ageing and eye.ppt
- 1. AGING AND THE EYE Mr. Mahendra Singh PhD (Scholar) M.Optom, FLVPEI Assistant Professor and consultant Optometrist. CL Gupta Eye Institute. UP India
- 2. WHAT IS AGING……..? • Decay of flesh, loss of vital substances, entropy, the victory of catabolism over anabolism. • It is wisdom without tranquility, compassion without passion . • Every night we are poorer by a day . • Aging is universal, progressive, inescapable, mainly intrinsic and generally deleterious.
- 4. WHAT CAUSES AGING……..? • THE GENETIC APPARATUS. • THE INTERCELLULAR SUBTANCE. • THE NOIONS EFFECTS OF THE ENVIRNOMENT. • CELLULAR HYPOFUNCTION.
- 5. • Sustained sub lethal injury leads to intracellular inclusion of GLYCOGEN,COMPLEX LIPIDS AND PIGMENTS. • Intercellular accumulation of amyloid are seen in aging tissues. • Some tissues grow old as direct result of wear and tear evident in teeth, bone, cartilage and joints.
- 6. IS AGING A DISEASE……..? • Normally aging affects all body function • It is difficult to separate the physiologic from pathologic ischemia. • Same effect can be produced by trauma, infection, toxins and metabolic disorder.
- 7. SCLERA • The sclera forms the posterior five sixth of the eyeball. • In children's the sclera is opaque, with a slight blue cast where it is thin and underlying pigment of the choroid shows through. • In adults the sclera is white in elderly persons. It may have a yellow tinge resulting from dehydration and lipid deposits. Which should not be confused with jaundice.
- 9. • Other age related changes include yellowing or browning due to exposure to ultraviolet light, wind and dust more random splotches of pigment. • A bluish cast due to thinning of the sclera that may occur with some diseases. • (e.g. RHEUMATOID ARTHRITIS)
- 10. CONJUNCTIVA • Its goblet cells produce mucin, which lubricates eyelid movements and provides a protective layer to slow evaporation of the tear film. • With age the number of mucous cell decreases, as a result of KERATITIS SICCA for no specific reason. • This change contributes to dry eye condition. Which is manifested by a scratchy sensation and chronic irritation.
- 12. • Often with increased redness from dilatation of blood vessels in the conjunctiva. • The increased redness commonly occurs because the conjunctiva is heavily vascularised. • Capillaries in the conjunctiva are fragile and burst easily. Resulting in a pooling of blood in the space between the sclera and the overlying conjunctiva.
- 13. LIMBUS • The limbus marks the junctions between the sclera and the cornea . • Although it is only 1.5 to 2 mm wide, the limbus contains the TRABECULAR MESHWORK AND THE CANAL OF SCHLEMM. • Which are important in maintaining correct intra ocular pressure.
- 14. AQUEOUS HUMOR • The aqueous humor must be continuously formed from blood plasma that is filtered through the ciliary body. • The aqueous is constantly reabsorbed back into the blood after it flows out through the canal of schlemm in the limbus. • With age, the value of the resting level of IOP can rise over time by as much as 25% without damaging vision.
- 16. • The mechanism for this normal increase is unknown. • Glaucoma results if the cannal becomes abnormally high. • Aqueous humor itself does not change with age
- 17. VITREOUS HUMOR • The vitreous humor is normally clear, but with age. Discrete opacities or structural changes leading to a general haziness may develop. • The vitreous undergoes liquefaction with age as a result, normal eye movement produce intermittent tension at the attachment points on the retina.
- 18. • This tugging stimulates the peripheral retina mechanically, causing vertically oriented flashing, almost always in the far temporal visual field.
- 21. CORNEA • The most important refractive portion of the eye. • ARCUS SENILIS is common in persons above 60 and has no clinical significance. • ARCUS SENILIS, which should not be mistaken for a cataract, is on the surface of the eye, not within it.
- 22. • Corneal sensitivity to touch decreases with age. • The threshold to touch double between ages 10 and 80, with the largest changes occurring after age 40. • The patient does not notice this change. Therefore , the cornea should always be examined for asymptomatic changes.
- 26. IRIS • The iris contains two sets of muscles that work together to regulate pupillary size and reaction to light. • With age , these muscles weaken, and the pupil becomes smaller, reacts more sluggishly to light , and dilates more slowly in dark. • Persons above 60 may complaint that objects are not as bright at outdoors.
- 27. • They also experience difficulty when going from a brightly lit environment to a darker one. • If V/A is normal . Patients need only reassurance that these changes are normal. • None of these changes results in decrease V/A. • RELATIVE PUPILLARY SIZE AND REACTION TO LIGHT.
- 28. LENS • Lens thickness and surface curvatures are changed by the actions of the ciliary muscle and suspensory ligaments (zonules). • The lens continuously grows during life and increase in density and weight. • These changes decrease the elasticity of the lens.
- 29. • Between the age of 40 and 50, the lens usually becomes so inelastic that close objects can no longer be brought into focus (presbyopia) without the assistance of corrective lenses. • Opacification of lens i.e. CATARACT
- 31. RETINA • The retina is difficult to examine in elderly patients because of their small pupils, increased random eye movements and lens opacities. • The retina, which glistens in younger persons, becomes duller with age. • The optic nerve tend to have less distinct margins and may appear slightly paler than in younger persons because of a loss of capillaries due to small-vessel disease secondary to atherosclerosis
- 33. • The macula, which in younger persons usually has a bright central foveal light reflex. May show no foveal reflex in elderly persons . • Yellowish white spots (drusen) often appear in the macular area. • The retina layers may become disrupted resulting in pigmentation and obscuring the view of underlying blood vessels.
- 35. • The arteries also demonstrate atherosclerotic changes, • The veins may show marked venous indentation at the AV crossing with slight proximal distention.
- 36. LIDS • With age, the orbicular oculi muscles (which squeeze the lids shut) decrease in strength. • ECTROPION. • Spasm of OOM may cause the lid margin to turn in (ENTROPION) • TRICHIASIS resulting in chronic irritation.
- 38. • The lids contain many glands that secrete sebum or sweat. • These glands drain externally to the skin surface of the lid. They can become blocked and swollen.
- 39. LACRIMAL GLAND AND TEAR DRAINAGE • Tear production by the lacrimal gland may decrease with age . • Abnormalities of the lacrimal system may result in decrease or increase tear production. • Normal tear production is measured with schemer test
- 40. ORBIT • With age , there is loss of periorbital fat, which surrounds and cushions the eye ball. • This loss of fat often causes enophthalmos. • An asymptomatic condition that often poses a cosmetic problem and may be corrected with surgery.
- 41. AGE-RELATED CHANGES IN OCULAR FUNCTION. • ARCOF may be divided into two groups. • Those related to vision . • Like refractive changes, visual acuity, contrast sensitivity, glair, haziness, flashing lights, moving spots, and visual fields. • RELATED TO EYE COMFORT. • Foreign-body sensation and headache.
- 42. REFRACTIVE CHANGES • With age, the lens becomes denser and less elastic , and accommodation is lessened. • PRESBYOPIA, a universal age-related change in vision beginning in persons in their 40s • It is corrected in myopic and hyperopic patients with separate reading or bifocal glass.
- 43. • Because accommodation is lost progressively from about ages 45 to 65, the reading lens usually must be changed every 2 or 3 years.
- 44. VISUAL ACUITY • Uncorrected V/A begins to decrease in a normal healthy persons around the age of 50. • The eye becomes more hyperopic and astigmatic with age. • These changes are independent of pupil and the lens changes and are thought to be a function of neurological changes in the visual pathways of the brain rather than of retinal changes.
- 45. • Small changes in visual acuity as a result of normal age-related brain changes. • In the absence of disease, V/A should be at or correctable to 20/20, even in very old persons.
- 46. CONTRAST SENSITIVITY • CS decrease with age at middle-spatial and high-spatial frequencies (>8 cycles/degree) • This change was originally thought to be due to the fact that elderly persons have smaller pupils and more lens opacities. • The loss of CS is now thought to be due to a loss of neurons in the visual pathway in the brain rather than to any retinal changes.
- 47. • This loss of contrast sensitivity has very little effect on the elderly persons life. • Currently this loss cannot be prevented or reversed.
- 48. HAZINESS, FLASHING LIGHTS, AND MOVING SPOTS • ARC in the vitreous humor can create noticeable and disturbing changes in vision, including haziness. • Vertically oriented flashing lights may also occur due to changes in vitreous. • Flashing lights in only one eye at a time. • No further evaluation needed if there is no changes in the visual function .
- 49. • In patient with myopia and uveitis and in many others in their late 50s and early 60s. Opacities appear as lines, spots , or clusters of dots moving slowly across the field of vision. • These opacities represent bits of vitreous humor that have coalesced and float freely in vitreous cavity.
- 50. • These floaters has no clinical importance . • If an ophthalmoscopic examination shows no retinal detachment, the patient should be reassured an encouraged to ignore the floater.
- 51. COLOR VISION • Color discrimination declines with age . • With age all three classes decline in sensitivity, resulting in a reduction of brightness discrimination. • Colors appear to be less bright, and contrast between colors are less noticeable to the elderly persons than to a younger.
- 52. • In persons >60, this ARC results in a reduction in discrimination of blue objects, which often appear grey. • People who use color discrimination in their professions e.g. artists, electricians . • Need to be alert to these changes and should avoid using blue ink over light blue or grey backgrounds.
- 53. DARK ADAPTATION • With age dark adaptation decreases. • This decline in sensitivity is due, almost completely, to ARC in pupil size and to increasing lens opacity. • The resulting loss of light reaching the retina due to the total decrease in dark adaptation with age.
- 54. • The amount of ambient light needed for reading by persons in their 60s is three times that needed by those in their 20s. • Therefore, increasing the amount of ambient light in all rooms in the home improves safety and productivity.
- 55. VISUAL FIELDS • The size of a normal visual field decrease by about 1 to 3 degree per decade. • For persons in their 70s or 80s, a visual field loss of 20 to 30 degree may result. • The peripheral retina has fewer neurons than the central retina, equal losses in the two areas have a greater effect on reducing V/A in the periphery.
- 57. • To track visual field changes across time for each patient, the examiner should perform VF test early in the day. • Before the patient tires, subsequent test should be performed at the same time of day to decrease variability in results
- 58. HEAD ACHE • In the elderly patient, headache may be due to ocular function. • Eye strain can produce tension headaches. • Headache in patients with acute glaucoma is a true ocular emergency and requires immediate attention.