Banele

A progressive eye disease in which the cornea (the clear, dome-shaped structure at the front of the eye that covers the iris and pupil) bulges outward in a cone shape. The cornea directs light into the eye and helps focus it on the light-sensitive retina at the back of the eye, which enables sharp vision. When the cornea becomes cone-shaped, it distorts light entry and blurs vision, and may cause sensitivity to light and glare.

As the cornea changes shape, its smooth surface also warps. This is called irregular astigmatism, and glasses cannot fully correct it. As the corneal curvature increases, the eye becomes progressively more myopic, so you may need new glasses more often. This is when hard contact lenses come in.

Keratoconus usually affects both eyes, though one eye can be affected more than the other. It normally starts in the teenage years or adulthood, and in some cases earlier. There is no cure yet, but there are ways to live with and manage it, especially if it is caught early, as it worsens over time when left untreated.

• Blurred vision, often with halos or rainbow-coloured rings around lights.
• Glasses that work for only a short period before you need a stronger prescription.
• Scarring that can lead to cloudiness in the eye, though not in every case.
• Intense sensitivity to light (photophobia), often during exposure to screens or fixed light sources, leading to discomfort and headaches.

There is no single known cause. Researchers believe genetic and environmental factors are involved. As someone living with keratoconus, I have noticed some potential causes:

• Allergies: They can cause itchy eyes, which leads to excessive rubbing. This weakens the cornea and can change its shape to a cone. Dark circles around the eyes are often a sign. Sinus problems can cause the same itchiness. This falls under environmental factors.
• Genetics: Studies show that in some cases keratoconus is passed down in families, and not always from a mother or father. It can come from more distant relatives.

There is no cure, but some treatments have been scientifically shown to improve the eyesight of people living with keratoconus.

Cross-linking uses ultraviolet (UV) light and may slow or stop keratoconus from progressing. You receive local anaesthesia, then riboflavin (vitamin B2) drops go into your eye for up to 30 minutes, followed by up to 30 minutes of UV light. The aim is to strengthen the bonds between the cornea's collagen fibres and surrounding proteins, which helps keep the cornea from getting steeper. Complications include:

• Eye discomfort
• Dry eyes
• Infection
• Keratoconus getting worse

Glasses or contact lenses. In the early stages, normal eyeglasses or soft contact lenses can correct vision. As keratoconus gets worse, glasses may not be enough because of irregular astigmatism, and you may need a special hard contact lens.

Cornea transplant. As my optometrist described it, this is typically a last resort for advanced keratoconus. The diseased cornea is replaced with tissue from a human donor. Vision is usually better afterwards, but it can take more than a year to stabilise, and some people still need a specialty contact lens. Complications include:

• Cornea graft rejection
• Infection
• Glaucoma, a group of progressive eye diseases that build up pressure inside the eyeball and can damage the back of the eye, leading to permanent vision loss

My name is Banele Mkhize. I had worn glasses for only two years when I was younger, and only one lens was prescribed. In March 2025, I went to an optometrist for glasses after my vision worsened over the years. He determined that I have keratoconus.

I then went to the ophthalmologist who had been with me for years. She confirmed keratoconus, but not at an advanced stage. When I told her what the optometrist had said, she discouraged cross-linking. It was a newer treatment with a high success rate, but because of my age and my still-developing eyes, she advised that it might be ineffective or carry greater risk during growth.

3D-printed cornea. Corneal transplantation remains one of the most effective treatments for advanced keratoconus, often restoring vision and halting progression. But it is limited by a global shortage of donor corneal tissue. 3D-printed corneas are a promising alternative. They are made with 3D bioprinting, which deposits biocompatible materials and cells in layers that closely replicate the anatomy and function of the human cornea.

The specialised bioprinter is called a Keratoprinter. It is designed to reproduce the curved, multilayered structure of the cornea using natural biomaterials such as collagen. The project aims to build a modular bioprinter that produces transparent, mechanically stable corneal tissue, using bio-based inks made from human-compatible materials. Digital tools would allow patient-specific customisation using corneal topography data.

Intracorneal ring segments (ICRS). These are small, crescent-shaped plastic devices implanted in the cornea to reshape its curvature and improve vision. They act as spacers between the collagen fibres, shortening the arc and flattening the central cornea. Models based on finite element analysis show the flattening is directly proportional to the thickness of the segment and inversely proportional to the corneal diameter where it is implanted. So a thicker segment in a smaller diameter flattens the cornea more.