GP Multifocal Fitting and Troubleshooting
Dr. Doug Benoit and Dr. Bruce Williams
Links to Case Studies:
Case 1
By: Dr. Doug Benoit
Patient JB, a 51 year old administrator, presented for a contact lens evaluation. She had previously worn soft contact lenses but stopped due to comfort issues and problems with near vision. She later underwent ECCE with a PC IOL in the left eye. Her refraction was:
OD -3.25-0.50x005 20/20, Add +2.25
OS -1.00 sphere 20/20, Add +2.75
Ks: OD 41.62/42.12@90
OS 41.37/42.25@90
Pupils were 4.5mm OU in average room light
HVID was 12.0mm OU
Lower lid was tangent to the lower limbus.
OD was dominant
Based on these factors and her work environment, an aspheric GP design was chosen.
The Reclaim HD from Blanchard Contact Lens was ordered using the on-line lens calculator, with the following parameters:
OD 8.00mm BC, -3.75 D, 9.5mm LD, Add +2.50, 3.0mm zone
OS 8.05mm BC, -1.50 D, 9.5mm LD, Add +3.00, 2.5mm zone
These lenses were comfortable on insertion and gave distance vision of 20/25 OD (OR -0.25 = 20/20), with 20/25 at near; OS 20/20 distance and near.
Each lens had a superior lid attachment fit, with the OS lens riding a bit higher than the OD. Movement was good in all positions of gaze. Fluorescein showed a slight apical clearance centrally (OD> OS) with good peripheral clearance OU.
Insertion and removal was demonstrated and practiced. Boston Simplus was dispensed for care after procedure review.
At the two week follow-up visit the patient noted good comfort 12+ hours per day. She felt that the vision was slightly off, distance and near, with the lenses, but had no spectacle blur upon lens removal. Manifest refraction and Ks were unchanged.
Distance vision was 20/30 OD (OR -0.75 = 20/20) and 20/20 OS
Near vision was 20/20- OD and 20/30 OS (OR +0.50 = 20/20)
The fit was unchanged, with the OS lens slightly higher, movement was good OU, and fluorescein patterns were the same also.
Based on the above, the following lenses were ordered:
OD 8.05mm BC, -4.25 D, 9.5mm LD, Add +2.50, 3.0 mm zone
OS 8.05mm BC, -1.50 D, 9.5mm LD, Add +3.50, 2.5mm zone
This change brought distance and near vision to 20/20 OD, OS, OU
Both lenses now had nearly identical superior central lid attachment, with good movement in all positions of gaze. Fluorescein use showed slight apical clearance OU with good peripheral clearance OU.
At the next follow-up appointment, the patient was very happy with the vision and comfort of her lenses. She continues to wear them 12 – 14 hours per day and experiences no spectacle blur on GP removal.
Case 2
By: Dr. Bruce Williams
Lens Selection:
Know what's available.
Ocular evaluation
Tears, pupil size and lids (position, fissure width, tone).
Age
(years) | Daylight
Diameter | Nighttime
Diameter |
| 20 | 5.0 | 8.0 |
| 40 | 4.0 | 6.0 |
| 50 | 3.5 | 5.5 |
| 60 | 3.0 | 4.25 |
| 70 | 2.5 | 3.0 |
| 80 | 2.0 | 2.5 |
Patient interview
Work space, lighting, sports and hobbies.
Present the options
Take plenty of time to present the options. Prepare the patient for the initial lens awareness.
Deciding on contact lenses for presbyopia.
Multifocal vs. Bifocal
When to use custom GPs for presbyopia
Soft lens drop outs.
Astigmats.
Adds over +1.50.
Fulltime lens wear.
Case #1
Refitting an aspheric multifocal causing significant spectacle blur with a center distance design.
Presenting spectacle rx. -5.75 -1.00 X 165. Glare, halos and distortion w/specs. Final rx after corneal rehab. -6.00 -2.00 X 175. Seamless transition from contacts to glasses.
Case #2
47yohf w/significant Progressive Myopic Retinal Degen.
OD: -28.50, 20/60
OS: -28.00, 20/200
+1.50 add.
Wearing BioCurve soft lenses for distance only.
Refit w/center distance gp improved distance and near to 20/40 OD. Reports much less lens discomfort and dryness. Does not have to remove the lenses several times a day for cleaning. Can now work comfortably at the computer all day.
Used a large diameter lens to maintain excellent centration over the very large pupil.
Think of GP’s whenever you are faced w/extremes.
Adjusting the seg height based and lower lid position.
Links to Case Studies:
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