Macular telangiectasia

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Macular telangiectasia
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Macular telangiectasia
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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.

Contents

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 . [1]

Early research

Diagram of the human eye showing macula and fovea Schematic diagram of the human eye en.svg
Diagram of the human eye showing macula and fovea

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. [2] [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

Cystoid Macular Oedema in patient with MacTel type 1 Eye diag.jpg
Cystoid Macular Oedema in patient with MacTel 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. [4]

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.[ citation needed ] 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. [4]

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. [4]

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. [4]

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. [4] A 2014 case study of a single type 1 macular telangiectasia patient concluded Bevacizumab was not effective, but Aflibercept produced beneficial results. [5]

Type 2 (MacTel)

Contemporary research has shown that MacTel is likely a neurodegenerative metabolic disease. [6] 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. [7]

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. [8]

Diagnosis of MacTel type 2 may be aided by the use of advanced imaging techniques such as fluorescein angiography (which may identify an abnormal capillary pattern), fundus autofluorescence, and OCT. These can help to identify the abnormal vessels, pigment plaques, retinal crystals, foveal atrophy and intraretinal cavities associated with this disorder.

Areas of focal RPE hyperplasia (pigment plaques) often develop in the paramacular region as a response to these abnormal vessels. Other signs of macular telangiectasia type 2 include right angle venules, representing an unusual alteration of the vasculature in the paramacular area, with vessels taking an abrupt turn toward the macula as if being dragged.

Fluorescein angiography (FA) is helpful in identifying the anomalous vasculature, particularly in the early stages of Type 2 disease. Formerly, FA was essential in making a definitive diagnosis. However, the diagnosis can be established with less invasive imaging techniques such as Ocular Coherence Tomography (OCT) and fundus autofluorescence. Some clinicians argue that FA testing may be unnecessary when a diagnosis is apparent via less invasive means.

Macular telangiectasia type 2 is commonly under-diagnosed. The findings may appear very similar to diabetic retinopathy, and many cases have been incorrectly ascribed to diabetic retinopathy or age-related macular degeneration. Recognition of this condition can save an affected patient from unnecessarily undergoing extensive medical testing and/or treatment. MacTel should be considered in cases of mild paramacular dot and blot hemorrhages and in cases of macular and paramacular retinal pigment epithelium (RPE) hyperplasia where no other cause can be identified.

Causes

In September 2019, researchers announced, "a combination of genetics, metabolism and biochemistry drives a disease such as MacTel". [9] [10]

Treatment

The most crucial aspect of treating macular telangiectasia is recognition of the clinical signs. This condition is relatively uncommon: hence, many practitioners may not be familiar with or experienced in diagnosing the disorder. MacTel must be part of the differential in any case of idiopathic paramacular hemorrhage, vasculopathy, macular edema or focal pigment hypertrophy, especially in those patients without a history of retinopathy or contributory systemic disease.

Treatment options are limited. Laser therapy may actually enhance vessel ectasia and promote intraretinal fibrosis in these individuals.

Monthly injections of VEGF inhibitors have not proven to be effective in non-proliferative MacTel type 2. [11] Ranibizumab (Lucentis) or bevacizumab (Avastin) may reduce vascular leakage, but neural atrophy may still occur in treated eyes. [12] In proliferative stages (neovascularisation), treatment with Anti-VEGF can be helpful.

Ciliary neurotrophic factor (CNTF) is believed to have neuroprotective properties and could thus be able to slow down the progression of MacTel type 2. According to the American Academy of Ophthalmology, a novel CNTF implant "is a semipermeable fiber membrane filled with human retinal pigment epithelium cells that secrete ciliary neurotrophic factor". During Phase 2 testing, the implant device was "shown to slow the progression of retinal degeneration compared with participants who received the sham treatment. Based on the positive Phase 2 results, two parallel Phase 3 studies were initiated... enrolling patients in the United States, Australia, and Europe to determine the safety and efficacy... for the treatment of MacTel". [13] In February 2019, the U.S. Food and Drug Administration granted "Fast Track" designation for approval of the device to treat macular telangiectasia type 2. [14]

Type 3

"Idiopathic macular telangiectasia type 3 is a rare, acquired, eye disease characterized by progressive visual loss, due to bilateral juxtafoveolar capillary occlusions, capillary telangiectasia, and minimal exudation. It is associated with systemic or cerebral vascular occlusive disease." [15]

Terminology

Type 3 macular telangiectasia is also called "occlusive idiopathic juxtafoveolar retinal telangiectasis". [16]

Related Research Articles

<span class="mw-page-title-main">Diabetic retinopathy</span> Medical condition

Diabetic retinopathy, is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries.

The National Eye Institute (NEI) is part of the U.S. National Institutes of Health (NIH), an agency of the U.S. Department of Health and Human Services. The mission of NEI is “to eliminate vision loss and improve quality of life through vision research.” NEI consists of two major branches for research: an extramural branch that funds studies outside NIH and an intramural branch that funds research on the NIH campus in Bethesda, Maryland. Most of the NEI budget funds extramural research.

<span class="mw-page-title-main">Macular edema</span> Medical condition

Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye and causes it to thicken and swell (edema). The swelling may distort a person's central vision, because the macula holds tightly packed cones that provide sharp, clear, central vision to enable a person to see detail, form, and color that is directly in the centre of the field of view.

<span class="mw-page-title-main">Macular degeneration</span> Medical condition associated with vision loss

Macular degeneration, also known as age-related macular degeneration, is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur.

<span class="mw-page-title-main">Central serous chorioretinopathy</span> Eye disease characterized by leakage of fluid under the retina

Central serous chorioretinopathy, also known as central serous retinopathy (CSR), is an eye disease that causes visual impairment, often temporary, usually in one eye. When the disorder is active it is characterized by leakage of fluid under the retina that has a propensity to accumulate under the central macula. This results in blurred or distorted vision (metamorphopsia). A blurred or gray spot in the central visual field is common when the retina is detached. Reduced visual acuity may persist after the fluid has disappeared.

<span class="mw-page-title-main">Intravitreal administration</span>

Intravitreal is a route of administration of a drug, or other substance, in which the substance is delivered into the vitreous humor of the eye. "Intravitreal" literally means "inside an eye". Intravitreal injections were first introduced in 1911 when Ohm gave an injection of air into the vitreous humor to repair a detached retina. In the mid-1940s, intravitreal injections became a standard way to administer drugs to treat endophthalmitis and cytomegalovirus retinitis.

Ranibizumab, sold under the brand name Lucentis among others, is a monoclonal antibody fragment (Fab) created from the same parent mouse antibody as bevacizumab. It is an anti-angiogenic that is approved to treat the "wet" type of age-related macular degeneration, diabetic retinopathy, and macular edema due to branch retinal vein occlusion or central retinal vein occlusion.

<span class="mw-page-title-main">Presumed ocular histoplasmosis syndrome</span> Medical condition

Presumed ocular histoplasmosis syndrome (POHS) is a syndrome affecting the eye, which is characterized by peripheral atrophic chorioretinal scars, atrophy or scarring adjacent to the optic disc and maculopathy.

<span class="mw-page-title-main">Angioid streaks</span> Medical condition

Angioid streaks, also called Knapp streaks or Knapp striae, are small breaks in Bruch's membrane, an elastic tissue containing membrane of the retina that may become calcified and crack. Up to 50% of angioid streak cases are idiopathic. It may occur secondary to blunt trauma, or it may be associated with many systemic diseases. The condition is usually asymptomatic, but decrease in vision may occur due to choroidal neovascularization.

<span class="mw-page-title-main">Choroidal neovascularization</span> Creation of new blood vessels in the choroid layer of the eye

Choroidal neovascularization (CNV) is the creation of new blood vessels in the choroid layer of the eye. Choroidal neovascularization is a common cause of neovascular degenerative maculopathy commonly exacerbated by extreme myopia, malignant myopic degeneration, or age-related developments.

<span class="mw-page-title-main">Central retinal vein occlusion</span> Medical condition

Central retinal vein occlusion, also CRVO, is when the central retinal vein becomes occluded, usually through thrombosis. The central retinal vein is the venous equivalent of the central retinal artery and both may become occluded. Since the central retinal artery and vein are the sole source of blood supply and drainage for the retina, such occlusion can lead to severe damage to the retina and blindness, due to ischemia and edema (swelling).

<span class="mw-page-title-main">Laser coagulation</span> Procedure widely used in eye surgery

Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades. During the procedure, a laser is used to finely cauterize ocular blood vessels to attempt to bring about various therapeutic benefits.

<span class="mw-page-title-main">Branch retinal vein occlusion</span> Medical condition

Branch retinal vein occlusion is a common retinal vascular disease of the elderly. It is caused by the occlusion of one of the branches of central retinal vein.

<span class="mw-page-title-main">Radiation retinopathy</span> Medical condition

Radiation retinopathy is damage to retina due to exposure to ionizing radiation. Radiation retinopathy has a delayed onset, typically after months or years of radiation, and is slowly progressive. In general, radiation retinopathy is seen around 18 months after treatment with external-beam radiation and with brachytherapy. The time of onset of radiation retinopathy is between 6 months to 3 years.

Punctate inner choroiditis (PIC) is an inflammatory choroiditis which occurs mainly in young women. Symptoms include blurred vision and scotomata. Yellow lesions are mainly present in the posterior pole and are between 100 and 300 micrometres in size. PIC is one of the so-called White Dot Syndromes. PIC has only been recognised as a distinct condition as recently as 1984 when Watzke identified 10 patients who appeared to make up a distinct group within the White Dot Syndromes.

Anti–vascular endothelial growth factor therapy, also known as anti-VEGF therapy or medication, is the use of medications that block vascular endothelial growth factor. This is done in the treatment of certain cancers and in age-related macular degeneration. They can involve monoclonal antibodies such as bevacizumab, antibody derivatives such as ranibizumab (Lucentis), or orally-available small molecules that inhibit the tyrosine kinases stimulated by VEGF: sunitinib, sorafenib, axitinib, and pazopanib.

<span class="mw-page-title-main">Intravitreal injection</span> Method of administration of drugs into the eye by injection with a fine needle

Intravitreal injection is the method of administration of drugs into the eye by injection with a fine needle. The medication will be directly applied into the vitreous humor. It is used to treat various eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and infections inside the eye such as endophthalmitis. As compared to topical administration, this method is beneficial for a more localized delivery of medications to the targeted site, as the needle can directly pass through the anatomical eye barrier and dynamic barrier. It could also minimize adverse drug effects on other body tissues via the systemic circulation, which could be a possible risk for intravenous injection of medications. Although there are risks of infections or other complications, with suitable precautions throughout the injection process, chances for these complications could be lowered.

<span class="mw-page-title-main">Pachychoroid disorders of the macula</span>

Pachychoroid disorders of the macula represent a group of diseases affecting the central part of the retina of the eye, the macula. Due to thickening and congestion of the highly vascularized layer underneath the macula, the choroid, damage to the retinal pigment epithelium and the retinal photoreceptor cells ensues. This leads to impaired vision. The best known representative of the pachychoroid disease spectrum, central serous chorioretinopathy, is the fourth most common cause of irreversible damage to the macula:.

Sickle cell retinopathy can be defined as retinal changes due to blood vessel damage in the eye of a person with a background of sickle cell disease. It can likely progress to loss of vision in late stages due to vitreous hemorrhage or retinal detachment. Sickle cell disease is a structural red blood cell disorder leading to consequences in multiple systems. It is characterized by chronic red blood cell destruction, vascular injury, and tissue ischemia causing damage to the brain, eyes, heart, lungs, kidneys, spleen, and musculoskeletal system.

Polypoidal choroidal vasculopathy (PCV) is an eye disease primarily affecting the choroid. It may cause sudden blurring of vision or a scotoma in the central field of vision. Since Indocyanine green angiography gives better imaging of choroidal structures, it is more preferred in diagnosing PCV. Treatment options of PCV include careful observation, photodynamic therapy, thermal laser, intravitreal injection of anti-VEGF therapy, or combination therapy.

References

  1. ↑ "Orphanet: Idiopathic macular telangiectasia type 3". www.orpha.net. Retrieved 2020-10-18.
  2. ↑ Christakis, Panos G.; Fine, Howard F.; Wiley, Henry E. (2019-03-22). "The Diagnosis and Management of Macular Telangiectasia". Ophthalmic Surgery, Lasers and Imaging Retina. 50 (3): 139–144. doi: 10.3928/23258160-20190301-02 . ISSN   2325-8160. PMID   30893446.
  3. ↑ Gass, J. D.; Blodi, B. A. (October 1993). "Idiopathic juxtafoveolar retinal telangiectasis. Update of classification and follow-up study". Ophthalmology. 100 (10): 1536–1546. doi:10.1016/S0161-6420(93)31447-8. ISSN   0161-6420. PMID   8414413.
  4. 1 2 3 4 5 Nowilaty, Sawsan R.; Al-Shamsi, Hanan N.; Al-Khars, Wajeeha (2010). "Idiopathic Juxtafoveolar Retinal Telangiectasis: A Current Review". Middle East African Journal of Ophthalmology. 17 (3): 224–241. doi: 10.4103/0974-9233.65501 . ISSN   0974-9233. PMC   2934714 . PMID   20844678. Copyright © Middle East African Journal of Ophthalmology. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
  5. ↑ Shibeeb, O'Sam; Vaze, Anagha; Gillies, Mark; Gray, Timothy (2014). "Macular Oedema in Idiopathic Macular Telangiectasia Type 1 Responsive to Aflibercept but Not Bevacizumab". Case Reports in Ophthalmological Medicine. 2014: 219792. doi: 10.1155/2014/219792 . ISSN   2090-6722. PMC   4198777 . PMID   25349755.
  6. ↑ Charbel Issa, Peter; Gillies, Mark C.; Chew, Emily Y.; Bird, Alan C.; Heeren, Tjebo F.C.; Peto, Tunde; Holz, Frank G.; Scholl, Hendrik P.N. (2013). "Macular telangiectasia type 2". Progress in Retinal and Eye Research. 34: 49–77. doi:10.1016/j.preteyeres.2012.11.002. PMC   3638089 . PMID   23219692.
  7. ↑ Heeren, Tjebo F. C.; Holz, Frank G.; Issa, Peter Charbel (2014). "First Symptoms and Their Age of Onset in Macular Telangiectasia Type 2". Retina. 34 (5): 916–9. doi:10.1097/IAE.0000000000000082. PMID   24351446. S2CID   21073667.
  8. ↑ Powner, Michael B.; Gillies, Mark C.; Tretiach, Marina; Scott, Andrew; Guymer, Robyn H.; Hageman, Gregory S.; Fruttiger, Marcus (2010). "Perifoveal Müller Cell Depletion in a Case of Macular Telangiectasia Type 2". Ophthalmology. 117 (12): 2407–16. doi:10.1016/j.ophtha.2010.04.001. PMC   2974049 . PMID   20678804.
  9. ↑ Labios, Liezel (September 11, 2019). "Study Uncovers Metabolic Cause for Rare Eye Disease". ucsdnews.ucsd.edu. Retrieved 2020-10-19.
  10. ↑ Gantner, Marin L.; Eade, Kevin; Wallace, Martina; Handzlik, Michal K.; Fallon, Regis; Trombley, Jennifer; Bonelli, Roberto; Giles, Sarah; Harkins-Perry, Sarah; Heeren, Tjebo F.C.; Sauer, Lydia (2019-10-10). "Serine and Lipid Metabolism in Macular Disease and Peripheral Neuropathy". New England Journal of Medicine. 381 (15): 1422–1433. doi: 10.1056/NEJMoa1815111 . ISSN   0028-4793. PMC   7685488 . PMID   31509666.
  11. ↑ Charbel Issa, Peter; Finger, Robert P.; Kruse, Kathrin; Baumüller, Sönke; Scholl, Hendrik P.N.; Holz, Frank G. (2011). "Monthly Ranibizumab for Nonproliferative Macular Telangiectasia Type 2: A 12-Month Prospective Study". American Journal of Ophthalmology. 151 (5): 876–886.e1. doi:10.1016/j.ajo.2010.11.019. PMID   21334595.
  12. ↑ Jennings, Katie. "One Blockbuster Drug Explains A Lot About Our Out-Of-Control Healthcare Costs". Business Insider. Retrieved 2021-01-12.
  13. ↑ "Neurotech Pharmaceuticals, Inc. Granted Fast Track Designation from the U.S. FDA for the Treatment of Macular Telangiectasia type 2" (PDF). neurotechusa. February 12, 2019. Retrieved January 14, 2021.
  14. ↑ Lee, Keng Jin (2019-02-15). "Novel implant for macular telangiectasia gains fast-track designation". American Academy of Ophthalmology. Retrieved 2021-01-14.
  15. ↑ "Orphanet: Idiopathic macular telangiectasia type 3". www.orpha.net. Retrieved 2021-01-06.
  16. ↑ "Idiopathic Macular Telangiectasia Type 3 disease: Malacards - Research Articles, Drugs, Genes, Clinical Trials". www.malacards.org. Retrieved 2021-01-06.

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