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 management. Um, so let's just, uh, 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, uh, anatomy, uh, pathophysiology of cataracts, um, what we can do to manage and treat cataracts, um, cataract surgery, and then also discussing the different types of, uh, intraocular lenses that a patient can choose. Um, so just starting with some overview, cataracts are the leading leading cause of blindness and vision impairment worldwide. Um, it affects nearly 20 million Americans, uh, 40 or older. Um, so that's about 1 in every 6 in this age range. And the um studies have shown by 2050, the number of uh people in the US with cataracts is expected to double from that 20 million to about 50 million. So it's an ongoing issue. Um, that we see every day in clinic care. 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, um, 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 ciliary prostheses 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 lens is that, uh, fat. Um, area behind that's lit up by the light, um, and it, 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 3 main parts. The first one is the nucleus, which is the middle part of the lens that is there at birth. And then you have, uh, 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 over 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 lens is actually in a capsule, so kind of we call it like the bag. Um, it's a basal lamina surrounding the lens, and it's made by the lens epithelium. Um, this is a very delicate structure and it's also thinner in the back of it, which can also lead to, um, post-op complications too during surgery. Um, and then the lens is held in place by zonnules, which are those, um, filaments that you can kind of see, um, on the picture on the left and also on the sublux lens on the right. Um, they're filaments of fibrin, and this, um, we get a lot of referrals for this as well for looking for a sublux lens in patients, um, with Marfan's, um, because they have mutations in that gene and can, which can lead to the weakening of those somnules. 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 3 millimeters in width and grows up to 6 millimeters. Um, and then the change in the thickness of the lens, um, there's a compens compensatory change in the, uh, 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 key features of it is that it's avascular and it lacks innervation, um, and, and depends on the vitreous and aqueous humor for nourishment. Um, and then the lens proteins, um, are very important to keep the lens clear. So the lens protein, um, this is the highest protein content of any tissue. Um, and the crystallines, uh, like I said, keep the refractor properties and essential functions of the lens, which is to, uh, maintain, um, Uh, the clarity. Um, and so there can be changes in these lens proteins throughout the, uh, life. Um, and then the functions of the lens obviously is to focus light on the retina there. Um, it also helps with accommodation. Um, I mentioned maintaining transparity, and it also has an absorption, absorption spectrum around, um, the shorter wavelengths, so it helps, uh, protect the retina 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 and they're entering prestopia. 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 ciliary muscles contract inwards, the zomnules relax, and then the lens becomes a little bit fatter to, um, focus up close. But once the lens starts to get pretty thick, And um it has more fibers growing around it. That lens isn't really able to change shape anymore so we lose that ability to accommodate. Um, so cataracts and aging, it's a normal age-related process, so it's gonna 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 crystallines that form protein aggregates. Um, and then those protein aggregates reduce transparency and increase pigmentation. So there are different types of cataracts depending on where it happens. in the lens. So you can have nuclear cataracts which happen more centrally, um, portalural cataracts that happen more, um, peripherally, and then posterior subcapsular cataracts, um, which happens, uh, 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, um, when we see, uh, cataracts throughout the different Uh, 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, uveitis, medications, surgery, or trauma, or age. 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, a diagram or graph showing the prevalence of cataracts, um, by both age and race. So once you're hitting like 70s, above 70s, you're almost at a 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, corticosteroids definitely can cause, uh, mostly posterior subcapsular cataracts, um, and that is dose and duration dependent. Um, phenothiazines can also, uh, um, cause cataracts as well as mitotics, uh, mitotics, um, including pilocarpine, which is actually one of the new eye drops, um, the beauty lens that they've been marketing a lot now. Um, so that could potentially, uh, make cataracts worse. Um, amiodarone, um, rarely is it visually significant cataracts, and then also, um, if you have excessive dosage of statins can, 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 exa actually exaggerated picture of it, uh, steelic cataract here that occurs with blunt trauma, but you can also get it with radiation, um, chemical penetration, or electrical. Um, metabolic cataracts as well occur. Um, 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 sorbitol that increases the osmotic pressure within the eye, uh, or within the lens, and then that leads to lens swelling. Um, so you can get changes in refractive power when the lens swells, um, and that change can be either myopic or hyperopic, so it kind of just depends. Um, but that's the reason why with patients that have uncontrolled blood sugar levels, their vision can definitely fluctuate. Um, but studies have shown that age-related lens changes are indistinguishable from diabetic lens changes except they just occur a little bit younger in age. Um, and then this also leads to decrease in accommodation and presbyopia can 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 myotonic 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 subcap 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 contrast sensitivity, harder to see in dim lighting, um, or at night, um, and then, uh, more sensitive to halos and glare at night. Um, occasionally, they can have diplopia either with monocular diplopia or with both eyes open. Um, and just reduce color discrimination. Things look a little bit more yellow, and more harder to to to distinguish between different colors. Um, so this is kind of just a schematic of what it would look like, um, with a clear lens versus somebody who has cataracts. So what do we do when people are coming in and complaining of these symptoms and we notice that it's the cataracts that's causing this. So, um, the first thing we always do is just update the glasses prescription. Um, and encourage UV protection, um, just kind of, um, more habits in, in their daily life to help with seeing. So increased lighting when reading, um, 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, uh, then we kind of, I'll go over 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 3 million Americans, um, to have, that have cataract surgery each year. Um, and the overall success rate is 95% or higher when performed in appropriate settings. Um, and there's a growing need for surgical resources. So the WHO proposed that between 2000 and 2020, the number of cataract surgeries performed 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 sufficiently to warrant surgery. So usually, um, ADLs have to be affected. Um, for insurance purposes, the best corrected visual acuity has to be worse than 2040. Um, sometimes they can get away with if their vision is better than 20/40, if their glare vision is worse than 20/40. So glare vision is when we shine a bright light into their eyes and see if that, um, makes their vision worse, um, because the cataract is scattering that light. And so usually with glare VA their vision, uh, decreases. Um, if they're having any diplopia or if the cataracts are asymmetrical, that's causing anisymmetropia or difference in lens, uh, or 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 any lens disease like glaucoma. Um, and then we always consider, um, patient's ability to cooperate in the operating room. So, um, deafness, claustrophobia, anxiety, restless leg syndrome, uh, tremors, or musculoskeletal disorders are also considered. Um, so once the patient is determined to have visually significant cataracts, uh, preoperatively, um, we Um, hope that there's optimal, optimal management of all medical problems first. So if they have uncontrolled diabetes or high blood pressure or any disorders, um, that needs to be, uh, under control first. Um, and then mentioning some pertinent medications here. So, um, if a person is on a, um, alpha-1 antagonist, so for instance, tamsulosin for BPH, um, this is usually noted because it can cause intraoperative floppy iris syndrome, making it harder for the iris to dilate during surgery. Um, and this can even occur after one dose and can, um, persist indefinitely. Um, so we make note of that. Um, and then any anticoagulants. So studies have been shown that, um, intraocular hemorrhagic events are rare in patients maintained on anticoagulants. Um, but medical complications are also rare in patients who stop their treatment before surgery. So normally, um, we'll consult with any doctors on whether or not they should stay on their 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 in the eye, poke the lens 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 extracapsular cataract extraction, um, where the, uh, capsule is kept intact with the lens is taken out. Um, incapsular cataract extraction is when the lens and the capsule is taken out. Um, and then IOL or intraocular lens implants came about around in 1949. Um, and then the most recent, um, advancement was phagos emulsification which is used today, um, in 1967. So we'll go over um the fatal emulsification. Uh, standard care in the United States is small incision, they go with foldable lens, um, implantation. So what they do is use an ultrasound tip to fragment the nucleus and emulsify any fragments and then aspirate it to remove any cortical 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 capsular 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, uh, any type of laser surgery for cataracts. So it's a little bit of a misconception cause it's not like LASIK or, and it's not anything that, um, uses, uh, lasers to help with the refractive mirror. So what they're actually doing with the laser-assisted cataract surgery. is the camera or ultrasound maps the eyes surface and lens. Um, and then that sends it to a computer program which programs the laser. Um, and then it'll 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, uh, the laser can also be used to soften the cataract. Um, studies have found that this reduces aberrations and irregular astigmatism, but, and overall the risk profile and refractive outcomes have not been, um, any superior to a standard fatal emulsification. Um, so an overview of the process, it is an outpatient surgery. Um, usually, they will do surgery on the worst side first. Um, in some rare cases, uh, they can do simultaneous surgery. On both sides. Um, and then the anesthesia is usually, uh, topical anesthesia, um, but in, in certain cases if the patient is too anxious or can't stay still, then they can do general anesthesia. Um, and then there's different steps, um, making the incision, um, in a visible elastic to maintain the shape of the eye, making the cut in the capsule, um, removing the lens, um, putting in the IOL, and then, uh, the closure. So I have a video here that maybe will 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, uh, and then they make the capsule reexis, um, so the hole in the front of the capsule, and then they insert the fago tip. Um, break up the, the lens material and then aspirate the lens material out, and then in the same incision that they make for the Phaco tip, they insert the um IOL 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 uh, capsule rupture, then they can put it in the sulcus, and that's the area between the iris and the lens. So, um, in the posterior chamber. Um, they can also, if, uh, there's Annual weakness, um, they will put the, they will suture the lens usually to the sclera. Um, and then there's, if there's any other complications there for some, 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 monofocal 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 monovision, making one eye for distance or one eye for near. 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, uh, correct for astigmatism, um, 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, uh, monofocal lens on the left, um, a toric lens is, is the second one, a multifocal lens is the third one, and then an accommodating lens is the fourth one. Um, so there's a few couple multifocal lenses. Uh, right now, the main one that's getting used is the panoptics, um, uh, versus restore, the, just the difference between the two is the panoptics is a trifocal versus restore is only a bifocal. Um, basically, the, if, if you can see in the photo on the third one here, There's different rings. So there, 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 compare with about clare and halos or reduced contrast sensitivity. Um, there's also an extended depth of focus, uh, called the symphony lens, um, that just creates a single elongated focal point. So this one is good for if the patient wants to be able to see like the computer and far away, but not necessarily for, um, 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 um 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 ciliar body and dominal 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 multifocals 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 panoptics. Um, post-op. For cataract surgery, the patients will be on an antibiotic eye drop, um, for a week, uh, non-sterile anti-inflammatory, um, for a week and then a steroid for a month, basically tapering off the steroid each week. Um, instructions that we give the patients is no bending over, no heavy lifting, no strenuous activity, um, no water near the eye, no 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, their, any residual refraction, um, reading glasses, and then we also dilate their eyes at that visit to take a look at the back of the eye. Um, so complications for cataract surgery are pretty rare, um, but they include a whole list of things. Um, but during surgery, the main things that can happen is posterior capsular perforation. In those cases, usually they have to use a different type of lens, um, intraocular lens replacement. Um, floppy iris syndrome, which we discussed with the tamsulosin, um, that is usually, um, fixed by just using some iris hooks to, for a better iris dilator, um, and then loose annules. Um, postoperatively. You can have spikes in blood pressure. Um, if there's persistent inflammation that can, uh, travel to the back of eye and cause macular edema, um, the energy that is put into the eye during surgery can lead to retinal detachments. Um, just regular inflammation can sometimes, uh, instigate a uveitis. Um, Anything left over after surgery in the eye, um, can lead to endophthalmitis or if there's like an open wound that can lead to endophthalmitis. If there's wound leak, that can lead to hypoteny, um, you have vitreous hemorrhage, uh, retained lens material, um, posterior capsular opacification, um, and, uh, lens dislocation. Um, so just going over endophthalmitis real quick here after cataract surgery. Um, this usually happens 2 to 5 days postoperatively. Um, risk factors include being, uh, older than 85, being male, um, and if there is a history of posterior capsule rupture during surgery. Um, the patient will come in complaining of a lot of pain. Um, usually vision is decreased. Uh, they can see the floaters, um, be sensitive to light, uh, and you'll see hyperemia, stenosis, edema, um, here, even there's a hypopion in the anterior chamber or just white blood cells collecting there at the bottom. Um, and there have been studies that show that intercameral antibiotics reduce the risk of postoperative bacterial endothritis. So some cataract surgeons are putting in, um, antibiotics during surgery. Uh, the biggest component against this is just causing antibiotic resistance. So it depends on the surgeon, but some people are putting in, um, antibiotics during surgery and then actually that reduces the amount of antibiotics that they have to use with drops. So there's now dropless cataract surgery where, um, they just inject everything in the eye and the patient doesn't have to worry about using any drops. But here at UCSF we're still um using the eye drops, the, the antibiotics, the NSAIDs, and the steroids. Um, the main complication or the most frequent complication that we get after cataract surgery that we see is the posterior capsule opacification or PCO. Um, basically, this happens if there is still some cortical fibers of the original lens left in the capsule, and those fibers continually, um, divide and propagate and then they create a film on the back, uh, posterior capsule. Um, so these, uh, images here showing kind of what you would see and 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 happens in about a third of patients at the five-year mark. Um, it also can lead to reduced contrast sensitivity and increased flare, and the fix for this is easy. It's just a laser procedure, um, or a YAG capsulotomy. So the bottom, um, image here is showing, uh, the PCO before the Yag capsulotom. And then the one on the right showing the PCO um after the eyeotomy. So they just need to make a small, um, clear hole basically to, for the patient to look through. So you just shoot, um 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, um, kind of worn glasses at least since they're 40 if they're If they're um far-sighted. Um, so glasses or contacts. Um, if the 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 eye, take out the old lens, um, replace it with a new one, the capsule will be fragile, the nonules 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 Doctor Jay Stewart who was here at UCSF ophthalmology. Um, he's one of the primary investigators or, um, actually inventor of, um, a light 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, um, visual outcome of the patient is too hyperoptic or too myopic, you can, um, shoot it with a lens at a certain area and it can change the refractive index and, and change their prescription a little bit. Um, but cataract surgery hasn't really advanced. Uh, by a lot in the past, in the more modern age, um, but there's definitely been a lot of advancements, um, mostly to help patients be less dependent on classes. 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 cause then they'll have options um for both being able to be uncorrected for distance and reading versus with LASIK or PRK, that will only fix one of the distances. Um, and that is all I have today.
