This newsletter will feature highlights from a very informative and contemporary webinar from GPLI Advisory Board member, Dr. Michael Lipson, entitled: “OrthoK: Initial Fitting Challenges and Problem-Solving”. It was presented Tuesday evening, March 16th, attended by almost 200 eye care professionals, and is now available online under the “Webinars” tab at www.gpli.info. We will also feature our webinar-based resources. Finally, GPLI Advisory Board member, Dr. Alan Glazier, who introduced – among other innovations – the very popular “ODs on FaceBook”, has recently introduced the first-ever optometry television show, entitled: “FluoreSCENE”. He highlighted the GPLI in a recent segment which will be discussed in the newsletter.
Education Spotlight:
“OrthoK: Initial Fitting Challenges and Problem-Solving”
Dr. Lipson highlighted the following areas:
1) Why Prescribe OrthoK?
=====a. Patients love great unaided vision
=====b. Slow axial elongation in myopic kids
=====c. Grow your practice (new service and GREAT referral ==========source)
2) What we know about OrthoK
=====a. It corrects myopia and provides good unaided visual ==========acuity
=====b. It is reversible and temporary
=====c. Patients report better Vision-Related Quality of Life
=====d. It is an attractive alternative to glasses or daytime CL’s
=====e. It slows myopia progression
=====f. It is safe
3) What we don’t know about OrthoK
=====a. How long good unaided vision remains after lens ==========removal
=====b. Why patients have a variable response
i. Individual differences
ii. Eccentricity
iii. Corneal rigidity
iv. Corneal thickness
v. Eyelids
vi. Tear quality
vii. Efficacy of slowing axial elongation
4) Candidacy for OrthoK
=====a. Progressing myopes
=====b. Motivated not to wear glasses
=====c. Expressed interest in myopia management
5) Be careful about . . .
=====a. Parent motivated; child is not
=====b. Questionable compliance (wear, lens care, follow-up)
=====c. High refractive astigmatism (> 1.75D)
=====d. Vertical/Horizontal elevation differences (> 35 microns)
=====e. High Myopia (> -4.50D)
=====f. Tight eyelids
=====g. Small aperture
6) Importance of corneal diameter
=====a. Critical for optimal fit, centration & fluid forces
=====b. Should be 92 – 95% of HVID; average HVID = 11.8; ==========OAD often between 10.8 – 11.4mm
7) Modes of Fitting OrthoK
=====a. Empirical
=====b. Diagnostic lenses
=====c. Topography-based software: good method because it is ==========difficult to truly determine the tear layer with ==========fluorescein if there is less than 20 microns of ==========clearance whereas topography is vital and allows you ==========to evaluate a number of important fitting factors ==========including corneal change.
=====d. One-night wear of diagnostic lens
8) Case Presentations
=====a. A series of three different case presentations, all young ==========people with different refractive data (among other ==========factors) were presented.
=====b. The decision-making process in managing these patients ==========is presented and discussed
9) Problem-Solving: Included but not limited to the following:
=====a. Centration (very important)
i. Can be improved:
===============1. Optimize lens diameters (larger is usually ====================better)
===============2. Use toric reverse or alignment curves
===============3. Increase overall sag
=====b. Difference Maps
i. Very important to obtain high quality difference ===============maps
ii. The map should illustrate:
===============1. Well centered central flattening
===============2. Uniform/smooth area of central flattening
===============3. 4 – 5mm diameter of central flattening
===============4. Uniform ring of paracentral steepening
=====c. Corneal Staining
i. Common at 1 – 2 days of wear; should be gone ===============within 1 week
ii. It could also be non-fit related (i.e., application ===============technique, removal technique, dryness)
iii. If fit-related, likely mechanical and sag can be ===============slightly increased (i.e., steepen fit)
=====d. Safety/Complications
i. Serious complications are rare but compliance ===============with lens wear and care is important
=====e. Over/Under-correction
i. If present recheck initial calculations
ii. You can change base curve radius without ===============affecting fit
iii. Slight over-correction (up to +1.25D upon ===============removal) is typically acceptable with kids
=====f. Decreased VA at End of Day
i. Refit with a higher myopia target
ii. Prescribe longer wearing time
iii. Prescribe small spectacle correction (i.e., -0.50 ===============to -1.00D)
=====g. Dryness
i. Lubrication is important
===============1. Pre-application
===============2. Just before sleeping
===============3. Pre-removal
===============4. During the day (without lens wear)
=====h. Night Glare
i. Typical in the first 1 – 2 weeks but not a ===============common long-term problem with kids
ii. Ensure good centration
iii. May need to increase the optical zone
iv. Can also prescribe Brimonidine
10) Bottom Line
=====a. Problem-Solving varies with fitting technique
=====b. Know your topographer
=====c. Know your lens design
=====d. Know your laboratory consultants and use them
*****
