1. Physiological Impact of Ageing Part II Ocular Changes

2. Eyelids

3. • progressive loss of tone and bulk. • Loss of tonus, reduced movement, reduced palpebral aperture (ptosis), decreased lid tension. • Changes in astigmatism with age. • More difficulty in lid evertion, greater CL comfort?, more difficulty getting CLs out? • Xanthelasma (xanthoma) raised yellowish plaques found on the upper and lower lids. common in elderly women can be associated with diabetes and  blood LDLs Eyelids

5. • Corneal shape changes - from with to against-the- rule astigmatism. • Corneal fragility increases with age. • Corneal sensitivity halves by 80 (esp. 40+) - easier CL wear, but possible greater problems (more regular after-care)- greater with arcus senilus? • Endothelial changes (cell density dec., increased polymegathism & pleomorphism) Cornea

6. Arcus Senilis • lipid infiltration of the peripheral cornea that is commonly seen in the elderly • characterised by being separated from the limbus by a narrow line of comparatively clear cornea. • asymptomatic and has little consequences for vision • if seen in Pxs < 40 can indicate  blood LDL level

8. Conjunctival ageing changes • Reduced arterial oxygen concentration to conjunctiva - less available to cornea? And increased overnight swelling with CLs? • Pingueculae more common with age. Can lift the lids away from the underlying conjunctiva - local area of drying and vascularisation.

9. Pingueculae

10. Pingueculae • age related change of the conjunctiva • associated with prolonged exposure to sunlight, wind, dust etc. • due to hyaline infiltration and degeneration of the elastic sub-mucous tissue. • occurs near the limbus in the palpebral aperture its apex points away from the cornea.

11. Pterygium

12. Concretions • Minute hard, yellow spots in the palpebral conjunctiva. • due to the accumulation of epithelial cells and mucous • can lead to abrasion of the cornea and persistent foreign body sensation in the eye.

13. Tear film changes • Decreased tear film stability (NIBUT). • ? No real change in tear volume. • Several drugs tend to reduce tear production & many are increasingly used with age. • Sxs of ‘dry eye’ may not always be elicited from older Pxs - reduced corneal sensitivity, and acceptance of this as ‘normal’ for age etc.

16. Pupil size changes with age Dark adapted eye Light adapted eye

17. Pupil size changes with age • Pupil gets smaller with age. • Increases depth of focus, range of near vision,  retinal illuminance. • ? Due to atrophy of dilator muscle fibres and inc. rigidity of iris blood vessels. • No change with gender, Rx and iris colour. • Greatest age changes at lowest luminances (mesopic 7 to 4mm, photopic 5 to 3mm)

19. Anterior Chamber changes • The anterior chamber depth dec. with age due to the increase in size of the lens. • (This can reverse in some patients with cataract, where lens size can decrease). • Leads to increases in IOP with age. • Leads to closed-angle glaucoma and need to check angles prior to pupillary dilation.

20. Ageing lens changes • Increased thickness with age (28%, 20-70). • Inc. hardening of nucleus & loss of elasticity of lens and capsule - loss of accommodation (zero at 55-60 years). • No need to binocular balance over 60 years, no point in measuring amplitude of accommodation for 60+.

24. Ageing lens changes • Increased light scatter: inc. cortical layers and inc. large aggregates in nucleus. Greater problems with glare. • Increased lens yellowing , i.e., increased absorption of blue light. Colour vision goes tritanopic with age (+ ? neural component). • Fluorophors increase with age. UV radiation leads to light scatter; UV tints?

26. Vitreous changes with age • Vitreous undergoes liquefaction and shrinkage (syneresis) with age. • Leads to increases in vitreous floaters, increase in PVDs (~60% over 65) and increases in the prevalence of retinal detachments.

27. Posterior Vitreous Detachment

28. Macular changes with age • No loss of cones, loss of central rods. • Disorganisation of rods and cones and lipofuscin accumulation. • Leads to inc. photostress recovery time. • No change in macular pigment with age. Macular pigment is very variable.

29. Macular drusen • Hyaline deposits between the RPE and Bruch’s membrane. • ? Due to small areas of hypoxia due to choriocapillaris age changes - leads to RPE malfunction and “spitting out” of collagen and basement membrane material = drusen. • Distinction between hard and soft drusen.

32. Peripheral retina ageing changes • Peripheral pigmentary degeneration seen in ~20% of 40+ - hypo and hyperpigmentation. • Peripheral drusen. • Inc. paving-stone degeneration (chorioretinal atrophy) - white areas of sclera with overlying choroidal vessels - closure of small area of choriocapillaris.

35. Visual pathway changes with age • No cell loss in LGN. • No loss of striate cortex neurons with age. • VEP changes with age suggest there are functional cell changes with age, perhaps linked to vascular changes.