Other Indications

There are some other indications for vitrectomy besides a non-clearing vitreous hemorrhage, and most of these are fairly obvious. For instance, referral is mandatory if the patient appears to be developing progressive traction that is threatening the macula, or if the macula has just been yanked off. Sometimes, however, making this call is not as easy as one would think. The traction can build up very slowly, often simulating refractory macular edema as the retina is slowly thickened like a...

Over how many sessions do you put in the treatment

For the average patient with early PDR there is not a lot of time pressure, so it makes sense to start with gradual treatment applied over at least two, and usually three, sessions. Although the original studies often did all the treatment in one session and it is within two standard deviations of accepted care to do it that way such an approach can be asking for trouble. One-stop shopping with a PRP almost always requires retrobulbar anesthesia with the attendant risks. There is also a higher...

Ocular Ischemic Syndrome Thermonuclear Retinopathy

Global ocular ischemia may be very difficult to diagnose, particularly if the patient already has lots of diabetic eye disease. You won't see it very often unless you have a practice full of patients with awful disease, but you do not want to miss it if it does show up because it can be treatable if caught early and disastrous if caught late. In the past this syndrome has had a number of confusing names, including retinopathy of carotid insufficiency and venous stasis retin-opathy (the latter...

Triamcinolone Acetonide

Steroids seem to be the ultimate Radiator Stop Leak for perifoveal capillaries. People initially went berserk when it became apparent that this drug could have a dramatic effect on reversing central cystic diabetic macular edema something for which laser alone is often frustratingly ineffective. However, with time, it has become apparent that for many patients the initial positive response seems to gradually weaken, and the long-term results are less stunning. A recent study even suggested that...

Diplomacy

Also, remember that if you refer uncharitably to previous laser treatment, it may just be a matter of time before what goes around comes around and your laser spots are being disrespected. More importantly, patients can be very frightened to learn about laser scars in the back of their eye because at some level they may imagine crazed doctors trying to carve up their vision in order to pay for Hummers. They also will assume that any vision problems they have are due to the scars they...

What about thrombolytics

You have no doubt been contacted by the interventional cardiologist on call about a patient who needs acute thrombolysis or heparin. Once again, the life-threatening nature of the problem trumps the eye, but the patient still deserves some sort of informed consent. It turns out that the literature suggests that most of the time patients with proliferative retinopathy will do well. For instance, the GUSTO-I trial Global Utilization of Streptokinase and t-PA for Occluded coronary arteries - I had...

What about intravitreal injections

There is more of a consensus that one does not need to worry about stopping anticoagulation at all in this setting these are tiny needles going through a relatively avascular space, and raising the intraocular pressure with the injection is likely to mitigate any bleeding.4 Should you check an INR Most doctors don't a history of stable anticoagulation seems to be enough. One can't argue against checking it if you get into trouble you will wish you had checked it, but the logistics of sending...

The diabetic differential diagnosis can be broken down into three situations where you can screw up

The first situation occurs when you have a patient with known retinopathy and a brand new disease shows up out of the blue. If the disease happens to be something that can look like diabetes, it can remain hidden within the preexisting retinopathy. Diseases such as these may be eminently treatable if you catch them in time, but they can make the patient much worse if you don't. The second situation occurs in a patient with known diabetes but who, until Table 1 Differential Diagnosis of...

Things that can hide in the signaltonoise ratio of diabetic retinopathy and can make things worse if you dont think of

Diabetics are allowed to get other diseases, so if you are totally in the diabetic retinopathy zone you may fail to notice something crucial. Typically the new disease is missed because the superimposed findings are simply attributed to worsening of the underlying diabetic retinopathy. It is a Bad Thing to overlook such problems because if any other disease is added to diabetic retinopathy, the resulting synergy can be far worse than either entity alone. One problem that can be hard to diagnose...

Direct View

Lente Goldmann

The direct view lenses are the easiest and most intuitive to use. The archetype is the Goldmann three mirror lens. This is the lens to have if you are stranded on your basic desert island, because it can do everything reasonably well. The direct non-inverted nature of the view means that once you get the lens on the patient, you are simply looking in a straight line through the pupil to the area of interest. The various mirrors then allow you to visualize segments of the periphery. Some...

But Enough On The Exam on to the disease

All of the above is about being able to identify macular edema in general, but the real enemy is known as clinically significant diabetic macular edema CSDME . This term is reserved for findings that indicate a very high risk of progressive visual loss. The exact criteria for CSDME should be burned into your brain at this point in your career, but here it is for reference Criteria for Clinically Significant Diabetic Macular Edema 1. Retinal thickening within 500 microns of the center of the...

What if there is a vitreous hemorrhage but no obvious neo

Although knowing when to intervene earlier is important, it is also good to know when to hold off. Such a situation may occur when you are faced with a patient who has a vitreous hemorrhage but no evidence of neovascularization. The DRS showed that a vitreous hemorrhage alone is generally not an indication for PRP, but this is true only if you are certain there is no neovascularization. If there is a localized preretinal hemorrhage that blocks the view of a section of the retina, or a dense...

Presentation

Cotton Wool Spots From Ois

The actual presentation varies along a multifactorial grid that includes the amount of the obstruction, the rate of obstruction, and the nature of the intraocular response induced by the ischemia. And all of this is can be scrambled up if you are seeing it in the setting of diabetic retinopathy early signs may be lost amongst the preexisting diabetic damage. This can be a problem. Remember the paragraph above that talked about the need to keep in mind the worst-case scenario when you make a...

Table Of Contents

A Tiny Bit of Statistics and a Big Pep Talk Know Your Weapons Lasers and Their Ilk Contact Lenses and the Wrangling Thereof Trust Me, I'm A Doctor Part One The Informed Consent for Treating Diabetic Macular Edema Actually Doing a Laser for Macular Edema The Chapter That is Really About Actually Doing a Laser for Diabetic Macular Edema Now What Post-Laser Management of Macular Edema Intravitreal Therapy and How It Fits Into Your Armamentarium Or Not Proliferative Diabetic Retinopathy and Other...

Posterior Segment

Most posterior segment issues have already been discussed in the preceding chapters but a little repetition is good, because you want to make it through your whole career without gaining personal experience with any of these problems. Perhaps the most disastrous mistake is to create an inadvertent foveal burn. Follow all the advice about constantly checking your location in the fundus and always know for sure where you are. Remember that you are far more likely to do something like this when...

Wrapping things up so we can get on to toasting retina in the next chapter

Once again, this is all a lot of information. Recognize that patients often want to distill this or any medical info into very simple terms. Sometimes, these distillations can be shockingly unrelated to the carefully thought-out reality you have presented. For instance, upon hearing that there may be side effects of the laser, some patients will immediately choose to take their risks with going blind from the diabetes as opposed to being made blind sooner with the laser. Usually, these thoughts...

What about doing a retrobulbar with Coumadin on board

First, check the stuff in Chapter 15 about how to minimize pain using various laser settings, etc. If none of that works, then surprise there are no proven guidelines to follow. Here are some things to consider You can try a sub-Tenon's or subconjunctival block, also mentioned in Chapter 15. You can get pretty good anesthesia in the region you inject, and there is less chance for a globe-threatening hemorrhage. If you need to do 360 degrees of treatment, though, you can end up with a lot of...

One Last Complication

Esperance Ophthalmologist

After having carefully reviewed all the different ways you can screw up with lasers, it is important to remember that perhaps one of the most worrisome complications is to have your treatment fail because it was inadequate. Generally, a less is more technique is the best way to go, because the fewer spots you need to place for any treatment the more vision your patient gets to keep. Unfortunately, if you don't put in enough spots to control the disease, then you for sure haven't done the...

Do you have to have an FA before a PRP No

An FA is not mandatory before treating isolated PDR. The great ophthalmic court in the sky should not frown upon you if you do not get one, especially because in many places it may not be an option. However, if it is available, you should consider doing the test for a few reasons 1. An FA can give you an idea of exactly where most of the capillary ischemia is in the periphery this will help you assess how bad the disease is, where to treat, and how aggressive you will need to be with your PRP...

Things that can really make you look bad if they show up in a diabetic with no prior retinopathy and you think they are

Brvo Sectoral Laser

The first section covered problems that can be invisible because they can superimpose themselves on pre-existing diabetic retinopathy, and you can miss them if you are not careful. Now it is time to turn to entities that, in and of themselves, can mimic diabetes. Most of these can be missed if they happen to show up in a diabetic patient that is, you would be more likely to think of them if the patient wasn't diabetic. Usually Occam's razor is spot-on, but sometimes it can slice you a piece of...

Puttingit All Together

OK, so now you have scoured the fundus for signs of IRMA or early PDR. Exactly why do you need to memorize the 4-2-1 rule and hunt around for all this stuff, anyway There is no question that one of the landmark studies in all of ophthalmology was the Diabetic Retinopathy Study DRS , which clearly demonstrated the usefulness of laser treatment in avoiding blindness back in the 1970s.2 Both the DRS and the ETDRS produced a host of papers the cited reference is an example. As part of this study,...

What if one eye is a lot worse than the other

Keep in mind that something strange may be going on in a patient who has very asymmetric disease. Diabetic retinopathy is almost always asymmetric to some extent, but you should worry if there is a big difference between the two eyes. The uveitis patient shown above is one example of this. However, there are two bad boys you really need to keep in mind central retinal vein occlusion CRVO and ocular ischemic syndrome OIS . Both of these can present with way more hemorrhages and more pronounced...

Anterior Segment Complications

Lenticular Sclerosis Red Reflex

Probably the most common problem is scruffing up the corneal epithelium. Diabetics, especially by the time they have retinopathy, tend to have a bad combination of decreased corneal sensation and anterior basement membrane abnormalities. This can predispose them to punctate epithelial erosions or even full-thickness epithelial defects from the use of the contact lens. Fortunately, this is not very common, and if there are symptoms they tend to be mild and self-limited meaning that they are a...

Anintroduction from the author

Diabetic Retinopathy Patient

This book is designed to transfer useful skills for the clinical management of diabetic patients. It does not start with the fundamentals instead, it is assumed that the reader has basic examination skills and is at least partially familiar with various tests, such as fluorescein angiography and optical coherence tomography. Nor does this text offer an in-depth discussion of basic science or an exhaustive review of the available literature. Like the Basic and Clinical Science Course from the...

References and Suggested Reading

Jampol LM, Ebroon DA, Goldbaum MH. Peripheral proliferative retinopathies an update on angiogenesis, etiologies and management. Surv Ophthalmol 1994 38 519-40. 2. Basu A, Palmer H, Ryder RE, Taylor KG. Uncommon presentation of asymmetrical retinopathy in diabetes type 1. Acta Ophthalmol Scand 2004 82 321-3. 3. Duker JS, Brown GC, Bosley TM, Colt CA, Reber R. Asymmetric proliferative diabetic retinopathy and carotid artery disease. Ophthalmology 1990 97 869-74. 4. Sindt SJ, Oh K. Idiopathic...

Patients without previously diagnosed diabetes and funny things in their retina that look diabetic

This is usually the easiest because even an ophthalmologist can diagnose diabetes. By the way, remember that we are talking about diagnosing Type 2 diabetes here Type 1 does not show up in your clinic with retinopathy as a presenting sign. Those patients show up in the ER with polydipsia, polyuria and ketoacidosis. How do you diagnose diabetes The pundits argue about this, but Table 3 shows the latest criteria. Just to make things confusing, there are three different sets of criteria those from...

What about operating on patients who are on Coumadin

It is well accepted that it is OK to do modern cataract surgery on uncomplicated, anticoagulated patients.3 Retinal surgery or even complicated anterior segment surgery is more likely to have problems with bleeding and there is no definitive study that provides a solid answer. Furthermore, you can be screwed no matter what you do If you stop the Coumadin and the patient has a pulmonary embolism or a stroke, there will always be some hired-gun expert to say you should have done something...

Front End Trouble Iris Neovascularization

Iris neovascularization is another form of proliferative diabetic retinopathy, and it usually indicates a very sick eye. First of all, though, do not be fooled by findings that may mimic true neovascularization. For instance, if you look carefully, you will often see tiny, reddish globular vessels on the pupil margin, especially if you study the iris prior to dilation in older diabetics. These vascular tufts may increase in number over time, but they do not usually cause any of the problems...

What is the best IOL

The best IOL is usually the one that you can put in best. Bestly Again, your diabetic patient is not the one on whom to try some slinky new IOL from the rep just use the tools that allow you to do your safest surgery. Some papers recommend using a lens with a large optic this will allow better visualization in case the patient ends up needing extensive laser or a vitrectomy. It is also helpful if the patient has a larger capsulotomy, especially given the tendency for diabetic capsules to...

Even More Factors to Consider

It would be great if this chapter could stop with that last paragraph, but there are some subtle nuances to consider when addressing issues of systemic control. Here they are Rapid Institution of Tight Control in Patients Who Have Been Poorly Controlled The rapid institution of tight control can result in temporary worsening of diabetic retinopathy in some patients. This effect was best demonstrated in the DCCT, wherein motivated study patients were treated very aggressively and brought under...

Anti Vascular Endothelial Growth Factor AntiVEGF Agents for Anterior Segment Neovascularization

Anterior segment neovascularization can be a great indication for intravitreal anti-VEGF therapy if you have access to it and assuming any posterior proliferative disease is controlled see Chapter 11 for details . Although aggressive laser is the mainstay of treatment injections are transient but the laser is perma-nent intravitreal treatment can slow down the disease, giving you time to treat the patient gradually. Anti-VEGF drugs can also help protect the macula if fast and furious laser is...

Optical Coherence Iography

Stratus Oct Average Retinal Thickness

OCT has revolutionized our ability to visualize the architecture of the retina, and it can be extremely valuable for evaluating and following patients with diabetic retinopathy. As with fluorescein angiography, this review will assume that the reader has some familiarity with OCT testing already and will not cover finer points of how the test works or interpretation. Fortunately, the data provided by OCT testing is fairly intuitive and fits right in with one's basic understanding of retinal...

Ndirect Lenses

Rodenstock Panfundoscope Lens

The indirect lenses will give you an excellent field of view compared to direct view lenses, but they require more finesse to obtain said field of view. An example of this type of lens would be the various Mainster lenses made by Ocular Instruments or the classic but no longer manufactured Rodenstock Panendoscope Figure 4 . Volk also makes a selection of indirect lenses Figures 5 and 6 . All of these lenses essentially do the same thing that your 90-diopter lens does, but they are stuck to the...

MOVING into the zone

The ETDRS recommended treating up to 500 microns from the center of the fovea, but this is close, and you may want to play it safe and stay 750 microns from the center in order to avoid trouble. This is an easy number to define just mentally split the diameter of the disc in half, and put one end at the center of the fovea. Until you have a lot of experience, or become cavalier usually they are the same , it is best to avoid getting close to the center. This is where observant patients can...

Differential Diagnosis

A Rose Is a Rose Is Type 2a Juxtafoveal Telangiectasis Usually you do not need to use your differential diagnosis powers with diabetic retinopathy, given that the patient already has the systemic diagnosis and the fundus findings are classic. This eliminates some brain strain but, as this book hopefully shows, the ease of diabetic diagnosis is more than made up for by the whole art of medicine thing. Still, you should never drop your guard completely, and you should always keep at least a...

Spot Size and a Bit About Spot Power

Focal Laser Scar

The main goal is to use the smallest size possible to minimize scar expansion. It is best to start with a 50-micron spot and adjust the power as discussed above some lasers only go down to 75 microns, which is OK, too . Be warned that 50 or 75 microns is small, and you need to be very careful that you are not using powers that can accidentally punch through Bruch's membrane. How do you know if you broke Bruch's It is usually pretty obvious. First of all, the patient may jump because you will...

Basic Science

Melanin Xanthophyll Absorption Retina

Didn't you read the intro This is not a basic science text. If you want basic science, get a real textbook. Or go to ARVO. Sheesh Know Your Weapons Lasers and Their Ilk This section really does not have a heck of a lot to do with patient care issues, but it is useful to have some idea about how the little demons inside the laser box do their thing. First of all, it is impossible to talk about lasers without rehashing the acronym. At some point in your career you may come across a pedant that...

The Informed Consent for Treating DME

Patient communication is extremely important when one uses lasers to treat diabetic retinopathy. You must remember that in spite of your best efforts to relate the concepts involved, there is a strong tendency for the patient's expectations to be very different from reality. It is certainly reasonable to provide the patient with ancillary information, such as discussions with office staff, video tapes, and handouts. But don't depend on such things to replace you. Besides, when was the last time...

The Informed Consent

Although the mechanics of doing a PRP can be daunting and will be covered at length in the next chapter perhaps the most difficult aspect of performing this procedure involves the informed consent. It can be very hard to provide an effective informed consent that gives the patient a fighting chance of actually understanding what on earth you are about to do to them. The general principles discussed in the section on informed consent for diabetic macular edema also apply here. However, a PRP is...

Diabetic Papillopathy

Or Non-Arteritic Ischemic Optic Neuropathy That Happens to Occur in Diabetics. This is an entity that does not quite fit into the categories of non-proliferative or proliferative disease. It is traditionally considered a relatively mild problem, but on occasion, it can be a real pain because it may create both a diagnostic and therapeutic challenge. It can also be easy to miss, especially if the patient has a lot of widespread macular edema that masks subtle swelling on the temporal aspect of...

The Disease

Diabetic Photograph

In macular edema, the problem stems from blood vessels that are leaky. In PDR, the problem stems from blood vessels that have simply died off. This starts in the periphery and gradually moves toward the center. The dead and dying retina then releases vasoproliferative factors that stimulate new blood vessels to grow Figure 1 . Figure 1. Ischemic peripheral retina emits vasoproliferative factors into the vitreous. If the blood vessels simply grew in isolation, without any vitreous to latch onto,...

Fluence jcm Power Watts x Time Seconds Energy Joules uence cm Spot Area cm Spot Area cm

We will try to stay away from the obligatory discussion of energy, work, radiometric terminology, etc. that often shows up at this point in real textbooks. The key thing is that your laser output has a certain level of mojo and you need to know exactly how to control it. Look at the last equation for fluence. Note that going up or down on power Watts or on exposure duration time creates a linear increase or decrease in the energy delivered. This means that if you are getting a good burn and you...

Hich Brings Us To

Diabetic Retinopathy Study Photo 10a

Although severe NPDR may be the ideal time to identify potential for trouble, proliferative diabetic retinopathy is your true enemy. Fortunately, PDR does not tend to be subtle. Even very small neovascularization at the disc NVD is readily apparent, simply because the vessels weave over the nerve in a path very different from the normal radial capillaries. Remember that NVD does not really need to be exclusively at the disc to be called NVD vessels within 1 disc diameter of the nerve also...

Nonclearing Vitreous Hemorrhages

The traditional indication for vitrectomy is a non-clearing vitreous hemorrhage. The exact timing of surgery is variable. It would be great if you could just memorize one number, but there is no automatic time to operate. There are guaranteed risks with surgery vitrectomy carries about a 2 to 5 complication rate, and that number goes up in eyes that are sicker or out of control. On the other hand, doing nothing can also be risky because you can't see the retina to be sure it is safe from...

Differential Diagnosis Issues

Unfortunately, when it comes to the differential diagnosis, there is nothing about the clinical exam that can definitively distinguish diabetic papillopathy from more ominous causes of optic nerve swelling. Most authors suggest that the diagnosis of diabetic papillopathy can be made if the patient is in the appropriate demographic and the vision and visual field are relatively reserved. This sounds reasonable, but one is still stuck with a patient who has a swollen optic nerve and, as a result,...

Doc my vision is really blurry in the morning

If patients develop edema that is in or around the fovea, you will often hear the above complaint. There are a few things you should consider when patients tell you this. First of all, OCT studies have suggested that macular edema is worse in the morning, presumably because the retina swells during the night, just like someone's ankles swell up if they spend a lot of time standing.3 Does this mean that they should sleep with a few pillows No one has looked at this. Maybe you could do an ARVO...

What About Warfarin

Warfarin Coumadin can sometimes be more difficult to sort out. Once patients on this medication hear that they could get blood in their eye from retinopathy, they and their doctors will become rightfully concerned about the use of this drug. This issue takes more finesse than the aspirin question. If patients are placed on Coumadin, it is because they need to be on it for life-threatening problems, or at least, that is what one would assume. A tedious but conscientious step is to make sure this...