The Cure to Blindness is Just in Sight

Blindness is a disease that affects over 285 million people per year. This number is crazy; so why haven’t we tried to eradicate it?

We have.

We just failed.

What if I told you there was a way we could succeed? Let's just say this solution includes the anatomy of the eye, different diseases, stem cells, miniature scaffolds, and cats.

(I’m joking no cats were harmed in the making of this article)

Aside from bad jokes, I've been creating a new word of the device to help deliver stem cells smoother into the optic nerve. Before we get into the complicated science behind that, I thought it would be wise to dive deep into the anatomy of our eyes 👁.

As we dive deep into optical nervous stem cells, it's important to keep the anatomy of the eye in mind. The eye is a human body has 6 main parts. These parts are crucial to your ability to see and interpret images. If any of these parts are damaged or insufficient, it will be impossible for the eye to function as it previously did. Some parts are not as crucial, they may only affect your ability to see clearly, or the moistness of your eye, but other parts can lead to legal blindness. Before I continue to dive into the problem, solution, pros, and cons, let's review the basic anatomy of the eye, why it's important for you, and what will happen if it's damaged.

Cornea. The cornea is the transparent part of the eye that covers the front portion of the eye. It covers the pupil (the opening at the center of the eye), iris (the colored part of the eye), and anterior chamber (the fluid-filled inside of the eye). The cornea’s main function is to refract or bend, light. The cornea acts as the eye’s outermost lens which is what makes it so important to the eye. It also functions like a window that controls and focuses the entry of light into the eye. The cornea contributes between 65- 75 percent of the eye’s total focusing power. Without the cornea, it would be nearly impossible to focus or see at all. If the corneal was damaged in any way If your cornea is damaged by disease, infection, or an injury, the resulting scars can affect your vision. This might block light from entering your eye, itching, and swelling, as well as the loss of vision.

Pupil. The pupil is the black centerpiece of an eye. The pupil’s function is the let light in and help focus int on the retina (keep reading to find out more about the retina) so that you can see. The muscles that are located in your iris control each pupil. The pupil is a crucial part of the eye because it controls how much light is let into the eye. When thinking of the pupil, I like to think of a camera. In a camera’s aperture, it can choose how much light to allow into the phot itself. This helps it so it does not become too bright or too dull. Similarly, the pupil changes with day and night (instead of a button). During the night, our pupils dilate to allows as much light in as possible so we can maximize our vision in the dark. On the other hand, in the bright sunlight, our pupils tend to shrink so that we do not have an excess amount of light (causing internal damage) and so that we can see normally. If you injure or damage your eye through blunt force trauma, it may damage the nerves that are controlling the pupil or iris, the pigmented parts of your eye. This can usually disrupt the normal responses that the pupils have to light levels. The injuries vary depending on the type of damage done although this is the most common and least severe.

Iris. Inside the eye, the iris is a thin structure that is responsible for controlling the diameter and size of the pupil as well as the amount of light that reaches the retina. Your eye color is defined by the iris itself. It is a part of the front of your eye, which means it's visible to other humans, and it is not on the internal portion. The iris connects to the long ciliary nerves and the short ciliary nerves. In the iris, the main artery is the long posterior ciliary arteries. Alongside the pupil, the iris is mainly responsible for regulating the amount of light that is permitted into the eye. If there is an excess amount of light or a reduction of light, your vision will be affected. The iris is one of the most muscular parts of the eye and in turn, it has to shrink the pupil if there is too much light and widen it if there is not enough. The iris is a crucial part of the eye because of its role to shrink and enlarge the pupil. If the iris is damaged in any way, it could lead to serious vision hampering. If a small tear occurs on the edge of the girls, it can lead to scarring on that area that eventually will block the draining system of the eye, which only leads to higher eye pressure and glaucoma. This is a very serious problem that will affect you all your life.

Lens. The lens is located inside the eye. Through the process of changing its shape, the lens also changes the focal distance of the eye. Simply, the lens focuses the light rays that pass through it (and onto the retina of course) in order to created clear images of objects for the brain that is positioned at various distances and light ranges. The lens of your eye is directly connected to your optical nerve. The lens is the portion of your eye that receives images. Alongside the help of light refraction, the lens is the main reason why you can see images (not just lights)! If the lens is by chance damaged, the consequences can vary. It is very hard to damage only your lens because it is on the inside portion of your eye. The amount of blurring depends on the extent of the detachment and dislocation. A partially detached lens may not cause any symptoms. When the ligaments that support the lens are damaged, the iris (the circular structure that gives the eye its color) also may lose support and my quiver.

Retina. The retina is a part of the eye that is a thin layer of tissue that lines the back of the eye. The retina is located on the inside portion of the eye, so it is not visible to other people. The retina is located near the optical nerve which attaches to the brain. The main purpose of the retina is to receive light that the lens has focused in on and then covert the light into neural signals for the brain, and finally to send these signals to the brain for visual recognition. The retina is crucial to the anatomy of the eye because it is what converts lights into different shapes for the brain to see. If the retina were damaged by chance, it could result in legal blindness. It is near to impossible to damage just the retina, but if you do it could result in paralysis (since it is so close to the brain and spinal cord.

Optic Nerve. The optic nerve is the nerve that connects the front portion of your eye to the brain itself. It does a lot of the communication of information as well. The optic nerve is located in the back of your eye. Another common name for the optic nerve is the second cranial nerve or cranial nerve VII. The main job of the optical nerve is to transfer visual images (like your environment or anything that you see) from the retina to the visual centers inside the brain. The retina converts these images into electrical impulses which the optical nerve delivers to the visual center. If an optic nerve is cut or damaged, it can result in severe damage loss and constant pain, color blindness, and if severe enough, paralysis.

These 6 main parts work together in almost perfect harmony. First, there is the cornea that refracts the lights so that the pupil can focus it. Once the pupil fully focuses it, the iris will control any excess light that manages to slip through. The lens helps with this process of narrowing down the light (or bringing it higher if it's dark outside). Finally, the light comes to the retina which converts it to images and then sends it through the optic nerve and into the brain.

Now that you know the parts, functions, and importance of the eye, it's time to get down to the root problem, blindness. As I have mentioned before, any damage to any part of the eye can cause a lot of damage. It can range from something as small as vision loss (which means you might have to wear glasses) to total blindness. Through various circumstances, blindness affects over 255 million people each year. 255 million people are either blind, wear glasses or some sort of visual aid, have a disease that causes blindness, or other reasons. Nevertheless, blindness is a huge problem that aids our world today.

You now know all about the parts of an eye and what happens if it's damaged, the seriousness behind blindness, but what even is blindness?

As I had previously mentioned, the types of blindness can range; it really just depends on what type of blindness you are talking about. Blindness can range from visual impairment and low vision to total and legal blindness. NCBI (National Center for Biotechnology Information) has declared four categories of blindness. The four categories in order of severity (least to most) are;

Low Vision. Low vision is a term that can be used to describe those whose vision cannot be fully corrected. The “title” of low vision goes to people whose eyesight is under -6.0. From -6.0–0, your vision can be corrected with glasses or other methods. Low vision unfortunately cannot be correct by any conventional method such as glasses, contact lenses, medicine, drug therapy, laser surgery, optical surgery, magnification, aids of any sort, or assistive technology. When your vision turns to this level, it is impossible to reverse, or so we thought.

Visual Impairment. Secondly, we have a visual impairment. Visual Impairment is a term that is used for someone who has a decreased function in their optical nerve and retina. As previously described, the optical nerve and retina are what transform light to images and transfer images to the brain. When this is damaged, it can (and will) interfere with day-to-day activities. People with visual impairments cannot do activities such as reading books, driving, watching tv, and other such activities. Visual impairment is a broad enough category that it also includes low vision.

Total Blindness. Third, we have total blindness. Total blindness is much worse than the first two types of blindness. Total blindness is a term that can be used to describe those who have a complete lack of light perception. This condition is common enough that it has a medical name associated with it, NLP, or no light perception. This condition is caused if you have damaged your cornea, pupil, and lens. Even if you damage one, it is likely that the infection or trauma to that part will spread at least to the other three main light precepting parts of the eye. Lucky, only about 15% of all people with blindness have total blindness (or NLP). Even so, the majority of those people have a split condition, where they can still see some light (often causing them to be placed in the visual impairment category).

Legal Blindness. Legal blindness is a term defined by the United States Social Security Administration (SSA) to determine those who are eligible to receive disability benefits, tax exemption programs, and rehabilitation training. SSA uses visual acuity or visual field results to determine this eligibility. A person is considered legally blind if he/she has central visual acuity of 20/200 or worse in the better-seeing eye with best correction (using glasses or contact lenses) at a distance, or if he/she has visual field restriction where the widest diameter is 20 degrees or less in the better-seeing eye.

In this paper, these will be the four types of blindness that we can potentially cure. Inside of these categories, there are subcategories that this treatment targets. Now that you know the main categories, let's break it down even further into the 3 specific types of conditions that stem cells can solve.

Cataracts. A cataract is a dense, cloudy area that forms in the lens of the eye. A cataract begins when proteins in the eye form clumps that prevent the lens from sending clear images to the retina. The retina works by converting the light that comes through the lens into signals.

Glaucoma. A glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for good vision. This damage is often caused by abnormally high pressure in your eye. With all types of glaucoma, the nerve connecting the eye to the brain is damaged, usually due to high eye pressure. The most common type of glaucoma (open-angle glaucoma) often has no symptoms other than slow vision loss. Angle-closure glaucoma, although rare, is a medical emergency and its symptoms include eye pain with nausea and sudden visual disturbance.

Diabetic Retinopathy. Diabetic retinopathy is caused by damage to the blood vessels in the tissue at the back of the eye (retina). Poorly controlled blood sugar is a risk factor. Early symptoms include floaters, blurriness, dark areas of vision, and difficulty perceiving colors. Blindness can occur.\

Is blindness curable? No, not yet. At first, scientist thought blindness could be cured with gene editing (and it may be), but a new solution has taken over the spotlight. Stem Cells have been proven to break through multiple medical fields, and now it will break through this field! Follow along to see the solution, innovation, and companies behind the revolution!

Currently, scientists are using stem cells to replenish the optical nerve. They hypothesize is that Stem-cell therapy could potentially cure blindness (the four types) even in the late stages of the disease or condition presented. Scientists have been testing hypothesis around the idea of IPSC to be artificially placed inside the brain on the optical nerve in order to rejuveante the connection between the visual center and the retina.

To truly understand this treatment, it is crucial that you understand what stem cells are. Stem cells are the body’s raw materials — cells from which all other cells with specialized functions are generated. Under the right conditions in the body or a laboratory, stem cells divide to form more cells called daughter cells. Basically, stem cells can be coaxed into becoming any cell type. Stem cells can be used to grow fresh retinal stem cells through IPSC (induced pluripotent stem cells). These stem cells can then be transplanted into the eye through a short procedure. This will be able to replace those retinal cells that have been damaged or hurt in any way.

As Incredible as this hypothesis originally was, scientists found that it often failed. Trial after trial, scientists couldn’t figure out what was wrong with the solution itself. They tried controlling the growth of IPSC, implanting them on different aspects the optical nerve, more stem cells, fewer stem cells; but they found nothing wrong with the stem cell growth. After a further biopsy study, scientists realized that it wasn’t the stem cells, optic nerve, or any other factor. It was the delivery method. Similarly, studies in animals have shown that only a small proportion of transplanted neurons are able to integrate correctly into the retina’s complex neural circuitry.

Aha! A lightbulb clicked in my head as I read that research paper. Although other scientists were trying other forms of surgery, I knew that we simply needed a transfer device so the stem cells wouldn’t act so hostile against the optic nerve cells, or vice versa. After hours and hours of research, I thought it would be best to use miniature scaffolds to deliver the stem cells.

Building Miniature Scaffolds

To overcome the challenges and problems listed above, scientists have been investigating the use of biomaterials. Biomaterials are regular materials that have been changed in a way to interact with biological systems. The hope behind biomaterials is that they could be used to improve the delivery of stem cell therapy, integrating the stem cells in the eye, and more!

An example of biomaterials is the bioscaffold. As the name may suggest, these scaffold-like structures allow cells to hold on to them in order to improve the chances of cell growth and survival in the eye. Scientists have already (successfully) developed these biomaterial scaffolds; of which closely resemble the correct conditions and environment of the retina tissue.

Scientists then attach the stem cells to the scaffolds before they are delivered into the eye through stem cell therapy. They attach it to the scaffolds before delivery because it may improve their chances of communicating with pre-existing cells and functioning properly once inside. This technique has been wildly successful in studies with mice and it is currently being tested on humans (clinical trials are in progress). Despite the challenges, scientists are constantly looking to treat eye diseases. The eye is an incredibly complex and fragile organ, which is why research in this area may take a bit longer than for other parts of the body.

There are still hurdles that need to be overcome, such as the delivery technique of stem cells, their integration with existing cells once inside the eye and the chance of immune rejection. However, ongoing research into the use of biomaterials to improve stem cell integration has had promising results and may overcome some of these initial challenges.

TLDR

- Parts of the eye. Understanding the anatomy of the eye before diving deep into its issues is key.

- Problem; 4 types of blindness. Total Blindness, Low Vision, Visual Impairment, Legal Blindness.

- Optical Conditions. 5 main types (along with statistics), as well as other common conditions.

- Cell Regeneration. Using Stem Cells to repair the optical nerve and other parts of the eye.

- Building Miniature Scaffolds out of Biomaterial. Using biomaterials to deliver the Stem Cells safely.