doctors of optometry | course notes...dr. maria k. walker earned her doctor of optometry and master...
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Doctors of Optometry | Course Notes
OD25 – 2 CE Scleral Lenses Basic Fitting to Advanced Problem-Solving
Monday, February 19, 2018 3:45 pm – 5:45 pm Georgia A/B – 2nd Fl
Presenter: Dr. Maria Walker Dr. Maria K. Walker earned her Doctor of Optometry and Master of Vision Science degrees from The New England College of Optometry. She then completed a residency in Cornea & Contact Lenses at Pacific University. Dr. Walker currently teaches at the University of Houston College of Optometry, and is pursuing her PhD in scleral lenses. Her main interests include contact lens optics, corneal physiology, scleral contact lenses, and multifocal lens performance.
Course Description
This 2-hour course provides a comprehensive discussion of fitting and evaluation of scleral contact lenses. It starts with basic description of the various lenses, designs, and overall fitting philosophy then progressing through every step of the fitting process. It will cover fitting for various conditions with both full scleral lenses and mini-scleral lenses. The course includes patient selection, pre-fitting diagnostic evaluation of the patient, specialized testing, initial diagnostic lens selection and evaluation, lens ordering, follow-up care, modification of the fit, problem-solving, specific care and handling of lenses and in-office management tips. The course is appropriate for those who have little to no experience with scleral lens fitting but, for those who have scleral experience, will also cover more advanced tips for solving the complex fitting challenges that sclerals can present.
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Doctors of Optometry | Course Notes
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Scleral Lenses: Basic Fitting to Advanced
Problem Solving Maria K Walker, OD, MS, FAAO, FSLS
BC Doctors of Optometry, Annual Conference 2018
•! Scleral lens indications
•! Scleral lens nomenclature
•! Fitting concepts for SGPs
•! Scleral lens application, removal, handling
•! Scleral lens fitting and management
•! Complications with sclerals
Intro to Scleral Lenses (SGP)
Scleral Lens Indications 1. Irregular astigmatism
!!Keratoconus / Pellucid Marginal Deg. !!Post Corneal Transplant !!Post Radial Keratectomy (RK) !!Post LASIK/PRK !!Post Intacs !!Corneal Scarring
2. Ocular surface protection !!Post surgical !!Ocular surface disease (OSD)
3. Other !!High Rx, amblyopia, myopia control, prosthetics, aphakia, and more…
Post Transplant
Post RK
Keratoconus
Post RK
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Photo Credit: Boston Sight Photo Credit: Boston Sight Photo Credit: Boston Sight Photo Credit: Boston Sight
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Tear Film Reservoir Scleral Lens
Scleral Lens Zones Optic Zone (OZ):
The central zone of the lens
Transition Zone (TZR): Peripheral to the OZ, between OZ and
limbal zone
Intermediate Zone (IZR): Peripheral to TZR, positioned over the
limbus
Landing Zone (LZR): Begins where the lens lands on the
conjunctival tissue
Scleral Lens Terminology Overall Diameter (OAD): longest diameter of lens
Total Sagittal Depth: “height” of the lens from base to apex
Base Curve (BC): curvature of the optic zone
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Sagittal Depth: Vault of the Lens
•! Diameter dependent
•! Base curve dependent
http://www.oculist.net/downaton502/prof/ebook/duanes/pages/v1/v1c055.html
Large Diameter = Deep SAG
Small Diameter =
Shallow SAG
Flat BC = Shallow
SAG
Steep BC = Deep SAG
Understanding Scleral Images
White light Cobalt Blue with NaFl
OCT image of lens on eye
Optic Zone (OZ)
Transition Zone (TZR)
Intermediate Zone (ITZ)
Scleral Lens Fitting
Landing Zone (LZR)
Fitting the Zones Optic Zone (OZ):
Vault
Transition Zone (TZR): Vault
Intermediate Zone (IZR): Vault
Landing Zone (LZR): Land evenly and smoothly
Fitting Technique: Fluorescein Fitting Technique: Fluorescein
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Ferris State Scleral Lens Fit Scale Tear Reservoir Layer
125um 475um It is Not Always Reasonable to Expect a Uniform Tear Reservoir Layer %
Optic and Transition Zones: Vault
100um
200um
400um
Scleral Lenses will “Settle” over time •! Expect 150-200 microns lens settling
Patrick Caroline
Apical Bearing
Ideal Clearance: ~200um
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Appropriate Limbal Clearance
Inadequate Limbal Clearance
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(Scleral) Landing Zone
Well-aligned Scleral Landing
Ideal Scleral Alignment
•! No blanching of blood vessels •! No impingement •! No edge lift
Photo credit: Greg DeNaeyer, OD
Avoid Scleral Bearing
Blanching
Impingement
Summary of Fitting Goals •! Optic/central and Transition zone: vault
•! 200um after settling
•! Intermediate Zone: vault •! 40-70um clearance
•! Landing Zone: landing •! Soft and wide landing
•! Minimal movement
•! Monitor for corneal edema
Scleral Lens Application Tools Scleral Lens Application
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Application
Step 1
Step 3
Step 2
Application Bubble
Application Considerations !!Dexterity (Parkinsons/tremors)
!!Eyelid apertures
!!Visual Status
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Removal
Problems with Removal?
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Almost always associated with technique RARELY because of fit or patient anatomy
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Patient Education is KEY
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Rigid Lens Cleaning Products Cleaning Products
“Super” cleaners / Polishes
Safe in the eyes
Scleral Lens Application Solution •! MUST be preservative free •! Sterile saline: most common solution
•! Vials: •! ScleralFil (B&L) •! Lacripure (Menicon) •! Addipack (generic)
•! Bottles: •! Purilens (generic)
Alternative Application Solutions
•! Preservative free artificial tears •! Autologous Serum – severe OSD
G*B,*H%1I%JC:13*:2)%
Preservative Toxicity
Always use preservative free application solutions
SGP Management
•! Visit 1: Baseline testing and Diagnostic fitting
•! Visit 2: Lens dispense and training
•! Visit 3 (1 week): Initial follow-up
•! Visit 4 (1 month): Secondary follow-up
•! Visit 5 (6-12 months): Long-term follow-up
SGP Baseline Testing
•! Vision, medications, history
•! Scarring, overall health of cornea
•! Corneal pachymetry (global)
•! Eyelid health
•! Intraocular pressure
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Baseline Data to Monitor Corneal Changes
-! Corneal Pachymetry (global) -! OCT -! Pentacam
-! Endothelial Cell Density -! Corneal Staining -! Neovascularization -! Corneal Scarring -! Watch out for…
-! Neo -! Microsystic edema -! Endothelial blebs, poly/pleo-morphisms
Corneal Scarring
Corneal Staining Follow-Up Examinations
•! Pre-lens removal: •! Fit and vision •! Beginning of day vision and comfort •! End of day vision and comfort •! Evaluate tear exchange
•! Post-lens removal: •! Monitor for corneal edema (pachymetry) •! IOP •! Corneal staining, scarring •! GPC, overall health check
Evaluating Tear Exchange •! Instill fluorescein over the top of the lens
and observe movement
Photo Credit: Pam Satjawatcharaphong, OD
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Signs of Corneal Hypoxia
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Epithelial “Bogging”
Eyelid Health Scleral Lens Complications •! Handling Complications
•! Application bubble •! Removal difficulties •! Surface non-wetting •! Poor patient education
•! Fit Complications •! Apical and/or limbal bearing •! Conjunctival impingement or edge lift
•! Impression rings •! Uneven landing zones •! Loose lens syndrome •! Tight lens syndrome
Application Bubble
Dimple Veiling%
Application Pearls •! CLEAN and DRY hands •! Grasp the eyelids at the lash margin •! Head parallel to ground and lens level during
application
Patient education is essential!
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Application Considerations Dexterity (Parkinsons/tremors)
Eyelid apertures
Visual Status
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“Lens is stuck on my eye!”
•! Attempt different peripheral locations •! Apply pressure to adjacent scleral tissue to break
suction •! Slide edge of plunger underneath lens and sclera
Removal Pearls Proper placement of plunger is key Wet the tip of the plunger for greater suction Slow and steady wins the race
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Removal
Surface Non-Wetting !.%D&"$,I1)*J$K)4,
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Rigid Lens Cleaning Products Boston
Menicon
Optimum
Polishes
Surface Treatment: Plasma •! Plasma Treatments
–! NOT a true coating –! Improves (initial) surface wettability
•! A finished lens is “bombarded with high-energy radio waves in an oxygen-rich environment” (Kurtis Brown, Menicon)
•! Oxygen radicals dislodge hydrocarbons (oils) and rearrange surface molecules ! carbon migrates away and nitrogen migrates towards lens
•! Ionizes the surface of the lens (attractive to liquids) •! Result: wettable lens surface
-! A true coating! -! Covalently bound to the surface of the lens
(after plasma treatment) -! Polyethylene glycol based coating to
improve lubricity and increase comfort and wearability of a rigid lens
-! Available on corneal, scleral, hybrid, and soft contact lenses
Surface Treatment: HydraPEG
90% water PEG-based polymer covalently (permanently) bonded to CL
Surface Treatment: HydraPEG
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Polyethylene Glycol (PEG)
Properties of PEG: Lubricious, viscous, dependent on the length of the polymer
and treatment of the surface
Tangible HydraPEG •! Separates the lens material from the tear film •! Optically-clear coating encapsulates the core
contact lens with a mucin-like hydrophilic shell.
Apical Bearing
Ideal Clearance: ~200um Epithelial breakdown
Epithelial breakdown
Punctate Staining
Limbal Bearing E1%)$&#,L%1+(1),
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Avoid Scleral Bearing
Blanching
Impingement
Excess Scleral Lift
Shadow
Uneven Scleral Bearing
Conjunctival Misalignment "!Conjunctiva / Sclera is toric in nature
"!Non-symmetrical surface "!Nasal side is flatter and higher "!Temporal side is steeper but lower
Toric Scleral Design
Scleral Elevation Map
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Conjunctival Impression Rings & Staining
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Scleral Lens Complications •! Management complications (acute)
•! Lens awareness •! Corneal edema •! Surface non-wetting, sensitivities to solutions •! Lens bearing, over-settling
•! Management complications (chronic) •! Apical and/or limbal bearing •! Corneal edema / bullous keratopathy •! Corneal epitheliopathy, infiltrates •! Corneal neovascularization •! Conjunctival prolapse •! Tear film fogging •! Lens deposits, scratches •! Inflammation, infection
Monitor Corneal Swelling •! Pentacam or handheld pachymeter
•! Baseline readings are key
34 um central swelling 5.2%
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1.! Michaud L, van der Worp E, Brazeau D, Warde R, Giasson CJ. Predicting esti-mates of oxygen transmissibility for scleral lenses. Contact Lens Ant Eye2012;35:266–71.
2.! Jaynes JM, Edrington TB, Weissman BA. Predicting scleral GP lens entrappedtear layer oxygen tensions. Contact Lens Ant Eye 2015;38:44–7.
3.! Compãn V, Oliveira C, Aguilella-Arzo M, Molla S, Peixoto-de-Matos SC,Gonzales-Meijome JM. Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses. Investig Ophthalmol Vis Sci 2014;55:6421–9.
19yo Newly Dx KC: Right Eye
•! 19yo hispanic male •! Dx with KC 4 years ago •! CXL OU in early 2017 •! Scleral lens wearer since 2016 •! No complaints with scleral lens wear, 16h per day
–! Occasional blur OS after several hours of wear (when probed)
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Post Transplant
•! White female •! 56yo •! PKP 2 years ago OD •! LKP 1 year ago OS – still no lenses •! Scleral lenses OD since 2016 •! No visual complaints or issues with sclerals
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Epithelial “Bogging”
Epithelial “Bogging”
!! Cause unknown
!! Non-nutritious saline beneath lens
!! Potential etiologies: !!Loss of glycocalyx layer
!!Epithelial edema
!!Osmotic imbalance
!! Patients asymptomatic
!! Does not appear to be long-term effect
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Treatment: •! Change application
solution
•! Change fit to decrease vault
•! Educate patients taking medicated drops
•! Educate patients on proper use of solutions
Patient education is the key to ScCL success
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What is in the Tear Fluid Reservoir (TFR)?
Mucous Components Aqueous Components
Proteins Lipids
…alterations in many anterior surface diseases
Application Solution Tear Fluid Reservoir Natural Tear Film
Midday Fogging
Baseline OCT
4h post application
8h post application
Managing the Fog Alter lens design to decrease excess clearance
Managing the Fog Alter lens design to decrease excess clearance
Managing the Fog
High viscosity application solution
Conjunctival Prolapse
Prolapse
Recessed Prolapse
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Conjunctival Prolapse
Inferiorly decentered lens
Elevation Map Axial Map
Conjunctival Prolapse
Conjunctival Prolapse
•! Cause: •! Negative pressure forces beneath the lens •! “low-lying” cornea
•! Effect: •! Potential neovascularization and limited nutrient
availability to limbal cornea
•! Management: •! Adjust peripheral lens fit •! Monitor if mild (<3 clock hours)
Inflammatory Response
!!Allergies
!!Solution sensitivity
!!Poor fitting lens
!!Surface debris toxicity
!!Infection
!!Material sensitivity (rare)
Inflammatory Response
Allergic response ! remove allergen ! consider steroid pulse
Material / Solution Sensitivity ! Change accordingly
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Infection: Microbial Keratitis
Author (year) SGP
Indica;on(s) Infec;ous Organism(s)
Taking steroids (y/
n)
Taking an;bio;cs (y/
n) Comments
Severinsky et.al. (2014) post-‐PK Not cultured Unknown Unknown poor compliance
Severinsky et.al. (2014) post-‐PK Not cultured Unknown Unknown poor compliance
Fernandes et.al. (2013) OCP & SS Staph., Corynebact., &
Microsporidia Y N epi defect
Farhat & Sutphin29 (2014) GVHD Acanthamoeba Y Y
Zimmerman & Marks8 (2014)
Neurotrophic kera55s 2^ HSK
Unable to determine on culture
N Y poor compliance
Microbial Keratitis Author (year) SGP Indica;on(s) Infec;ous Organism(s)
Taking steroids (y/n)
Taking AB (y/n)
Comments
Rosenthal et.al. (2000) PED post-‐PK Mycobacterium abcessus Y Y epi defect
Rosenthal et.al (2000) PED post-‐PK Streptococcus pneumonia Y Y
Rosenthal et.al. (2000) PED post-‐PK Strep & Staph Y Y epi defect
Rosenthal et.al. (2000) PED post-‐PK Staphylococcus epidermidis Y Y epi defect
Kalwerisky et.al.(2012) Exposure
keratopathy MRSA N Y
Kalwerisky et.al.(2012) Exposure
keratopathy Pseudomonas aeruginosa N Y
Major Risk Factors: Ocular surface disease (Epithelial compromise)
Steroid use
1.2
1.7
2
10
19.5
0 10 20
RGP
Daily Wear*
DailyDisposable*
Occasional*Over Night
Wear
Over NightWear*
Incidence per 10,000
* Hydrogel lens materials only (silicone hydrogels not included) Dart J., Epidemiology of MK – Have Silicone Hydrogels Had Any Impact? Paper presented at British Contact Lens
Association Clinical Conference, June 2007 from The incidence of contact lens related microbial keratitis in Australia. Stapleton F, Keay L, Edwards K, Naduvilath T, Dart J, Brian G, Holden B in submission.
Australian MK Incidence Study Additional Unknown Complications
Epithelial and Endothelial long-term Health Long term effects of Conjunctival Compression Long term Limbal Health Implications
Looking ahead… • Scleral Lenses currently indicated for
irregular corneas
• Ongoing research will help us learn about the acute and physiological effects of these lenses
• Caution should be taken when fitting normal corneas
Thank you!
Please feel free to email me with any questions: