Video Grand Rounds: Tips for your GP Fits
Dawn Lam, MSc, OD, FAAO
Annie Chang, OD, FAAO
Abstract:
For the everyday practitioner, fitting GP lenses may seem intimidating; however,
there is a niche of patients where GP lenses are simply the best refractive option.
This course will utilize videos and patient cases to discuss common troubleshooting strategies and fitting tips for regular corneas.
Learning Objectives:
1. To review GP fluorescein patterns for regular corneas
2. To discuss patient cases with the use of fluorescein pattern video clips
3. To provide strategies for problem solving fitting tips through the use of patient
cases
1. Fluorescein pattern assessments (Videos)
a. Apical relationship
b. Type of cornea
i. Spherical
ii. Toric
c. Centration
d. Tear exchange
2. Case #1 – Poor Comfort (A)
a. Differential diagnosis
i. Lens edge
ii. Lens fit
iii. Foreign body
iv. Non-adaptive
b. Video
i. Sphere lens on toric cornea
c. Resolution
i. Bitoric lens design
3. Case #2 – Poor Comfort (B)
a. Differential diagnosis
i. Lens edge
ii. Lens fit
iii. Foreign body
iv. Non-adaptive
b. Video
i. Temporal decentration of GP lens
c. Causes of GP decentration
i. Corneal warpage
ii. Irregular cornea
iii. Flat fitting lens
iv. Small diameter lens
v. Tight eyelids
d. Resolution
i. Increase optic zone and overall diameter
e. Benefits of larger diameter lens
i. Better centration
ii. Better stability
iii. Improved comfort
iv. Allows for larger OZ
4. Case #3 – Glare and halos
a. Differential diagnosis
i. Uncorrected astigmatism
1. Flexure
2. Lenticular astigmatism
ii. Decentered lens
b. Video
i. Decentered lens, pupil looking through the junction between
the optic zone and peripheral curves
c. Resolution
i. Increase optic zone and overall diameter
5. Case #4 – Intermittent blur
a. Differential diagnosis
i. Dry eyes
ii. Non-wetting front surface
iii. Poorly positioned lens
b. Video
i. Heavy lens decentering inferiorly
c. Resolution
i. Increase optic zone and overall diameter
d. Dangers of larger diameter lens
i. Heavier lens
ii. Thicker lens
iii. Thicker edge or center thickness
6. Case #5 – End of day redness
a. Differential diagnosis
i. 3 and 9 o’clock staining
ii. Lens binding
iii. Dry eyes
b. Video
i. Poor lens movement resulting in 3 and 9 o’clock staining
c. Resolution
i. Reduce edge thickness
ii. Change fit to increase lens movement
iii. Adjust edge lift