George L Spaeth, Parul Ichhpujani

Transcription

1 Journal of Current The Glaucoma Ethics of Treating Practice, or September-December Not Treating Glaucoma 2009;3(3):7-11 The Ethics of Treating or Not Treating Glaucoma George L Spaeth, Parul Ichhpujani Anna V Goldberg Glaucoma Service, Wills Eye Institute, 840 Walnut Street, Philadelphia, USA Abstract: Managing glaucoma has practically become synonymous with lowering intraocular pressure. This article examines the goals of glaucoma therapy, and the risk of treatment as opposed to its benefits. Answering ethical concerns regarding when to treat glaucoma so as to effectively delay disease progression would significantly reduce the economic burden of this disease. Keywords: Glaucoma pharmacotherapy, target IOP, disk damage. INTRODUCTION Glaucoma is one of the commonest eye diseases in the eye, accounting for more irreversible blindness than any other condition. 1,2 Realistic estimates of the costs associated with diagnosing and treating glaucoma are difficult to make, but they are definitely in the billions of dollars. 3,4 Even more difficult to measure is the human misery caused by the disease for those who have it and for their relatives and friends. It would seem self-evident, then, that treating patients with glaucoma is something that should be done and that is ethical. However, the issue is by no means so simple. For every patient who is diagnosed with glaucoma, there are probably ten who are considered possibly to have glaucoma, because distinguishing between those who have glaucoma and those who do not is difficult, at least in the early stages of the disease. 5,6 A diagnosis of glaucoma is wrong in many of such cases; thus treatment is unnecessary, expensive and introduces health problems of its own. Prior to discussion of whether treating patients with glaucoma is ethical or not, it is important to define what we mean by glaucoma. Glaucoma is the process in which the tissues of the eye (particularly the optic nerve and the retina) become progressively damaged in characteristic ways, the damage is always, at least partially related to intraocular pressure. 7 Some of those affected with glaucoma become sufficiently damaged that they become disabled. 8 The significance of glaucoma, then, is that it can cause disability. However, nobody starts with glaucoma damage. As mentioned, in its early stages it is difficult to determine who will go on to become blind from glaucoma and who has a condition which may cause little or no visual loss. Most physicians are sincerely interested in trying to help patients preserve health, and, where possible, restore patient s health. The usual word used to describe the method physicians and other health care professionals use to help their patients is treatment. In most physicians and indeed patients minds, treatment involves use of medications or some modality, such as laser, radiation or traditional surgery, which will affect the tissues. When considering the issue of the ethical aspect of treating or not treating patients with glaucoma, we will be thinking in terms of this usual concept of treatment. From an ethical point of view, failure to act is as significant as acting. It is not just chance that the general confession in the Prayer Book of the Episcopal Church 9 states that we should confess that, We have left undone those things which we ought to have done, and we have done those things which we ought not to have done. Deciding not to treat, then, merely because one has concerns about the harmful effects of treating, is unethical. Simply saying, Just do no harm 10 is not an excuse, if to do nothing allows probable visual loss to occur. The decision not to treat is just as much a decision as is a decision to treat. Though there are other considerations, the simplest test of whether an action is medically ethical is whether that action benefits the patient. The benefit must exceed the problems associated with treatment. Because every treatment has problems, no treatment is indicated unless the problems that would develop in the absence of treatment are worse than the problems caused by the treatment. Figure 1 graphically depicts the spectrum of health in patients with glaucoma. As can be quickly seen, the graph divides patients into three groups: those with no definite findings of glaucoma (the Green Zone), those with a definite 7

2 George L Spaeth, Parul Ichhpujani Fig. 1: Glaucoma graph abnormality, such as a moderate field defect in one eye, but who have not yet developed sufficient visual loss that they have symptoms (the Yellow Zone), and finally, those individuals in whom disability already exists because of marked loss of vision (the Red Zone). 7 At the top of the graph, in the green area, is the zone in which at the time of the first examination it cannot be said that the person has any glaucoma, or any damage associated with glaucoma. A person in the Green Zone may be predisposed to getting glaucomatous damage, and may even eventually go blind, but the likelihood of that occurring is extremely difficult to determine with certainty. In contrast, patients in the Yellow Zone already have definite damage. Their optic nerve is unquestionably abnormal. Probably their retinal nerve fiber layer is abnormally thin. They have reproducible visual field loss. Such patients, then, can be distinguished from those in the Green Zone because they are no longer in an area where it is questionable that they have glaucoma. However, the amount of damage is still slight enough that they do not have any symptoms. They are, then, not bothered by their glaucoma. They have no dis ease. But there is also a third group of patients with glaucoma, those in the Red Zone. When patients develop advanced optic nerve and retinal nerve fiber layer damage, they have so much visual loss that they become partially or even totally disabled. When individuals are in the Red Zone, then, we know that they are diseased. Objectives of care include preventing anybody from getting into the Red Zone, that is preventing disability from developing, and, if an individual is already in the Red Zone, preventing her or his disability from becoming worse. Ideally we should like to lessen the amount of disability. Our overall objective as physicians is to help patients be as healthy as they can so they can celebrate their lives. One way that ophthalmologists can do that is by preserving their patients vision. When sufficient visual loss is present and disability already exists, then, treatment is justified, but only if it can lessen the disability or, at the least, prevent the disability from worsening, and, in addition, accomplish this in a way that the likelihood that the treatment will make the person worse is less than the likelihood that the treatment will help. Consider a patient with far-advanced glaucoma (Disk Damage Likelihood Scale 11 score of 8 or 9) in each eye (Fig. 2). Such individuals have far-advanced visual field loss, often cutting into fixation. In such cases, lowering intraocular pressure surgically can cause sudden permanent irreversible loss of vision. Somewhere around 3 to 5% of those with glaucoma so severe that it already affects the visual acuity due to the advanced visual field loss will develop wipe out or snuff out. 12 This means that their vision will go from something like 20/40 down to something like Fig. 2: Disk damage likelihood scale 8

3 The Ethics of Treating or Not Treating Glaucoma hand movements immediately following the surgery and it will not return. Before subjecting a patient to a 3 to 5% risk of very serious worsening, then, it must be clear that without the surgery the patient would deteriorate from (in this case) 20/40 vision to finger counting vision. Therefore, even when disability exists treatment is not automatically ethical. It is only ethical if the likelihood of the beneficial effects of treatment exceeds the likelihood of harmful effects. Now let us consider a more usual situation, specifically, in which the patient is thought to have glaucoma, or thought perhaps to have glaucoma, as would be the case in around 90% of patients with ocular hypertension. However, in none of these patients is any disability present due to the glaucoma. When no disability exists, treatment is only justified if there is a reasonable level of certainty that without treatment disability will develop. Our goal is to preserve health and development of disability. We should note, then, when looking at the Glaucoma Graph (Fig. 1) that our goal is not to prevent our patients from moving from the Green Zone to the Yellow Zone. If the patient dies before reaching the Red Zone, physicians will have done their job well. To repeat, then, preventing the development of asymptomatic changes, or asymptomatic damage, is not the appropriate objective of care. It is not appropriate because the efforts made will themselves introduce problems that by definition will exceed the benefits because there is no benefit of treatment in a patient who will not develop symptoms if not treated. There is at present no evidence that initiating treatment prior to development of field loss is more effective than preventing further field loss than when treatment is started after field loss has developed. 13 It is possible that once field loss has developed the eye is more easily damaged and, therefore, the person is more likely to have further field loss. Such individuals have already demonstrated that they have the capacity to get worse. However, that last statement is very different from saying that the initiation of treatment after field loss has developed is less likely to be successful in preventing enough field loss to cause disability. That latter consideration has not been established. Even more convincingly, there is no evidence at all that starting treatment before visual field loss develops will be more likely to prevent people from becoming disabled by the glaucomatous process. The treatment increases the likelihood of having a psychiatric episode 14,15 and of developing cataracts. 16 As shown in the Collaborative Initial Glaucoma Treatment Study, 17 there is an immediate decrease in visual acuity following the initiation of surgical treatment for glaucoma, and while the changes are less dramatic, there are similar changes that occur following the initiation of treatment with medicines. We need to consider the ethical issues regarding the treatment of glaucoma with medicines, laser, radiation or surgery. Blind people can be helped by keeping their eyes healthy enough so that their eyes can be retained, or by relieving pain. The use of medications to attempt this is appropriate. Some physicians sometimes consider performing a surgical glaucoma procedure in a blind eye which is painful. Before that is done, however, the physician must tell the patient that the performance of such a procedure may lead to blindness in the other eye. Because tube-shunt procedures, cyclodestructive procedures and filtering procedures have all been associated with the development of sympathetic ophthalmia, it is hard to consider how these surgeries would be ethically justifiable to treat a blind eye. In some patients the need for relief of pain and the desire to preserve the globe may be sufficiently intense that patients will actually choose to have surgery despite the risk of blindness in the other eye. When patients make such choices, however, the physician must be absolutely certain that the patients truly understand the risk that is being taken. Furthermore, the physician must be reasonably certain that the recommended treatment will relieve pain or cure the problem. When patients have severe visual loss (the Red Zone), as shown in Figure 1, it is easy to justify medicinal treatment. Preservation of vision increases patients ability to care for themselves. Lowering intraocular pressure in patients with advanced glaucoma can prevent progressive field loss. It can be beneficial without being harmful. It is an appropriate allocation of resources to treat those who are already at least partially incapacitated. Further disability can be prevented by reasonably inexpensive and reasonably safe treatments. When patients are in the Yellow Zone, that is to say, they have definite glaucoma damage with absence of symptoms, it is highly reasonable to consider treatment. The test, however, must be that there needs to be relative 9

4 George L Spaeth, Parul Ichhpujani certainty that without treatment disability will develop. Because it has already been demonstrated by virtue of the person being in the Yellow Zone that the eye has the capacity to deteriorate, it is reasonable to assume that further deterioration will continue. However, the rate of that deterioration must be sufficiently rapid, and the duration of the deterioration continue must be sufficiently long that it is likely that the person will develop disability. The ethical aspects of treating patients who have no definite damage, however, are different (Table 1; Green zone). When patients are in the Green Zone, treatment has less than a 10% likelihood of being beneficial, but is almost certain to cause problems. Furthermore, allocation of resources to treat individuals who, by and large, do not need treatment, results in those resources being withdrawn from people who could benefit from treatment. Using the number needed to treat (NNT) method, it has been shown that 20 people with ocular hypertension need to be treated to prevent 1 person from getting glaucoma. 19 Resources are limited, and when they are used for one purpose, they cannot be used for another. Up to this point we have been considering treatment as the word is usually utilized. However, treatment in a broader sense means an action designed to alter beneficially a particular situation. The goal of treatment of all patients with glaucoma and those suspected of having glaucoma is the same, specifically, enhancing their quality of life, helping them celebrate life, allowing them to be as healthy as they can. This is accomplished not only by the use of medicines, laser or surgery, but also by encouraging, giving realistic hope and transferring affection and love of life to the patient. 18 Ethical principle Autonomy Beneficence Nonmalificence Justice Table 1: Ethical principles of glaucoma treatment Red May preserve Can help Can harm Preservation of indepence, highly cost effective Yellow Green May help or hurt Decreases Usually helps?helps Usualy harms Harms less than helps Preserves autonomy Expense to patients and society more than the benefits In this sense every patient with every stage of glaucoma is deserving of treatment. Such types of treatment are always ethical. REFERENCES 1. Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and Br J Ophthalmol 2006;90: Grehn F. World health problem of glaucoma. J Glaucoma 2001; ( 5 Suppl 1): Jonsson B, Krieglsten G. Primary Open-angle Glaucoma: Differences in International Treatment Patterns and Costs. Oxford: Isis Medical Media Ltd, Kobelt G, Jönsson L, Gerdtham U, Krieglstein GK. Direct costs of glaucoma management following initiation of medical therapy. A simulation model based on an observational study of glaucoma treatment in Germany. Graefes Arch Clin Exp Ophthalmol 1998;236: Stewart WC, Stewart JA, Nassar QJ, Mychaskiw MA. Costeffectiveness of treating ocular hypertension. Ophthalmology 2008;115: Peeters A, Schouten JS, Webers CA, Prins MH, Hendrikse F, Severens JL. Cost-effectiveness of early detection and treatment of ocular hypertension and primary open-angle glaucoma by the ophthalmologist. Eye. 2008;22: Spaeth GL. Defining glaucoma, defining disease: The 1998 Dohlman Lecture. Int Ophthalmol Clin 1999;39: Jampel HD. Glaucoma patients assessment of their visual function and quality of life. Trans Am Ophthalmol Soc 2001;99: Clement Moore Butler. In: The Book of Common Prayer: Interpreted by Its History (2nd ed).wm Morrison, Harvard University, Smith J. Origin and Uses of Primum Non Nocere Above All, Do No Harm! J Clin Pharmacol 2005;45: Henderer JD. Disc Damage Likelihood scale. Br J Ophthalmol. 2006;90: Costa VP, Smith M, Spaeth GL, Gandham S, Markovitz B. Loss of visual acuity after trabeculectomy. Ophthalmology 1993;100: The AGIS Investigators. The Advanced Glaucoma Intervention Study (AGIS): 7, The relationship between control of intraocular pressure and visual field deterioration. Am J Ophthalmol. 2000;130: Pappa C, Hyphantis T, Pappa S, Aspiotis M, Stefaniotou M, Kitsos G, et al. Psychiatric manifestations and personality traits associated with compliance with glaucoma treatment. J Psychosom Res 2006;61: Mabuchi F, Yoshimura K, Kashiwagi K, Shioe K, Yamagata Z, Kanba S, et al. High prevalence of anxiety and depression in patients with primary open-angle glaucoma. J Glaucoma 2008;17:

5 The Ethics of Treating or Not Treating Glaucoma 16. Jampel H. Trabeculectomy: More effective at causing cataract surgery than lowering intraocular pressure? Ophthalmology 2009;16: Wahl J. Results of the Collaborative Initial Glaucoma Treatment Study (CIGTS).Ophthalmologe 2005;102: Hamelin N. The physician-patient relationship in glaucoma. J Fr Ophthalmol 2008;31(6, Suppl 2): Coleman AL, Singh K, Wilson R, Cioffi GA, Friedman DS, Weinreb RN. Applying an evidence-based approach to the management of patients with ocular hypertension: Evaluating and synthesizing published evidence. Am J Ophthalmol. 2004;138(3,Suppl1):3-10. George L Spaeth (gspaeth@willseye.org) If we value independence, if we are disturbed by the growing conformity of knowledge, of values, of attitudes, which our present system induces, then we may wish to set up conditions of learning which make for uniqueness, for self-direction, and for self-initiated learning. Carl Rogers 11