Macular Telangiectasia (MacTel)

What is Macular Telangiectasia (MacTel)?

Macular telangiectasia (MacTel) is an eye condition that affects the macula. While there are several types, type 2 is the most common. It develops when there are problems with the tiny blood vessels around the fovea, which is located in the center of the macula and is responsible for the sharpest central vision. MacTel type 2 usually affects both eyes, but one eye may be worse than the other.

In more advanced cases of Mac-Tel type 2, new blood vessels form under the retina and can leak fluid or bleed, which is called subretinal neovascularization, or it can also progress to development of a macular hole.

Symptoms

Symptoms of MacTel type 2 often develop gradually and can include:

Blurry or distorted central vision
Difficulty with reading
Trouble seeing at night
Formation of a dark spot
Straight lines appearing wavy

Risk Factors

Macular telangiectasia (MacTel) type 2 is most often diagnosed between the ages of 40-50. Specific risk factors include:

Diabetes
Smoking
High blood pressure (hypertension)

Diagnosis

Your Texas Retina physician will begin by dilating your pupils and examining your retina. Since macular telangiectasia (MacTel) type 2 occurs inside the retina, your doctor may also conduct specialized imaging tests to make an accurate diagnosis. These can include:

Fluorescein Angiography (FA)

In this test, a small amount of vegetable-based dye is injected into a peripheral vein, usually in the arm. This dye lights up the retina’s vascular network so detailed images can be taken. These images can indicate whether any blood vessels are leaking and how much leakage there is.

Optical Coherence Tomography (OCT)

In this non-invasive test, a special camera is used to photograph your retina. It scans the retina and provides very detailed images and measurements of the retina and macula. Sometimes it will uncover tiny areas of fluid or retinal irregularity not readily apparent to a retina specialist during a microscopic exam.

Optical Coherence Tomography Angiography (OCT-A)

Optical coherence tomography angiography (OCT-A) has emerged as a non-invasive technique for imaging the microvasculature of the retina and the choroid. Unlike FA, it does not require an injectable dye. OCT-A measures the reflection of a laser light on the surface of moving red blood cells to accurately depict vessels through different segmented areas of the eye. Even when standard OCT scans appear normal, an OCT-A can reveal changes deep in the capillary plexus, where MacTel 2 often begins.

Treatment

For many years, there was no effective treatment for macular telangiectasia (MacTel) type 2. In some cases, intravitreal injections of anti-VEGF medications, like Avastin, Lucentis and Eylea, have been used to try to slow the growth of “leaky” blood vessels with limited effectiveness. In March 2025, the U.S. Food and Drug Administration (FDA) approved Encelto (NT-501 implant), a cell-based gene therapy, which is the first disease-modifying treatment for MacTel type 2.

Encelto is a small capsule, about the size of a grain of rice, that is surgically placed inside the eye to release a naturally occurring protein called ciliary neurotrophic factor (CNTF). The capsule contains living cells that have been genetically modified to continuously produce and release CNTF, which can directly reach the retina and help preserve certain light-sensing cells in the retina known as photoreceptors, slowing the rate of vision loss.

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