Contact lens in practice - week 3 mfl trouble shooting

mfl trouble shooting process

1.Optimal sphero-cyl correction

2. Derive BVS ( up to date eye test with right rx) astig > 1.00D Cyl will require toric or GP CLs

3. Place BVS in a trial frame

• • push further + power wants to optimise the vision they have

• • want to add more plus power in the centre , if maximum plus in distance .allows you to fit lowest add

4.FCC refined near addition

• • Select lowest add possible

5.Select a trial

• • Allow lens to settle, let patient walk around the practice

• • Assess with full illumination

• • Use loose lenses or flippers

• • Select appropriate reading material, often a cell phone

• • 6/HAPPY

Alcon mfl powers and add

+6.00D -10.00D in 0.25 steps

add- low medium and high

alcon determining power

Determine initial CL power using vertex-corrected, most PLUS, spherical equivalent distance Rx,

then add +0.25D for each eye.

Determine the spectacle ADD, then select the contact lens ADD (LO, MED, HI) using the chart:

alcon add high medium and low

low- up to 1.25

medium- 1.5-2.00

high- 2.25-2.50

alcon specatcle and add example trials

( +1.00 was 0.75) alcon requires you to add 0.25

baushe and lomb lens parameters

bause and lomb adds

low - 0.75-1.5

high- 1.75 -2.50

specatcle refraction remains the same

right and left eyes should ahve the same adds ( 2 high adds or 2 low adds)

bauche and lomb troubleshooting near issues

low adds-

• up the add in non-dominant eye

• -if still issues add +0.25 sph lens in non dominant eye

high adds-

• add 0.25 D sphere

bauche and lomb troubleshooting distance issues

low adds-

• modified monovision , only sphere and not mfl in dominant eye

high adds-

• lower add in the dominant eye

• if further issues add -0.25DS in dominant eye hand held assessing BV in normal illumination

coopervision monthly parameters

coopervision- biofinity and proclear fitting ADDs

CD design, not found in the other mfl

3 Pieces of info needed to order lens:

• ◦ Distance power

• ◦ Add power: this is specific to a power and not low, medium, high

• ◦ Is the lens CD or CN

Only lens that the ocular dominance is critical before selecting

the trial as you need to determine which eye received the CN in higher

adds

◦ +1.75 can go either way, pt dependent, usually start with lowest add

coopervision- proclear 1 day mfl fitting boost sphere table

coopervision- proclear 1 day mfl fitting boost sphere

use table to see if add 0.5 or 1.25

add the boost to the best sphere

that gives you trial lens

coopervision clariti multifocal fitting

evaluation and refinement

jphnson and johnson powers and add

2x weekly

+6.00 to -9.00

LOW +0.75 to +1.25

MID +1.50 to +1.75

HIGH +2.00 to +2.50

CN

johnson and johnson specifications

BEFORE over refraction

• Distance

• Check the binocular VA at distance and near first

• Then monocular VA distance and near. If not optimal, perform an O/R

• BE are open

• Use loose lenses

• Ret is not feasible as multiple powers are within the pupil zone

over refraction steps

• Binocular rather than monocular refraction

• • fog with +0.75 DSph or +1.00 DSph do not occlude the eye

• • check to ensure VA fogged by 2 lines

• Start by adding + power in 0.25 D steps while viewing distance chart

• • if +0.25 D accepted, add to trial frame & continue until drop in VA reported

• • check ±0.25 D, only add Minus power if more letters become readable

• • Repeat for the other eye Finally, repeat the ±0.25 D checking with pt viewing chart binocularly

• • present flippers binocularly simultaneously & resist adding more minus power

overefraction add when to do

• Small changes in distance powers can have a large influence on near acuity.

• Recheck the near VA for every change made to the distance

• Remember additions in contact lenses are usually only available in +0.50 steps

overrefraction add

• Measure near acuity under binocular conditions

• If near acuity close to what is expected, don't assess further, proceed to a trial period.

• If near acuity isn't as good as expected, measure acuity monocularly, occluding each eye in turn, to achieve acceptable near acuity (0.25 D steps)

• If near addition still insufficient, refer to manufacturer's troubleshooting guide

iacle troubleshooting distance

low adds- -0.25 ds dom

high add- -0.25 ds dom

if still issues:

Use a low ADD on the dominant eye

and a high add on the non-dominant eye

mixed adds-

Add –0.25 D to the dominant eye

if troubleshooting

iacle troubleshooting near

2 Low adds: low add = dom high add = non dom

2 high adds : add 0.25 to non dom

Mixed adds: +0.25 non dom , if not high adds both eyes