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Macular telangiectasia is a condition of the retina, the light-sensing tissue at the back of the eye that causes gradual deterioration of central vision, interfering with tasks such as reading and driving. Type 1, a very rare disease involving microaneurysms in the retina, typically affects a single eye in male patients, and it may be associated with Coats' disease. Type 2 (referred to as MacTel) is the most common macular telangiectasia. It is categorized as "macular perifoveal telangiectasia", a neurodegenerative metabolic disorder, correlated with diabetes and coronary artery disease. It generally affects both eyes and usually affects both sexes equally. Type 3 is an extremely rare, poorly understood neurological disease of the retina. It is characterized by occlusion and telangiectasia of the capillaries of the fovea in one or both eyes, as well as some exudation. Early research Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary researchers describe three types collectively known as idiopathic juxtafoveal telangiectasia: macular telangiectasia type 1, macular telangiectasia type 2, and macular telangiectasia type 3. Both macular telangiectasia and age-related macular degeneration (AMD) lead to photoreceptor atrophy and loss of central vision. The two diseases may be distinguished by symptoms, clinical features, and pathogenesis. The natural history of macular telangiectasia suggests a slowly progressive disorder. A retrospective series of 20 patients over 10 to 21 years showed deterioration of vision in more than 84% of eyes, either due to intra-retinal edema and serous retinal detachment (Type 1) or retinal pigment epithelium (RPE) scar formation or neovascularization (Type 2). Type 1 Type 1 idiopathic macular telangiectasia patients are typically males, 40 years old or older. Pathophysiology Type 1 may be defined as an acquired capillary ectasia (a focal expansion or outpouching) and dilation in the parafoveal region, leading to vascular incompetence. Telangiectatic vessels develop micro-aneurysms that leak fluid, blood, and occasionally, lipid. Macular telangiectasia type 1 has been called as a variant of Coats' disease. Treatment Treatment options for Type 1 include laser photocoagulation, intravitreal injections of steroids, or anti-vascular endothelial growth factor (VEGF) agents. Photocoagulation was recommended by Gass and remains to date the mainstay of treatment. It seems to be successful in causing resolution of exudation and VA improvement or stabilization in selected patients. Photocoagulation should be used sparingly to reduce the chance of producing a symptomatic paracentral scotoma and metamorphopsia. Small burns (100–200 μm) of moderate intensity in a grid-pattern and on multiple occasions, if necessary, are recommended. It is unnecessary to destroy every dilated capillary, and, particularly during the initial session of photocoagulation, those on the edge of the capillary-free zone should be avoided. Intravitreal injections of triamcinolone acetonide (IVTA) which have proved to be beneficial in the treatment of macular edema by their anti-inflammatory effect, their downregulation of VEGF production, and stabilization of the blood retinal barrier, were reported anecdotally in the management of Macular telangiectasia type 1. In two case reports, IVTA of 4 mg allowed a transitory reduction of retinal edema, with variable or no increase in visual acuity (VA). As expected with all IVTA injections, the edema recurred within 3–6 months, and no permanent improvement could be shown. In general, the effect of IVTA is short-lived and complications, mainly increased intraocular pressure and cataract, limit its use. Indocyanine green angiography-guided laser photocoagulation directed at the leaky microaneurysms and vessels combined with sub-Tenon’s capsule injection of triamcinolone acetonide has also been reported in a limited number of patients with Macular telangiectasia type 1 with improvement or stabilization of vision after a mean follow-up of 10 months. Further studies are needed to assess the efficacy of this treatment modality. Recently, intravitreal injections of anti-VEGF agents, namely bevacizumab, a humanized monoclonal antibody targeted against pro-angiogenic, circulatory VEGF; and ranibizumab, a FDA-approved monoclonal antibody fragment that targets all VEGF-A isoforms, have shown improved visual outcome and reduced leakage in macular edema from diabetes and retinal venous occlusions. In one reported patient with Macular telangiectasia type 1, a single intravitreal bevacizumab injection resulted in a marked increase in VA from 20/50 to 20/20, with significant and sustained decrease in both leakage on fluorescein angiography (FA) and cystoid macular edema on optical coherence tomography (OCT) up to 12 months. It is likely that patients with Macular telangiectasia type 1 with pronounced macular edema from leaky telangiectasis may benefit functionally and morphologically from intravitreal anti-VEGF injections, but this warrants further studies. Today, laser photocoagulation remains mostly effective, but the optimal treatment of Macular telangiectasia type 1 is questioned, and larger series comparing different treatment modalities seem warranted. The rarity of the disease, however, makes it difficult to assess in a controlled randomized manner. A 2014 case study of a single type 1 macular telangiectasia patient concluded Bevacizumab was not effective, but Aflibercept produced beneficial results. Type 2 (MacTel) Contemporary research has shown that MacTel is likely a neurodegenerative metabolic disease. MacTel is correlated with hypertension and diabetes mellitus. Although MacTel has been previously regarded as a rare disease, it is in fact probably much more common than previously thought. The subtleness of early symptoms of MacTel may cause mis-diagnosis by optometrists and general ophthalmologists. Terminology MacTel may also be referred to by various names, including (idiopathic) juxtafoveolar telangiectasia, or parafoveal telangiectasis, depending on the source. All refer to the same disease. Signs and symptoms Typical patients present with a mean age of 55–59 years, and a wide range of symptoms from totally asymptomatic to substantially impaired; in most cases however, patients retain functional acuity of 20/200 or better. Metamorphopsia (visual distortions) may be a subjective complaint. Due to the development of paracentral scotoma (blind spots), impaired reading ability may be the first symptom of the disease. Diagnosis Type 2 MacTel commonly occurs in both eyes, and occurs equally in males and females. Histopathology studies have shown a loss of Müller glia markers in the clinically altered area. Diagnosis of MacTel type 2 may be aided by the use of advanced imaging techniques such as fluorescein angiography (which may identify an abnormal ca.... Discover the Katie Powner popular books. Find the top 100 most popular Katie Powner books.