Feb 22, 2017 - Scleral Lens Education Society (Board member, T). PROS & CONS- RGP. PROS. â» Optics. â» Handling. â» Cost. â» Easy to fit. CONS. â» They ...
2017‐02‐22
FOUR ACES IN YOUR HAND: HOW CAN YOU LOSE? Dr Langis Michaud OD FAAO FSLS FBCLA Professor
Honorarium received as a speaker (S) or a consultant (C), as a research fund (R) or travel grant (T)from the following organizations
Allergan (S,C)
Alcon
Bausch & Lomb (S,C,T)
Cooper Vision (S)
Johnson & Johnson Vision Care (R,T)
Blanchard Labs (S,C,R,T)
Sanofi (S,R,T)
Synergeyes (S,T)
Scleral Lens Education Society (Board member, T)
(S,R)
DISCLOSURE
PROS
CONS
Optics
They HURT
Handling
THEY HURT
Cost
THEY HURT
Easy to fit
Except overnight
THEY HURT
THEY HURT
Must be worn with piggy back
THEY HURT
You can lose them in a blink
PROS &
CONS- RGP
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2017‐02‐22
PROS
CONS
Comfortable – THEY DO NOT HURT
Fully customizable
Easy to handle
Wide variety of parameters
PROS &
Cost
Not so predictable
Oxygen delivery
Limited applications
May be cumbersome (10 peripheries)
CONS – CUSTOM SOFT
Piggy backs Initial comfort Visual acuity
SCLERALS √
Long term comfort
√ RGP can decenter
Stable, better v.a.
Clinical application
Fewer
Fully customizable
Fitting /Learning curve
Easier
Longer
Cumbersome
Lenses < 15 mm are preferable
Handling Designs (toric)
Front
Front
Designs (MF)
N/A
Better outcome
Higher /less
Lower / More
Cost /convenience
SCLERALS VS PIGGY BACKS
SMALL RGPs Initial comfort
√
Long term comfort Visual acuity Corneal astigmatism (spherical lens)
SCLERALS √
=
=
Up to 3 D 3-9 o’clock stg ?
Up to 3.5 D No corneal stg
Fitting /Learning curve
Easier
Longer
Handling
Easier
Lenses < 15 mm are preferable
Designs (toric) Designs (MF)
Front/ bi-toric
Front
Corneal warpage
Lens is stable Better outcome for high ametropia
SCLERALS VS SMALL RGPS
2
2017‐02‐22
KC , 26 y.o. PhD student
Former RGP wearer
Underwent CXL
Referred to be fitted in CL
No lens wear x 12 wks
Rx OD -6.75 -3.25 x 35 20/40
OS -4.50 -4.50 x 115 20/30
Complaints: poor vision at all distances
Assessment
Moderate KC
Steepest K : 49.00 D
Corneal thinnest point: 475 um
Striae and Vogt’s
CR 1
KERATOCONUS REFRACTION
CROSS-LINKING INDICATIONS
CLINICAL PEARLS
RGP lenses
KC design
Fitted according to manufacturer’s recommendation
2D steeper than average than K
Outcome
Lenses well centred, expected fluo pattern
VA 20/25 OD 20 /25 OS 20/20 OU
Issues with inferior edge lift
Resolved with quadrant specific pc and piggy back
TRIAL 1
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2017‐02‐22
Not able to wear more than a few hours /day.
Does not want to sustain lens wear
Hates to wear 2 types of lenses
Once worn: exceptional visual acuity, stable
Options post CXL
Sclerals:
Glasses: reduced VA
Custom Soft Lens : ??
does not want to handle
DISCOMFORT, OTHER OPTIONS
Custom soft lens
Quadrant specific adjustment
Parameters
BC 8.6 / 14.5
Peripheries A1-2/ 30-215 standard A3-4 /260-315 steep 2
Pwer OD -6.00 -2.75 x 45 (WTR rotation) OS -4.00 -4.00 x 120 (5 deg)
VA OD 20/25 OS 20/20-2 OU 20/20
Patient relatively comfortable (feels lens movement) and happy
At Follow-up, reported good comfort and VA – No issues with ocular health over time
Limited wearing time – provided with glasses
TRIAL 2 – F/U
Keratoconus vs normo-tensive glaucoma
Keratoconus vs sleep apnea
CLINICAL PEARLS
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2017‐02‐22
Corneal diameter is #1 factor to fit soft lenses
20% of the patients are showing > or < cornea
We need custom soft lenses….. If possible disposable!
However
Not a go-to-lens for a majority of patients (variable rate of success)
Once used
Fitted flatter than soft lenses (tear exchange)
Do not lose time if 2nd trial is not conclusive (toric especially)
CLINICAL APPLICATIONS: SOFT CUSTOM LENSES
Corneal hypoxia
Epithelial fragility post cross linking
Compliance
Lens replacement rate
Extended lens wear / Extended-wear
Long-term comfort
Thick lens, deposits, etc.
POTENTIAL OCCURENCE
Cold chemical with rub and rinse step
Hydrogene Peroxide
KC vs atopy
CARE REGIMEN
5
2017‐02‐22
Y.L.,
46 Y/O, Asian contact lens wearer
Visual
needs
Computer and near work mostly (> 10Hr / day)
High myopia and astigmatism
Complaints about near + intermediate visual acuity
Refraction
OD -7.00 -1.00 x 20
20/20
OS -7.50 -1.00 x 160
20/20
Add +1.25
CASE NO. 2
Tried soft lens MF
Did not see well at all distances
Tried monovision
Not able to adapt, especially during computer work
Fitted with 2-weeks SiHy disposable lenses
Needs UV protection – outdoor activities
CLD – episodic
Unstable VA : windy conditions
CASE HISTORY
Slit
lamp
(-) Blepharitis or MGD
(-) Cornea SPK
(+) Conjunctival hyperemia,1+
TBUT 9 sec OU
Tear meniscus = 0.15 mm (Oculus keratograph)
Pupil size: 5.5 mm
DES
Syndrome – Reduced aqueous production (or Mixed)
Near tasks reduces blink rate (Computer / Smartphone / Near)
Environmental conditions (air conditionning, rugs, dust, etc)
(-) Allergies or Systemic contributors (medication, topical drugs, health issues )
CASE NO. 2 – FACTORS IN PLAY
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2017‐02‐22
Treat and manage episodic eye dryness
Address refractive issues
Astigmatism and presbyopia
Needs a toric design if astig >0.75D
MANAGEMENT
DIAGNOSIS OF DED Rule Out
Evaluate Symptoms Tear quality Tear volume Anterior segment
Acuity SLE with attention to MGD TBUT Tissue integrity
Medicamentosa Blepharitis Conditions that mimic DED
Primarily Aqueous Deficient DED
Primarily Evaporative DED Follow-up Appointment • • • •
Systemic disease (incl. allergy)
Follow-up Appointment • • • • •
Acuity Tear volume SLE TBUT Tissue integrity
MGD = meibomiam gland dysfunction; SLE = slit lamp examination; TBUT = tear break-up time
Screening, Diagnosis and Management of Dry Eye Disease: Practical Guidelines for Canadian Optometrists, Canadian Journal of Optometry (CJO), 2014 (in press)
OVERVIEW OF MANAGEMENT OF EPISODIC DED Lubrication
• The main stay of therapy across the full spectrum of DED • Lipid based in case of MGD
Ocular Considerations
• Hot compresses (DIE x 2-3 wks; then 2-3X /wks) • Lid hygiene +shampoo • Modifications to contact lens wear
Non-ocular Considerations
• Environmental modification (humidity, air movement, screen use) • Alcohol use • Smoking • Hormonal status • Sleep apnea
Screening, Diagnosis and Management of Dry Eye Disease: Practical Guidelines for Canadian Optometrists, Canadian Journal of Optometry (CJO), 2014 (in press)
21
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2017‐02‐22
Once the ocular surface is restored and tear film stabilized
Eye dryness: DD/ hypergel / MF/ UV protection
Astigmatism:
Eye Dryness and astigmatism : Sclerals
RGPs, hybrids
CONTACT LENS OPTIONS
MF souples Eye dryness
RGP- régulier
RGP sclérales
Hybrides
Monovision
X
X
√
√
√
√
√
√
√
X
Astigmatisme
X
Unstable
√
√
√
X
Centration (vs pupil)
Vs design
X
Needs translation
√
√
X
Lid aperture
X
X
√
Plan B
Plan A
X
Handling
X
X
√
√
√
X
Comfort
√
√
√
√
√
Visual needs (3D)
Hypergel DD /UV
MF souples Toriques
Plan B: Smaller scleral ( DHA)
Lipid-based tears
Oral / topical combo medication (?)
Long term
Cyclosporine (off label)
MANAGEMENT
CYCLOSPORINE AND LID MARGIN DISEASE ?
Off-label use
Lid margin disease associated with increased inflammatory markers on the ocular surface
Studies show …
Decreased viscosity of
Increased TBUT
Increased Schirmer scores
Resolution of lid telangiectasia
Improved symptoms
Better efficacy at three-month follow-up than Tobradex
gland secretions
4 1
BE AWARE : ROSACEA
A CHRONIC INFLAMMATORY DISORDER
AFFECTED AREAS Subtype Subtype Subtype Subtype
CLASSIFICATIO N (4 subtypes)
1: Facial redness (erythematotelangiectatic rosacea) – flushing and persistent redness, visible blood vessels may also appear 2: Bumps and pimples (papulopustular rosacea) – persistent facial redness with bumps or pimples, often seen following or with subtype 1 3: Skin thickening (phymatous rosacea) – skin thickening and enlargement, usually around the nose 4: Ocular irritation (ocular rosacea) – watery or bloodshot appearance, irritation, burning or stinging
Subtypes: http://www.rosacea.org/sites/default/files/images/faces_of_rosacea.gif
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2017‐02‐22
HYPERGEL: IDEAL FOR ROSACEA Material generated with a surface acting as a dehydration barrier
Tensioactive monomer (poloxamère 407) concentration is higher at the material surface level, which becomes a permanent characteristic of the material. This is why Hypergel mimics the lipid layer of the eye and helps to maintain lens structure and hydration.,3,8
.
Hyfrophilic molecules of polyvinylpyrollidone (PVP) adheres to the macromere and can adsorb up to 40% of their molecular weight in water
[ 43 ]
Combination of molecules and macromeres leads to 98% hydration retention along the day6
Contact lens options
Ocular surface treatment first done
Scleral lenses considered to improve symptoms
Vision
Eye dryness (CLD)
Contamination /exposure to pathogens (operating room)
Use of oblate designs to minimize minus power
IN THIS CASE
A spherical surface has a Q value of 0
Cornea is a parabola with a periphery flatter than the centre
Q is negative (-0.25)
Induces spherical aberrations
Added to the crystalline lens Q (-0,25 in young; 0 in older)
PROLATE VS OBLATE
15
2017‐02‐22
OBLATE SCLERAL LENSES Goal: To reduce central clearance when found excessive
•
Clinical applications: oblate corneas •
Post –Lasik /RK
•
Post-graft
Design:
•
central curve is made flatter while the fit over the limbus and at the edge remains the same
•
Flatter central curve generates less negative power
To lower minus power of scleral lenses
Prolate Corneas
Keratoconus
Irregular corneas
To reduce induced lens HOA and
spherical aberrations of the eye
To improve presbyopic correction
Reduced minification
Effective more add power
Seeing through a -25D
NEW CLINICAL APPLICATIONS
Outcome
Visual issues resolved (due to larger optic zone)
OBLATE
Multifocal scleral lenses
Eye dryness resolved after treatment and CL refit
No more CLD
OUTCOME
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2017‐02‐22
Scleral lenses for normal corneas
Oblate profiles vs prolate surfaces
CLINICAL PEARLS
Identifying a need
Vision
Comfort
Educate the patient about the technology
Benefits
Limits
Handling
Cost
Convenience
Handling
Care regimen
WHAT DOES IT NEED TO SWITCH PATIENTS FROM SOFT TO SCLERAL LENSES
COMFORT
Never touch the cornea
No lens to lid interaction / no lens movement
Constant hydration of the ocular surface
Optimal landing on the conjunctiva
No lens dehydration
VISION
Larger optic zone (8-9 mm)
Full compensation of corneal irregularity
Better centration
Reduced HOA
Gas permeable material optics
Optimal fluid layer thickness required
No lens dehydration
SCLERAL LENSES CAN HELP
17
2017‐02‐22
High refractive errors
Larger optic zone: less high order aberrations
Centration
Physiological issues associated with RGPs (3-9 o’clock, corneal warpage, etc.)
Improved overall visual acuity
Astigmatism
No rotation and no visual fluctuation
Larger optic zone
A spehrical scleral can compensate up to 3.5 D of corneal astigmatism
No dehydration with time
POTENTIAL CLINICAL APPLICATIONS FOR NORMAL CORNEAS
Sports /outdoors activities
UV protection
No exposition to dust, particules, foreign body as for small RGPs
Corneal protection
Allergy /Challenging environement
Reduced exposition to allergen
RGP materials compatible with concurrent use of topical meds
POTENTIAL CLINICAL APPLICATIONS
18
2017‐02‐22
Presbyopia
Stable lens
Full compensation for astigmatism
Friendlier for the presbyopic eye environment (dryness, tear film stability, etc.)
Compensation for corneal irregularities
Symptomatic patients
Contact lens induced Dry Eye
No preservative agent / solution toxicity
POTENTIAL CLINICAL APPLICATIONS
FOUR ACES IN YOUR HAND
Custom soft lenses
RGPs /piggy back
Hybrids
Sclerals
How can you lose ?
CONCLUSION
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