Idiopathic Juxtafoveal Macular Telangiectasia (MacTel)
MacTel is a disorder of the blood vessels which supply the
macula. MacTel refers to a curious, very poorly understood condition
of the blood vessels around the fovea (juxtafoveal) which become dilated
and incompetent, like varicose veins but on a much smaller scale.
While MacTel does not usually cause total blindness, it commonly causes loss
of the central vision, which is required for reading and driving vision, over a
period of 10-20 years
There are two forms of idiopathic juxtafoveal retinal telangiectasia (IJRT): unilateral and bilateral.
The unilateral form, (Type 1 or aneurysmal telangiectasia) ,occurs almost exclusively in males and is asymptomatic until after age 40. In this group, lipid exudate is common, while pigment plaques and retinal crystals are rare.
The bilateral form, (Type 2 or perifoveal telangiectasis), occurs equally in males and females. Type 2IJRT is typically discovered between the ages of 40 and 60 years,with a mean ageof 55–59 years
Laser photocoagulation has been the recommended treatment early in the course of Type I IJRT to help suspend the exudative process and diminish macular oedema. In contrast, laser therapy is not considered a viable treatment option for Type 2 IJRT, unless frank neovascularization is evident on fluorescein angiography.
Additional therapies include surgical removal of CNV, photodynamic therapy with verteporfin and treatment with anti-VEGF drugs such as Lucentis or Avastin.
However, these treatment modalities should only be considered in cases of marked and rapid vision loss secondary to macular edema or CNV. Otherwise, a conservative approach is recommended, since many of these patients will stabilize without intervention.