Lecture #5: Case Management 1: Lenses

management considerations for accommodative and non-strabismic vision anomalies?

- correction of significant refractive error

- added plus or minus lens power

- prism

- occlusion

- VT

- surgery

why is it important to correct significant refractive errors?

- accommodative dysfunction can develop due to over or under accommodation

- uncorrected refractive error may result in a high phoria and greater demand on the vergence system

- sensory fusion may be disrupted due to imbalance between the two eyes

-pt may have poor fusional ability due to blurred retinal images

what are refractive error evaluation methods?

- static ret

- dry subjective refraction

- cycloplegic refraction

when should you do a cycloplegic refraction?

- esphoria/esotopia

- latent hyperopia suspect

- high hyperopia

- variable/ difficult refraction

- fluctuating reflex with ret

for children, from birth to 1 year old what is cyclo dose?

2gtts of 0.5%, cyclopentolate, 5 minutes apart

what 40 mintues

for children less than a year old what is cylo dose?

2 gtts of 1.0% cyclopentolate, 5 minutes apart

wait 40 minutes

when to consider rx for hyperopia?

>/= +1.50

when to consider rx for myopia?

>/= -1.00

when to consider rx for astigmatism?

>/= -1.00

when to consider rx for anisometropia?

1.00D (sphere or cyl)

AC/A ratios can influence the vergence posture of the eyes thus for esos we should ___________ plus.

a. minimize

b. maximize

maximize plus and minimize minus

AC/A ratios can influence the vergence posture of the eyes thus for exos we should ________ plus.

a. minimize

b. maximize

minimize plus and maximize minus

after prescribing to pts with non-stab disorders when should you follow up?

follow up in 4-6 weeks to monitor symptoms and reassess any abnormal accommodative or binocular findings with pt wearing SRx

what is the purpose of adding plus lenses?

- decrease the demand on the accommodative system

- reduce the magnitude of esophoria at near

what is the purpose of adding minus lenses?

decrease the magnitude of exotropia

added lenses are effective in changing the magnitude of the phoria in which situtation?

a. high AC/A

b. low AC/A

a. high AC/A conditions such as (convergence excess or divergence excess)

how can the minimum ADD power be determined?

- gradient or calculated AC/A ratio

- trail framing

- MEM

the primary test finding in determining if additional lenses are appropriate is the AC/A ratio for vergence dysfunction and MEM for accommodative dysfunction

ex" pt has accommodative insufficiency

MEM: +2.00

what would be tenative add based on the MEM?

Rx based on leaving the normal MEM left over

so tentative add would range from +1.25 to +1.75

what is option 2 for calculating MEM?

ddx: accommodative insufficency

- subtracting 0.50D from the MEM as starting point so with MEM=2.00 the tentative add= 1.50

what is tentative add based on NRA/PRA?

- ddx: accommodative insufficency

NRA/PRA= +3.00/-1.00

tentative add is +1.00 to balance the NRA/PRA

+2.00/-2.00 (plus would decrease by 1 and increase by -1.00)

which are preferred in children?

a. FT 28

b. PALs

a. FT 28

for children less than 10 years old where should you fit the seg height?

fit seg height at the lower pupil margin

for older children and adults where should you fit the seg height?

fot seg heigh at lower lid margin

what are the 4 conditions that may benefit from added PLUS lenses?

- convergence excess

- basic esophoria: eso far and upclose

- accommodative insufficiency

- ill-sustained accommodation

what are conditions that may benefit from added minus lenses?

- high exophoria

- divergence excess