Treatment Modalities for Idiopathic Macular Telangiectasia: An Evidence-Based Systematic Review of the Literature

Navigated Focal Laser of Macular Telangiectasia Type I (Adult-Onset Coats' Disease)

We aimed to evaluate the anatomical and functional outcome of selective photocoagulation of idiopathic macular telangiectasia type 1 by navigated focal laser (Navilas, OD-OS GmBH). Consecutive patients with idiopathic macular telangiectasia type 1 were included in the analysis. All patients were treated with navigated focal laser, planned on multimodal imaging. Seven eyes of seven patients were retrospectively analyzed. Navigated laser photocoagulation of idiopathic macular telangiectasia type 1 successfully occluded the microaneurysms, inducing regression of macular edema and exudation, significative improvement in best-corrected visual acuity at 3 (P = 0.035) and 6 months (P = 0.034) and a decrease in central macular thickness at 3 (P = 0.01) and 6 months (P = 0.01). Patients with idiopathic macular telangiectasia type 1 are ideal candidates for navigated laser treatment. Navigated focal treatment has been shown to be effective and safe in occluding aneurysmal dilations without any side effects. [Ophthalmic Surg Lasers Imaging Retina 2024;55:545-551.].

Oncostatin M Reduces Pathological Neovascularization in the Retina Through Müller Cell Activation

Purpose

Continuous vision loss due to vasoproliferative eye disease still represents an unsolved issue despite anti-vascular endothelial growth factor (VEGF) therapy. The impact of signal transducer and activator of transcription 3 (STAT3) signaling on retinal angiogenesis and its potential use as a therapeutic target remain controversial. In vitro, oncostatin M (OSM), as a strong STAT3 activator, possesses robust proangiogenic activity. This study investigated to what extent the proangiogenic effects of OSM translate to the in vivo setting of vasoproliferative eye disease.

Methods

The in vitro effect of OSM on endothelial cells was investigated in the spheroid sprouting assay and through RNA sequencing. The mouse model for oxygen-induced retinopathy (OIR) was used to evaluate the impact of OSM in vivo. Signaling patterns were measured by western blot and retinal cryosections. Primary Müller cell cultures were used to evaluate the effect of OSM on the Müller cell secretome. Murine retinal vascular endothelial cells were isolated from OIR retinas using fluorescence-activated cell sorting (FACS) and were used for RNA sequencing.

Results

Although OSM induced pro-angiogenic responses in vitro, in the OIR model intravitreal injection of OSM reduced retinal neovascularization by 65.2% and vaso-obliteration by 45.5% in Müller cells. Injecting OSM into the vitreous activated the STAT3 signaling pathway in multiple retinal cell types, including Müller cells. In vitro, OSM treatment increased CXCL10 secretion. RNA sequencing of sorted vascular endothelial cells at OIR P17 following OSM treatment indicated downregulation of angiogenesis- and mitosis-associated genes.

Conclusions

In vivo, OSM reveals a beneficial angiomodulatory effect by activating Müller cells and changing their secretome. The data highlight contradictions between cytokine-induced effects in vitro and in vivo depending on the cell types mediating the effect.

DIRECT LASER PHOTOCOAGULATION TO THE DILATED RIGHT-ANGLED VESSEL IN THE MANAGEMENT OF PROLIFERATIVE TYPE 2 MACULAR TELANGIECTASIA

PURPOSE

To report a case of proliferative Type 2 macular telangiectasia treated successfully with direct laser photocoagulation to the right-angled vessel.

METHODS

Descriptive case report.

CASE DESCRIPTION

A 61-year-old man, with no past medical history, was diagnosed and treated previously elsewhere for bilateral proliferative Type 2 macular telangiectasia. He complained of recent onset decrease in vision in his right eye for last 2 months. Right eye visual acuity was counting fingers at 3 m and left eye was 6/18. Fundus examination showed proliferative Type 2 macular telangiectasia in both eyes with active neovascular complex in the right eye. Direct thermal laser photocoagulation to the tips of the right-angled vessels with single-spot PASCAL Synthesis (Topcon Medical Laser System) at 532 nm wavelength was done. After laser, reduction in the hyporeflective space height was noted on optical coherence tomography. No additional intravitreal anti-vascular endothelial growth factor injections were required. At the last 6-months follow-up visit, visual acuity improved to 6/36, N18 in the right eye.

CONCLUSION

Direct laser photocoagulation to the right-angled vessel can be considered as possible treatment option for proliferative Type 2 macular telangiectasia, especially in patients nonresponsive to anti-vascular endothelial growth factor therapy. However, long-term follow-ups are required to see whether it is possible to maintain the efficacy.

Intravitreal Bevacizumab for Choroidal Neovascular Membrane in Macular Telangiectasia Type 2

We report a case of macular telangiectasia type 2 with an associated choroidal neovascular membrane and its treatment. A 54-year-old female presented with a history of gradual vision loss in both eyes. A physical exam showed visual acuity of 20/40 in both eyes and significant metamorphopsia in the right eye. A fundus examination of the right eye was remarkable for right-angled vessels in the juxtafoveal region and subretinal fibrosis temporal to the fovea. A fundus examination of the left eye revealed intraretinal crystals in the juxtafoveal region and right-angled vessels. Optical coherence tomography and angiography confirmed the diagnosis of macular telangiectasia type 2 as well as the presence of a choroidal neovascular membrane in the right eye. The patient was treated with 18 intravitreal injections of anti-vascular endothelial growth factor agent in the right eye for two years, with five to six weeks between each treatment, which resulted in the membrane's stability. Our report suggests that anti-vascular endothelial growth factor therapy via intravitreal injection may be beneficial in treating choroidal neovascular membranes in patients with macular telangiectasia type 2.

Clinical Features of Untreated Type 2 Macular Telangiectasia and Efficacy of Anti-Vascular Endothelial Growth Factor Therapy in Macular Neovascularization

Objectives:

To compare best corrected visual acuity (BCVA), central macular thickness (CMT), and central choroidal thickness (CCT) in patients with type 2 macular telangiectasia (MacTel 2) and a control group and to evaluate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment in MacTel 2 patients with macular neovascularization (MNV).

Materials and Methods:

We conducted a retrospective chart review of consecutive MacTel 2 patients who underwent a full ophthalmologic examination including BCVA and dilated fundus examination with slit-lamp biomicroscopy, fluorescein angiography, and optical coherence tomography imaging at baseline and follow-up visits. BCVA, CMT, and CCT were compared between all identified patients (n=26) and a control group (n=30). A subgroup analysis was performed among eyes with MNV (n=7) before and after treatment.

Results:

CMT and CCT were significantly lower in the MacTel 2 group compared to the control group. Forty-one treatment-naive eyes without MNV proliferation showed no significant change in BCVA, CMT, or CCT during follow-up. Eight eyes of 7 MacTel 2 patients developed MNV during follow-up. All of the patients were treated with intravitreal anti-VEGF.

Conclusion:

It is important to closely follow MacTel 2 patients for MNV development. To avoid adverse effects, we prefer to monitor patients who have not yet developed MNV. Patients with proliferative MacTel 2 with decreasing visual function may benefit from intravitreal anti-VEGF treatment.

Bilateral Type 1 Idiopathic Macular Telangiectasia in a Female Patient: Multimodal Imaging of a Rare Presentation

We report a bilateral case of type 1 idiopathic macular telangiectasia (IMT) in a female patient. A 40-year-old otherwise healthy female with gradual vision loss since 2 years ago with best-corrected visual acuity of 20/400 in both eyes was referred. Her past medical history was negative for any systemic disease including diabetes and systemic hypertension. Color fundus photography showed bilateral loss of normal foveal reflex with macular edema. Fluorescein angiography demonstrated symmetric perifoveal telangiectasia mainly in the superior and nasal macula in both eyes with late staining and leakage. Spectral-domain optical coherence tomography revealed significant intraretinal fluid bilaterally and subretinal fluid in the left eye. Optical coherence tomography angiography (OCTA) revealed obvious saccular parafoveal capillary telangiectasia and capillary dropout as well as decreased vascular density in both superficial and deep capillary plexus. Deep capillary plexus involvement in OCTA was more evident than superficial plexus. Based on the patient's medical history and multimodal imaging, the diagnosis of bilateral IMT type 1 was made. The patient underwent 5 intravitreal monthly injection of bevacizumab in both eyes, which resulted in macular edema resolution. However, after 3 months of discontinuation of intravitreal bevacizumab, macular edema relapsed. In conclusion, type 1 IMT can occur bilaterally in an otherwise healthy female patient as a very rare presentation. To the best of our knowledge, this case is the 4th case of bilateral type 1 IMT reported in a female.

Visualization of microaneurysms in macular telangiectasia type 1 on optical coherence tomography angiography before and after photocoagulation

PURPOSE

To evaluate changes in the visualization of microaneurysms (MAs) in cases of macular telangiectasia (Mac Tel) type 1 on optical coherence tomography angiography (OCTA) before and after treatment with direct photocoagulation and to evaluate their relationship with treatment efficacy.

METHODS

The study included 12 eyes from 12 patients (8 men, 4 women; mean age 72.1 years) with Mac Tel type 1 accompanied by cystoid macular edema. OCTA for the evaluation of MAs was performed before and 15 min and 6, 12, and 24 weeks after photocoagulation. The best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were also evaluated.

RESULTS

A total of 73 MAs were detected within the areas of macular edema on OCTA, and 39 of these underwent photocoagulation. At 15 min after treatment, 17 MAs were no longer visible on OCTA. At 6 weeks, two MAs had reappeared, whereas five additional MAs were no longer visible. The CRT in eyes with resolved MA was significantly less than that in eyes with persistent MAs (p = 0.016). At 24 weeks, seven eyes had no visible MAs, and the BCVA was not significantly different from baseline.

CONCLUSION

OCTA can monitor changes in the visualization of MAs associated with Mac Tel type 1 after direct photocoagulation. Eyes in which MAs disappeared after treatment could recover from cystoid macular edema.

Multimodal Imaging Findings and Treatment with Dexamethasone Implant in Three Cases of Idiopathic Macular Telangiectasia Type 1

This is a report of 3 patients diagnosed with idiopathic macular telangiectasia type 1 (MacTel 1) at Medical Retina Center of the University of Eye Clinic of Genova and then prospectically followed for a mean time of 26 months between 2016 and 2019. It is the first report of patients affected by MacTel 1 treated with dexamethasone (DEX) implant as a first choice of treatment. Aim of our study is to better characterize the disease using a multimodal wide-field imaging and to determine efficacy of DEX implant on MacTel 1 in terms of central macular thickness (CMT) and best-corrected visual acuity (BCVA). MacTel 1 is a rare unilateral disease, characterized by telangiectatic retinal capillaries, cystoid macular edema, and lipid deposition occurring temporal to the fovea. Patients underwent a comprehensive ophthalmic examination, BCVA, swept-source optical coherence tomography (SS-OCT), SS-OCT angiography (SS-OCTA), ultra-widefield (UWF) color, and fluorescein angiography (FA) fundus photograph. All the patients presented monolateral reduced BCVA and macular edema with increased CMT evaluated by SS-OCT. With SS-OCTA, we showed that the telangiectasia-associated vascular changes originate in the deep retinal vascular plexus and as a consequence macular edema and exudation develop causing vision loss. Furthermore, UWF imaging helped us to highlight vascular changes typical of Coats Disease at the far retinal periphery. All the patients were treated with DEX intravitreal implant, showing a decrease in CMT and a stabilization of visual acuity. Due to the recurrent nature of macular edema, patients underwent a mean of 4 DEX implants during the follow-up period. In order to address the clinical features of this uncommon disease avoiding diagnostic errors, it might be important to use a multimodal imaging approach. The anatomical and functional beneficial effects of DEX implant were well evident although transient.

CNTF Prevents Development of Outer Retinal Neovascularization Through Upregulation of CxCl10

Purpose

Ciliary neurotrophic factor (CNTF) is a well-characterized neurotrophic factor currently in clinical trials for the treatment of macular telangiectasia type II. Our previous work showed that CNTF-induced STAT3 signaling is a potent inhibitor of pathologic preretinal neovascular tuft formation in the mouse model of oxygen-induced retinopathy. In this study, we investigated the effect of CNTF on outer retinal and choroidal angiogenesis and the mechanisms that underpin the observed decrease in outer retinal neovascularization following CNTF treatment.

Methods

In the Vldlr^–/– and laser-CNV mouse models, mice received a one-time injection (on postnatal day [P] 12 in the Vldlr^–/– model and 1 day after laser in the Choroidal Neovascularization (CNV) model) of recombinant CNTF or CxCl10, and the extent of neovascular lesions was assessed 6 days posttreatment. STAT3 downstream targets affected by CNTF treatment were identified using quantitative PCR analysis. A proteome array was used to compare media conditioned by CNTF-treated and control-treated primary Müller cells to screen for CNTF-induced changes in secreted angiogenic factors.

Results

Intravitreal treatment with recombinant CNTF led to significant reduction in neovascularization in the Vldlr^–/– and laser-CNV mouse models. Treatment effect in the Vldlr^–/– was long-lasting but time sensitive, requiring intravitreal treatment before P19. Mechanistic workup in vitro as well as in vivo confirmed significant activation of the STAT3-signaling pathway in Müller cells in response to CNTF treatment and upregulation of CxCl10. Intravitreal injections of recombinant CxCl10 significantly reduced outer retinal neovascularization in vivo in both the Vldlr^–/– and laser-CNV mouse models.

Conclusions

CNTF treatment indirectly affects outer retinal and choroidal neovascularization by inducing CxCl10 secretion from retinal Müller cells.

Management of Idiopathic Macular Telangiectasia Type 2

Macular telangiectasia type 2 (MacTel) is a relatively rare disease without established treatments. Although MacTel was previously considered a primarily vascular condition, the thinking on its pathogenesis has shifted to it now being considered principally a neurodegenerative disease. This has resulted in a subsequent change in the approach to treatment toward neuro-protection for the non-proliferative phase of this disease. Carotenoid supplementation has had mixed results. Ciliary neurotrophic factor (CNTF) has demonstrated some promising early results, but further study is necessary to determine its actual effect. Some structural improvements have been seen in the non-proliferative phase with oral acetazolamide but without accompanying functional improvement. Anti-vascular endothelial drugs have been studied and not found to have benefit in the non-proliferative phase of disease but have demonstrated significant structural and functional value in the treatment of secondary neovascularization. There is no level I evidence for the various proposed MacTel treatments, and efforts need to be directed toward conducting multicenter randomized trials to better understand possible treatments for this condition.

Idiopathic macular telangiectasia type 2: A six-year study with multimodal imaging of a presumed unilateral case

Purpose

To present a rare manifestation of macular telangiectasia type 2 (MacTel type 2) followed up for over six years.

Methods

A 61-year-old woman with one year history of blurred vision of her left eye was referred.

Results

Whereas the funduscopy, spectral-domain optical coherence tomography (SD-OCT), fluorescein angiography (FA), and fundus autofluorescence (FAF) were normal in the right eye, they revealed noticeable findings typical of MacTel type 2 in the left eye. After over six years follow-up, OCT-angiography (OCTA) showed no remarkable difference between the two eyes, and en face OCT showed subtle abnormal change in the right eye as well as typical pathological changes in the left eye.

Conclusion

MacTel type 2 can present unilaterally and remain so for a long time. The role of multimodal imaging in diagnosis and follow-up is of utmost importance.