Macular telangiectasia

Macular telangiectasia describes two distinct retinal diseases affecting the macula of the eye, macular telangiectasia type 1 and macular telangiectasia type 2. Macular telangiectasia describes two distinct retinal diseases affecting the macula of the eye, macular telangiectasia type 1 and macular telangiectasia type 2. Macular telangiectasia (MacTel) type 1 is a very rare disease, typically unilateral and usually affecting male patients. MacTel type 2 is more frequent than type 1 and generally affects both eyes (bilateral). It usually affects both sexes equally. Both types of MacTel should not be confused with Age-related macular degeneration (AMD), from which it can be distinguished by symptoms, clinical features, pathogenesis, and disease management. However, both AMD and MacTel eventually lead to (photoreceptor) atrophy and thus loss of central vision. The etiology of both types of MacTel is still unknown and no treatment has been found to be effective to prevent further progression. Because lost photoreceptors cannot be recovered, early diagnosis and treatment appear to be essential to prevent loss of visual function. Several centers are currently trying to find new diagnostics and treatments to understand the causes and biochemical reactions in order to halt or counteract the adverse effects. Contemporary research has shown that MacTel type 2 is likely a neurodegenerative disease with secondary changes of the blood vessels of the macula. Although MacTel type 2 has been previously regarded as a rare disease, it is in fact probably much more common than previously thought. The very subtle nature of the early findings in MacTel mean the diagnoses are often missed by optometrists and general ophthalmologists. Due to increased research activity since 2005, many new insights have been gained into this condition since its first description by Dr. J. Donald Gass in 1982. Patients with idiopathic macular telangiectasia type 1 are typically 40 years of age or older. They may have a coincident history of ischemic vascular diseases such as diabetes or hypertension, but these do not appear to be causative factors. Macular telangiectasia type 2 usually present first between the ages of 50 and 60 years, with a mean age of 55–59 years. They may present with a wide range of visual impact, from totally asymptomatic to substantially impaired; in most cases however, patients retain functional acuity of 20/200 or better. Metamorphopsia may be a subjective complaint. Due to the development of paracentral scotomota (blind spots), reading ability is impaired early in the disease course. It might be even the first symptom of the disease.