Page 36 - July-August 2020

CAN DRINKING EYE DROPS FOR SYNTHETIC

TEA HELP RETINAL VEIN GEL TO REPAIR
PREVENT OCCLUSION CORNEA
MACULAR

Moorfields Eye Hospital and UCL
DISEASE? Researchers at Columbia Institute of Ophthalmology, UK, have
University Irving Medical Center developed an unusual way to treat
have developed eye drops that could a perforated or thinning cornea (the
A number of publications across prevent vision loss after retinal vein clear layer at the front of the eye
the UK recently reported that occlusion (RVO). which allows light in). The technique
drinking tea could be beneficial to Retinal vein occlusion is caused uses a gel that can repair holes in the
eye health. when a major vein that drains blood cornea without the need for a corneal

The article stated that ‘daily tea from the retina is blocked, typically transplant.
drinking could reduce the risk of due to a blood clot. Owing to this, Perforation or thinning of the
developing glaucoma and cataracts, blood and other fluids leak into the cornea that sometimes occurs due
among the most common potentially retina, damaging the specialised to an injury or infection can block or
sight-threatening eye conditions’. light-sensing neurons called scatter light entering the eye,
It said that ‘tea catechins may also photoreceptors. affecting all aspects of vision.
protect against age-related macular Presently, transplantation with a donor
degeneration (AMD)’. RVO is usually treated with drugs cornea is the standard treatment for
that reduce fluid leakage from blood corneal blindness – however, due to a
The Macular Society, UK, vessels and abnormal blood vessel major worldwide shortage of cornea
decided to look at the science behind growth. However, these therapies donors, alternative treatments have
these claims. Geraldine Hoad, require repeated injections directly become necessary.
Macular Society research manager, into the eye and often the treatment
said: “There is currently not enough is not fully successful in preventing The new treatment offers several
evidence to definitively say vision loss. advantages. The use of synthetic
that drinking tea can help to collagen in lieu of human collagen
prevent AMD. According to Carol M. Troy, MD, brings the cost down considerably,
PhD, who led the studies, the new while reducing the risk of immune
“We do know that AMD is treatment targets an enzyme called rejection. The fact that it is done in
caused in some way by oxidative caspase-9, which is assumed to be an outpatient clinic instead of an
stress in the eye damaging retinal chiefly involved in programmed cell operating theatre, further reduces
pigment epithelium (RPE), a thin death, a tightly regulated mechanism costs and is more practical for both
layer of cells at the back of the eye. for naturally eliminating damaged or the hospital and the patient. Also,
Catechins found in tea – particularly excess cells. the method does not require light
green tea – have been shown to exposure to help the gel to set –
have anti-oxidative properties. “We believe these eye drops this benefits patients with corneal
Some scientists believe that these may offer several advantages over inflammation as they are very
antioxidants could work to reduce existing therapies. Patients could sensitive to light.
oxidative stress in the RPE cells, but administer the drug themselves
further research would be needed and wouldn’t have to get a series Moorfields Eye Hospital and UCL
to find out if this had any effect in of injections. Also, our eye drops Institute of Ophthalmology consultant
slowing down or stopping AMD. target a different pathway of ophthalmic surgeon, Bruce Allan, said:
retinal injury and thus may help “We are looking forward to this work
“Anti-VEGF drugs are currently patients who do not respond to progressing to clinical trials and believe
used in the treatment of wet AMD, the current therapy” says Carol M. that it has the potential to transform
preventing the growth of unwanted Troy, MD, PhD, Professor, Columbia corneal care in the future.”
or unhealthy blood vessels. A University Vagelos College of
previous study has tentatively Physicians and Surgeons. The international project involved
suggested that green tea extract may collaboration between scientists in
have anti-VEGF effects, but again, The study was published in Canada, the US, Belgium, Australia,
there is no conclusive proof of this.” Nature Communications. Sweden and the UK.

| JULY-AUG 2020 | 32 OPHTHALMIC NEWS