What are the major formsof vision loss in childhood and in adulthood, and what can each and all of us do in order to find out if wehave one of these conditions and therefore treat it effectively? Yeah, that's great. You know, let's start byjust reminding ourselves what are the major causes of vision loss? And these are going to differwhere you are in the world,.
But the number one cause of low vision is actually refractive error. People who need glasses, and especially in othercountries, affordability, access, can't even get glasses, okay? So that's just refractive error, but that's fundamentally correctable. The next most common causeof vision loss is cataract. Cataract is the blurring,.
The aging of the lens insidethe eye, behind the cornea. We talked about how that is responsible for focusing light on the back of the eye. It also has to be clear enough that the light gets through the lens. And a cataract is a normal aging process. You know, as I said, ifwe all live to a hundred or 110 years old, we'll all get cataracts. We'll all need cataract surgery.
We actually, in the eye clinic, we see cataracts years or even decades before they're affecting yourvision in a meaningful way. So the cataracts areforming and that's okay, but at some point they get bad enough that it's time to take them out. We've actually solved for cataract surgery pretty efficiently. We can do a four to eight minute surgery,.
Maybe if we're taking our time, it's 10 or 12 minutes of surgical time. Take out a cataract, it works beautifully 99 pointsomething percent of the time. We put a plastic, a clear plastic lens inside the eye, exactly where your lens used to be. And there's even lenses that can flex or focus light from far and near.
So cataract is fundamentally a, there's still room for improvement, but it's fundamentally a solved problem. The problem is that worldwide, there aren't enough cataract surgeons, there's not access to care, the machinery or the lenses costs too much moneyin developing countries to get out to the number ofpeople who would need them.
So it's actually just,again, an access to care. Cataract is a reversible, treatable, easily treatable problem, but it's number two on the list of causes of vision loss in the world because we don't haveenough access to care, we need a lot more sort of programming around global ophthalmology, global eye care to solve for cataract,.
Just to bring that solution to countries around the world. Then after that, you starthitting the eye diseases that lead to what arecurrently irreversible, non-reversible causes of vision loss. The number one cause ofirreversible vision loss in the world is glaucoma. So what is glaucoma? Glaucoma's actuallyprobably a little cluster.
Or constellation of diseasesthat we lump together. It's a degenerative diseaselike a neurodegeneration. We talk aboutneurodegenerations in the brain like Alzheimer's and Parkinson's. Glaucoma is a neurodegenerative disease. Instead of affecting one ordifferent area in your brain, it happens to affect the optic nerve that connects the eye to the brain. And we need our optic nerves.
To carry all the visual information from the eye to the brain. And so if your optic nerveis degenerating in glaucoma, and I should add, there areother optic neuropathies, so-called diseases ofoptic nerve degeneration. For example, you can get astroke of the optic nerve. You can have an inflammatory disease like multiple sclerosis, called optic neuritis thataffects the optic nerve.
So you can get other optic nerve diseases. But glaucoma is by far themost common optic neuropathy. And the problem is, justlike spinal cord injury, which is also part of thecentral nervous system, right? The brain, the spinal cord,the retina, the optic nerve, that's the central nervous system, and there's no regeneration. And that's why spinal cord injury leads to permanent paralysis.
Well, optic nerve injury or optic nerve degenerationunfortunately leads to permanent vision loss. So in the case of glaucoma,how do we get ahead of that? Glaucoma has two major risk factors. One is increasing age. There are actually infantile and pediatric glaucomas unfortunately, and those can be much more aggressive,.
Much more damaging when theypresent so early in kids, in babies, and in children. Most of the kind of run of themill glaucoma usually presents in adulthood and even in the aging adults. So much more common after 50 or 60 or 70 years old, increasing. The other main risk factor for glaucoma is increasing eye pressure. The eye actually, youknow, it stays inflated.
It's a balloon. It has to stay inflated. We need some amount of eyepressure to keep our eye as an inflated balloon. But if the eye pressure goes too high, and we talked about this before, you won't even feel it ifit slowly gets too high. If the eye pressure goes toohigh, that causes glaucoma. And that's one of thethings that we talked about, you really include in acomprehensive eye exam.
When you're just gettinga screening checkup at your eye care provider, at your optometrist orophthalmologist office, they're going to check your pressure, and just as a screening tool, check to make sure it's not too high. We can treat glaucoma today by trying to reduce theimpact of that high pressure by lowering the eye pressure.
So we have treatments for glaucoma that target the eye pressure. We have medications like eye drops, we have lasers that canbe used inside the eye that can also lower the eye pressure. And ultimately, if we need them, we also have surgeries thatcan also provide an outflow that lets the fluid out ofthe eye in a controlled way so that the eye pressurecan be brought back down.
Into normal ranges. Again, the reason thatglaucoma ends up being the number one cause ofirreversible blindness in the world is number one, we can't get those therapieseverywhere in the world, the affordability of eyedrops,the access to lasers, or surgical proceduresaround the world isn't equal to what it is here. And even within our country,.
People may not be accessinghealthcare effectively to get screened for glaucomaor to get treated for glaucoma. The other big problem with glaucoma is that it affects ourperipheral vision first, and only very late in thedisease does it pinch in and finally pinch offthe center of our vision in typical glaucomas. And that's a real problembecause we don't notice if our peripheral vision is down.
You know, our peripheralvision isn't that good to begin with. And if you're driving and youcan see a pedestrian step off the sidewalk, you think yourperipheral vision is fine, but actually your peripheral vision could already startbeing damaged by glaucoma and you won't notice itin regular daily life. And that's where theimportance of screening and early detection reallycomes in for glaucoma.
What we don't have for glaucoma, we can come back to like kindof what's the cutting edge of the future in these eye diseases? What we don't have aretreatments that really target the optic nerve degenerative process and we can come back and talk about that. So that's glaucoma and optic neuropathies. Then the next two major causes of currently largelyirreversible vision loss.
Are age-related macular degeneration and diabetic retinopathy. Now age-related maculardegeneration is just like it sounds, major risk factor isage, it's very common. And actually, in thedeveloped world, you know, countries that are more developed, also countries thathave a larger Caucasian, White population, it's more common in certainpopulations than in others.
It actually is definitely aleading cause of vision loss in the elderly population, for example, in the United States. And there's two formsof macular degeneration, but they both end up targetingthe same part of the retina. And that part of the retinais really like the rods and the cones that we talked about before. The rods do your lowlight vision at nighttime. Primarily, your cones docolor vision and bright light,.
You know, sort of normallighting that we experience through most of our awake day. And in that back of the retina, you can have what's calleddry macular degeneration, which is a slow, thankfully slow, but slow insidious diseasethat causes the degeneration of the rods and cones and also the support cells thathelp feed the rods and cones and take care of the rods and cones.
They're called RPE cells,retinal pigment epithelium. It's not really critical, of course, the names of every different cell type, but these are like thelight collecting cells in our eyes and the retina and they degenerate inmacular degeneration. And in the dry form, there'sthis slow degeneration, but some percent ofpeople with the dry form of macular degenerationwill actually convert.
To what's called the wet form. It's called wet because new blood vessels actually grow inappropriatelyunder and even into the retina and new blood vessels, unlikeour mature blood vessels, tend to be leaky. And so the fluid leaks outof those blood vessels, gets into the retina,interferes with vision, and that can lead to a muchmore acute loss of vision. Now, we have some treatmentsfor wet macular degeneration.
We have injections thatcan go into the eye that actually fight against the molecules that are causing thosenew blood vessels to grow. And these are antibodies thatcan be injected into the eye and they can be very effective controlling patients'wet macular degeneration. It's been a much bigger uphill battle, even over the last decadeas advances are being made, to really try to knock back.
Or slow down even the dryform of macular degeneration. There was just someexciting news even just in the last few months. The first successful trials of a treatment for the dry form have just shown success in properly randomizedcontrolled human clinical trials, phase three clinical trials. So it's an exciting time. Those new treatments arenot going to be a panacea.
They slow the progression, like the anatomic progression of the disease maybe by 20 or 25%. So patients are stillgoing to get worse even with those treatments. So there's still a lot more to be done to really knock back macular degeneration. I want to mention, youmentioned retinitis pigmentosa. That's like an inherited form.
Of a type of macular degeneration. It's also affecting the rods and cones and also the support cells, the RPE cells in the back of the eye. retinitis pigmentosa is an inherited form. There are actually manydifferent genes you could have that could leave to retinitis pigmentosa. In aggregate, if you add up all the people with all those different genes,.
And it can be very devastating 'cause it can really affect the vision, knock out your vision very early in life, including in children and evenversions of that in babies. But you add that all up, it's still much less common in aggregate than macular degeneration. But in a way, it's quite a bit more severe because it does affectpeople much earlier in life.
So I sort of clump those to together, macular degeneration,retinitis pigmentosa, degeneration of the rods and cones and the support cells,the RPE support cells. And then you can't havethis part of the discussion about what are thedevastating eye diseases without bringing up diabetic retinopathy, especially because diabetesunfortunately really continues to grow in, especially let'ssay in the United States,.
Certainly in the developedworld, you know, as we, especially Type 2 diabeteswith eating habits, exercise habits contributingto a proliferation of some of the risk factors for Type 2 diabetes, metabolic syndrome, obesity. We're unfortunatelyseeing a proliferation, a growth in the numberof people with diabetes. And with the growth in diabetesunfortunately comes a growth of the complications of diabetes.
And one of the majorcomplications of diabetes is damage to the retina inside the eye, and we call that diabetic retinopathy. And there, again, some ofthe same damage that occurs, especially when in diabetes, again, some new blood vessels are growing or blood vessels are leaky. Some of that can be treated with, it used to be lasers.
And now more commonlyis often being treated with some of the same injectable drugs that are treating macular degeneration. But there's still a lot ofvision loss with diabetes and diabetic retinopathy. I think that's an area where,again, early screening, making sure if you have diabetes, that's an indication where you definitely have to be going in.
And getting your at least annual exam with an eye care provider or having someone take a photograph of the inside of your eyeand rate that photograph to say if you have anydiabetic retinopathy or not. [MUSIC PLAYING]