Ageing and the eye Flashcards
What are the normal parts of ageing in relation to the eye?
Lids, Lens, Zonules, Vitreous, Retina, Contrast sensitivity
Contrast sensitivity reduces, particularly in mid and high spatial frequencies.
What is the effect of age on upgaze?
Usually symmetrically reduced upgaze
downgaze remains normal
What were the findings of the study on ocular motility in the elderly?
Significant reduction in elevation; no significant reduction in depression, ab- and ad-duction.
How does ageing affect reflexive pro-saccades?
Less affected by ageing, suggesting relative unimpaired parietal cortex.
What is significantly affected by ageing in voluntary anti-saccades?
Cognitive input is affected, indicating vulnerability of the FEFs in the frontal cortex.
What cognitive functions decline with age related to eye movements?
Focused attention, task switching, working memory.
What happens to saccade latency with age?
Increased and more variable latency in the elderly due to increased central processing time.
Is the accuracy of horizontal saccades affected by age?
Accuracy not affected.
What is the peak velocity trend of saccades with age?
Not affected; small reduction only for large amplitude saccades.
What is the trend in vertical saccades for the elderly?
Increased and more variable latency; lower peak velocity; most saccades are hypometric.
What is a significant finding regarding fixation and saccadic intrusions in the elderly?
No change in fixation with age; tonic oculomotor control system is resistant to degeneration.
What is the proposed reason for reduced upgaze in the elderly?
Disuse, inferior recti stretched due to lower lid sagging.
How do extraocular muscles compare to other muscles in the context of ageing?
EOMs remain anatomically and functionally intact during ageing.
What age-related changes occur in cranial nerve nuclei?
Motor neurons in the 3rd, 4th, and 6th CN nuclei do not decline with age.
What significant change occurs in the 3rd cranial nerve with age?
Significant increase in myelin thickness of axons.
What changes in the midbrain are noted with ageing?
No significant difference in neuronal density, glial cell density, or neuron: glial cell ratio between young and aged groups.
What is the prevalence of strabismus with increasing age?
Increased prevalence of heterophoria.
What is the mean age of onset for age-related distance esotropia?
50 years.
What are the proposed reasons for increasing excyclotorsion with age?
- Age-related sagging of LR
- Degeneration of LR-SR connective tissue band
- Reduced phoria adaptation
What are the summary effects of ageing on eye movements?
- Symmetrical reduction of ductions (upgaze)
- Normal fixation
- Increased latency of saccades and smooth pursuit
- Delays and inaccuracies in complex eye movements
- Intact voluntary/reflexive eye movements
- Intact CN, CN nuclei, and midbrain
- Structural changes in peripheral and extraocular muscles
- Increased incidence of strabismus
Fill in the blank: The study showed that the incidence of SWJ is similar in younger and older participants, but there is more _______ in SWJ in elderly participants.
individual variability
True or False: The number of motor neurons in the 3rd cranial nerve declines significantly with age.
False
What anatomical changes occur in the extraocular muscles during ageing?
Snapped muscles during surgery are more prevalent in elderly patients.
What are common anatomical ocular changes associated with ageing?
Changes in lids, lens, zonules, vitreous, and retina; reduced contrast sensitivity.
