It’s Tuesday 12th March … Happy World Glaucoma Day!

World Glaucoma Week (10 – 16^th March 2024) is a collaborative effort between the World Glaucoma Association and the World Glaucoma Patient Association, celebrating a decade of success. The week is dedicated to raising awareness about glaucoma, often referred to as the “silent thief of sight.”

Glaucoma encompasses a range of eye diseases that lead to progressive damage of the optic nerve, responsible for transmitting visual information to the brain. If untreated, glaucoma typically advances without warning or noticeable symptoms, resulting in gradual vision loss and potentially blindness. Once vision is lost, it is usually irreversible, earning glaucoma the title of “silent blinding disease.”

Globally, glaucoma is the second leading cause of blindness. Alarmingly, up to 50% of those with the condition in developed countries are unaware they have it, and this figure can rise to 90% in less developed regions.

There are various types of glaucoma, with some developing as a complication of other eye disorders (known as “secondary” glaucoma), while the majority are classified as “primary,” arising without a known cause. It was once thought that high intraocular pressure (IOP) was the primary cause of glaucoma, but it is now understood that individuals with normal IOP can also develop the disease. Consequently, IOP is considered a risk factor alongside other elements such as black race, family history, high myopia, and age.

Some forms of glaucoma can be congenital or occur during childhood, but most cases appear after the age of 40, with prevalence increasing with age. There is no significant difference in glaucoma rates between men and women. The most common types of adult-onset glaucoma include Primary Open Angle Glaucoma (POAG), prevalent among individuals of Caucasian and African descent, and Angle-Closure Glaucoma (ACG), which is more frequently seen in individuals of Asian descent. ACG can be chronic like POAG or, in acute cases, present as a painful condition leading to rapid vision loss.

Currently, there is no cure for glaucoma, and any vision loss is irreversible. However, medications and surgical options (both traditional and laser) can slow or prevent further loss of vision. Therefore, early detection is crucial in limiting visual impairment and preventing progression to severe visual disability or blindness. Eye care professionals can identify glaucoma in its early stages and recommend appropriate actions. Visit your local opticians for vision and glaucoma screening or consult a doctor if you have either sudden pain in the eyes with redness and blurred vision.

Image – reproduced under Open Access from Hsu E, Desai M. Glaucoma and Systemic Disease. Life. 2023; 13(4):1018. 

Keratoconus (KC), covered in depth in our earlier blog post, is an uncommon degenerative eye condition characterised by the progressive thinning of the normally round and dome-shaped cornea. The thinning results in the formation of a cone-like bulge, typically at the centre of the cornea. If left untreated, Keratoconus can lead to significant visual impairment and potential legal blindness. The condition typically starts in adolescence or early adulthood. While the precise cause of keratoconus remains unknown, experts believe it arises from a combination of genetic and environmental factors. Various sources suggest an association between long-term eye rubbing and the development of Keratoconus, as it may change the shape of the front of the eye.

World Keratoconus Day serves as an initiative aimed at increasing awareness, providing education, and offering support to individuals living with keratoconus and their families. It instills hope for those grappling with the challenges posed by this debilitating condition. Many affected individuals, often young, find their lives significantly impacted by severe visual impairment or blindness. Unfortunately, the solution to their condition is underfunded in the public healthcare system in South Africa. This invisible disability takes a tragic toll on various aspects of life, affecting education, employment, and mental health.

The Eyes2Eyes Foundation launched a custom design Scleral Lens Programme at the Groote Schuur Cornea Clinic in June 2021. 90 young patients diagnosed with advanced keratoconus joined our programme in 16 months. A total of 102 scleral lenses have been funded for disadvantaged patients with advanced keratoconus. Scleral lenses are precision custom lenses that smoothen the optical surface to reduce the irregularities of the corneal surface. Eyes2Eyes has established a strong team of skilled professionals in South Africa and New Zealand, dedicated to world class care for patients in the Western Cape.

How can I help – right now?

• Donation to Eyes2Eyes to continue supporting the Scleral Lens Programme. Photos of the clients that we have supported can be found on our social media channels, especially our Eyes2Eyes Instagram Page
• Peruse the World KC Day Toolkit from the National Keratoconus Foundation (United States) and raise awareness of the condition through social media channels
• If you are living and affected with Keratoconus, enter the “Keratoconus & Me” photo competition run by the National Keratoconus Foundation (United States)

More information on Keratoconus can be found at the following link: https://nkcf.org/understanding-kc/

The cornea is the clear front surface of the eye. Have you ever wondered about the significance of a Cone-Shaped Cornea is, and how it could affect vision? The word keratoconus comes from the Greek words ‘keras’, meaning cornea, and ‘conus’, meaning cone, which together means ‘cone- shaped’ cornea.

Keratoconus affects all ethnicities and both sexes. The highest rates typically occur in 20- to 30-year-olds, but it is fairly common for it to be found in adolescents. It often develops in the 2^nd and 3^rd decades of life and tends to progress until the 4^th decade. While it is commonly found as an isolated eye condition, it sometimes can coexists with other eye and multi-system diseases.  

This disease is more aggressive in children than in adults and can have debilitating consequences for their vision as the condition deteriorates. Given its onset usually during their formative adolescent/adult years keratoconus can fundamentally alter the psychosocial profile of individuals. Even if their visual acuity can be corrected, patients with keratoconus are still likely to experience significant impact on their quality of life (1). The combined visual deterioration and psychological stress may debilitate patients from achieving their academic potential and contributing meaningful to their communities and economy.

Keratoconus is considered a bilateral and asymmetric (i.e. one eye is typically more severely affected than the other) (2-6) eye disease which results in the progressive thinning and steepening of the cornea leading to irregular astigmatism (i.e. irregular contouring of the cornea along its surface, affecting the way in which light enters the eye) and reduced visual acuity (i.e. less “seeing power” for the eye) (7-9). Images may also appear distorted, and the eyes may become more sensitive to glare and light.

Our understanding of the mechanism behind the development of keratoconus remains limited. The interplay between genetic and environmental factors have been associated with the cause and progression of this disease. Keratoconus progresses because of a combination of simultaneously occurring destructive and healing processes.

Acanthamoeba Keratitis

Acanthamoeba is a genus of single-celled amoeba commonly found in water and soil environments. Some species of Acanthamoeba are also capable of causing infections in animals. Some species of Acanthamoeba are also capable of causing serious infections in humans, including brain infections, skin infections, and acanthamoeba keratitis (an eye infection that targets the cornea). Acanthamoeba keratitis affects the cornea and can cause significant pain, redness, blurred vision, sensitivity to light, and the sensation of something in the eye. It is most common in people who wear contact lenses, but anyone can get the infection. It is so painful because the outermost surface of the cornea is exquisitely sensitive – it has a nerve density that is 300–600 times that of the skin! (1). To prevent this relatively rare infection, it is so important to practice good hygiene, especially when handling contact lenses. Never use tap water on your contact lenses, because acanthamoeba can be found in tap water. Acanthamoeba can also survive in chlorinated swimming pools (2) so protecting your contact lenses with goggles if you cannot take them off completely is a good idea. If left untreated, acanthamoeba keratitis it can lead to corneal ulcers, serious vision loss and even blindness. Treatment involves the use of anti-amoebic medications and may also include surgical removal of infected tissue. Early diagnosis and prompt treatment are crucial for the best outcome – seek eye care urgently.

Bottom Image: Corneal melting and new inflammatory growth of blood vessels in a patient with Acanthamoeba keratitis. They lost vision in this eye. Reproduced via open access (3)

References

1. Zander E, Weddell G. Observations on the innervation of the cornea. J Anat. 1951;85(1):68-99.
2. Kaji Y, Hu B, Kawana K, Oshika T. Swimming with soft contact lenses: danger of acanthamoeba keratitis. The Lancet Infectious Diseases. 2005;5(6):392.
3. Lorenzo-Morales J, Khan NA & Walochnik J: An update on Acanthamoebakeratitis: diagnosis, pathogenesis and treatment. Parasite, 2015, 22, 10.

Eyes are rich sensory organs (so practically speaking, they have feelings!). They eyes are happier when they are healthier – they function better and for longer, and there is less need to seek care from optometrists and ophthalmologists. Five general everyday tips are included below that could be used to keep your eyes in good health.

1. Protect your eyes from the sun

UV (ultraviolet) rays, which are given off by direct sunlight, can be harmful to your skin and eyes. If you have consistent sun exposure, without proper eye protection, there is a higher risk of developing cataracts. Certain UV rays of greater intensity are also more aggressive towards the retina. Your thin skin around your eyes can also develop skin cancer and wrinkles. Be sure to wear UV-protective sunglasses even on cloudy days.

2. Have a well-balanced, nutrient rich diet

Eating bright and colourful vegetables can help protect and fortify your eyesight. Orange carrots are full of beta carotene, which is the precursor of Vitamin A. This vitamin is a valuable antioxidant that helps reduce molecular stress and renew cells in the eyes. Oranges and peppers contain Vitamin C, Vitamin E, zeaxanthin, and lutein. These nutrients lower your risk of developing macular degeneration. Green vegetables, like broccoli, kale, lettuce, and peas, also contain valuable nutrients for your cornea and other eye structures. Some light cooking will keep most of their nutrients intact.

3. Don’t smoke

The free-radicals in tobacco smoke make smoking harmful to the eye in two main ways. Firstly, the direct irritation caused by the smoke coming into contact with the eye, which irritates and damages the cornea. The free radicals are responsible for damaging the lipids and proteins in the eyes and causing deposits to form on the surface of the eye’s lens— leading to cataract development. Secondly, there are systemic effects of smoking reduces blood oxygen, damages the blood vessels and causes widespread inflammation. The cumulative effect of this could cause damage to the insulating layer between the retina and the blood vessels that nourish it, potentially leading to degeneration of the macula, which is responsible for receiving light at the centre of the eye.

4. Take regular eye breaks

If you are concentrating on your computer or general work tasks at a desk all day, you can develop eye strain. To rest your eyes, try to concentrate on blinking – it is easy to forget when you are very focused. Try blink for three to four seconds at a time for about two minutes. This will help lubricate your eyes. The tears will cleanse your eyes to improve your focus. It is also valuable to rest your eyes completely from your tasks. For example, every 20 minutes, you could look at something 20 feet away for 20 seconds.

5. Exercise

Exercise improves blood flow throughout the body and removes waste products from all your organs. Exercise is especially good for supplying the retina and optic nerve with important nutrients so that they work optimally. Exercise is also important for corneal nourishment. Additionally, long-term exercise has the effect of reducing the pressure inside your eyes, which prevents permanent damage to your optic nerve. Without a working optic nerve, light signals will not be sent from the eye to the brain, causing vision loss. However, it is important to not be too strenuous with exercise (e.g. with very heavy weights) as this can cause damage! Equally, if you feel pain in your eyes during exercise, it is advisable to take a break and seek medical attention if the problem persists.