Time to Open Our Eyes this World Sight Day

It’s worth pausing for a moment to think about our eyes and the wonderful sense of vision that they provide for us. As I write this, I look out through my window and I see the sky and the beauty of autumn. I sometimes remember to feel that this is a privilege, not to be taken for granted.

Many millions of people globally don’t have this pleasure – some have never seen, some have lost their sight going through life. Vision impairment and blindness can have major effects on all activities of life, for many people savagely pruning their natural potential.

Globally, as with almost everything, those underprivileged through geography or poverty are affected the most by sight loss. Conditions easily and routinely corrected in wealthy settings, such as an unoperated cataract and uncorrected refractive errors, are still the leading causes of vision impairment globally. Millions of children can’t read because they simply can’t get the spectacles they need. More complex causes such as age-related macular degeneration, glaucoma, diabetic retinopathy and ocular infections, can largely be addressed effectively within the health infrastructure of wealthy economies. Without this, they are a tragic untreated fact of life.

Cause for Hope

There have been lots of successes in tackling the causes of blindness. Possibly the commonest surgical procedure in the eye is to treat cataracts. The first written description, in Sanskrit, dates to around 600 BC in India. The procedure is now rapid and sophisticated, replacing the defective lens with a plastic implant.

Treatment of parasitic diseases of the eye in tropical countries was revolutionized by the Nobel Prize-winning research of William Campbell on river blindness. The drug, ivermectin, was made available for free to developing countries by its patent owner Merck.

Research over the past couple of decades into the causes of vision impairment has also been highly successful. Diabetic retinopathy, ‘wet’ macular degeneration and other conditions are now greatly helped by anti-VEGF drugs that were developed in the early 2000s to inhibit the growth of abnormal blood vessels in the eye.

Treatment of inherited retinopathies remains a challenge and an opportunity. There are many of these, perhaps the most notable being retinitis pigmentosa, in which gene defects impair the structure of proteins that transduce light in the eye to nerve impulses. The first gene therapy to receive FDA approval was ‘Luxturna’ for a specific mutation causing retinitis pigmentosa RPE65 and patients are now benefiting from this. A considerable number of trials of both gene and cell therapy are listed on ClinicalTrials.gov. Additionally, CRISPR/Cas9 gene editing for another inherited retinopathy, Leber’s, is in clinical trial with reported vision improvement in patents.

Overall, research is making rapid strides in evolving advanced treatments to stop vision deteriorating and even to restore sight to some extent. The confined environment of the eye makes it an excellent environment in which to explore complex somatic genetic therapies before introducing them to other organs.

Opening Our Own Eyes

Meanwhile, people with vision impairment get on with their lives. Many, like our Paralympic athletes who refuse to be limited by their disability, are inspirational. But most visually disabled people contend daily with the kinds of problems of which the fortunate rest of us are blissfully unaware. Even navigating their local streets, they must contend with dog fouling on the pavement and obstructions in their way. A small errand that is trivial for most of us can be, for them, a major expedition to navigate difficult public transport and avoid smartphone-focused passers-by. We could all improve their lives by a small bit of foresight and care.

Heading into this time of year, full of color in nature, with blue skies, red fruits and russet leaves, it is a good time to think about our sight and about those who lack it. How can we support our impaired fellow citizens through small considerate acts that clear their way? How research on vision treatments has been so fruitful and will continue to lead new approaches to cure other diseases. And how we need to make geography less relevant for those with simple and easily corrected sight impairment.

Fighting Blindness – Irish charity funding research into treatments for sight loss
Foundation Fighting Blindness – World’s Leading private funder of retinal disease research