate agreement between both modalities

Macular Pigment Distribution as Prognostic Marker for Disease Progression in Macular Telangiectasia Type 2

PURPOSE To evaluate macular pigment distribution pattern as a prognostic marker for disease progression in patients with macular telangiectasia type 2 (MacTel). DESIGN Retrospective cohort study. METHODS In this single-center study, 90 eyes of 47 patients were analyzed. Macular pigment optical density (MPOD) was measured with dual-wavelength fundus autofluorescence. Eyes were graded into MPOD distribution classes 1 to 3 with increasing loss of macular pigment and grading was performed masked by 2 independent graders. Best-corrected visual acuity, reading acuity, total scotoma size in fundus-controlled perimetry (microperimetry), and break of the ellipsoid zone (EZ) in optical coherence tomography (en face measurement) were defined as functional and morphologic outcome parameters and evaluated at baseline and after 60 months. RESULTS After a mean review period of 59.6 months (±standard deviation 5.2 months), no change between MPOD classes was observed compared to baseline. Morphologic and functional deficits were limited to the area of MPOD loss. At last follow-up, a significant mean decrease of visual acuity and reading acuity as well as a significant mean increase of scotoma size and EZ break were observed in eyes assigned to MPOD classes 2 and 3, while outcome parameters remained stable in eyes of class 1. CONCLUSIONS The results indicate that MPOD and its distribution may serve as a prognostic marker for disease progression and functional impairment in patients with MacTel

Stereoscopic Vision in Macular Telangiectasia Type 2

PURPOSE: To investigate stereoscopic vision in patients with macular telangiectasia type 2 and correlate a paracentral sensitivity loss to reduced stereoscopic function. METHODS: In a prospective single-center study, 50 patients with macular telangiectasia type 2 and 25 age-matched controls were investigated. Stereoscopic function was evaluated with Lang I, Titmus and TNO-test. Sensitivity of the central 16° was tested using fundus-controlled perimetry (microperimetry). Functional loss was quantified as depth, size and localization of scotomata. RESULTS: Both Titmus and TNO-test revealed significantly reduced stereoscopic vision in patients compared to controls (both, p<0.0001). This applied even to patients with only relative or monocular paracentral scotomata. A strong correlation was observed for reduced stereoscopic vision with horizontal scotoma size and with the distance of scotomata from the foveal center. CONCLUSIONS: The results indicate that stereoscopic vision is impaired early in patients with MacTel type 2. A paracentral sensitivity loss, even if mild and limited to one eye, may considerably interfere with stereoscopic function despite normal visual acuity. Projection of paracentral scotomata within the patient`s central visual field plays an important role in stereoscopic vision and should be considered when interpreting stereoscopic test results

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. Patients' eyes were divided into three groups considering predefined criteria from funduscopy, OCT, and fluorescein angiography, thus reflecting the disease severity (“early,” “advanced,” and “neovascular”). Quantitative analyses of vessel density (VD), skeleton density (SD), and fractal dimension (FD) were conducted in the superficial and deep retinal plexus and in the avascular layer. The choriocapillaris was analyzed for mean signal intensity and percentage of nondetectable perfused choriocapillaris-area (PNPA). / Results: The deep retinal plexus showed a progressive decrease of mean VD, SD, and FD in the temporal parafovea in all disease stages. In the superficial layer, VD, SD, and FD were significantly decreased in the temporal parafovea of advanced and neovascular stages, while these parameters did not differ from controls in early stages. In MacTel, signals of blood flow were also detectable at the level of the avascular layer and showed a significant increase with disease progression. The choriocapillaris in MacTel showed a significant increase of mean PNPA and a decrease of mean signal intensity in comparison to controls. These findings were consistent in all disease stages. / Conclusions: Quantitative OCT-A data show a progressive rarefication of the retinal microvasculature in MacTel. We propose an altered choriocapillaris perfusion as a possibly early alteration of the disease

Macular telangiectasia type 2 - Visual acuity, disease endstage and the MacTel Area. MacTel Project Report No. 8

Purpose: To report the visual acuity measures from the MacTel registry study and to investigate and describe phenotypic findings in eyes with substantial vision loss due to MacTel type 2 Design: Cross-sectional multi-center study. Subjects: Participants of the Natural History Observation (and Registry) of MacTel Study. Methods: Best–corrected visual acuity (BCVA) data, retinal imaging data and clinical data were accessed from the MacTel study databases in May 2019. Main Outcome Measures: Frequency distribution of BCVA and its relation to age. Morphological changes in eyes with very late disease stages, defined by a BCVA ≤ 20/200. Average retinal thickness of ETDRS fields on OCT. Dimensions of the area affected by MacTel (MacTel area). Results: BCVA was ≤20/50 in 37.3% and ≤20/200 in 3.8% of 4449 eyes of 2248 patients. 18.4% and 0.7% of all patients had bilateral BCVA ≤20/50 and ≤20/200, respectively. There was an asymmetry between right and left eyes (median BCVA 71 versus 74 letters), a finding supported by more advanced morphological changes in right eyes. BCVA correlated with participant’s age, but the effect size was small. If a neovascularization or macular hole was present, bilateral occurrence was frequent (33% or 17%, respectively), and BCVA was >20/200 (79% or 78% respectively) or ≥20/50 (26% or 13%, respectively). Eyes with advanced disease (BCVA ≤20/200) showed the following characteristics: 1) Atrophy of the foveal photoreceptor layer with or without associated subretinal fibrosis; 2) an affected area, termed here the “MacTel area”, limited to a horizontal diameter not exceeding the distance between the temporal optic disc margin and foveal center, and the vertical diameter not exceeding approximately 0.85 times this distance. Exceptions were eyes with large active or inactive neovascular membranes; 3) reduced retinal thickness measures within the MacTel area; and 4) less frequent retinal greying and more frequent hyperpigmentations compared to eyes with better BCVA. Conclusions: Severe vision loss is rare in MacTel and is related to photoreceptor atrophy in most people. Results indicate disease asymmetry with slightly worse vision and more advanced disease manifestation in right eyes. MacTel-related neurodegeneration does not spread beyond the limits of the “MacTel area”

Effect of Dark Adaptation and Bleaching on Blue Light Reflectance Imaging in Macular Telangiectasia Type 2

PURPOSE: In patients with macular telangiectasia Type 2, blue light reflectance imaging reveals an oval, parafoveal area in the macula that has increased reflectance compared with its surrounding. Here, we examine how dark adaptation and photobleaching can affect the blue light reflectance imaging pattern. METHODS: Prospective study of patients with macular telangiectasia enrolled in the MacTel Natural History Observation Study. After dark adaptation, a sequence of images was obtained with a confocal scanning laser ophthalmoscope at 488 nm. Change of reflectance patterns was analyzed over time. RESULTS: Eighteen eyes from 16 patients were analyzed. Initially, increased reflectivity in the parafoveal area resulted in higher gray values compared with the paramacular surrounding on blue light reflectance imaging. The difference between parafoveal and paramacular reflectance intensity decreased steadily during imaging, from 17.7 gray-value units (95% confidence interval: 12.1-23.2) down to 2.8 (95% confidence interval: -0.8 to 6.5) after around 30 seconds, and recovered after 5 minutes of dark adaptation. CONCLUSION: A bleaching effect was evident in our study. Understanding these changes is important for both diagnosis and assessment of blue light reflectance phenotype in patients with macular telangiectasia and could also provide further insights into the pathophysiology of this disease

MACULAR TELANGIECTASIA TYPE 2: Quantitative Analysis of a Novel Phenotype and Implications for the Pathobiology of the Disease

PURPOSE: To investigate retinal microcystoid spaces in macular telangiectasia type 2 with spectral domain optical coherence tomography. METHODS: Retrospective review of 135 patients enrolled in the MacTel Natural History Observation and Registry Study at Moorfields Eye Hospital, United Kingdom. One hundred seventy-two eyes from 86 patients who had a comparable scan protocol of at least 30 μm interval were included for analysis. Retinal microcystoid spaces were identified and segmented and metrics analyzed. RESULTS: From 172 eyes of 86 patients, microcystoid spaces were found in 11 eyes (6.4%) from 8 patients (9.3%). The mean number of microcystoid spaces per eye was 12.9 ± 18.2. Most were located in the inner nuclear layer. The inferonasal quadrant of the macula was the least commonly affected region. Microcystoid spaces were distributed entirely within the assumed macular telangiectasia area on blue light reflectance in all but 2 eyes (4 of 142 microcysts). The median diameter of the microcystoid spaces was 31 μm (range 15 μm-80 μm). CONCLUSION: Microcystoid spaces as a phenotype of macular telangiectasia should be considered in the differentials for microcystic edema. Understanding the pathogenesis of these lesions may provide further insight into the role of Müller cell dysfunction in this disorder

Contrast sensitivity and visual acuity under low light conditions in macular telangiectasia type 2

BACKGROUND/AIM: Macular pigment optical density (MPOD) is centrally depleted early on in macular telangiectasia type 2 (MacTel). Contrast sensitivity (CS) might be related to MPOD, and thus impaired in early MacTel. The effect of low luminance was assessed on both CS and best corrected visual acuity (BCVA). METHODS: This is a cross-sectional study. Pelli-Robson charts were used for CS testing at 1 m in photopic (110 lux) and mesopic (1 lux) conditions. BCVA was tested with ETDRS charts and low luminance visual acuity (LLVA) with a 2.0 log unit neutral density filter. MPOD was obtained with dual-wavelength autofluorescence. RESULTS: One hundred and three eyes of 52 patients with MacTel (mean±SD age 62.9±10.2, range 35-77) were compared with 34 healthy eyes of 17 controls (mean±SD age 65.2±7.4, range 53-78). CS was significantly lower in the eyes with MacTel. This impairment was higher in low light conditions (low light contrast sensitivity (LL-CS)). Eyes at the early stages of MacTel had significantly lower LL-CS than controls, but normal (photopic) CS. The results were similar but less pronounced for BCVA/LLVA. Decrease in CS was correlated with loss of MPOD. CONCLUSIONS: Low light conditions have a detrimental effect on visual performance in MacTel. Impaired CS might correlate with MPOD depletion as a pathognomonic finding in MacTel. Functional impairment might precede structural disintegration, indicating dysfunction at the cellular level. The applied tests might be useful as additional functional assessments in clinical routine and as outcome measures in future interventional clinical trials

Electrophysiological Characterization of Macular Telangiectasia Type 2 and Structure-Function Correlation

PURPOSE: To investigate the electrophysiological features of macular telangiectasia Type 2 and their relationship to structure as determined by optical coherence tomography imaging. METHODS: Forty-two eyes from 21 patients enrolled in the Macular Telangiectasia Natural History Observation Study were reviewed. All patients had full-field and pattern electroretinography (ERG; PERG) with some patients additionally having multifocal electroretinography (mfERG; N = 15) or electrooculography (N = 12). Multiple linear regression modeling assessed the relationship between the ellipsoid zone break size on optical coherence tomography and the central mfERG response. RESULTS: Full-field ERG and electrooculography were normal in all eyes. Six eyes (14%) from five patients had subnormal PERG P50 amplitudes. Twenty-two of 30 eyes (73%) had reduced central or paracentral stimulus on mfERG. There was a significant correlation between ellipsoid zone break size and both the P1 amplitude (R = 0.37, P = 0.002) and P1:N1 ratio (R = 0.32, P = 0.002) of the central response on mfERG. CONCLUSION: The electrophysiological findings in macular telangiectasia Type 2 are those of localized central dysfunction and are consistent with the structural data available from imaging and histologic studies. The ellipsoid zone break size correlates with mfERG reduction. The reduced mfERG P1:N1 ratio is consistent with inner retinal dysfunction

Longitudinal Assessment of Remnant Foveal Cone Structure in a Case Series of Early Macular Telangiectasia Type 2

PURPOSE: To determine the extent of remnant cone structure within early foveal ellipsoid zone (EZ) lesions in macular telangiectasia type 2 longitudinally using both confocal and split detector adaptive optics scanning light ophthalmoscopy (AOSLO). METHODS: Spectral domain optical coherence tomography (SDOCT), confocal and split detector AOSLO were acquired from seven patients (10 eyes) with small (early) EZ lesions on SDOCT secondary to macular telangiectasia type 2 at baseline, 6 months, and 12 months. The presence of cone structure on AOSLO in areas of EZ loss as well as cones at 1° eccentricity, and their change over time were quantified. RESULTS: By split detector AOSLO, remnant cone structure was identified within and on the borders of all foveal EZ lesions. Within the extent of these lesions, cone spacing ranged from 4.97 to 9.95 µm at baseline, 5.30 to 6.10 µm at 6 months, and 4.99 to 7.12 µm at 12 months. Four eyes with significantly smaller EZ lesions showed evidence of recovery of EZ reflectivity on SDOCT B-scans. Remnant cone structure was identified in some areas where EZ reflectivity recovered at the following time point. Eyes that showed recovery of EZ reflectivity had a continuous external limiting membrane. CONCLUSIONS: Remnant cone structure can persist within small SDOCT-defined EZ lesions, which can wax and wane in appearance over time. AOSLO can help to inform the interpretation of SDOCT imaging. TRANSLATIONAL RELEVANCE: The absence of EZ in early macular telangiectasia type 2 and other retinal conditions needs careful interpretation because it does not always indicate an absence of underlying cone structure. The integrity of the external limiting membrane may better predict the presence of remnant cone structure and recovery of EZ reflectivity