I'm Dr. Susan Thoms, and I'll be introducing this course on cataract surgery, I'm a comprehensive ophthalmologist, and have been doing cataract surgery for 35 years. I practice in the University of Michigan Livonia Center for Specialty Care. It's a satellite office. The overview of my section, I'll be discussing common types of cataract, criteria for cataract surgery, the pre-operative evaluation of the patient, the informed consent process and then documentation. There are many types of cataract, the four that I'll just mention here are nuclear sclerosis, cortical, posterior subcapsular, and mature. A nuclear sclerotic cataract is the most common type seen with aging, I think almost everybody by age 70 does show some nuclear sclerosis in the lens of the eye. It's usually graded on a scale of 1 to 4, and I've seen some lenses that are extremely dense yellow, almost brown. I might even give them a 4++ grading. Even with the yellowing in the lens the vision can be good, and it certainly does affect color perception. A lot of these patients will experience a myopic shift because of this. A cortical cataract is slightly different, it's kind of a white fluffy material in the cortex of the lens. If the cortex is cloudy in the peripheral portion it doesn't often affect vision, but if it's more central, it can certainly cause glare from headlights or in bright sunlight. A posteriors subcapsular cataract is often seen in a younger patient, it can be related to taking prednisone. It forms in the posterior part of the lens at the posterior capsule. These patients can often experience very good vision in the darken room, such as the exam room, but they have severe sun and headlight glare that can almost be debilitating. We don't see mature cataracts very often in the United States they are much more common in developing nations. With this type of cataract the vision is extremely poor, it can progress very quickly from a cortical cataract to a mature lens. As you can see in the photo, there is really no view of the fundus, and this eye has to be examined with some other modalities to determine that the back of the eye is okay. We'll be discussing those later in the talk. There are several criteria for cataract surgery, the most important is that the patient has to express a lifestyle impairment. They have to describe a problem with reading or driving, something that impairs their daily activities. The insurance companies have their own set of criteria for cataract surgery. That is 20/50 vision or worse. Or, if the vision is better than 20/50, it has to glare to 20/70. Or at the very least, demonstrate a decrease in two lines of vision with glare testing. And then of course, you have to have the expectation that the sight will improve, by removing the cataract. The preoperative evaluation must be thorough and is very important. We must record the best corrected visual acuity and yes, that does mean you have to do a refraction. Patients with nuclear sclerosis will often improve a lot with a little bit of increase in their minus in their prescription, and might not have to have cataract surgery right away. Glare testing can be performed with a brightness acuity tester, the BAT, B-A-T, or it can be done in room light. On the BAT tester, there are three levels, low, medium, and the high, for the light, I find medium is probably the best for duplicating real life glare situations. Anybody will glare down with high, even if they don't have any cataract, and that might not be a true reading. Room light can do a very similar thing, especially as shown here with the reading lamp facing the patient and the room light's on. Most patients with a cataract will glare down a couple of lines of vision. A preoperative evaluation can also include looking at the red reflex. This can be done either with a direct opthalmoscope or with a retnoscopy streak. This is vital if you have a patient where the vision is quite poor but the cataract on slit-lamp examination doesn't look that bad. The direct opthalmoscope or the retinoscopy streak with the red reflex can give you an idea of whether the cataract is significant. Muscle balance examination is also very important. Here you see a patient with a small right exotropia. You have to consider that if that is old, the patient might be amblyopic in that eye, or if it is recent and possibly due to the decrease vision in their eye, they might experience some post operative diplopia. The pupil examination is important especially if the view into the eye is poor. We have to check for an afferent pupillary defect as shown in this diagram here. And tonometry, also very important as just part of routine examination, and part of testing for glaucoma. The pre-operative evaluation also has to include a thorough slit-lamp examination, both undilated and dilated. Besides, checking for the type and severity of the cataract, we need to look at cornea for any gutatta or Fuch's dystrophy. The lens for signs of pseudoexfoliation which could complicate the surgery. And iridodialysis, which might indicate a trauma, there's a small iridodialysis right there on the iris that would indicate prior trauma. Fundus examination with the dilated pupil is vital, looking for any macular, optic nerve or peripheral retinal pathology. Macular degeneration, would be major factor in post operative visual outcomes and has to be determined preoperatively. If the vision is worse than the cataract would suggest, we have to look for optic atrophy. Some other type of neurologic issue, and then the peripheral retina has to be examined for any sign of lattice degeneration, which might predispose the patient to a retinal tear or a retinal detachment. There are some non-routine additional testings that might be indicated that would be pachymetry or endothelial cell counts for Fuch's corneal dystrophy. And the slide on the left, we are performing pachymetry, and then the right is an endothelial cell count. Also non-routine testing would be fluorescein angiography or an ocular coherence tomography for macular pathology. This could be used in macular degeneration looking for corneal neovascularization, diabetic retinopathy, checking pre-operatively for macular edema or something like an epiretinal membrane. We'd want to know prior to the cataract surgery, whether there is any edema present. A potential acuity meter or a PAM test is sometimes useful in these patients with macular pathology. I haven't found it all that accurate, but sometimes it can give an idea of what the acuity might be after the surgery. Other non-routine testing important would be visual field examination of the patient has a history of glaucoma. If there is a visual field defect in approaching on the macular this could affect the outcome. Would also be important in anybody with the history of stroke or neurologic problems. If there is a mature cataract and there is no view of the fundus, a B scan ultrasound would be important, looking for any pathology such as a melanoma or retinal detachment. Now once we've determined that the patient is a candidate for cataract surgery that the cause of the visual symptoms is the cataract and there's expectation that the vision will improve with surgery. Then we have to perform lens measurements, get the consent and get medical clearance from the primary care physician. Another talk will address the intracular lens measurements, I will talk about the consent process. There are four elements to informed consent. Competence, the patient has to understand the nature and the consequences of his or her actions. Disclosure, the patient is presented information in a manner that they can understand. The patient has to indicate that they comprehend the condition and the procedure. And choice, the patient has to make an unforced decision to have the procedure. Documentation of the informed consent is far more than a signature on a consent form. That is a piece of paper that will really not hold up in court, the patient just needs to say they didn't understand it. The risks of the surgery have to be explained, we obviously can't list all the risks when we're talking to the patient. But the patient does need to understand that there are some basic risks inherent in the surgery. This discussion of the risks should be documented in a clinic note by the physician. We have to manage expectations and in this day and age the expectations get higher and higher as patients anticipate everything will be perfect, and it will be immediate. We have to fully disclose any eye conditions such as, macular or corneal diseases which could effect the visual outcome. We have to discuss underlying conditions such as pseudoexfoliation that might make the surgery more complicated. And we have to discuss with them that they may still need to wear glasses after surgery. It's important to differentiate those patients who want surgery to improve function, or if they just want to function without glasses. There are some pitfalls that we can encounter doing the informed consent process. The explanation can be too technical, it can be brief, rushed, or coercive. I recommend against delegating it to a non-physician or to a video. The patient has to be allowed to interact and ask questions. Determining competency is not always easy, some of the patients we're dealing with have some mild dementia. If they are not competent, they have to have a legal guardian sign, and then we have to actually determined than that person is truly the legal guardian. Non-English speaking patients are also a challenge, often a family member is doing the translating, and we of course, have no idea what they are actually telling the patient. And the one that I find particularly difficult is the patient puts the burden of the decision back to the physician. I try to guide them so they make their own decision, but then they ask, well, what should I do? What would you do? And I usually will turn it right back to the patient and say, are you bothered in your day to day activities? And if the answer to that is yes, then, I agree that they should have surgery. This is just a copy of the University of Michigan consent form that we use. I'm not going to go through it here, you can certainly read it at your leisure. And I've prepared a short video of giving a sample consent speaking with the patient about the process of cataract surgery. >> So, you'd mentioned that you want to have cataract surgery in your right eye? >> Mm-hm. >> So now we just need to talk about the potential risk involve in surgery. In the scheme of things cataract surgery has lower risk, than most other surgeries but nonetheless, it's still not risk free. You have to remember that anything you do in life you know has a potential for risks. Anytime you get in your car to drive there is a chance that you can get into a car accident or get hit by a drunk driver. Fortunately, cataract surgery is a very successful surgery, I would say 97% of the time patients have an uneventful course. >> Okay, good. >> So the recovery time is relatively quick, patients have good vision, and are generally happy with the results. I would say a small number of patients have what we call a rocky road, where things such as bleeding, inflamed eye, elevated eye pressure, swelling of the cornea or retina, or even a retinal detachment can occur. I would say this happens in about 1 to 2% of patients, and usually, even if those happen, the patients can still do well in the end. The recovery time may be a little bit longer but most of these conditions that I mentioned are treatable. So the patient just has to be a little more efficient. Extremely rarely, vision loss is a potential outcome of surgery. If something very significant happens such as a bad infection or severe bleeding, then vision loss is a potential outcome. But like I said, it's extremely rare and we take every precaution against one of those things happening. >> Good. >> So, we had also mentioned or discussed the lens implant that we're going to use. >> Right. >> And you said that you wanted better distance vision without glasses, correct? >> That's correct, right. >> So while our lens calculations are quite good, and most of the time we get patients what they want, there's still a small chance that you could end up with a residual prescription and need for glasses and even for distance after surgery. But, I anticipate that you'll be better on then what you have now. >> Okay. >> If you have any questions? >> Yes, after the procedure, when can I go back to work? >> I usually recommend the patient's take about a week off of work. During that week, you'll be using drafts quite often. Your eye may be a little uncomfortable or irritated, and we recommend no heavy lifting or repetitive bending. So after a week, then usually you can return to work. >> Great. >> All right. Well, if you don't have any more questions, we can get you scheduled and signed up for surgery. >> Can't wait to get it done. >> Sounds good. >> Mm-hm. >> Then we have to document everything in the patient's clinic note. We have to document the reason for the surgery, which eye, the target refraction and the discussion of the lens options, risks of surgery, how well the pupil dilates, the type of anesthesia. We have to note if there are any special needs for that patient, such as a Malyugin Ring, iris hooks, trypan blue, Miostat, capsule tension ring. And we would like to note, I had that if the patient is extremely anxious or claustrophobic, and draping the patient would be difficult. Or if they have very squeezy eyelids, all of these information is important to have handy when you're going into the operating room. We also have to have documentation that the lens measurements were performed. And the lens calculated, the consent has been signed, and a post operative appointment has been made. There should be no longer than three months between the evaluation and the surgery. Lots of things can happen, especially in an elderly patient, in months following the evaluation, and we would want to avert any post operative surprises. This is just a sample clinic note for the assessment and plan portion of the note. I won't read it, but it basically reviews all the information that we just discussed. Thank you for your attention for this introduction to cataract surgery. Another speaker will now continue with the cataract course.
