Visual Impairment in Older People: the Nurse’s Role

By reading this article and writing a practice profile, you can gain a certificate of learning. You have up to a year to send in your practice profile. Guidelines on how to write and submit a profile are featured at the end of this article.

Aim and intended learning outcomes

The aim of this article is to provide an overview of the role of the nurse in the treatment and management of several common ocular conditions that cause visual impairment in older people. These conditions include:

* Cataract.

* Age-related macular degeneration.

* Acute dosed angle glaucoma.

* Primary open angle glaucoma.

* Diabetic retinopathy.

The importance of the nurse’s role in meeting the individual needs of the visually impaired older person is outlined. Knowledge of these conditions and an awareness of the implications of sight loss and their significant impact on daily living activities can help the nurse to plan and provide quality evidence-based care. By being able to provide information about available treatments, support groups and low vision services, the nurse can promote the delivery of a more effective healthcare service. Current national health policies are explored as strategies to help alleviate the predicted burden of visual impairment.

After reading this article you should be able to:

* Define the common ocular diseases that cause visual impairment in older people.

* Identify the signs and symptoms of ocular conditions that cause either a gradual or sudden loss of vision.

* Describe the treatment options available for older people with ocular disease.

* Outline the principles of assessment for older people with visual impairment.

* Discuss the role of the nurse in managing the care of older people with visual impairment.

Summary

This article provides an overview of the role of the nurse in the treatment and management of several common ocular conditions that cause visual impairment in older people.

Key words

* Nursing: care

* Older people

* Visual impairment

These key words are based on subject headings from the British Nursing Index. This article has been subject to double-blind review.

Introduction

In the UK sight loss is largely an age-related phenomenon – 70 per cent of all people with sight problems are aged 65 and over (Department of Health (DH) 2001). It is estimated that by 2025 one fifth of the UK population (12.8 million people) will be over the age of 65. However, the number of people aged 80 and older will grow fastest and reach 3.5 million by the year 2025 (DH 2001). It is this age group that is most likely to experience serious sight problems. Thus, with the predicted growth in the older population, the common ocular conditions listed will increase the incidence of visual impairment in older people. Therefore, one of the priorities of the National Service Framework for Older People (DH 2001) is to provide evidence-based specialist care to improve eye health screening and low vision services.

Impact on health services

The NHS and local authorities spend almost 20 billion annually on long-term and residential care, and nursing homes to support older people with visual impairment (DH 2001). Helping these people to maintain independence in their own homes would be much more cost- effective and would also help to reduce the burden of failing sight on health services in the future.

Currently, the NHS spends 1.7 billion annually on treating hip fractures resulting from falls, mainly in older people whose failing eyesight has often been a contributory factor (DH 2001). Legood et al (2002) found that older people with sight problems are seven times more likely to fall and sustain a serious injury. Rehabilitation and mobility training to reduce the risk of falls could significantly reduce costs. The treatment of poor vision combined with exercise and hazard management in the home have produced an additional 14 per cent reduction in the annual fall rate in the UK (Day et al 2002). Thus, older people and healthcare professionals should be aware of the importance of regular eye examinations.

Anatomy of the eye

The eyeball consists of three layers known as tunics (Figure 1). The outer tunic consists of the cornea and the sciera. The sciera is the white, protective outer coat, and the cornea is a transparent structure at the front of the eye that allows the entry of light. The middle tunic contains the iris, the ciliary body and the choroid. The choroid is a rich, vascular coat that lines the posterior segment of the eye and nourishes the retina. The third layer, lining the back of the eye, forms the retina, which is a complex nervous tissue layer, responsible for converting light rays into electrical signals and relaying them via the optic nerve to the brain for the interpretation of vision. The cone cells, responsible for daylight vision, are concentrated in the macula, an area of central, detailed and colour vision. The rods, responsible for night vision, are scattered across the peripheral retina (James ef al 2003). The optic disc is an area where the central retinal vein and nerve fibres leave and the central retinal artery enters.

Figure 1. The structure of the eye

The transparent lens focuses light onto the retina. The ciliary body contains the ciliary muscle that controls the shape of the lens for near or distance vision and the ciliary processes that secrete aqueous humour and help to maintain intra-ocular pressure. The iris is attached to the ciliary body and controls the amount of light entering the eye via the pupil. The lens lies behind the iris and is supported by the suspensory ligament (zonule) that runs between the lens and the ciliary body. The drainage angle is formed by the iris and cornea. Schlemm’s canal, situated in the sciera, conducts the aqueous humour from the anterior chamber into the venous system (James et al 2003). The anterior chamber lies behind the cornea and in front of the lens. The posterior chamber lies between the iris, lens and ciliary body (James et al 2003). Aqueous humour is present in both chambers. Vitreous humour is present in the vitreous cavity.

The conjunctiva lines the surface of the eye and eyelids, except for the cornea (James et al 2003).

Common ocular conditions

Cataract This is an abnormal progressive condition of the lens. A cataract is an opacity of the lens which causes it to become greyish white in colour (Kanski 2003). Causes can be classified as acquired and congenital (Box 1). Most cataracts are associated with ageing (James et al 2003) and are bilateral, although the rate of progression in each eye is seldom equal. Older people with cataracts often find that their everyday activities, like driving, reading, watching television and even walking, become increasingly difficult. The discovery of a cataract requires the GP to refer the patient to hospital. Some opticians can also refer patients directly to hospital thus bypassing the GP.

Treatment Surgery is the only way to treat a cataract. Treatment options include the insertion of a small plastic intra-ocular lens (IOL) using a technique called phacoemulsification of lens, or extracapsular cataract extraction. Phacoemulsification, where the tip of an instrument is introduced into the eye through a small incision and localised high frequency waves break the cataract into minute pieces which are then removed from the eye, is usually carried out in the operating theatre under local anaesthetic. After the lens is ultrasonically fragmented and removed through a suction device, the posterior capsule is left for insertion of the IOL. Extracapsular cataract extraction involves the removal of the nucleus, cortex and anterior capsule, again leaving the posterior capsule intact for IOL insertion. Following both procedures glasses are often not needed except for reading. Occasionally, where an IOL cannot be inserted, an intracapsular cataract extraction can be performed involving removal of the whole lens. Following this procedure, the resulting aphakic vision requires correction with aphakic glasses or contact lenses.

The nurse’s role An important part of the nurse’s role is pre- and post-operative patient education to provide the necessary help and support. During pre-operative assessment the patient will be given health education leaflets. The nurse will demonstrate how to instil eye drops safely and also stress the importance of hand washing before undertaking this procedure to prevent the onset of ocular infection. Concordance with prescribed therapy after surgery will be emphasised. The patient will be advised to observe the eyes daily for signs of excessive redness, swelling or stickiness, which may indicate the presence of infection.

More importantly, if pain in and around the eye, or sudden reduced vision is experienced, the patient will need to contact the hospital immediately since these symptoms may signal the onset of ocular complications such as secondary glaucoma or retinal detachment. The nurse provides the patient with a cartella shield (a light plastic cover placed over the affected eye and secured to the skin) to wear at night as protection. Patients without complications are followed up either by a telephone call made on the first or second day post-operatively, or they are required to attend a hospital clinic appointment one or two weeks later to check their visual acuity and assess the effects of surgery.

Box 1. Causes of cataract\Box 2. Signs and symptoms of cataract

Age-related macular degeneration Age-related macular degeneration (AMD) is a painless disease of the macular area, most often clinically apparent after the age of 50 (Kanski 2003). The retinal pigment epithelia that nourish the macula and remove its metabolic waste start to age and become less efficient, allowing fatty, yellow, metabolic waste products to accumulate in the retina. The cells in the macula break down causing loss of sight in the central part of the field of vision, but leaving the peripheral, or side vision, unaffected. It is the leading cause of visual impairment in people over the age of 65 in the UK. Owen et al (2003) estimate that there are currently 214,000 people in the UK with visual impairment caused by the condition. This number is expected to increase to 239,000 by the year 2011. Signs and symptoms of AMD are shown in Box 3.

Classification ‘Dry’ (atrophie) AMD is the most common cause of the disease (Kanski 2003). It accounts for approximately 85 per cent of those affected, but only 10 per cent of these older people are registered blind (Sadler 2002). A gradual deterioration of the macula occurs due to a build up of waste material and lack of proper nutrition. It progresses slowly and usually results in a mild to moderate loss of sight. Usually, it does not cause a total loss of reading vision. However, after ten years the effects may be more severe. There is currently no treatment (Sadler 2002).

Box 3. Signs and symptoms of age-related macular degeneration

‘Wet’ (neovascular) AMD is less common but devastating because it can lead to severe sight loss within months (Kanski 2003). It is caused by the growth of abnormal blood vessels in the macula. These vessels bleed and leak into the macula, leaving the surface of the retina uneven. The outcome is blurred and distorted central vision. Subsequent scar tissue may create irreversible blind spots. Its progress can be stemmed by laser photocoagulation or photodynamic therapy (Sadler 2002).

Causes Although the cause of AMD is not fully understood, a combination of predisposing factors are thought to be responsible. These are age, diet and nutrition, sunlight, genetics, smoking and gender. Recent research suggests that smoking, which reduces protective antioxidants in the eye, more than doubles the risk of AMD (Seddon et al 1996). The condition is also twice as common in people who smoke more than 20 cigarettes daily than in non-smokers (Seddon et al 1996). Similarly, research suggests that nutrition may play an important role in AMD. Some epidemiological studies have concluded that people who eat a diet rich in carotenoids (antioxidants) have a lower risk of this condition. The diet may also protect against cataracts (Age-related Macular Degeneration Study Group 1996).

Treatment There is no cure for AMD. However, during the early stages of ‘wet’ AMD, a small number of people may benefit from either laser treatment or photodynamic therapy. These treatments aim to seal the leaking blood vessels and prevent further vision loss. Photodynamic therapy is a two-step process. The patient receives an intravenous injection, in the hand or arm, of a photosensitising dye (verteporfin). The dye circulates through the body and adheres to the walls of the abnormal blood vessels beneath the macula. At this stage, laser light is applied to the area to activate the dye and close the leaking blood vessels (Slakter 2003). After the treatment the dye remains in the body for approximately 24 hours. Therefore, the patient should be advised to avoid continued direct exposure to sunlight and ultraviolet light for five days to prevent potentially severe sunburn. The patient may also experience a mild temporary reduced vision that is sometimes associated with this treatment (Slakter 2003). The nurse should reassure the patient that vision usually returns within a few days.

Photodynamic therapy is a cost-effective treatment when it enables an older patient to retain sight and live independently without the expense of long-term social support. However, the therapy may only preserve, not improve, vision since damage to the macula cannot be reversed (Sadler 2002).

The nurse’s role The nurse’s role in providing patient education and counselling for this condition is important. Visual loss can lead to loss of independence and self-esteem, and result in depression because the patient can no longer recognise faces, read clearly or drive (Sadler 2002). The nurse can help a patient through this ‘grieving’ process by offering counselling, organising aids for low vision and arranging social support. It is also often advantageous to put the person in touch with patient groups such as AMD Alliance, and the Royal National Institute of the Blind (RNIB) (see useful organisations at the end of the article).

Patient education is a significant part of the nurse’s role. The nurse can provide useful information to help overcome the practical problems of daily living, especially with activities such as reading and writing. They can refer patients to the low vision aids hospital clinic, the visually impaired team, social services and the rehabilitation team. The nurse can provide advice about magnifying devices and largeprint materials to assist with reading. Books, newspapers and magazines recorded on tape are also available. Talking equipment, such as watches, microwave ovens and kitchen scales, all help to compensate for the loss of detailed vision. Improving lighting around the home and using a reading lamp may also relieve some of the frustration and distress of decreased vision. Tinted lenses are useful in reducing glare. Advice should be given about the need to visit the optician once every two years for an eye test, since eye tests are now free for people over the age of 60. The Macular Disease Society offers essential help and support in meeting a wide range of needs.

Box 4. Signs and symptoms of acute closed angle glaucoma

Acute closed angle glaucoma Acute closed angle glaucoma is a condition in which intra-ocular pressure is increased as a result of obstruction of aqueous outflow by partial or complete closure of the angle by the peripheral iris (Kanski 2003). The onset of this condition is unusual before the age of 45. It is an ocular emergency and must be treated immediately to avert an irreversible loss of sight. Signs and symptoms are listed in Box 4.

Anatomical pre-disposing factors There are two main pre- disposing factors:

* Older people with hypermetropia (long-sightedness or an inability of the eye to focus on near objects). The hypermetropic eye is small with a shallow anterior chamber and a narrow drainage angle. Older women are more at risk than men (Kanski 2003).

* Pupil dilation. This may be precipitated by instilling dilating drugs such as atropine 1%, poor light, or emotions such as fear, anxiety, stress and sadness (Kanski 2003).

This anatomical structure combined with sudden pupil dilation will precipitate contact between the iris and cornea. This closes off the drainage angle resulting in a build up of aqueous humour and increased intra-ocular pressure. Figure 2 illustrates a normal drainage angle and Figure 3 illustrates the effects of pupil dilation on the drainage angle in acute closed angle glaucoma.

Treatment Initially, medical treatment is given to reduce the intra-ocular pressure and constrict the pupil. Failure to reduce the intra-ocular pressure within 24 hours will lead to irreversible total loss of sight. Treatment for acute closed angle glaucoma may vary according to hospital policy and patient need, but essential principles underpin the treatment regimen. Acetazolamide 500mg, a carbonic anhydrase inhibitor, is given intravenously as a stat, that is, once only, dose to reduce the intra-ocular pressure by decreasing the production of aqueous humour in the eye. Timolol 0.5%, a sympathetic beta-blocker, and aproclonidine 0.5%, an alpha selective adrenergic agonist, are instilled as eye drops stat. They have a local effect similar to acetazolamide in further helping to reduce the production of aqueous humour. Dexamethasone 0.1% and hypromellose 0.5% eye drops are then instilled every 15 minutes for one hour. They reduce inflammation and congestion in the eye. Analgesia and anti-emetics may be given as required. After one hour, the visual acuity is rechecked and the intra-ocular pressure measured. If it has decreased to less than 30mmHg, the patient can be discharged on timolol 0.5% twice daily to the affected eye and pilocarpine 2% eye drops to both eyes, and dexamethasone 0.1% and hypromellose 0.5% two hourly to the affected eye. Pilocarpine constricts the pupils which, in turn, may help to open the drainage angle and allow the aqueous humour to escape more easily. If the intra-ocular pressure is greater than 30mmHg, but has decreased by more than 5mmHg since the initial reading, then topical therapy is repeated and the visual acuity and pressure are checked again in one hour. If there is no change in the intra-ocular pressure, intravenous mannitol 1-2g/kg over 45 minutes will be given and the pressure is rechecked in one hour. The patient’s admission for further treatment will be discussed with the consultant in the absence of improvement (Kanski 2003).

Figure 2. Drainage angle and normal flow and drainage of aqueous humour from the eye

Figure 3. Obstructed drainage angle in acute closed angle glaucoma

Definitive treatment will be surgical. A peripheral iridotomy, using YAG (yttrium aluminium garnet) laser, or sometimes surgery, will be performed on both eyes to prevent an attack occurring in the unaffected eye. A pinpoint-sized hole is made in the iris to allow free flow of aqueous between the anterior and posterior chambers of the eye. Gonioscopy (examination of the drainage angle) will be performed to document any changes. On discharge, depending on hospital policy and t\he patient’s needs, dexamethasone 0.1 % and hypromellose 0.5% eye drops may be prescribed four times daily for one week, then twice daily for a further week.

Primary open angle glaucoma Primary open angle glaucoma (POAG) has a non-dramatic onset, and generally occurs after the age of 40 years. It is one of the leading causes of blindness worldwide (Kass et al 2002). Individuals are at an increased risk of developing this condition because of elevated intra-ocular pressure or ocular hypertension (Kass et al 2002). Gordon et al (2002) confirm that age, cup-disc ratio and intra-ocular pressure are predictive factors for the development of POAG in individuals with ocular hypertension. Individuals with an intra-ocular pressure of between 24-32mmHg should be identified and assessed for the risk of developing POAG since they are more likely to benefit from early treatment (Kass et al 2002). The signs and symptoms of POAG are listed in Box 5.

Treatment A reduction in intra-ocular pressure is the main way to prevent major sight loss (Gordon et al 2002, Kass et al 2002) and thus concordance with ocular hypotensive treatment is vital. Latanoprost 0.005% eye drops, a topical prostaglandin, may be prescribed to increase the uveoscleral outflow of aqueous humour from the eye and dorzolamide 2% eye drops, a topical carbonic anhydrase inhibitor, may be prescribed to effectively lower intra- ocular pressure.

Surgery is necessary when pressure remains uncontrolled resulting in further deterioration of sight and visual field loss. Laser trabeculoplasty is performed using argon laser to cut several tiny holes in the trabecular meshwork. This causes scars that on contraction will widen the channels of the meshwork and make it easier for the aqueous humour to flow out and reduce the pressure in the eye. An optional treatment is a trabeculectomy (creation of a fistula) that provides an alternative route for drainage of aqueous humour out of the eye to reduce the pressure and prevent further damage. Gonioscopy should also be performed annually because the anterior chamber becomes shallow with age (Kanski 2003).

The nurse’s role The majority of older people with this condition are based in the community and not admitted to ophthalmic wards. Thus, the nurse’s role is focused on patient education for self- management and control of the condition.

Box 5. Clinical features of primary open angle glaucoma

The most important aspect of the nurse’s role is to prevent a total loss of sight. After AMD, glaucoma is one of the principal reasons for people needing to register as blind. Concordance with treatment is thus vital to gain good control of the condition since there is no cure.

The patient will require general help and support with understanding the condition and treatment. The nurse should stress the need to maintain the intra-ocular pressure within normal limits to preserve existing sight and, more importantly, to prevent any further visual field loss. Asking questions about the older person’s vision and visual problems, especially at night and when walking down steps and curbs, is vital in assessment and ongoing evaluation. Teaching the older person how to instil eye drops safely and at the appropriate time and the importance of hand washing before instillation are essential. The need to attend regular clinic appointments to monitor further deterioration in the condition should also be stressed. Relatives should be made aware of the need for regular sight tests every two to three years since there is an increased familial risk of developing the condition. Eye tests are free for relatives of people with glaucoma (age 40 and over) (RNIB 2004).

Diabetic retinopathy Diabetic retinopathy is a vascular complication of diabetes mellitus in which the small retinal blood vessels tend to degenerate after some years. It is also characterised by ocular haemorrhage and exudate plus the growth of new blood vessels and connective tissue and is a major cause of blindness in older people (NICE 2002). Its incidence is related primarily to duration and control of the diabetes (Kanski 2003) that is, it occurs in people with a long history of poorly controlled diabetes. Many people will be asymptomatic until the disease is very advanced. After 20 years from the onset of diabetes, more than 60 per cent of people with type 2 diabetes will have diabetic retinopathy (NICE 2002). Maculopathy is the major cause of visual loss for people with type 2 diabetes.

Box 6. Classification of diabetic retinopathy

James et al (2003) have classified diabetic retinopathy according to the stage reached and presenting clinical features (Box 6).

Treatment Treatment options include laser photocoagulation for focal and diffuse maculopathy, and proliferative retinopathy. Vitrectomy is performed for persistent vitreous haemorrhage and tractional retinal detachment involving the macula. Government guidelines, however, stress that the risk of visual impairment and blindness is substantially reduced by a care programme that combines methods for early detection with effective treatment of diabetic retinopathy (NICE 2002).

The key issue in screening for diabetic retinopathy is to identify those patients with sight-threatening retinopathy who may require preventive treatment. Screening and treatment for diabetic retinopathy will not eliminate all cases of sight loss, but can play an important part in minimising the number of patients with sight loss due to retinopathy. The aim of a retinal screening programme is to ensure that a yearly examination of all people in a given area who have diabetes is performed (Walker and Rodgers 2002). Essentially, screening patients can be achieved through direct and indirect ophthalmoscopy, and digital photography. Guidelines for retinal screening in type 2 diabetes suggest that digital photography and indirect ophthalmoscopy are the most reliable methods for screening (NICE 2002).

The nurse’s role Older patients with diabetes should be educated about the risk of developing ophthalmic conditions directly attributable to their medical condition and should understand the basic pathology. When the patient begins to experience any obvious visual abnormalities, it is vital to investigate the problem promptly. During a nursing assessment, the patient may complain initially of the signs of vitreous haemorrhage such as ‘floaters’, which look like small, black insects or a lacy curtain across the field of vision. Macular involvement may be revealed by the patient’s description of a general deterioration in fine and colour vision that is not improved by wearing a range of spectacles. Such symptoms require an urgent medical referral.

Although treatment strategies such as laser photocoagulation and vitrectomy are successful, older patients with diabetes need to be made aware of a number of risk factors as part of a preventive programme (Chew 2004). The rate of microvascular complications may be prevented or retarded with good medical treatment (Chew 2004). As a health educator, the nurse should provide older patients and their families with reliable evidence and advice about the importance of maintaining good blood glucose control. Maintaining good blood glucose levels is set at preferably below HbA1c 6.5-7.5 per cent according to the individual’s target (NICE 2002). The target is based on the risk of macrovascular and microvascular complications. People with type 2 diabetes need to have an ongoing structured evaluation, every two to six months, to assess the risk factor. An increased severity of diabetic retinopathy is associated with poorer blood glucose control (Klein et al 1994, Lloyd et al 1995).

It is vital to stress the importance of adhering to prescribed anti-hypertensive treatment since patients with hypertension have a worse visual prognosis. Maintaining good blood pressure control is considered to be at or below 140/80mmHg (NICE 2002). Intensive blood pressure control in people with type 2 diabetes is associated with a decreased risk of retinopathy progression (UK Prospective Diabetes Study Group 1998). The nurse should also emphasise concordance with drug therapy to lower serum cholesterol levels, since elevated levels are associated with an increased severity of retinal hard exudate which results in decreased visual acuity (Chew et al. 1996, Klein et al. 1991). Therefore, regular checking of visual acuity is important to assess the onset of any severe pathological changes in the retina.

Box 7. Useful organisations

Clearly, the nurse can make a significant contribution to the overall preventive programme by emphasising the importance of early detection and treatment. Concordance with treatment can help to prevent loss of sight, or at least reduce its severity. However, the nurse also needs to be aware that visual impairment in diabetes is often compounded by the loss of self-management skills that may have psychosocial implications (Hall and Waterman 1997). Loss of confidence in controlling diabetes may result in a lack of interaction with people. The fear and embarrassment of hypoglycaemia and the inability to cope with the situation in public places can produce further difficulties (Hall and Waterman 1997). Similarly, reactions to loss of vision can be overwhelming and lead to psychological distress such as depression, suicidal thoughts and anxiety (Hall and Waterman 1997). The nurse needs to discuss these issues with both the patient and relatives and give ongoing psychological support to help the patient maintain self-management of the condition.

Conclusion

Visual impairment in older people presents a future challenge for nurses since sight loss is largely an age-related process. The incidence of common ocular conditions will increase with a predicted growth in the older population. Early diagnosis and prompt treatment are instrumental in improving or preserving sight for as long as possible and providing the o\lder person with a better quality of life. Thus, nurses play an important role as health educators in providing older people with relevant information, help and support to gain sufficient control over the management of their visual problems to maintain self-esteem, confidence and re-establish guality of life

TIME OUT 6

The nurse has a significant role in providing patient education and advice for the older person with visual impairment. Reflect on what you have read and outline what advice you think patients with the following conditions would require.

* A patient with a cataract.

* A patient with age-related macular degeneration.

* A patient with primary open angle glaucoma.

* A patient with diabetic retinopathy.

TIME OUT 7

Now that you have completed the article, you might like to write a practice profile. Guidelines to help you are on page 55.

NS273 Watkinson S (2005) Visual impairment in older people: the nurse’s role. Nursing Standard. 19, 17, 45-52. Date of acceptance: August 12 2004.

Online archive

For related articles visit our online archive at: www.nursing- standard.co.uk and search using the key words above.

TIME OUT 1

Before addressing the main ocular conditions, write down your knowledge of the anatomy of the eye, listing the main structures and their functions.

TIME OUT 2

Reflect on the above definition of a cataract. Before referring to Box 2, attempt to make a list of the possible signs and symptoms that a patient developing a cataract may exhibit.

TIME OUT 3

Before reading the next section, consider the different types of service available for people with age-related macular degeneration. Visit the websites of the Macular Disease Society (www.macular disease.org) and National Institute for Clinical Excellence (NICE) (www.nice. org.uk) for further information.

TIME OUT 4

Take some time to make a comparison between acute closed angle glaucoma and primary open angle glaucoma. Make some notes on the main differences in clinical features and approach to treatment.

TIME OUT 5

Revise your knowledge of type 1 and type 2 diabetes and their treatment and management. Visit the National Service Framework for Diabetes website at www.diabetes.org.uk/NSF/ to consider the set standards of care.

REFERENCES

Age-related Macular Degeneration Study Group (1996) Multicentre ophthalmic and nutritional ARMD study. Part 1: design, subjects and procedures. Journal of the American Optometric Association. 67, 12- 29.

Chew E (2004) Medical Management of Diabetic Retinopathy. www.light house.org/aging_vision/spring2004/m edical.htm (Last accessed: November 19 2004.)

Chew E et al (1996) Association of elevated serum lipid levels with retinal hard exudate in diabetic retinopathy. Early treatment diabetic retinopathy study (ETDRS) Report 22. Archives of Ophthalmology. 114, 9, 1079-1084.

Day L et al (2002) Randomised factorial trial of falls prevention among older people living in their own homes. British Medical Journal. 325, 7356, 128.

Department of Health (2001) National Service Framework for Older People. London, The Stationery Office.

Gordon M et al (2002) The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Archives of Ophthalmology. 120, 6, 714-720.

Hall B, Waterman H (1997) The psychosocial aspects of visual impairment in diabetes. Nursing Standard. 11, 39, 40-43.

James B et al (2003) Lecture Notes on Ophthalmology. Oxford, Blackwell Science.

Kanski J (2003) Clinical Ophthalmology. Oxford, Blackwell Publishing.

Kass M et al (2002) The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Archives of Ophthalmology. 120, 6, 701-713.

Klein R et al (1994) Relationship of hyperglycemia to the long- term incidence and progression of diabetic retinopathy. Archives of Internal Medicine. 154, 19, 2169-2178.

Klein B et al (1991) The Wisconsin Epidemiologic Study of Diabetic Retinopathy. XIII. Relationship of serum cholesterol to retinopathy and hard exudate. Ophthalmology. 98, 8, 1261-1265.

Legood R et al (2002) Are we blind to injuries in the visually impaired? A review of the literature. Injury Prevention. 8, 2, 155- 160.

Lloyd C et al (1995) The progression of retinopathy over 2 years: the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study. Journal of Diabetes Complications. 9, 3, 140-148.

National Institute for Clinical Excellence (2002) Management of Type 2 Diabetes Retinopathy: Early Management and Screening. www.nice.org.uk/pdf/diabetesretino pathyguideline.pdf (Last accessed: November 19 2004.)

Owen C et al (2003) How big is the burden of visual loss caused by age-related macular degeneration in the United Kingdom? British Journal of Ophthalmology. 87, 3, 312-317.

Royal National Institute of the Blind (2004) Understanding Glaucoma. www.rnib.org.uk/xpedio/groups/ public/documents/ publicwebsite/ public_rnib003655.hcsp (Last accessed: December 13 2004.)

Sadler C (2002) Limited vision. Nursing Standard. 16, 42, 14-15.

Seddon J et al (1996) A prospective study of cigarette smoking and age-related macular degeneration in women. Journal of the American Medical Association. 276, 14, 1141-1146.

Slakter J (2003) Photodynamic Therapy. www.vrmny.com/PDT.htm (Last accessed: November 19 2004.)

UK Prospective Diabetes Study Group (1998) Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes: UKPDS 38. British Medical Journal. 317, 7160, 703- 713.

Walker R, Rodgers J (2002) Diabetic retinopathy. Nursing Standard. 16, 45, 46-52.

In brief

Author

Sue Watkinson RN, BA, MSc, PhD, PGCEA, OND(Hons), is senior lecturer, research studies, Faculty of Health and Human Sciences, Thames Valley University, London. Email: sue.watkinson@tvu.ac.uk

Copyright RCN Publishing Company Ltd. Jan 5-Jan 11, 2005