Idiopathic Perifoveal Telangiectasia
Idiopathic Perifoveal Telangiectasia, also known as macular telangiectasis, is a peculiar retinal vascular disorder that affects the central portion of the macula. Its pathogenesis is unknown; however, other features of the disease, such as its clinical manifestations and unrelated imaging to document its nature are well–recognized by the ophthalmic community.
This is a disorder that surfaces in the fourth to sixth decade with no specific gender or racial predilection.
Dilated retinal capillaries occur around the temporal aspect of the foveal area, eventually encircling the fovea completely. There may be some degree of asymmetry but the disorder is virtually always bilateral. The dilated capillaries become associated with pigmentation which migrates below the retina, vitreoretinal interface glistening crystals, and leakage noted on fluorescein angiography. There is also an inner lamellar cyst which can be imaged with Ophthalmic Coherence Tomography (OCT). These changes at the fovea correlate back to the visual function with regard to acuity.
In the course of the disease, there are two distinct phases, one, a non–proliferative, where there is just leakage of retinal capillaries, and the more advanced form where new blood vessels begin to proliferate from the deep retinal circulation under the retina or proliferative stage. When the latter stage evolves, there is further anatomical disorganization of the retina with development of a fibrotic scar with associated loss of vision. The neovascularization proliferates from the retinal circulation rather from the choroid neovascularization which is more characteristic of neovascular age–related macular degeneration.
There is no known treatment, although several modalities have been studied, including laser photocoagulation, photodynamic therapy, and one or more pharmacological agents administered in the periocular space or within the vitreous itself. These include steroids and anti–vasogenic drugs. An international study directed by the National Eye Institute, entitled “Mactel”, is currently under investigation at numerous centers throughout the world. (https://web.emmes.com/study/mactel/index.htm)|
Fluorescein angiogram demonstrating perifoveal leakage in the non–exudative form. (Click image for full size image.)
Fluorescein angiogram demonstrating exudative scarring of the foveal region. (Click image for full size image.)
OCT demonstrating the inner lamellar cyst often present in the non–exudative form.