Serving an aging population, U.S. health care providers see patients developing cataracts every day – and the right therapeutic decisions preserve not only vision but quality of life. Optometrist Emily Eng, OD, MS, FAAO, starts with a refresher on eye anatomy and the factors that make lenses get cloudy, then describes what patients want to know about cataract surgery (the most performed procedure in all of medicine), including pre- and post-op care.
So today's topic that I will be covering is cataract surgery, Cataract surgery and management. Um So let's just go ahead and jump in. Um The objectives for today's kind of talk is to first before we go into cataract surgery um Talk about cataracts, anatomy, physiology, path of physiology of cataracts. Um What we can do to manage and treat cataracts. Um Cataract surgery and then also discussing the different types of inter ocular lenses that a patient can choose. Um So just starting with some overview, Cataracts are the losing leading cause of blindness and vision impairment worldwide. Um it affects nearly 20 million Americans 40 year older. Um So that's about one in every six in this age range. and the studies have shown by 2050 the number of People in the us with cataracts is expected to double from that 20 million to about 2050 million. So it's an ongoing issue um that we see everyday in clinic here. Um Before we start talking about cataracts, we kind of need to know about the lens. Um So the lens is this this is an ultrasound of the front segment of the eye. The lens sits behind the iris um which is behind the cornea um and it's held there in place by the celery processes there. Um But kind of getting a better look at this would be show here. Um So this first picture on the left is what we see when we're looking in the microscope um The lenses that fat area behind that's lit up by the light. Um And you can see it there in a dilated eye sitting behind the iris. Um and going further into the anatomy of the lens. Um So it has basically three main parts. The first one is the nucleus which is the middle part of the lens that is their birth. And then you have secondary lens fibers that grow and surround it. Um And those are made from the epithelium of the cornea and those are always dividing throughout life. So this is one of the reasons why we have cataracts is because of the continued growth of the lens and those added fibers um every year. Um And then if we have some leftover fibers after cataract surgery, this can lead to one of the um post op complications that I'll go for later. Um It's also important to know about the um support of the lens and um what is used to hold it in place. So their lenses actually in a capsule. So kind of we call it like the bag. Um It's a basic lamb in a surrounding the lens and it's made by the lens of ophelia. Um This is a very delicate structure and it's also thinner in the back of it which can also lead to post op complications to during surgery. Um And then the lens is held in place by Daniels which are those filaments that you can kind of see um on the picture and the left and also on the subjects lens on the right um Their filaments of vibrant and this we get a lot of referrals for this as well for looking for a subject's lens in patients with more fans because they have mutations in that gene and can which can lead to the weakening of those samuels. Um so the lens changes shape as I as I mentioned before, it's always growing. So when we start off as a baby it's around three in width and grows up to six. Um And then the change in the thickness of the lens um There's a compensatory compensatory changes in the refractive gradient of the lens. That's why when your lens continues to grow your prescription doesn't continue to get worse and worse. Um Some cute features of it is that it's a vascular and it lacks innovation. Um And and depends on the vitreous and increased humor for nourishment. Um And then the lens proteins are very important to keep the lens clear. So the lens protein, this is the highest protein content of any tissue. Um And the crystalline lens like I said keep the refractive properties and functions essential functions of the lend which is to maintain the clarity. Um And so there can be changes in these lines protein throughout life. Um And then the functions of the lens obviously is to focus light on the red other. Um It also helps with accommodation. Um I mentioned maintaining transparent e and it also has an absorption spectrum around um the shorter wavelengths. So it helps protect the right now from those damaging shorter wavelengths. Um And then just talking a little bit about accommodation because we see it a lot um when we get patients that are around like 40 or 45 they're entering cassio pia. Um And one of the reasons is because of the um reduced ability for the lens to change shape. So um this diagram here is just kind of showing you what happens when you we accommodate. So the axillary muscles contract. In words the Daniels relaxed and then the lens becomes a little bit fatter to focus up close. But once the lens starts to get pretty thick and um it has more fibers going around it. That lens isn't really able to change shape anymore. So we lose that ability to accommodate mm hmm. Um So cataracts and aging. It's a normal age related process. So it's going to happen to everyone. Um basically what's happening is the nucleus will undergo compression and hardening. Um That's what we call nuclear sclerosis. Um And then there's also chemical modifications to the crystalline lens that form protein aggregates. Um And then those protein activites reduced transparency and increased implementation. So there are different types of cataracts depending on where it happens in the lens. So you can have nuclear cataracts which happened more centrally. Um coral cataracts that happened more preferably. And then post interior sub capsule er cataracts which happens in the back, right underneath the capsule. Um And then this uh diagram here is showing a kind of rating scale of what we use when we see cataracts throughout the different stages. Um So the left is a clear lens and then um slowly gradually getting more milky and more yellow um throughout age. So um risk factors for cataracts include UV exposure, smoking certain systemic diseases. Um You ve itis medications, surgery or trauma or age. Mhm. Um and so the risk increases with each age or with each decade starting at 40. Um And by 75 years old half of white americans have cataracts. So this is kind of just a diagram a graph showing the prevalence of cataracts by both age and race. So once you're hitting like seventies above seventies you're almost at 40 or 50%. Um People with cataracts um And then just going over some medications here that can cause cataracts that we should be aware of. Um cortical steroids definitely can cause mostly posterior sub counselor cataracts um And that is dose and duration dependent. Um You know advertising's can also um cause cataracts as well as my optics on my topics including pilot carbine which is actually one of the new eye drops. Um The view of the lens that they've been marketing a lot now. Um So that could potentially uh make cataracts worse. Um And deodorant um rarely is it visually significant cataracts. And then also um if you have excessive dosage of statins, skin can induce some cataracts. Um Different types of trauma can cause cataracts. This picture here shows um kind of what it normally looks like or very exactly actually exaggerated picture of a stellar cataract here that occurs with blunt trauma but you can also get it with radiation. Chemical penetration or electrical um metabolic cataracts as well occur. The biggest one being with diabetes. So what happens with when you have uncontrolled glucose levels? The blood glucose increases which leads to um lens glucose level increases. And then the glucose is converted to serve it'll that increases the osmotic pressure within the eye or within the lens. And then that leads to lens swelling. Um So you can get changes in refractive power with the lens swells. Um And that change can be either myopic or hypertrophic. So it kind of just depends but that's the reason why with patients that have uncontrolled blood sugar levels, their visions can definitely fluctuate. Um But studies have shown that age related lens changes are indistinguishable from diabetic lens changes except they just care a little bit younger in age. Um And then this also leads to a decrease in accommodation and presidential book that occur sooner as well. Um These are other types of metabolic cataracts that you can get. The one on the left here is typically seen with wilson's disease. And then the one on the right here is typically seen with my own tonic dystrophy. Um So what do patients usually complain about with cataracts if they're noticing them? Um The main one is like they say they're looking through some sort of film or dirty windshields. Um It usually happens pretty gradually but with um posterior sub caps or cataracts, those can happen more um quickly than than your other nuclear or cortical cataracts. Um They complain of cloudy, blurry, dim vision, decreased contest sensitivity, harder to see in dim lighting um Or at night um And then his more sensitive to halos and glare at night. Occasionally they can have diplo pia either with binocular diplo pia or with both eyes open. Um And just reduced color discrimination. Things look a little bit more yellow more harder to distinguish between different colors. Um So this is kind of just a schematic of what it would look like um with a clear lines versus somebody who has cataracts. So what do we do when people are coming in and complaining of these symptoms and we noticed that it's the cataracts that's causing these. So um the first thing we always do is just update the glasses, prescription um and encourage UV protection. Um Just kind of more habits in their daily life to help with seeing. So increased lighting when reading, trying stronger reading glasses. Um But patients always ask like what can we do to slow it down or what can we do to stop the progression. Um there hasn't been really anything um supportive but um so dietary intake and nutritional supplements have demonstrated minimal effects on the prevention or treatment of cataracts. So Once it's determined that cataract surgery would be a good option for the patient um then we kind of I'll go over the that on the next slide. But um cataract surgery is the most effective and common procedure performed in all medicine. Um usually there's an average of three million Americans um to have that have cataract surgery each year. Um and the overall success rate is 95% or higher would have performed in appropriate settings. Um And there's a growing need for surgical resources. So the W. H. O. Proposed that between 2000 and 2020 the number of cataract surgeries performed will worldwide will need to triple. Um so uh considerations for cataract surgery, the main one is to determine if the visual function is going to um improve significant sufficiently to warrant surgery. So usually um 80 s have to be affected. Um for insurance purposes The best corrected visual acuity has to be worse than 2040. Um sometimes you can get away with if their vision is better than 2040 if they're glare vision is worse than 2040. So Glare vision is when we shine a bright light into their eyes and see if that makes their vision worse because the cataract is scattering that light. And so usually with glare V. A. Their vision decreases um If they're having any diplo pia. Or if the cataracts are asymmetrical asymmetrical that's causing anti symmetric pia or difference in lens or a difference in refractive error between the two eyes that are too hard to for the patient to get used to. Um Or if there's anyone did use disease like glaucoma. Um And then we always consider the patient's ability to cooperate in the operating room. So um deafness, claustrophobia, anxiety, restless leg syndrome. Tremors or musculoskeletal disorders are also considered. Um So once the patient is determined to have visually significant cataracts um pre operatively. Um We I hope that there's optimal optimal management of all medical problems first. So if they have uncontrolled diabetes or high blood pressure any disorders um that needs to be under control first. Um And then mentioning some pertinent medications here. So um if a person is on a alpha one antagonists. So for instance tim's loosen for BPH. Um This is usually noted because it can cause intra operative floppy iris syndrome making it harder for the iris to dilate during surgery. Um And this can even occur after one dose and can persist indefinitely. Um So we make note of that. Um And then any anticoagulants. So studies have been shown that um intra ocular hemorrhagic events are rare in patients maintained on anti prevalence. Um But medical complications are also rare in patients to stop their treatment before surgery. So normally um will consult with any doctors on whether or not they should stay on there. Anticoagulants or or if they should be taken off of it for the surgery. Um So this is just a brief overview of the history of cataract surgery. The first known type of surgery was couching where they just um stuck a needle and like put blends out Um and just let it fall to the bottom of the eye. That was first noted in the 5th century BC. Um There's extra capsule er cataract extraction um where the capsule is kept intact but the lens is taken out um inter capsule cataract extraction is when the lens and the capsules taken out. Um And then I. L. Or intraocular lens implants came about around in 1949. Um And then the most recent advancement was Figo's multiplication which is used today um in 1967. So we'll go over the fake demystification. Uh Standard care in the United States is small incision safeco with political lens um implantation. So what they do is use an ultrasound tip to fragment the nucleus and emulsify any fragments and then aspirated to remove any critical materials leaving the capsule intact. Um And this is done with a very small incision. So there's no sutures usually and the and the healing time is very fast. Um They found that it's been important to keep the capsule er bag in place to maintain separation between the anterior and posterior chambers. Um A lot of patients now come in asking about laser cataract surgery or um like any type of laser surgery for cataracts. So it's a little bit of a misconception because it's not like LASIK or and it's not anything that uses lasers to help with the refractive error. So what they're actually doing with the laser assisted cataract surgery is the camera or ultrasound maps the ice or business lines. Um And then that sends it to a computer program which programs the laser. Um And then it will tell the laser the exact location, size and depth for different incisions. So that's for the corneal incision for the opening of the capsule and the lens. The laser can also be used to soften the cataract. Um Studies have found that this reduces aberrations and irregular stigmatism but and overall the risk profile and effective outcomes have not been any superior to standard multiplication. Um So an overview of the process. It is an outpatient surgery. Um Usually they will do surgery on the first side first. In some rare cases they can do simultaneous surgery on both eyes. Um And then the anesthesia is usually topical anesthesia um But in certain cases if the patient is too anxious I can't stay still. Then they can do general anesthesia. Um And then there's different steps making the incision. Um putting invisible plastic to maintain the shape of the eye making the cut in the capsule and removing the lens um putting in the L. And then the closure. So I have a video here that made me want to play but I'm not sure if it will. Um It looks like it is not. Um But it's a pretty simple process here. Um They would make the incision on the front of the eye they put and then they make the capsule Alexis. Um So the hole in the front of the capsule and then they insert the tip, Break up the the lens material and then ask great lens material out. And then in the same incision that they make for the fake oh tip. They insert the I. O. L. Or lens implant and then they just close it up so it's pretty simple. Usually takes less than 30 minutes. Um with little complications. Um And so the intraocular lens placement is usually if everything goes well in the bag or in the capsule. Um If there is cap capsule rupture then they can put it in the sarcophagus and that's the area between the iris and the lens. So um in the posterior chamber um They can also if there's daniel weakness um They will put the they will suture the lens usually to this clara. Um And then there's if there's any other complications there for some reason they can't put the lens on the in the posterior chamber. Then they'll use an anterior chamber um lens. Um And so going into the options for intraocular lenses insurance will cover only a mono focal lens. So that will focus either at one distance, so either distance intermediate or near only. So they'll usually need glasses afterwards. Um If a patient wants to be able to see far away and up close and they don't want to pay for a premium lens, then they can consider doing mono vision. Making one eye for distance or one I Premier. Um Usually we'll trial them in contact lenses first to see if they're able to adapt to that. Um And then there are also new lenses now that correct for astigmatism but those are also usually not covered by insurance. Um And then going over the premium lenses here. Um So this this photo here at the top right shows the mono focal lens on the left. Um Historic lens is the second one. A multifocal lenses, the third one and then accommodating lens is the fourth one. Um So there's a few couple multifocal lenses right now. The main one that's getting uses the pan optics um versus restore just the difference between the two is the pan optics is a trifle local versus restores only a bifocal. Um basically the if you can see in the photo on the third one here, there's different rings. So they're in those different rings. There's different powers and that will give you either the distance power or the reading power depending on where you're looking through. Um And that just kind of happens automatically. The brain will kind of know which one to to focus on with these. A lot of patients could wear with about claire and halos or reduce contraband sensitivity. Um There's also an extended depth of focus called the symphony lens. Um That just creates a single elongated focal point. So this one is good for or if a patient wants to be able to see like the computer and far away but not necessarily for reading or up close. But you also get better contrast less aberrations. Um With these lenses that you patients have noted that they see starbursts. There's also an accommodating lens available on the market. It's called the crystal lens. This isn't used very often because it's pretty unreliable and it doesn't always move with the still your body and daniel movement. Um And then there was a study that's been done that had basically showed there's not really a difference between these lenses for uncorrected distance vision. Um But multi vocals have significantly better uncorrected near vision. Um So like I said, the main one that we're using now in the clinic that I see a lot is the pan optics. Um Post up for cataracts surgery. The patients will be on an antibiotic eyedrops. Um for a week. Uh Non steroidal anti inflammatory um for a week and then a steroid for a month basically tapering off the steroids each week um instructions that we give locations. There's no bending over, no heavy lifting, no strenuous activity. Um No water near the I know makeup and then to wear an eye shield at night all for about a month. Um And then follow up. We will see them the first day after surgery, a week after surgery and then a month and the month appointment they're ready for. Um There any residual reflection reading glasses and then we also dilate their eyes at that visit to take a look at the back by. Mhm. Um So complications architects surgery are pretty rare um But they include a whole list of things. Um But during surgery the main things that can happen is mr capsule er preparation. And those cases usually they have to use a different type of lens inter ocular lens replacement um floppy iris syndrome. Which we discussed with the camps Allison um That is usually um fixed by just using some irish hooks to for a better iris dilator. Um And then loose Daniels. Um Post operatively you can have spice and the pressure um If there's persistent inflammation that can travel into the back thigh and cause macular edema. Um The energy that is put into the eye during surgery can probably two rental attachments. Um Just regular inflammation can sometimes uh instigate a UBI itis. Um Anything left over after surgery and lie can lead to endocarditis or if there's like an open wound that can lead to endocarditis if there's wound leaks that can lead to hip hop to me. Um Camp vitreous hemorrhage, retained lens material. Um Post your capsule or apple pacification. Um and lens dislocation. Um So just going over and Oxfam itis real quick here after cataract surgery. Um this usually happens 2-5 days post operatively. Um risk factors include being older than 85 being male. Um And if there is a history of poster capsule rupture during surgery, the patient will come in complaining of a lot of pain. Um Usually vision is decreased, they can see floaters um be sensitive to light uh and you'll see high premium to hypnosis Adina. Um Here even there's a hippo peon in the entire chamber, just white blood cells collecting there at the bottom. Um And there has been studies that show that intercultural antibiotics reduce the risk of postoperative bacterial endocarditis. So some cataract surgeons are putting in um and dramatics during surgery. The biggest proponent against this is just causing antibiotic resistance. So it depends on the surgeon but some people are putting in some antibiotics during surgery. And then actually that reduces the amount of antibiotics that they have to use with drops. So there's now drop lys cataract surgery where um they just inject everything in the eye and the patient doesn't have to worry about using any drugs. But here at UCSF we're still um using the eye drops the the automatics, the insides and the steroids. Um The main complication are the most frequent complication that we get after cataract surgery that we see is the posterior capsule pacification or PCO. Um basically this happens if there is still some cortical fibers of the original ones left in the capsule. And those fibers continually divide and propagate and then they create a film on the back post your capsule. Um So these images here showing kind of what you would see on what the patient would see. They usually complain of just reduced vision like seeing through a film. Um This is the most common complication. It about happens in about a third of patients at the five year mark. Um It also can lead to reduce contrast sensitivity and increase player. And the fix for this is easy. It's just a laser procedure or capsule artemis to the bottom image here showing the PCO before the yeah caps lock key and then the one on the right showing the PCO after the cops on me. So they just need to make a small clear hole, basically two for the patient to look through. So you just shoot a few places in a circle and then it just kind of falls down. Um so what about when there are undesired visual outcomes with cataract surgery? Um usually patients are happy to wear glasses after surgery because they've kind of worn glasses at least since they're 40 if they're if they're farsighted. Um So glasses or contacts. Um If patient is very unhappy with their outcome and and they don't want to have be dependent on glasses, then we can consider refractive surgery like LASIK or PRK. Um And then lens exchanges are very rare. Um Just because you have to go back in the I take out the old lens, replace it with a new one, the capsule be fragile. Lasagnas will be um loose. So that's not done very often unless the patient is very very unhappy. Um And uh there is now not on the market but in the works um Studies. It's actually by dr j Stewart who is here at UCSF Archaeology. Um He's one of the primary investigators are actually inventor of light and adjustable intraocular lens where um they can, the theory is that they can alter the refractive index of the lens by just shooting it with the laser. So if you have an undesirable visual outcome of the patient is hydrophobic or too myopic. You can shoot it with the lens of a certain area and it can change the refractive index then and change their prescription a little bit. Um But cataract surgery hasn't really advanced by a lot in the past in the more modern age but there's definitely been a lot of advancements um mostly to help patients be less dependent on glasses. Um So that's always the goal. Um So usually if the patient is around 50 or 60 and they're asking about LASIK, I just usually will tell them to wait for cataract surgery because then they'll have options um for both being able to be uncorrected for distance and reading versus with LASIK for care, K that will only fix one of the distances. Um, And that is all I have today, mm hmm.
