Senescence And The Eye Flashcards
Age is accompanied by and increase or decrease in VF
Decrease
What causes the VF loss in old age
Loss of cells and decrease in the transparency of the ocular media
As we age are we able to tell speed of objects
No
What causes the higher incidence of car accidents among elderly
The inability to determine the speed of moving objects
What changes occur in the cornea
Decreased wound healing
What changes occur in the onrela endothelium
Decrease in ell density
What is Corneal arcus
- Most common aging change
- cholesterol, and cholesterol ester deposits
- no clinical significance in elderly, but in people under 40 something else could be wrong
By age 50 the occurrence is arcus is______
By age 80?
50%
100%
What changes occur in the sclera
Fatty deposits cause sclera to yellow
Prtoeoglycans decrease and sclera thins and losses elasticity
What changes occur in the anterior chamber
Narrows
(More significant in women)
No age related increase in IOP in healthy people with pressures below 22 mmHG
What changes happen in the iris
Dilator muscle becomes strophic, sphincter muscle becomes sclerotic
Harder to dilate the pupil in elderly
What changes occur in the ciliary body
No significant correlation between loss of ciliary muscle contractile ability and age
What changes occur in the crystalline lens
Presbyopia, cataracts
Patients should use UV protection
Lens grows throughout life
Majority of the increase in thickness occurs between 8-40 y.o.
Also an increase in surface curvatures, forward movement of the center of the lens, decrease in anterior chamber depth
What changes occur into vitreous
Vitreous liquefaction (Vitreal syneresis)
As HA dissolves the macromolecules move out of the collagen network, and cause the fibrils to coalesce into fibers an bands
What is PVD
One of the most common abnormalities that occurs at the posterior retinal vitreous interface
What is Weiss’ ring
When glial tissue is torn away from the vitreous and a circular condensation can be seen in the vitreous
What changes occur in the choroid
Calcifications and deposits in the inner collagenous layer are responsible for drusen (increase with age)
As lysosomal activity of RPE decreases with age, atypical material may accumulate in Bruchs membrane
What changes occur in the lamina cribrosa
Nerve fibers passsing through the openings more susceptible to injury, contributing to an increased susceptibility to glaucomatous damage
What changes happen in the retina
Fovea reflex dims
Accumulations of drusen are located in Bruchs membrane of the choroid are seen as pinpoint deposits in the retina
35-50% of CNS neurons are lost during a lifetime, the # of retinal neurons will decrease with ganglion cell loss
Number of RPE is reduced from 4,000 to 2000
Peripappilary chorioretinal atrophy are pale, temporal crescent, age related degeneration of RPE and Bruchs membrane
Decrease in neuroretinal rim tissue
vertical optic cup diameter and area of theoptic cup both increase
What changes occur in the EOMs
Constant partial depression may contribute to the impaired ability to elevate the eyes
What changes occur in orbital adnexa
More pronounced changes in lid margin position (ectropion and entropion)
Increase in incidence with age related changes in orbicularis muscle tone
What changes occur in the lacrimal system
Tearing may be caused by eversion of the lower punctuation due to eyelid position or stenosis of the assuages in the lacrimal drainage system
-some studies find that the bask rate of tear secretion diminishes after age 40, contributing to dry eye, incidence increases with age
Incidence of vascular engorgement at the lid margin an plugged Meibomian gland pores
What changes occur in ocular circulation
Endothelial dysfunction can occur with age and can result in increased vascular tone, a reduction in vessel distensibility and decrease in tissue perfusion
