Genetic basis of glaucoma

Northwestern Medicine scientists and international collaborators discovered mutations that cause improper drainage and a buildup of ocular pressure leading to one form of congenital glaucoma, and identified a path towards future treatments for the disease. Susan Quaggin, MD, chief of Nephrology and Hypertension in the Department of Medicine and director of the Feinberg Cardiovascular Research Institute, was senior author on the studies.

Glaucoma is a leading cause of blindness around the globe, and elevated intraocular pressure (IOP) is an important risk factor for the disease. Developmental defects in the anterior chamber of the eye, including a drainage vessel called Schlemm's canal, can lead to a particularly severe form of glaucoma in children known as primary congenital glaucoma (PCG).

Previous studies from Quaggin and her collaborators have shown loss-of-function mutations in the angiopoietin (ANGPT) receptor TIE2/TEK in families with PCG, and that ANGPT/TIE2 pathway activity is critical for Schlemm's canal development.

 In the JCI study, Quaggin and her colleagues used mice models to explore the importance of individual components of the ANGPT/TEK pathway, finding mice without the growth factor ANGPT1 had severely deformed and small Schelmm's canals. In addition, loss of TIE2/TEK, the angiopoietin receptor, had a similar effect.

Both ANGPT1 and TIE2/TEK are essential to form the drainage system of the eye to regulate intraocular pressure and prevent Glaucoma. Researchers found two human subjects with loss-of-function mutations in ANGPT1 within an international group of PCG patients, further supporting a causative role for ANGPT1 in the disease.

In the PNAS study, Quaggin and her colleagues searched for ways to influence the molecular pathway they'd identified. In particular, inhibition of TIE2/TEK has been linked to vessel leakage and inflammation, so finding a way to activate TIE2/TEK was a priority. Using mouse models, investigators found inhibition of a protein called VEPTP allowed ANGPT2 to be used as a TIE2/TEK activator, providing a blueprint for a pharmacological solution.
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Luxturna for treating inherited retinal disease

Luxturna (voretigene neparvovec) is an adeno-associated viral (AAV) vector gene therapy for the treatment of patients with vision loss due to confirmed biallelic RPE65-mediated inherited retinal disease (IRD). Luxturna is approved for the treatment of patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy that leads to vision loss and may cause complete blindness in certain patients.

Hereditary retinal dystrophies are a broad group of genetic retinal disorders that are associated with progressive visual dysfunction and are caused by mutations in any one of more than 220 different genes. Biallelic mutation carriers have a mutation (not necessarily the same mutation) in both copies of a particular gene (a paternal and a maternal mutation). The RPE65 gene provides instructions for making an enzyme (a protein that facilitates chemical reactions) that is essential for normal vision.

 Mutations in the RPE65 gene lead to reduced or absent levels of RPE65 activity, blocking the visual cycle and resulting in impaired vision. Individuals with biallelic RPE65 mutation-associated retinal dystrophy experience progressive deterioration of vision over time. This loss of vision, often during childhood or adolescence, ultimately progresses to complete blindness.

Luxturna works by delivering a normal copy of the RPE65 gene directly to retinal cells. These retinal cells then produce the normal protein that converts light to an electrical signal in the retina to restore patient’s vision loss. Luxturna uses a naturally occurring adeno-associated virus, which has been modified using recombinant DNA techniques, as a vehicle to deliver the normal human RPE65 gene to the retinal cells to restore vision. Luxturna should be given only to patients who have viable retinal cells as determined by the treating physician(s).

 Treatment with Luxturna must be done separately in each eye on separate days, with at least six days between surgical procedures. It is administered via subretinal injection by a surgeon experienced in performing intraocular surgery. Patients should be treated with a short course of oral prednisone to limit the potential immune reaction to Luxturna. The most common adverse reactions from treatment with Luxturna included eye redness (conjunctival hyperemia), cataract, increased intraocular pressure and retinal tear.
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Drinking tea reduces the risk of glaucoma

A daily cup of tea slashes the risk of developing a serious eye condition. People who drink a cup of hot tea at least once a day are 74 per cent less likely to be diagnosed with glaucoma - a severe eye problem. But coffee, iced tea and soft drinks don't seem to make any difference, the researchers found.

The University of California team found a significant link between tea and glaucoma. Glaucoma, one of the leading causes of blindness, causes fluid pressure to build up inside the eye, damaging the optic nerve.

The scientists believe the antioxidants and natural anti-inflammatory chemicals in tea may play a role in protecting against this process. Glaucoma becomes more common with age, and is a significant cause of blindness.

Tea is a healthy drink, rich in antioxidant polyphenols such as tea catechins and other flavonoids. However, in this research it wasn't the type of tea or its strength that appeared protective, rather the temperature at which it was drunk.
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Outbreak of eye syphilis

According to data from the Centers for Disease Control and Prevention.
Ocular syphilis, which can cause blindness and blurry vision, develops out of a syphilis infection in the spinal cord, which spreads to the eye. Ocular syphilis can involve any part of the eye, but it typically causes inflammation of the middle layer of the eye. It can blur vision, leads to vision loss, and can even travel up into the brain.

A chronic bacterial disease, syphilis can be contracted by other means but is typically a sexually-transmitted disease.
In very rare cases, it can be spread through prolonged kissing, as well as the more common routes of transmission: vaginal, anal and oral sex.
It comes from the bacteria Treponema pallid umbrella. Syphilis is notoriously difficult to diagnose since its symptoms are similar to other conditions - a runny nose and soar throat.

In the early stages, patients can receive an injection of Benzathine penicillin G. This will not undo the internal damage but will eliminate the infection. For those with latent syphilis - and are not sure how long they had it - doctors recommend having three doses of the penicillin injection, seven days apart from each other.
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Blood sugar monitor without finger pricks

U.S. regulators have approved the first continuous blood sugar monitor for diabetics that doesn't need backup finger prick tests. Current models require users to test a drop of blood twice daily to calibrate, or adjust, the monitor.

The pain of finger sticks and the cost of testing supplies discourage many people from keeping close tabs on their blood sugar, which is needed to manage insulin use and adjust what they eat.

The Food and Drug Administration has approved the device, which continuously monitors diabetics' blood sugar levels without requiring backup finger prick tests. Current models require users to test a drop of blood twice daily to calibrate, or adjust, the monitor.

Too-high blood sugar levels can damage organs and lead to heart attacks, strokes, blindness and amputations. Very low blood sugar can cause seizures, confusion and loss of consciousness.

The device was approved for adults with Type 1 or Type 2 diabetes, this device cannot be used with an insulin pump, a device worn against the skin that allows users to inject insulin as needed, but the company is planning improvements to eventually enable that.
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Facts about glaucoma

There are an estimated 64 million people worldwide with glaucoma, a group of eye conditions in which the main nerve to the eye - the optic nerve becomes damaged.

Optic nerve carries information about what is being seen from the eye to the brain - but when it becomes damaged, vision is lost.

According to the Glaucoma Research Foundation, it is now a leading cause of blindness. It's common in men and
women over the age of 40, and if left untreated it can lead to up to 40 per cent of sight being permanently damage.

There are often no early symptoms of glaucoma, but when it becomes more advanced, signs may include missing or patchy sight or even serious loss of vision.

However, if detected early, it can be managed and useful sight can be maintained for years to come.
Although ten per cent of people with glaucoma who receive proper treatment still experience loss of vision.

Regular check-ups with an optician every two years, or one to two years if you’re over 40 is recommended. A
recent study found it may be possible to predict glaucoma in this way up to ten years in advance. Glaucoma is treated
with eye drops which must be used for a long period of time.

Artificial intelligence has potential to fight blindness

Researchers from the Byers Eye Institute at Stanford University have discovered a way to use artificial intelligence to fight condition of diabetes that affects the eyes.

Researchers  used deep-learning methods to create an automated algorithm to detect diabetic retinopathy. Diabetic retinopathy (DR) is a condition that damages the blood vessels at the back of the eye and later cause blindness.

 Artificial intelligence-based grading algorithm can be used to identify, with high reliability, which patients should go for treatments.

Dr. Leng and his colleagues created an algorithm based on more than 75,000 images from a wide range of patients from different ethnicities, and then used it to teach a computer to identify healthy patients and those that need treatment.

Dr. Leng's algorithm could identify all disease stages with an accuracy rate of 94 percent. Opthalmologist diagnose
 the presence and severity of diabetic retinopathy by direct examination of the back of the eye.