Eyesight in the Elderly

Original Editor - Wendy Walker

Top Contributors - Wendy Walker, Lucinda hampton, Scott Buxton, Kim Jackson and Lauren Lopez  

Introduction - The Aging Eye

Old Faces in the Streets of Kosovo.jpg
As we age, our sensory modalities (including vision) show gradual deterioration and most of the major eye diseases are age-related. The prevalence of these sight-threatening diseases dramatically increases above 75 years of age. World estimates overall:
  • 285 million people who have some visual impairment; 256 million with low vision, and about 40 million who are blind or have significant visual impairment.
  • 65% of those with visual impairment and 82% of those who are blind are over 50 years of age[1].

The Aging eye - 3 categories of possible problem

  1. Impairments of Visual Function
  2. Common eye problems associated with aging
  3. Eye Diseases and Disorders

Quality of life and Adaptions

  • The impact of ageing changes in the eye has a significant effect on the quality of life in the elderly.
  • Older people must adapt to problems eg reduced visual field, decrease in visual acuity, delayed dark adaptation, reduced colour perception and decreased power of accommodation resulting in presbyopia.
  • Taken together, these different visual problems all lead to impairment of visual function
  • With other sensory systems failing through age or medical conditions eg diabetes, neuropathy, deafness - extra reliance is placed upon vision for a person to gain critical information from their surroundings in order to remain steady.

It is important to remain vigilant of the need for regular eye appointments (NHS provides free annual eye tests to those above the age of 75, such is the importance of eye sight and falls risk it is now part of the NICE falls guidelines).

Impairments of Visual Function

Eye.png

Visual Field Reductions

  • Decrease in peripheral and upper visual fields.
  • Early stage this may be as a result of decreased pupil size admitting less light to the peripheral retina
  • Later changes result from decreased retinal metabolism. 
  • Loss of retrobulbar fat results in the eyes sinking more deeply into the orbits which leads to a mechanical restriction of upper gaze[2].

Functional effects:

  • reduced awareness of the lateral field of view can cause difficulties when driving
  • reduced upper visual field vision results in the individual being less aware of high traffic and street signs

Reduced Visual Acuity - Ability of the eye to discriminate fine details of objects, frequently (not inevitably) declines with age.

  • An increase in the thickness of the lens
  • Loss of elasticity of lens
  • Results in decreased ability to see clearly (particularly affects near objects).
  • Iris no longer changes width and Pupil size remains small in both dim and bright light, resulting in deterioration in night vision.
  • Other contributing factors are loss of photoreceptors within the retina and possibly changes in the geniculostriate pathway[3].

Functional effects:

  • need for reading glasses or contact lenses
  • may require hand-held magnifiers when doing sewing or craft work

Accommodation Difficulties - ie the ability of the eye to focus images on the retina independent of object distances.

  • Both the cornea and the lens lose transparency, the lens thickens and becomes more rigid and the ciliary muscle weakens.
  • All of which cause the lens to gradually loose its ability to change shape and focus at varying distances[4].
  • This is generally labelled presbyiopia, which means "old eye".
Glasses.jpg

Functional effects:

  • initially require reading glasses
  • later bifocals or varifocals are frequently required as focusing on even distant objects is impaired

Reduced Colour Perception

Changes in the retinal cones and the visual pathways, as well as in the lens, lead to the eye becoming less sensitive to colours that have shorter wavelengths, ie. blues, greens and violets (the cooler colours) and pale pastel and grey colours may become more difficult to distinguish.

Functional effects:

  • may struggle to see furniture if not brightly coloured or in bright light, so can bump into it leading to falls

Slower Dark Adaptation - ie ability of the eye to become more visually sensitive after remaining in darkness for a period of time

  • Delayed in older people.
  • Metabolic changes in the retina result in reduced oxygen supply to the rod-dense area of the retina and the reduction in pupil size both contribute to this problem[5].

Functional effects:

  • difficulty adapting to darkness, especially abrupt and extreme changes in light levels
  • risk of falls at night or in low light situations

Other Common Eye Problems

Floaters - tiny specks or “cobwebs” that seem to float across visual feild.

  • May see them in well-lit rooms or outdoors on a bright day.
  • Can be a normal part of aging.
  • Sometimes they are a sign of a more serious eye problem, such as retinal detachment.

Tearing (or having too many tears)

  • Can come from being sensitive to light, wind, or temperature changes
  • Can come from eye condition "dry eye" See below
  • Wearing sunglasses may help. So might eye drops. Sometimes tearing is a sign of a more serious eye problem, like an infection or a blocked tear duct. Your eye care professional can treat these problems.
Ectropion eye photo.jpg

Eyelid problems - Can result from different diseases or conditions.

  • Common eyelid problems include red and swollen eyelids, itching, tearing, and crusting of eyelashes during sleep.
  • May be caused by Blepharitis (treated with warm compresses and gentle eyelid scrubs). Cause not always found but can include: having eyelash mites or lice; bacterial infection; medication side effects; a malfunctioning oil gland[6]
  • Ectropion eye (see R image) - lower eyelid turns or sags outward, away from your eye, exposing the surface of inner eyelid. This condition can cause eye dryness, excessive tearing, and irritation. Ectropion may be due to several factors, including facial paralysis and injury. The most common cause is muscle relaxation due to aging. Without treatment, ectropion can lead to serious problems with your cornea and even blindness. Eye lubricants can help ease symptoms, but surgery is usually necessary to achieve full correction. Most people who have the surgery experience a positive outcome[6].

Medical Eye Conditions Affecting Older People

Macular Degeneration

Macular Degeneration (AMD).png

Age-related macular degeneration (AMD) is a common, polygenic disease in which multiple genetic variants as well as environmental, lifestyle factors contribute to disease risk, each adding a small to moderate amount of increased risk[7]. The risk of developing the disease is three-fold higher in people who have a family member with AMD than in those without a first-degree relative with AMD[8].

Symptoms of AMD include:

  • Loss of central vision, with peripheral vision unaffected
  • Trouble discerning colours
  • Reduction in contrast sensitivity
  • Blurred vision
  • Slow recovery of visual function after exposure to bright light

Glaucoma

Glaucoma is currently defined as a disturbance of the structural or functional integrity of the optic nerve that causes characteristic atrophic changes in the optic nerve, which may also lead to specific visual field defects over time[9]. This disturbance usually can be arrested or diminished by adequate lowering of intraocular pressure (IOP).

Glaucoma is the second leading cause of blindness in the world[10] (surpassed only by cataract, see below, which is a reversible condition).

In glaucoma the loss of vision often occurs gradually over a long period of time, and symptoms only occur when the disease is quite advanced. Once lost, vision cannot normally be recovered, so treatment is aimed at preventing further loss.

Treatment can involve medications to lower intra-ocular pressure (IOP), laser or conventional surgery.

Cataracts
Photograph by Rakesh Ahuja, MD, from Wikipedia
  • Senile cataract is a vision-impairing disease characterized by gradual, progressive thickening of the lens.
  • One of the leading causes of blindness in the world today, and is treatable by surgery.
  • Main cause of visual impairment and blindness in the world.

Recent studies done show

  • China[11], India[12], Canada[13], Japan[14], and Denmark[15], identified cataracts as the leading cause of visual impairment and blindness, with statistics ranging from 33.3% (Denmark) to as high as 82.6% (India),
  • 1.2% of the entire population of Africa is blind, with cataract causing 36% of this blindness
  • In the Punjab plains, the overall rates of occurrence of senile cataract 67% for ages 70 years and older.

As a cataract worsens, it gradually reduces the amount of light entering the eye causing;

  • Blurring of vision
  • Glare in bright lights or when driving
  • A change in the spectacle prescription
  • Some doubling of vision
  • Colours appear to be faded

Corneal diseases and conditions

  • May cause redness, watery eyes, pain, problems with vision, or a halo effect of the vision (things appear to have an aura of light around them).
  • Infection and injury are some of the things that can hurt the cornea.
  • Treatment may be simple—for example, changing eyeglass prescription or using eye drops.
  • In severe cases, surgery may be needed.[16]

Dry eye

  • Occurs when tear glands function poorly.
  • Cause stinging or burning or a sandy feeling as if something is in the eye, or other discomfort.
  • More common as people get older, especially for women.
  • Possible simple treatments - Use a home humidifier or air cleaner, special eye drops (artificial tears), or ointments[16].
Risk of diabetes and exercise.png

Diabetic retinopathy.

  • Develops slowly and often has no early warning signs. I
  • A dilated eye exam should be undertaken at least once a year.
  • Blood sugar, blood pressure, and cholesterol need be kept under control and can prevent diabetic retinopathy or slow its progress.
  • Laser surgery may prevent it from getting worse[16].
The 5 minute video below is a summary of 5 common eye diseases.
[17]


References

  1. Chader GJ, Taylor A. Preface: the aging eye: normal changes, age-related diseases, and sight-saving approaches. Investigative ophthalmology & visual science. 2013 Dec 1;54(14):ORSF1-4.Available from:https://iovs.arvojournals.org/article.aspx?articleid=2127318 (last accessed 26.6.2020)
  2. Melore GG: Visual function changes in the geriatric patient and environmental modifications. In Melore GG, editor: Treating vision problems in the older adult, St. Louis, MO, 1997, Mosby
  3. Spear PD: Neural basis of visual deficits during aging. Vision Res 33:2589–260, 1993
  4. Linton AD: Age-related changes in the special senses. In Linton AD, Lach HW, editors: Matteson & McConnell’s Gerontological nursing: concepts and practice, ed 3, Philadelphia, PA, 2007, Saunders/Elsevier
  5. Melore GG: Visual function changes in the geriatric patient and environmental modifications. In Melore GG, editor: Treating vision problems in the older adult, St. Louis, MO, 1997, Mosby
  6. 6.0 6.1 Health line Ectropian eye Available from:https://www.healthline.com/health/ectropion (last accessed 26.6.2020)
  7. Seddon JM, Sobrin L. Epidemiology of age-related macular degeneration. In: Albert D, Miller J, Azar D, Blodi B, eds. Albert & Jakobiec's Principles and Practice of Ophthalmology. Philadelphia, Pa: WB Saunders; 2007:413-422
  8. Seddon JM, Ajani UA, Mitchell BD. Familial aggregation of age-related maculopathy. Am J Ophthalmol. Feb 1997;123(2):199-206
  9. Bathija R, Gupta N, Zangwill L, Weinreb RN. Changing definition of glaucoma. J Glaucoma. Jun 1998;7(3):165-9.
  10. Kingman, Sharon (2004). "Glaucoma is second leading cause of blindness globally". Bulletin of the World Health Organization 82 (11): 887–8.
  11. You QS, Xu L, Yang H, Wang YX, Jonas JB. Five-Year Incidence of Visual Impairment and Blindness in Adult Chinese The Beijing Eye Study. Ophthalmology. Jan 4 2011
  12. Murthy GV, Vashist P, John N, Pokharel G, Ellwein LB. Prevelence and causes of visual impairment and blindness in older adults in an area of India with a high cataract surgical rate. Ophthalmic Epidemiol. Aug 2010;17(4):185-95.
  13. Maberley DA, Hollands H. The prevalence of low vision and blindness in Canada. Eye(Lond). 2006/03;20(3):341-6.
  14. Iwase A, Araie M, Tomidokoro A, Yamamoto T, Shimizu H, Kitazawa Y. Prevalence and causes of low vision and blindness in a Japanese adult population: the Tajimi Study. Ophthalmology. Aug 2006;113(8):1354-62
  15. Buch H, Vinding T, Nielsen NV. Prevalence and causes of visual impairment according to World Health Organization and United States criteria in an aged, urban Scandinavian population: the Copenhagen City Eye Study. Ophthalmology. Dec 2001;108(12):2347-57
  16. 16.0 16.1 16.2 nih gov aging and your eyes Available from:https://www.nia.nih.gov/health/aging-and-your-eyes (last accessed 26.6.2020)
  17. Nuffeild Hospital. Common eye diseases. Available from: https://www.youtube.com/watch?v=ObPPUwbsiRQ (last accessed 17.5.2019)