Presbyopia Flashcards
(23 cards)
Most people have an onset of presbyopia in what age range?
35 and 45
By how much does accommodative amplitude change per year? Around what age does this start?
Decreases by 0.25-0.40D per year. This starts around age 12.
True or false: men become presbyopic slightly earlier (1-3 years) than females, partly due to the fact that men don’t take care of their eyes.
False; females become presbyopic 1-3 years earlier than men. It is thought to be due to females being less in denial about the onset, as well as their working distance being slightly closer (and therefore more dioptrically demanding).
Which tend to become presbyopic sooner, hyperopes or myopes?
Hyperopes.
Some symptoms of presbyopia include blur at near (either constant or later in the day or week), headache that goes away with rest or removal of near task, avoidance of near hobbies, arms being “too short”, decreased near efficiency and/or comprehension, distance blur following near tasks, etc. Diplopia can also occur. Explain why diplopia can occur with the onset of presbyopia.
This typically occurs in a patient who is fairly exophoric and/or has poor near PRV values, and has gotten by so far by using accommodation to help near fusion. Now that accommodation has diminished, the vergence dysfunction is revealed.
True or false: during presbyopia, there is an average of about 1.00D myopic shift
False; it is about 1.00D hyperopic shift
How much and what kind of astigmatic change typically occurs during presbyopia?
About 0.25D ATR shift per decade
During presbyopia, what happens to the stimulus AC/A? To the response AC/A?
Stimulus stays constant or decreases slightly, response increases notably.
What happens to the following near measurements as presbyopia progresses?
Accommodative posture Vergence posture PRV NRV PRA NRA
Accommodative posture: more plus (greater lag) Vergence posture: more exo PRV: no blur, overall decrease NRV: no blur PRA: decreased NRA: no change
Basing your assessment off of accommodative amplitude alone, when would you label a person as a presbyope? What about by accommodative amplitude as well as acommodative demand?
Accommodative amplitude alone: anything less than 5.00D
Amplitude and demand: when the amplitude is less than 1/2 of the demand.
Which accommodative dysfunction may appear similar to presbyopia? What might be the main key to differentiating the two?
Accommodative insufficiency. Age might be the main key to differentiation: presbyopia is usually older.
Which vergence dysfunction could be similar to presbyopia, in terms of its effect on PRA? What can help determine whether the reduced PRA is due to presbyopia or this vergence condition?
Convergence excess. Monocular PRA improvement over binocular PRA indicates CE, whereas nonimprovement indicates presbyopia. Age can also help with the differentiation.
There are many ways to calculate an add estimate for a patient. Briefly describe how to use PRA and NRA results to estimate the add.
Using the gross lens powers, find the midpoint between PRA and NRA. This is the estimated near SVL. The dioptric difference between this and the distance SVL is the add.
Note that if the net PRA value (from the starting lens) is more than the net NRA, no add is indicated via this method.
Monocular NRA and PRA values can be to determine adds for each eye individually. What sorts of patients might require unequal adds?
Unilateral pseudoaphakes, high aniso (4D or more), strabismus, amblyopia.
How would you modify crossed cylinder results to find an estimated near lens for your presbyopic patient? What other test provides similar results to CC tests for near lens estimation, but is objective?
If your patient is an early presbyope, cut 0.25 to 0.50 plus to find the estimated near lens.
If your patient is an established presbyope, the crossed cylinder findings are probably a good estimated near lens.
Low neutral is an objective way to to estimate a near lens that works similarly to CC tests.
With a presbyope, what sorts of lenses would need to be in place to do near vergence testing?
BCC or near subjective lenses
If your patient has an accommodative amplitude of 5.00D and their working distance is 40cm, what add would you prescribe for them? Work out your answer with the amplitude vs demand method.
Max amplitude they should use = (5.00D/2) = 2.50D
Demand = (1/.4m) = 2.50D
Add: none
If your patient has an accommodative amplitude of 6.00D and their working distance is 25cm, what add would you prescribe for them? Work out your answer with the amplitude vs demand method.
Max amplitude they should use = (6.00D/2) = 3.00D
Demand = (1/.25m) = 4.00D
Add: +1.00 (bridges the gap between half of their amplitude and the demand)
If your patient has an accommodative amplitude of 3.50D and their working distance is 44cm, what add would you prescribe for them? Work out your answer with the amplitude vs demand method.
Max amplitude they should use = (3.50D/2) = 1.75D
Demand = (1/.44m) = 2.25D
Add: +0.50 (bridges the gap between half of their amplitude and the demand)
If your patient has an accommodative amplitude of 1.00D and their working distance is 40cm, what add would you prescribe for them? Work out your answer with the amplitude vs demand method.
Max amplitude they should use = (1.00D/2) = 0.50D
Demand = (1/.40m) = 2.50D
Add: +2.00 (bridges the gap between half of their amplitude and the demand)
True or false: with increasing lens powers, the stimulus to accommodate changes with a constant target.
True. For increasing myopic lens compensation, the stimulus decreases. For increasing hyperopic lens compensation, the stimulus increases.
Assuming the target distance is held constant, how is a myope’s accommodative demand changed as their vertex distance increases? This implies that presbyopic myopes will likely find some relief in wearing _______ (spectacles/contact lenses).
Their accommodative demand decreases (“plus add” effect).
This implies that presbyopic myopes will likely find some relief in wearing spectacles.
Assuming the target distance is held constant, how is a hyperope’s accommodative demand changed as their vertex distance increases? This implies that presbyopic hyperopes will likely find some relief in wearing _______ (spectacles/contact lenses).
For low to moderate hyperopes, their accommodative demand increases (“minus add” effect).
This implies that low to moderate presbyopic hyperopes will likely find some relief in wearing contact lenses.
