Multimodality imaging in macular telangiectasia 2: A clue to its pathogenesis

Right-angled vessel characteristics in different stages of type 2 macular telangiectasia (MacTel)

PURPOSE

To study right-angled vessels (RAV) in disease progression and macular neovascularization in type 2 macular telangiectasia (MacTel) eyes.

METHODS

This retrospective image analysis study examined type 2 MacTel patients' multicolour® and OCT imaging records from January 2015 to March 2023. Age, gender, laterality, visual acuity, systemic disease, and follow-up duration were recorded. RAV characteristics were assessed using OCT and multicolour® images. This study examined RAV characteristics and type 2 MacTel disease stage.

RESULTS

In total, 270 eyes of 146 patients (97 females, 66%) with a mean age of 60.77 ± 9.34 years were studied. 153 (57%) eyes showed RAV. The non-proliferative stage of type 2 MacTel had either no RAV or a normal-calibre right-angled vein, while the proliferative stage had a right-angled artery and a dilated or normal-calibre RAV [p < 0.001]. RAV characteristics differed at the final follow-up (p < 0.001). 11 eyes transitioned from non-proliferative to proliferative after a median period of 26 months (range: 5-96 months). RAV characteristics changed from a normal calibre right-angled vein at presentation to a normal calibre vein and artery in 6 (55%) eyes and to a dilated vein and artery in 5 (45%) eyes respectively.

CONCLUSION

RAV characteristics may indicate type 2 MacTel stages. A right-angled artery in type 2 MacTel may indicate proliferative disease.

Unraveling the mysteries of macular telangiectasia 2: the intersection of philanthropy, multimodal imaging and molecular genetics. The 2022 founders lecture of the pan American vitreoretinal society

PURPOSE

Offer a personal perspective on the scientific advances on macular telangiectasia type 2 (MacTel2) since the launch of the MacTel Project in 2005.

DESIGN

Literature review and personal perspective.

METHODS

Critical review of the peer-reviewed literature and personal perspective.

RESULTS

Generous financial support from the Lowy Medical Research Institute laid the foundations of the MacTel Project. MacTel Project investigators used state of the art multimodal retinal imaging and advanced modern biological methods to unravel many of the mysteries surrounding MacTel2. Major accomplishments includes elucidation of the pathogenic role that low serine levels, elevated 1-deoxysphingolipids and other mechanisms induce mitochondrial dysfunction which lead to Müller cell and photoreceptor degeneration; the use of objective measures of retinal structures such as the area of ellipsoid zone disruption as an outcome measure in clinical trials; the demonstration that the ciliary neurotrophic factor slows down retinal degeneration and the development of a new severity scale classification based on multimodal imaging findings.

CONCLUSIONS

MacTel2 is a predominantly metabolic disease characterized by defects in energy metabolism. Despite relatively good visual acuities, MacTel2 patients experience significant visual disability. The Mac Tel Project has been instrumental in advancing MacTel2 knowledge in the past two decades.

Characteristics of retinal pigment clumps in Type 2 macular telangiectasia (MacTel)

OBJECTIVE

To assess the relationship of retinal pigment clump (RPC) size and its location with visual acuity and retinal neovascularisation in eyes with type 2 macular telangiectasia (MacTel).

METHODS

In this cross-sectional study, eyes diagnosed with type 2 MacTel showing RPC were included. Area occupied by pigment was measured on the multicolour image using the area tool on the Spectralis, Heidelberg machine. Pigment location within retinal layers was noted with OCT. Analysis was performed to identify factors associated with poor vision and proliferative disease.

RESULTS

Sixty-two eyes of 42 patients diagnosed with type 2 MacTel and RPC were included. The mean age was 64.31 ± 10.19 years. There were 13 (31%) males and 29 (69%) females in the study. 74% of patients were diabetics and the mean logMAR visual acuity of the participants was 0.619 ± 0.359. Univariate and multivariate binary logistic regression analysis identified female gender (p = 0.026), increasing RPC size (p = 0.008) and its presence above the outer plexiform layer (p = 0.006) to be associated with poor vision and proliferative disease in type 2 MacTel.

CONCLUSION

Our data identified female gender, larger pigment size and its location above the OPL to be associated with poor vision and proliferative disease. This data may be useful for further improving the current system for staging disease severity in type 2 MacTel.

Structural-vascular-functional correlation in type 2 non-proliferative macular telangiectasia

PURPOSE

To correlate the structural-vascular-functional changes in type 2 non-proliferative macular telangiectasia (MacTel) using optical coherence tomography (OCT) angiography (OCTA).

METHODS

In this retrospective study, OCTA and enface OCT image analysis of eyes with confirmed diagnosis of non-proliferative type 2 MacTel was performed. The 'MacTel area' was calculated by marking the outer boundary of an area affected by MacTel on superficial (SCP) and deep capillary plexus (DCP) on OCTA images and photoreceptor layer (PRL) on enface OCT scan. At every follow-up OCTA scan visit, best-corrected visual acuity, MacTel area and stage of disease was documented. Analyses between disease stage, MacTel area and logMAR visual acuity was carried out.

RESULTS

In total, 38 single-visit OCTA scans of 22 patients were included. The mean age was 58.9 ± 10.98 years. An increase in disease severity stage correlated positively with MacTel area in SCP segmentations slab (r = 0.334; p = 0.04) and logMAR visual acuity (r = 0.338; p = 0.038). No correlation in the DCP area or PRL area (p > 0.05) was noted with disease stage. A statistically significant positive correlation was noted between the structural changes in PRL layer with vascular changes in SCP (p = 0.021) but not in DCP (p = 0.199). No correlation of visual acuity with changes in SCP, DCP or PRL was noted (p > 0.05).

CONCLUSION

OCTA is a useful adjunct for determining disease severity in type 2 non-proliferative MacTel by assessing the structural-vascular changes. Further longitudinal studies need to be considered in future for understanding the pathomechanism of retinal damage in type 2 MacTel.

Use of OCT Angiography to Diagnose and Manage Atypical Presentations of Macular Telangiectasia Type 2

Macular telangiectasia Type 2 (MacTel) is a bilateral acquired retinal disease characterized by both vascular changes and atrophy of the retina. The purpose of this case series is to highlight the use of optical coherence tomography angiography (OCTA) as a non-invasive imaging modality to distinguish atypical MacTel from other macular conditions with similar presentations. We performed a retrospective review of patients referred to our academic retinal practice with unconfirmed or misdiagnosed MacTel between July 2017 and July 2021. Patients' OCTA imaging findings were reviewed to guide the appropriate diagnosis and management of atypical MacTel. Fifteen eyes from eight patients were included in this study. Six patients were referred with previous diagnoses of either full-thickness macular hole, lamellar hole, vitreomacular traction (VMT), postoperative cystoid macular edema (CME), or diabetic macular edema (DME). Two patients were referred to us to confirm the diagnosis of MacTel. OCTA revealed telangiectatic vessels in the temporal parafovea of all 15 eyes. OCTA also highlighted previously undiagnosed subretinal neovascularization (SRNV) in seven eyes. OCTA imaging is a valuable imaging modality to distinguish MacTel from other macular conditions, whose treatment courses vary substantially. Due to its ease of use, it holds immense potential in the future as treatments for non-proliferative MacTel emerge.

Microvascular changes precede visible neurodegeneration in fellow eyes of patients with asymmetric type 2 macular telangiectasia

IMPORTANCE

Macular telangiectasia type 2 (MacTel) is bilateral disease with characteristic alterations of the macular capillary network along with decreased macular pigment in the parafoveal area. The purpose of this study was to highlight that some eyes show microvascular changes which precede any visible neuronal changes on spectral-domain optical coherence tomography (SD-OCT).

METHODS

This observational study was conducted at a tertiary eye institute. From a registry of 630 patients with MacTel, we identified 4 patients with typical MacTel characteristics in only one eye with no visible changes on colour photographs or SD-OCT in the fellow eye. These 4 patients had findings of MacTel documented by colour fundus photograph, multicolour imaging (MCI), fundus autofluorescence (FAF), confocal blue reflectance (CBR), SD-OCT, and OCT-Angiography (OCT-A) in one eye. OCT-A was performed in MacTel patients using the High-resolution Spectralis (Heidelberg Engineering) module with a full-spectrum probabilistic approach and we employed a 30° x 15° (~8.8 mm × 4.4 mm) scan pattern covering the macula. MCI was done at the end so as to avoid fading the confocal blue reflectance hyperreflectivity seen in MacTel.

RESULTS

On OCT-A, all 4 fellow eyes showed telangiectasia and foveal avascular zone changes in the superficial and deep capillary plexuses with no changes on SD-OCT. None of the eyes showed typically increased reflectance on CBR around the foveal area.

CONCLUSION

These findings show that microvascular changes on OCT-A may occur before visible neurodegenerative changes on OCT, providing new insights into the course of the disease.

Demographic and Multimodal Imaging Features of Macular Telangiectasia Type 2: Korean Macular Telangiectasia Type 2 Study - Report No. 2

Purpose: To investigate the demographic and multimodal imaging features of macular telangiectasia (MacTel) type 2 in Korea and their relationship with visual acuity and the clinical stage.Methods: A retrospective multicentre cross-sectional study was conducted in six tertiary hospitals in Korea and the study included 84 patients. Demographic data and imaging data of fundus photography, fundus autofluorescence (FAF), confocal blue-light reflectance (CBR), fluorescein angiography (FAG), and optical coherence tomography (OCT) were collected.Results: The Korean patients with MacTel type 2 were predominantly female (75%), and the mean logMAR visual acuity was 0.282 ± 0.280 at initial presentation. Most commonly presented signs were the loss of retinal transparency in fundus photographs (68.3%); increased autofluorescence in FAF (83.6%); increased blue reflectance involving the centre in CBR (68.0%); telangiectatic vessels in FAG (88.2%); and hyporeflective cavities in OCT (77.7%). The eyes diagnosed in the first half of the study period (2009-2014) showed a tendency to be diagnosed at more advanced severe stages than those diagnosed in the second half of the study period (2015-2019), using new severity scales based on FAG, FAF and OCT findings.Conclusion: The clinical features of MacTel type 2 in Korean patients assessed by newer imaging modalities suggest that Korean patients and the Caucasian-dominant population show similar presentations. This study showed that MacTel type 2 can be diagnosed in the earlier phase of the disease by using new imaging modalities and through better understanding of the disease.

Optical coherence tomography angiography findings of fellow eye of proliferative macular telangiectasia type 2: Long term study

PURPOSE

To report the characteristics of non-proliferative fellow eyes in patients with unilateral proliferative macular telangiectasia type 2 (MacTel).

METHODS

This was a multicenter, retrospective study and included fellow eyes of eyes with subretinal neovascular membrane (SRNVM). Multimodal imaging including fundus photography, optical coherence tomography (OCT), and OCT angiography (OCTA) was performed. OCT and OCTA measurements included central macular thickness (CMT), subfoveal choroidal thickness (SFCT), foveal avascular zone (FAZ) area and qualitative parameters such as distortion or enlargement of FAZ, increased inter-vascular spacing, dilated, tortuous vessel at margin of FAZ, crowding of vessel, and loss of choriocapillaris (CC).

RESULTS

Thirteen fellow eyes of 13 patients with mean age of 63.6 ± 12.0 years were included. Fellow eyes had various stages of the diseases - stage 2 (four eyes), 3 (six eyes), and 4 (three eyes). OCTA showed increased intervascular spacing (8; 61.5%), dilated (11; 84.6%), and elongated vessels (8; 61.5%) at the margin of the FAZ, crowding of vessels (6; 46.2%), capillary non-perfusion areas outside the FAZ (4; 30.8%), and areas of CC loss (4; 30.8%). Mean follow-up was 9.1 ± 12.9 months. Out of six eyes with follow-up of ⩾12 months, two developed SRNVM at 18 and 33 months with OCTA showing crowding and entanglement of dilated retinal vessels in deep capillary plexus at baseline which corresponded to the area affected by SRNVM.

CONCLUSION

Fellow eyes of proliferative MacTel showed established disease stages on OCTA with progressive capillary crowding and entanglement of vessels likely corresponding to the future site of SRNVM.

Quantitative analysis of retinal microvascular changes in macular telangiectasia type 2 using optical coherence tomography angiography

PURPOSE

To evaluate retinal vascular changes on optical coherence tomography angiography (OCTA) in patients with macular telangiectasia type 2 (MacTel 2) and to assess their correlation with visual acuity.

METHODS

Twenty-six patients (52 eyes) with MacTel 2 and 20 age-matched controls (40 eyes) were included. Fundus examinations, including fundus autofluorescence, swept-source optical coherence tomography, and OCTA, were performed. Differences in the vascular density in the fovea and parafovea, the area of the foveal avascular zone, and the diameter of the ellipsoid zone defect of the two groups were analyzed.

RESULTS

The foveal vascular density of the superficial capillary plexus was significantly lower in the MacTel 2 group than in the control group (p = 0.027). The vascular density in the entire deep capillary plexus was also significantly less in the MacTel 2 group than in the control group (all p < 0.05). The mean diameter of ellipsoid-zone disruption on OCT in the MacTel 2 group was 634.6 ± 104.3 𝜇m. The foveal avascular zone areas of the superficial and deep capillary plexuses were significantly enlarged in the MacTel 2 group compared to those in the control group (0.45 ± 0.12 mm2 vs. 0.27 ± 0.08 mm2, p < 0.001; 0.56 ± 0.15 mm2 vs. 0.40 ± 0.14 mm2, p = 0.001). In addition, the enlarged foveal avascular zone of the superficial and deep plexus was negatively correlated with best corrected visual acuity (logMAR) in MacTel 2 patients (p = 0.013, r = -0.642 and p = 0.042, and r = -0.511, respectively).

CONCLUSIONS

Retinal vascular density changes occur in the superficial fovea and in the entire deep capillary plexus of patients with MacTel 2. The enlarged foveal avascular zone areas of the superficial and deep plexuses were prominent in the MacTel 2 group, and this enlargement correlates with worsened visual acuity.

An optical coherence tomography-based grading of diabetic maculopathy proposed by an international expert panel: The European School for Advanced Studies in Ophthalmology classification

AIMS

To present an authoritative, universal, easy-to-use morphologic classification of diabetic maculopathy based on spectral domain optical coherence tomography.

METHODS

The first draft of the project was developed based on previously published classifications and a literature search regarding the spectral domain optical coherence tomography quantitative and qualitative features of diabetic maculopathy. This draft was sent to an international panel of retina experts for a first revision. The panel met at the European School for Advanced Studies in Ophthalmology headquarters in Lugano, Switzerland, and elaborated the final document.

RESULTS

Seven tomographic qualitative and quantitative features are taken into account and scored according to a grading protocol termed TCED-HFV, which includes foveal thickness (T), corresponding to either central subfoveal thickness or macular volume, intraretinal cysts (C), the ellipsoid zone (EZ) and/or external limiting membrane (ELM) status (E), presence of disorganization of the inner retinal layers (D), number of hyperreflective foci (H), subfoveal fluid (F), and vitreoretinal relationship (V). Four different stages of the disease, that is, early diabetic maculopathy, advanced diabetic maculopathy, severe diabetic maculopathy, and atrophic maculopathy, are based on the first four variables, namely the T, C, E, and D. The different stages reflect progressive severity of the disease.

CONCLUSION

A novel grading system of diabetic maculopathy is hereby proposed. The classification is aimed at providing a simple, direct, objective tool to classify diabetic maculopathy (irrespective to the treatment status) even for non-retinal experts and can be used for therapeutic and prognostic purposes, as well as for correct evaluation and reproducibility of clinical investigations.

Idiopathic macular telangiectasia type 2: Prevalence and a morphometric and phenotypic study

OBJECTIVE

Type 2 idiopathic macular telangiectasia (MacTel2) is a rare retinal disease that has still not been well-defined. The aim of the present manuscript is to describe the clinical features by multimodal retinal imaging, to present the functional characteristics, and to estimate the prevalence of the disease.

METHODS

A retrospective study was conducted on the 12 eyes of 6 patients with MacTel2. Fundus colour photographs, fundus autofluorescence, fluorescein angiography, optical coherence tomography (OCT), and OCT-angiography were performed and subsequently analysed. Visual acuity (VA) was prospectively recorded. The prevalence was established based on the patients referred to a specialised macular diseases unit. Minimum follow-up period was 18 months.

RESULTS

Prevalence of MacTel 2 in our study was 0.12%. Clinical features were presented using multimodal retinal imaging. VA remained stable during follow-up. Three patients developed choroidal neovascularisation (CNV), requiring intravitreal treatment with antiangiogenic agents.

CONCLUSIONS

The prevalence of the disease found was 0.12%. The study using multimodal imaging allows a more accurate diagnosis and follow-up of this pathology. The VA is maintained during the 18-month follow-up (P=.492). Patients who develop CNV and are treated with antiangiogenic agents appear to respond adequately to them. More studies are needed to establish these conclusions.

When is macular edema not macular edema? An update on macular telangiectasia type 2

Macular telangiectasia type 2 (Mac Tel 2) also known as idiopathic perifoveal telangiectasia and juxtafoveolar retinal telangiectasis type 2A is an enigmatic disease of unknown etiology. It manifests both neurodegenerative and vasculopathic characteristics.

It manifests itself during the fifth or sixth decades of life. Clinical characteristics include minimally dilated parafoveal capillaries with loss of the retinal transparency in the area involved, absence of lipid exudation, right-angled retinal venules, superficial retinal refractile deposits, hyperplasia of the retinal pigment epithelium (RPE), foveal atrophy and subretinal neovascularization (SRNV). Optical coherence tomography (OCT) images typically demonstrate outer retinal abnormalities and the presence of intra-retinal hyporeflective spaces that are usually not related with retinal thickening or fluorescein leakage. The typical fluorescein angiographic finding is a deep intraretinal hyperfluorescent staining in the temporal parafoveal area. With time this fluorescein hyperfluorescence involves the whole parafoveal area but does not extend to the center of the fovea. Long-term prognosis for central vision is poor, because of the development of SRNV or macular atrophy. Its pathogenesis remains unclear but multi-modality imaging with fluorescein angiography, spectral domain OCT, adaptive optics, confocal blue reflectance, short wave fundus autofluorescence, OCT angiography, and clinicopathological correlations implicate Müller cells. Currently there is no known treatment for this condition.