diagnose and treat glaucoma and any resulting visual impairment.

Transcription

1 Overview Do you have a client who has been diagnosed with glaucoma? Do you wonder what this diagnosis means? If so, you are not alone. Glaucoma affects tens of millions of people worldwide. Despite its prevalence, many people lack accurate information about this disease. Therefore, the goal of this course is to provide glaucoma-related information that helps you take a supportive role during your client's adjustment to life with glaucoma. This course includes five lessons. Lesson 1 discusses the human eye and forms of glaucoma. Lesson 2 explains how a doctor diagnoses glaucoma. Lesson 3 describes common treatments for this disease. Lesson 4 discusses the emotional impact of visual impairment. And finally, Lesson 5 explains ways to continue daily activities when vision loss occurs. The material in this course is informational only; it constitutes neither the advice of a medical doctor nor that of a rehabilitation specialist. These professionals are best qualified to Overview i

2 diagnose and treat glaucoma and any resulting visual impairment. For your convenience, some lessons begin with a section called Key Terms, which introduces words that may be unfamiliar. Each lesson also includes section reviews, which are for your personal development only. Therefore, when you complete a section review, do not send your responses to your Hadley instructor. Rather, check your comprehension by comparing your answers with those provided. You can always contact your instructor, however, to clarify concepts. You are required to submit five assignments to your instructor, one at the end of each lesson. If you are ready to learn about glaucoma, begin Lesson 1: What Is Glaucoma? Overview ii

3 Lesson 1: What Is Glaucoma? Glaucoma is a group of eye diseases involving damage to the optic nerve and characteristic loss of peripheral (outer) vision. Elevated eye pressure is also usually present. If left undiagnosed and untreated, glaucoma can result in blindness. Glaucoma occurs most often in people over the age of 40, but it can also strike infants, children, and young adults. What does it mean to have glaucoma? What puts a person at risk of developing this disease? Lesson 1 explains the workings of a healthy eye. It also describes the progression and risk factors of glaucoma. First, the lesson discusses primary open-angle glaucoma, the most common form of the disease. Then, it discusses some less common forms, including normal-tension, closed-angle, congenital, and secondary glaucoma. Recognizing glaucoma helps you take a supportive role during your client's adjustment to life with glaucoma. Lesson 1: What Is Glaucoma? 1

4 Objectives After completing this lesson, you will be able to a. explain the workings of a healthy eye b. describe primary open-angle glaucoma c. describe less common forms of glaucoma Key Terms The following terms appear in this lesson. Familiarize yourself with their meanings so that you can use them in your course work. anterior chamber front compartment of the inner eye that is filled with aqueous fluid and is surrounded by the cornea, iris, lens, and pupil aqueous humor fluid that fills the anterior and posterior chambers of the eye; nourishes eye tissue and provides pressure to help maintain the shape of the eye closed-angle glaucoma (CAG) an eye disease in which the iris and the lens block the movement of fluid between the chambers of the eye ciliary body Lesson 1: What Is Glaucoma? 2

5 tissue that is located behind the iris; produces aqueous humor cornea clear tissue covering the front of the eye through which rays of light enter the eye intraocular pressure (IOP) pressure inside the eye iridocorneal endothelial syndrome (ICE) a condition that causes the cornea to form scars that connect to the iris and block the drainage angle iris thin membrane shaped like a disc that gives the eye its color; controls the amount of light passing through the pupil lens part of the eye that is located behind the iris and that focuses light on the retina normal-tension glaucoma (NTG) a form of glaucoma in which damage occurs to the optic nerve without eye pressure exceeding the normal range optic disk Lesson 1: What Is Glaucoma? 3

6 back of the retina where nerve fibers come together and form the optic nerve optic nerve bundle of nerve fibers that is located at the back of the eye and that carries impulses (visual stimuli) from the retina to the brain posterior chamber part of the eye that is situated behind the anterior chamber, or between the iris and the lens, and is filled with aqueous fluid primary open-angle glaucoma (POAG) an eye disease that causes damage to the optic nerve as a result of the eye s drainage canals becoming clogged pupil opening in the center of the iris through which light passes; appears as a dark circle retina innermost part of the eye; turns light into impulses, which are sent to the brain through the optic nerve Schlemm s canal Lesson 1: What Is Glaucoma? 4

7 collecting pipe that is located below the trabecular meshwork and that carries aqueous humor away from the eye sclera a thin yet tough protective shell that surrounds the eye and is known as the white of the eye trabecular meshwork system of drains located between the iris and the cornea; main pathway for aqueous humor leaving the eye uveoscleral pathway minor pathway for aqueous humor leaving the eye; fluid drains through the sclera The Healthy Eye This section describes some basic facts about the human eye and how it works. This information will give you a better understanding of glaucoma and its effect on vision. It will also provide you with the vocabulary necessary for discussing this disease. Note, however, that this is not an in-depth study of the eye. Such detail is beyond the scope of this course. To start the Lesson 1: What Is Glaucoma? 5

8 reading, select the Next button below. Once you have completed the reading, continue to the section review. How does a person see? Rays of light containing information about shape, color, and movement enter the eyes. The eyes send this information to the brain, which then interprets it. For example, the eyes might detect rays of light as green, brown, tall, and swaying. Upon receiving these details, the brain creates a matching image of a tree. This example is, of course, simplified. Now consider this process in terms of parts of the eye. To start, the sclera is a thin yet tough protective shell that surrounds the eye and is known as the white of the eye. The front part of the sclera is called the cornea, or the clear tissue through which light enters the eye. The cornea bends the light, which then passes into the anterior, or front, chamber of the inner eye. The cornea, iris, lens, and pupil surround this chamber, which contains a fluid called aqueous humor. In the back of the chamber, the iris, a thin membrane shaped like a disc, gives the eye its color. The opening in the center of the iris is called the pupil. It appears as a dark Lesson 1: What Is Glaucoma? 6

9 circle. By controlling the size of the pupil, the iris regulates the amount of light coming through the cornea. For example, on a sunny day, the iris constricts the pupil, or makes it smaller, letting in less light. On a cloudy day, the iris dilates, or widens, the pupil, letting in more light. Light passes through the pupil to the lens, which is located behind the iris. The lens focuses incoming light onto the retina, the innermost part of the eye. The retina turns the light into impulses, which are sent to the brain through the optic nerve. Finally, the brain converts these impulses into the images that a person sees. Also note that the optic nerve consists of more than one million nerve fibers, which originate in the retina. The point where the fibers come together to form the optic nerve is called the optic disk. A few additional parts of the eye are relevant to the study of glaucoma. The ciliary body, located behind the iris, produces a fluid called aqueous humor. It flows into the posterior chamber, which is located between the lens and iris. From there, the fluid passes through the pupil and into the anterior chamber. This fluid Lesson 1: What Is Glaucoma? 7

10 nourishes eye tissue and provides pressure to help maintain the shape of the eye. This pressure is called intraocular pressure (IOP). If all is well, the fluid made within the eye equals the amount of fluid leaving the eye. In which case, the IOP is normal, or between 12 and 21 millimeters of mercury (mmhg). For the most part, aqueous humor leaves the eye through the trabecular meshwork, or the tiny drains located between the cornea and the iris. After passing through these drains, the fluid enters Schlemm s canal. This vessel works like a pipe and carries the fluid away from the eye. In addition, the uveoscleral pathway is a minor route for aqueous humor outflow. In this case, the fluid passes through the middle of the eye, draining through the sclera. Now study the following diagram of the human eye. Although basic, it includes most parts of the eye mentioned in this discussion. Lesson 1: What Is Glaucoma? 8

11 Ciliary Body Schlemm's Canal Anterior Chamber Optic Disk Posterior Chamber Trabecular Meshwork Description: Eye Diagram (black and white) Credit: Adapted from illustration NEA08, courtesy of National Eye Institute, National Institutes of Health Lesson 1: What Is Glaucoma? 9

12 This section explained the basic parts of the human eye and their functions in order to help you better understand glaucoma. Section Review Review the information in this section by answering the following true/false and multiple-choice questions. Use the Check Answer button to get the correct answer and an explanation. True/False Indicate whether the following statements are true or false. Note that inadvertent keystrokes may change your answers. 1. The sclera is known as the white of the eye. Correct! The statement is true. The sclera is known as the white of the eye. 2. Fluid leaves the eye through only one route. Correct! The statement is false. Fluid leaves the eye through the trabecular meshwork, and to a lesser extent, through the uveoscleral pathway. Lesson 1: What Is Glaucoma? 10

13 3. The pupil controls the size of the iris. Correct! The statement is false. The iris controls the size of the pupil. 4. The optic nerve consists of more than one million nerve fibers. Correct! The statement is true. The optic nerve consists of more than one million nerve fibers. Multiple Choice Select the best item to answer each of the following questions. Note that inadvertent keystrokes may change your answers. 5. Which part of the eye produces aqueous humor? a. retina b. cornea c. ciliary body d. optic nerve Correct! The answer is (c). The ciliary body produces aqueous humor. 6. Which of the following is the clear tissue that covers the front of the eye? Lesson 1: What Is Glaucoma? 11

14 a. retina b. optic nerve c. ciliary body d. cornea Correct! The answer is (d). The cornea is the clear tissue that covers the front of the eye. 7. Which of the following is the thin membrane shaped like a disc that gives the eye its color? a. iris b. lens c. pupil d. retina Correct! The answer is (a). The iris is the thin membrane shaped like a disc that gives the eye its color. 8. Which part of the eye focuses light onto the retina? a. iris b. lens c. pupil d. retina Lesson 1: What Is Glaucoma? 12

15 Correct! The answer is (b). The lens of the eye focuses light onto the retina. If you found these questions difficult, review the section reading. If you are satisfied with your answers, select the Next button to proceed. Primary Open-Angle Glaucoma (POAG) This section discusses primary open-angle glaucoma. To start the reading, select the Next button below. Once you have completed the reading, continue to the section review. Although several types of glaucoma exist, the most common one is POAG. This form of glaucoma takes its name from the angle between the cornea and the iris where the trabecular meshwork is located. The term primary means "occurring for no known reason." This section describes the progression and risk factors of POAG. During this discussion, refer back to the previous section, as needed, to review parts of the eye and their functions. POAG is an eye disease that causes damage to the optic nerve. How does this occur? To start, recall that Lesson 1: What Is Glaucoma? 13

16 the ciliary body produces a fluid called aqueous humor. This fluid circulates through the posterior and anterior chambers. Then it leaves the eye primarily through the trabecular meshwork and Schlemm s canal. This fluid also maintains IOP. Sometimes, however, the drainage system in the eye becomes clogged. In particular, with POAG, Schlemm's canal suffers blockage. Because the eye is a closed compartment, the aqueous humor cannot escape. Instead, it builds up, causing the IOP to rise. Elevated IOP is not necessarily dangerous. In some people, however, it damages the eye, and in particular, the optic nerve. Why the optic nerve? It is the weakest point in the eye, and therefore, gives way under the increased pressure. Damage occurs at the part of the optic nerve called the optic disk. A normal optic disk looks like a doughnut. It has a rim surrounding a central area called the cup. With glaucoma, the rim gets thinner, and the cup gets larger. This process is known as cupping. It occurs as elevated IOP destroys optic nerve fibers. Lesson 1: What Is Glaucoma? 14

17 Once a sufficient number of nerve cells are destroyed, blind spots begin to form in the field of vision. These blind spots usually develop first in the peripheral field, which includes top, sides, and bottom vision. For example, people may miss seeing objects out of the corner of their eye. To compensate for this type of vision loss, a person can simply turn his or her head. Therefore, this loss often goes unnoticed until the optic nerve is greatly damaged. By this time, large blind spots already exist. If the disease goes unchecked, the field of vision continues to narrow, resulting in tunnel vision. A person now sees as if looking through a tube. The following pictures show a scene as someone with healthy eyesight sees it, and then as someone with tunnel vision sees it. Lesson 1: What Is Glaucoma? 15

18 Description: Scene as viewed by a person with healthy vision Credit: National Eye Institute, National Institutes of Health Reference: EDS01 Lesson 1: What Is Glaucoma? 16

19 Description: Scene as viewed by a person with tunnel vision Credit: National Eye Institute, National Institutes of Health Reference: EDS02 In later stages of the disease, the central, or straightahead, vision deteriorates. This is the vision used for reading, driving, and recognizing people or objects. Glaucoma reaches its final stage when most optic nerve fibers have died, resulting in blindness. Any loss of vision from glaucoma is irreversible, as nothing can presently restore dead nerve cells. Despite the harm it causes, POAG has no early warning signs neither pain nor other symptoms. In fact, vision Lesson 1: What Is Glaucoma? 17

20 stays seemingly normal until the more advanced stages of the disease. Because of this, POAG is often called the sneak thief of sight. Some symptoms that may develop in later stages of the disease, however, include the following: mild eye pain night blindness blurred vision decreased response to magnification reduced peripheral vision increased illumination requirements inability to adjust the eyes to darkness difficulty focusing on close work halos around bright lights Once detected, glaucoma usually responds well to treatment. Even with proper treatment, a small number of people with POAG still lose their vision. Also, this disease is chronic, or ongoing. Therefore, anyone diagnosed with it, must commit to following a lifelong treatment plan. Everyone has some risk of developing this form of glaucoma. Certain factors, however, increase a Lesson 1: What Is Glaucoma? 18

21 person's chances of getting the disease. These factors include the following: Age: POAG occurs more often in older people, especially those over the age of 60. Diabetes: POAG occurs more often in people with diabetes. Also, the longer a person has diabetes, the greater his or her risk of developing POAG. Extreme Myopia (Extreme Nearsightedness): Distant objects appear blurry to people who are nearsighted. People with extreme myopia have larger optic cups, making them more prone to POAG. Family History: If you have family members, especially immediate relatives, with POAG, you are at a much higher risk of developing this disease. Immediate relatives include mother, father, sister, and brother. Not everyone with a family history, however, develops POAG. High Blood Pressure: Those with high blood pressure have a greater risk of developing POAG. Other systemic health problems are also sometimes associated with this disease. They include migraine headaches and poor circulation. Lesson 1: What Is Glaucoma? 19

22 Ocular Hypertension: This term refers to increased IOP, the most important risk factor in predicting whether a person will get POAG. A glaucoma suspect is a person with increased IOP, but without damage to the optic nerve and visual fields. About one-third of these people will go on to develop POAG. Race: POAG is the most common cause of blindness in individuals of African origin. In fact, African Americans are more likely to develop POAG and more likely to go blind from the disease than other ethnic groups. Moreover, African Americans show signs of POAG starting at age 35, while other groups show signs after age 40. Mexican Americans, especially those over age 60, are also at higher risk of developing this disease. Risk factors are not causes of, but are associated with, glaucoma. Therefore, even if a person has a risk factor, he or she will not necessarily develop the disease. Doctors recommend that people at higher risk have annual eye exams. For conditions that can cause glaucoma, see the section titled Secondary Glaucoma in this lesson. Lesson 1: What Is Glaucoma? 20

23 This section discussed the progression and risk factors of POAG, the most common form of glaucoma. With this disease, clogging in Schlemm's canal causes a buildup of aqueous humor in the eye. In turn, IOP increases, often damaging the optic nerve. If left untreated, POAG can result in blindness. Moreover, because it has no early warning signs, POAG is often called the sneak thief of sight. Section Review Review the information in this section by answering the following true/false and multiple-choice questions. Use the Check Answer button to get the correct answer and an explanation. True/False Indicate whether the following statements are true or false. Note that inadvertent keystrokes may change your answers. 1. POAG is the most common form of glaucoma. Correct! The statement is true. POAG is the most common form of glaucoma. Lesson 1: What Is Glaucoma? 21

24 2. POAG takes its name from the angle between the cornea and the iris. Correct! The statement is true. POAG takes it name from the angle between the cornea and the iris. 3. Age is the most important risk factor in predicting whether a person will develop POAG. Correct! The statement is false. Ocular hypertension is the most important risk factor in predicting whether a person will develop POAG. 4. Risk factors for glaucoma are direct causes of the disease. Correct! The statement is false. Risk factors for glaucoma are associated with the disease but do not cause it. Multiple Choice Select the best item to answer each of the following questions. Note that inadvertent keystrokes may change your answers. Lesson 1: What Is Glaucoma? 22

25 5. In POAG, what does primary mean? a. occurring due to injury b. occurring for no known reason c. related to central vision d. related to peripheral vision Correct! The answer is (b). In POAG, primary means occurring for no known reason. 6. In some people, what part of the eye does elevated IOP damage? a. optic nerve b. ciliary body c. sclera d. cornea Correct! The answer is (a). In some people, elevated IOP damages the optic nerve. 7. Which of the following applies to POAG? a. It shows early warning signs. b. It occurs less often in people with diabetes. c. It occurs more often in older people. d. It has no relation to family history. Lesson 1: What Is Glaucoma? 23

26 Correct! The answer is (c). POAG occurs more often in older people. 8. Which field of vision does POAG affect first? a. intraocular b. central c. aqueous d. peripheral Correct! The answer is (d). POAG first affects peripheral vision. If you found these questions difficult, review the section reading. If you are satisfied with your answers, select the Next button to proceed. Other Types of Glaucoma This section discusses the progression and risk factors of less common forms of glaucoma. They include normal-tension, closed-angle, congenital, and secondary glaucoma. To start the reading, select the Next button below. Once you have completed the reading, continue to the section review. Lesson 1: What Is Glaucoma? 24

27 Normal-Tension Glaucoma (NTG) With this rare form of glaucoma, IOP stays within the normal range. Nonetheless, the optic nerve and visual field suffer damage typical of POAG. NTG tends to be more aggressive than POAG in that it affects central vision sooner. Otherwise, the two diseases follow a similar course. Risk factors for NTG include a family history of the disease, Japanese ancestry, and a history of heart disease. NTG has no definitive cause. Doctors believe it is due, in part, to poor blood flow to the optic nerve. A mechanical weakness of the optic nerve is another possible cause. This disease is also known as low-tension glaucoma or normal pressure glaucoma. Closed-Angle Glaucoma (CAG) This disease often has a swift onset that creates a medical emergency. The pupil dilates too much or too quickly. This action pushes the iris over the trabecular meshwork. In this position, the iris acts like a stopper, completely blocking the drainage angle. As a result, fluid can no longer leave the eye. Instead, it builds up, causing a sudden and severe rise in eye pressure, or an angle-closure glaucoma attack. Lesson 1: What Is Glaucoma? 25

28 In this situation, a doctor must lower the IOP as soon as possible to stop damage to the eye. Without treatment, blindness can result in as few as one or two days. Chronic glaucoma or cataracts may also develop. Therefore, it bears repeating: CAG often results in a medical emergency. In people with CAG, an attack may occur anytime the eyes dilate, as when entering a dark room. Drugs that dilate the pupil can also trigger this condition. These include antidepressants, cold medications, and antihistamines, as well as some medications to treat nausea. The pupil also dilates when a person is excited or anxious. Therefore, an acute glaucoma attack may occur during times of stress. Most people develop CAG without any warning signs prior to an attack. Possible symptoms, however, include the following: blurred vision redness of the eye severe eye pain tender eyeball hard eyeball Lesson 1: What Is Glaucoma? 26

29 swollen eye vision deterioration halos around objects severe headache nausea vomiting Not all people with CAG experience an acute attack. Instead, some people have minor attacks that end on their own when the pupil constricts. These attacks may have some or no symptoms. They also range in seriousness. Other people develop chronic angleclosure glaucoma. In this case, the iris gradually closes over the trabecular meshwork. At the same time, scar tissue forms between these two structures. The IOP rises only after a significant amount of scarring has occurred enough to block the drainage angle. In this case, treatment can prevent an acute attack, but the chronic form of the disease still develops. The following are risk factors for CAG: age over 40 Asian descent Lesson 1: What Is Glaucoma? 27

30 Inuit descent (Note that Inuit refers to the Eskimo people of North America and Greenland.) family history farsightedness narrow angle women Recall that risk factors are associated with glaucoma but do not cause it. Moreover, people with risk factors do not necessarily develop the disease. They should, however, have a complete eye exam every year. Finally, CAG can be primary (occurring for no known reason) or secondary (occurring due to previous illness or injury). This disease is also known as acute glaucoma and angle-closure glaucoma. Congenital Glaucoma This rare form of glaucoma occurs in babies and young children. A doctor usually diagnoses the disease within the first year of life. Infants may have the following symptoms: sensitivity to light, enlargement of the eye, cloudy corneas, and excessive tearing. These Lesson 1: What Is Glaucoma? 28

31 symptoms result from incorrect or incomplete development of the trabecular meshwork during the prenatal period. These structural defects cause slow drainage, resulting in high IOP. As in other forms of glaucoma, the optic nerve suffers damage. Surgery, however, when done promptly, can correct structural defects and thereby save a child s vision. Genetics usually plays a role in this type of glaucoma. In fact, most cases are inherited. Infection in the mother during pregnancy is also a risk factor. This includes certain viral infections such as rubella. People between the ages of 3 and 30 can develop a similar form of the disease called juvenile glaucoma. Secondary Glaucoma Secondary glaucoma may be mild or severe. It may also be either open- or closed-angle glaucoma. It can result from other medical conditions, including the following: eye surgery eye injuries (trauma) eye tumors eye inflammation advanced cataracts Lesson 1: What Is Glaucoma? 29

32 Glaucoma develops when these conditions cause a mechanical disruption or physical change in the drainage system. Trauma to the eye may include a blow, chemical burn, or penetrating injury. Moreover, glaucoma as a result of trauma can occur immediately after the injury or years later. Also, use of steroids or cortisone may increase eye pressure. If not treated, elevated IOP may lead to glaucoma, as in any case of ocular hypertension. Eye drops that are steroids most frequently cause IOP to rise. Therefore, doctors usually monitor people taking this form of medication. Elevated IOP occurs less often with oral steroids. Moreover, people who use inhalers to control asthma may possibly develop elevated IOP. Note, however, that these cases are known to occur only when dosage is high and is taken for an extended period. Secondary Open-Angle Glaucoma Two of the most common forms of secondary openangle glaucoma are pigmentary and pseudoexfoliative. Pigmentary glaucoma usually starts between the ages of 20 and 50. In those who are affected, flakes of Lesson 1: What Is Glaucoma? 30

33 pigment from the iris fall into the aqueous humor. They flow toward the trabecular meshwork where they accumulate. As a result, this structure becomes clogged. In turn, the IOP increases, threatening damage to the optic nerve. Many people with this glaucoma experience blurry vision and eye pain after exercising. For the most part, however, this disease has no symptoms. Pigmentary glaucoma has several risk factors. It is more common in men than in women. It is also more common in people who are nearsighted. Moreover, people with pigment dispersion syndrome, which causes flaking of pigment from the iris, are likely to develop this glaucoma. With pseudoexfoliative glaucoma, a whitish material builds up on the lens of the eye. As the iris moves, it rubs this material off the lens. Pigment also falls off the iris. Both materials accumulate on the trabecular meshwork. As a result, this structure becomes clogged. In turn, IOP increases, sometimes to very high levels, thereby damaging the optic nerve. For unknown Lesson 1: What Is Glaucoma? 31

34 reasons, this glaucoma often appears in one eye long before the other. This form of glaucoma has several risk factors. It is more common among people of European descent. It is also more common in people over the age of 50. Moreover, people with exfoliation syndrome, which causes flaking of the lens and iris, are likely to develop this glaucoma. Finally, this syndrome sometimes produces open- and closed-angle glaucoma in the same individual. Secondary Closed-Angle Glaucoma Several forms of secondary closed-angle glaucoma exist. Iridocorneal endothelial (ICE) syndrome leads to one of them. With this syndrome, the cornea forms scars that connect to the iris and block the drainage angle. Symptoms include distortion of the iris and pupil, as well as swelling of the cornea. The syndrome is usually present in only one eye. It also occurs more often in women between the ages of 30 and 50. Like other forms of glaucoma, the one associated with this syndrome may itself produce no symptoms. As with any glaucoma, however, it can lead to optic nerve Lesson 1: What Is Glaucoma? 32

35 damage and blindness. Moreover, as mentioned earlier, if an acute glaucoma attack occurs, consider it a medical emergency. Neovascular glaucoma is another form of secondary closed-angle glaucoma. With this disease, blood vessels form in the angle of the eye and block the trabecular meshwork. This glaucoma may produce no symptoms, but many people experience a chronically red, painful eye. In addition, this glaucoma is severe and difficult to control. It is also associated with other disorders such as diabetes. Poor vision is another risk factor. Like others, this form of glaucoma can lead to blindness. Moreover, in its acute form, it is a medical emergency. This section discussed the progression and risk factors of less common forms of glaucoma. They include NTG, CAG, congenital glaucoma, and secondary glaucoma. Like POAG, these forms of the disease can result in blindness. To protect vision, doctors recommend regular eye exams, which are discussed in Lesson 2. Lesson 1: What Is Glaucoma? 33

36 Section Review Review the information in this section by answering the following true/false and multiple-choice questions. Use the Check Answer button to get the correct answer and an explanation. True/False Indicate whether the following statements are true or false. Note that inadvertent keystrokes may change your answers. 1. CAG often results in a medical emergency. Correct! The statement is true. CAG often results in a medical emergency. 2. Asian descent is a risk factor for CAG. Correct! The statement is true. Asian descent is a risk factor for CAG. 3. Congenital glaucoma results from a structural defect in the iris. Lesson 1: What Is Glaucoma? 34

37 Correct! The statement is false. Congenital glaucoma results from a structural defect in the trabecular meshwork. 4. Scars block the trabecular meshwork in neovascular glaucoma. Correct! The statement is false. Blood vessels block the trabecular meshwork in neovascular glaucoma, whereas scars block this structure in glaucoma resulting from ICE syndrome. Multiple Choice Select the best item to answer each of the following questions. Note that inadvertent keystrokes may change your answers. 5. Which of the following applies to NTG? a. It has no definitive cause. b. It involves elevated IOP. c. It results from exfoliation. d. It is a common glaucoma. Correct! The answer is (a). NTG has no definitive cause. Lesson 1: What Is Glaucoma? 35

38 6. In a person with CAG, when might an acute glaucoma attack occur? a. when the pupil constricts b. when the pupil dilates c. when the angle is open d. when IOP is normal Correct! The answer is (b). In a person with CAG, an acute glaucoma attack might occur when the pupil dilates. 7. Which of the following is a risk factor for CAG? a. wide drainage angles b. narrow drainage angles c. an enlarged optic nerve d. an enlarged ciliary body Correct! The answer is (b). Narrow drainage angles are a risk factor for CAG. 8. Which of the following applies to pseudoexfoliative glaucoma? a. It is more common in children and young adults. b. It is more common in people of Asian descent. Lesson 1: What Is Glaucoma? 36

39 c. Whitish material builds up on the lens of the eye. d. Whitish material builds up on the ciliary body. Correct! The answer is (c). With pseudoexfoliative glaucoma, whitish material builds up on the lens of the eye. If you found these questions difficult, review the section reading. If you are satisfied with your answers, select the Next button to proceed. Summary This lesson described some basic parts of the human eye, as well as their functions. It also discussed the progression and risk factors of POAG, the most common form of glaucoma. Moreover, this lesson discussed the progression and risk factors of some less common forms of glaucoma. They include normaltension, closed-angle, congenital, and secondary glaucoma. Select the Next button to proceed to the assignment. Lesson 1: What Is Glaucoma? 37

40 Assignment 1 This assignment consists of two parts. (100 points total) Part 1 has ten multiple-choice questions, which will be computer graded. Part 2 has ten short-answer questions based on scenarios, which will be sent to your instructor for grading. You need to complete and submit the entire assignment at one time, as you cannot save partial work. Once you have completed all the questions, select the Submit Assignment button. Then you can review your results for Part 1. If you are unsure of an answer, select the appropriate section reading link below. When you are ready to return to this page, use the Back button or Alt+left arrow. This way any work you had done will still be present. If you select any other link or close the browser before selecting the Submit Assignment button, your work will be deleted and you will have to begin again. Review Section 1 Reading: The Healthy Eye Lesson 1: What Is Glaucoma? 38

41 Review Section 2 Reading: Primary Open-Angle Glaucoma (POAG) Review Section 3 Reading: Other Types of Glaucoma Part 1: Multiple Choice Select the best item to answer each of the following questions. Check your answers before you select the Submit button. Inadvertent keystrokes may have changed your answers. (4 points each, 40 points total) 1. What fluid flows through the posterior and anterior chambers of the eye? a. ciliary body b. optic nerve c. aqueous humor d. trabecular meshwork 2. Which part of the eye turns light into impulses? a. iris b. retina c. lens d. pupil Lesson 1: What Is Glaucoma? 39

42 3. Which part of the eye carries impulses to the brain? a. retina b. cornea c. ciliary body d. optic nerve 4. What is the opening in the center of the iris? a. lens b. cornea c. pupil d. retina 5. Which part of the eye do the cornea, iris, pupil, and lens surround? a. ciliary body b. peripheral vision c. Schlemm s canal d. anterior chamber 6. With POAG, where in the eye does clogging occur? a. optic nerve b. ciliary body Lesson 1: What Is Glaucoma? 40

43 c. posterior chamber d. Schlemm's canal 7. Which of the following applies to a cupped optic nerve? a. The cup is enlarged. b. The cup is smaller. c. The rim is bright red. d. The rim is enlarged. 8. How soon can blindness occur if an acute glaucoma attack goes untreated? a. one or two days b. one or two weeks c. one or two months d. one or two years 9. Which of the following is a risk factor for CAG? a. age below 40 b. nearsightedness c. Inuit descent d. European descent Lesson 1: What Is Glaucoma? 41

44 10. Which of the following applies to pigmentary glaucoma? a. It is a primary form of glaucoma. b. Flakes of pigment fall off the iris. c. Flakes of pigment fall off the retina. d. Whitish material builds up on the lens. Part 2: Short Answer Respond to the following questions with brief, complete answers. You can type your answers directly into the textboxes provided below, or copy and paste your answers from a word-processing file into the textboxes. Note, however, that you need to answer all the questions at one time, as you cannot save your work. (60 points total) Scenario 1 You are teaching a course on glaucoma with Dr. Roberts, an ophthalmologist, who wants you to explain in your own words how a healthy eye works. 11. Write an explanation of the workings of a healthy eye that you can present to your class. (10 points) Scenario 2 Lesson 1: What Is Glaucoma? 42

45 Later in the course, Dr. Roberts describes one type of glaucoma that is triggered by fluid in the eye building up quickly, thereby causing a sudden and severe rise in eye pressure. When an acute attack of this type of glaucoma occurs, blindness can result in as few as one or two days if a person doesn't receive emergency medical treatment. 12. Identify what type of glaucoma Dr. Roberts is describing, and explain two events that might trigger this condition. (3 points) 13. List five risk factors for this type of glaucoma. (5 points) 14. List five possible symptoms associated with this type of glaucoma. (5 points) Scenario 3 Dr. Roberts spends one class session discussing some of the less common types of glaucoma. He explains NTG, congenital glaucoma, pigmentary glaucoma, pseudoexfoliative glaucoma, ICE, and neovascular glaucoma. Lesson 1: What Is Glaucoma? 43

46 15. Identify one symptom for each of these six lesscommon types of glaucoma. (6 points) 16. Identify one risk factor for each of these six lesscommon types of glaucoma. (6 points) 17. Identify three symptoms found in more than one of these types of glaucoma. Include in your answer the types of glaucoma associated with these symptoms. (6 points) 18. Identify three risk factors found in more than one of these types of glaucoma. Include in your answer the types of glaucoma associated with these risk factors. (6 points) Scenario 4 One of your clients comes to you very concerned. She says that she has been having trouble seeing things to the side, and that sometimes she feels as if she is looking through a tunnel. She also tells you she hasn't gone to an ophthalmologist, because she doesn't feel any pain. She's hoping the problem is temporary and will go away on its own. She knows you've been working closely with Dr. Roberts, so she asks your opinion. Lesson 1: What Is Glaucoma? 44

47 19. What type of glaucoma do you think your client has? List at least two symptoms that led you to that conclusion. (3 points) 20. Explain why it's important for your client to see an ophthalmologist, by listing at least five symptoms that may develop if she leaves her glaucoma untreated. (10 points) You have successfully submitted this assignment. Your instructor will shortly receive an with your answers. Select the Next button below to view your results for Part 1. Lesson 1: What Is Glaucoma? 45

48 Lesson 1: What Is Glaucoma? 46