Our eyes are comprised of many different structures and membranes. The back of each eye houses the retina, a tissue that contains layers of cells and enables us to sense light. Within this area is a thin, multi-layered elastic tissue known as the Bruch’s membrane, which preserves the blood-ocular barrier. The Bruch’s membrane thickens with age, and certain systemic diseases can also cause the elasticity of the membrane to decrease. When this happens, angioid streaks can form.
If you have angioid streaks in one or both eyes, it is possible to remain asymptomatic and maintain perfect vision for a long time. In many cases, however, these fine cracks in the membrane expand, leading to visual impairment. The effects of angioid streaks are much more severe if the cracks extend into the center of the retina. Those with angioid streaks are also at risk for membrane rupture and the formation of new blood vessels known as macular choroidal neovascularization (CNV). The most serious complication of angioid streaks is the development of CNV blood vessels, which is also common in those afflicted with wet age-related macular degeneration (AMD). This means that vision loss in individuals with angioid streaks is similar to those with AMD.
This eye condition was first described in the late 1800s, when doctors realized that the dark red or grey-colored lines radiating from around the optic nerve area were not additional blood vessels. The lines are typically narrow and jagged, and almost always appear bilaterally. Angioid streaks can worsen due to further loss of elasticity, mineral deposits within the membrane, and the CNV abnormal blood vessels that can developinside the cracks. These complications within the retina can cause distortion, the formation of blind spots, and progress loss of central vision.
This condition can cause enough problems on its own, but having angioid streaks could indicate the presence of another disease elsewhere in the body. These systemic diseases are mostly elastic tissue diseases and include Ehlers-Danlos syndrome, Paget’s disease, and pseudoxanthomaelasticum (PXE). Patients with sickle-cell anemia may also have angioid streaks, although other forms of anemia, from iron deficiencies, do not develop the. The presence of angioid streaks in individuals with sickle-cell anemia is likely due to calcium deposits within the Bruch’s membrane. Many patients with angioid streaks test positively for an inherited condition.
In most cases, angioid streaks can be diagnosed during a regular eye exam. It is important to visit your optometrist on a regular basis so that any issues such as angioid streaks can be caught early on. The condition is typically diagnosed by fundoscopy or fluorescein angiography. If it isnot possible for your optometrist to determine the borders of the neovascular membrane due to nearby hemorrhages or lesions, Indocyanine Green angiography may be used.
Some individuals diagnosed with angioid streaks are also found to have patterns of yellowish leopard-skin or peau d’orange spotting. In general, angioid streaks are rare, but they are sometimes confused with other, more common conditions due to the range of appearance and clinical characteristics. In several past case studies examined by the Wills Eye Hospital in Philadelphia, angioid streaks have been misdiagnosed as other degenerative or inflammatory diseases including ocular histoplasmosis, ocular toxoplasmosis, myopia, and retinal vasculitis. The patients in these studies were sometimes incorrectly treated, and many of them were also found to have pseudoxanthomaelasticum (PXE).
Angioid streaks can cause brittleness within the Bruch’s membrane and the retina, which means that afflicted individuals have fragile eyes. Any trauma to the head or eyes could cause choroidal rupture or hemorrhaging, leading to significant visual impairment. Optometrists typically recommend sturdy, polycarbonate eyeglasses, and protective goggles must be worn during sporting activities.
Early diagnosis is essential to helping prevent the worsening of angioid streaks and the development of CNV vessels. Laser treatments and surgeries may help halt the progression of the condition, which means that many patients achieve visual stabilization and will not face complete vision loss. For those with existing or developing impairments, however, a huge variety of low vision aids now exist. Visit Low Vision Technologies to see what tools you could use to help you retain independence and make your everyday life easier.