Accommodation Anomlies

Question 1

Components of accommodation a

Answer 1

• blur driven
• proximal
• cognitive
• tonic
• convergence accommodation

Question 2

What is bur driven. Accommodation

Answer 2

• chromatic aberration gives cue as to direction of adjustment needed
• pupil size can can also increase depth of focus and reduce blur

Question 3

What is proximal accommodation

Answer 3

• occurs for targets up to 3m away

Question 4

What is cognitive accommodation

Answer 4

• mental effort increases the level of accommodation

Question 5

What is tonic accommodation

Answer 5

• resting point of accommodation

Question 6

What is convergence accommodation

Answer 6

• produced as eyes converge
• for every 10 dioptres forced convergence about 1 dioptre accommodation occurs

Question 7

Aspects of accommodation

Answer 7

• near point of accommodation
• accommodation facility
• accommodation response

Question 8

Why is it important to measure accommodation

Answer 8

• assess if the amplitude is the same in both eyes
• assess if it’s Normal for the patients age
• is amplitude sufficient of their needs

Question 9

What is the AC/A ratio

Answer 9

• accommodative convergence/accommodation ratio
• normal if 4:1or less
• gradient method

Question 10

What is accommodation facility

Answer 10

• a measure of the eyes ability to change accommodation status
• reduced accommodation facility may create near vision problems
• training the accommodation facility can result in an improvement

Question 11

How to measure accommodation facility

Answer 11

• flipper lenses
• +2.00DS
• introducing these lenses will relax the commodity on and stimulate accommodation
• measure binocularly in first instance
• if abnormal, measure monocularly

Question 12

What is accommodation lag

Answer 12

• if the accommodation response is less than the stimulus

Question 13

What can accommodation lag indicate

Answer 13

• presbyopia
• uncorrected hypermetropia
• reduced amplitude of accommodation

Question 14

How to identify accommodation lead/lag

Answer 14

• monocular estimation method
• Nott Method

Question 15

What is the Monocular estimation method

Answer 15

• px wears full distance prescription
• a near chart is attached to the front of the retinoscope
• measure px habitual working distance
• dim room lights
• px fixes on suitable sized letter on near chart
• perform ret at habitual working distance
• observe ligh reflex
• record neutralising lens
• positive lenses = lag
• negative = lead

Question 16

What is Nott dynamic retinoscopy

Answer 16

• px wears full distance correction
• masure working distance
• px fixes on word of suitable size
• dims lights
• perform ret at 10cm behind at near chart with streak vertical
• if not neutral change position
• measure distance that it is neutral

Question 17

What is accommodation insufficiency

Answer 17

• px has reduced amplitude of accommodation compared to age normal
• ill-sustained accommodation
• paralysis
• paresis = very reduced
• unequal amplitude
• possible convergence insufficiency

Question 18

What is accommodation paralysis,and symptoms

Answer 18

• px has lost ability to exert accommodation completely
• may be associated with convergence paralysis

Symptoms
- blurred her vision
- diplopia
- possible dilated pupil

Question 19

What causes accommodation insufficiency

Answer 19

• drugs
• trauma to the eye
• head injury
• 3rd CNP
• midbrain disorders
• pineal tumour
• alcoholism

Question 20

What is accommodation infacility

Answer 20

• px struggles to focus from distance to near
• dynamics of accommodation are slowed down

Symptoms
- blurred vision when changing fixation
- reduced accommodation for age

Question 21

What is accommodative spasm

Answer 21

• contraction of the ciliary muscles causing excessive accommodation
• distance vision is blurred
• usually asssoiated with convergence spasm
• may happen in young hyperopia