EXTENDED WEAR

(Hydrogel and RGP)

Objectives of this lecture:

1. To be able to determine good candidates for extended wear

2. To be able to identify and manage RGP and hydrogel extended wear complications

I. Extended Wear - Lenses are FDA approved to be worn for 7 full days with an overnight break (i.e., 8-10 hours minimum); however, lenses may be worn in shorter cycles (i.e., 3-4 days) or occasionally extended wear, referred to as flexible wear (i.e., weekends).

A. "Possible" Benefits to the Patient

1. Convenience
2. Good visual acuity upon awakening
3. Decreased care
4. Irregular hours
5. Convenient for travel, camping & hunting
6. Reduced lens handling
7. Decreased lens damage and loss

RGP vs. Hydrogel

RGP	Hydrogel
Oxygen transmission Decreased deposits Decreased lens diameter Increased lens movement Quality of vision Fewer ulcers/Acanthamoeba Less dehydration Can modify & verify	Convenience to patient Ease of fitting Initial comfort Less dessication Decreased adherence Availability of parameters Less distortion Wettability

1. Candidates for Extended Wear

A. Good candidates

1. Successful hydrogel or RGP DW patients* (Soft EW failures may make good RGP EW patients)
2. High myopes
3. Occupational needs
4. Compliant patients
5. Elderly or aphakic patients*

B. Poor candidates

1. First time wearers
2. Lazy/noncompliant patients
3. Minors
4. Patient with ocular pathology or condition, especially anterior segment (Keratoconus, unhealthy aphakes, corneal dystrophy)
5. Diabetic patient
6. Radial keratotomy
7. Low Rx
8. Chronic allergies
9. DW CL complications
10. . Smokers
11. . Compromised cornea, lids or tears

1. Hydrogel Materials

1. Extended Wear Sphericals

1. Low Water Content/Thin lenses (30-50%)

O3/O4 (B&L), Cooper Clear & Vantage Thin(CooperVision), CSI Clarity FW (WJ)

2. Medium Water Content (50-70%)

Softcon EW (Ciba), CO Soft 55FW (California Optics), LL-55 (Lombart Lenses), Edge III 55 (Ocular Sciences), Hydrocurve II & Soft Mate II (WJ), Sunsoft Sunflex, Durasoft 3 - D3X4 & D3X3 (WJ), Biocurve Soft EW (Biocurve)

3. High Water Content (> 70%)

CW 79 (B&L), Permaflex Natural & Permalens (CooperVision), LL-70 (Lombart Lenses)

4. EW Handling Tints (spherical)

Zero 4 (Ocular Sciences), Optima FW (B&L), Vantage Thin FW (CooperVision), CSI FW (WJ) Custom, Revolution (Sunsoft), Durasoft 3 Litetint D3LT (WJ)

5. EW Cosmetic Enhancers (spherical)

O3/O4 Natural Tints (B&L), Vantage Thin Accents FW (CooperVision), Hydron Versa-scribe tints (Ocular Sciences)

6. Opaque Tints (spherical)

Durasoft 3 Colors - D3OP & Durasoft 3 Complements D3CO (WJ)

7. UV Protection
   Permaflex UV (CooperVision), Precision UV, Durasoft 3 UV & Durasoft 3 Optifit Toric UV (WJ), Acuvue & Acuvue 2 (Vistakon)

B. Extended Wear Torics

1. Clear torics

Hydrasoft Toric XW (Coast Vision), Hydrocurve 3 (WJ), Sunsoft Eclipse & Sunsoft Toric,

2. Tinted torics
   Durasoft 3 Optifit Toric Colors, Complements & Durasoft 3 Optifit (Vis. tint) (WJ)

C. Disposable Extended Wear Sphericals

1. Focus 1-2 weeks & Focus 1-2 weeks Softcolors (Ciba)
2. Seequence, Optima FW & Soflens 66 (B&L)
3. Acuvue & Acuvue 2 (Vistakon)
4. Hydron Biomedics 55 (Ocular Sciences)
5. Precision UV, Fresh Look Litetint, Colors & Color Enhancers (WJ)

D. Frequent Replacement Sphericals

1. Optima FW/O3/O4 (B&L)
2. Focus Monthly, Focus Monthly Softcolors & Focus Monthly Toric (Ciba)
3. Preference DW/FW, Frequency 55, Hydrasoft Toric FW (Coopervision)
4. Gentle Touch DW/FW, Durasoft 3 Optifit and toric ColorBlends (WJ)
5. Multiples FW & DW, Multiple Torics (Sunsoft)
6. Hydron Proactive FW (Ocular Sciences)

E. Silicone-Hydrogels

1. Pure Vision (B&L)
2. Focus Night & Day (Ciba) (Not available in the US yet)

F. Multifocals

1. Acuvue Bifocal (Vistakon)
2. Additions (Sunsoft)
3. Focus Progressives (Ciba)

9. RGP Materials

A. Silicone/Acrylates- Do not use

1. Paraperm EW (Paragon) Dk = 56
2. Polycon HDK (PBH) Dk = 40 *No longer available

B. Fluoro-Silicone/Acrylates

1. Fluoroperm 92 (Paragon) Dk = 92*
2. Fluoroperm 60 (Paragon) Dk = 60*
3. Equalens (Polymer Tech.) Dk = 64*

*UV absorber available in the above three lens materials

4. Fluorocon (WJ) Dk = 60
5. Fluoroperm 151 (Paragon) Dk = 151
6. Menicon SF-P (Menicon USA) Dk=159
7. Menicon Z (Menicon USA) Dk=163-250 FDA approval ?
8. Benefits of F-S/A

• Deposit Resistance
• Increased Wettability
• Stable
• Durable
• Oxygen Permeability
• UV absorber?

9. Preliminary Evaluation

1. Case History

Why do you want to wear your contact lenses extended wear?
What does the patient really want (flexible wear, solution-free system)?
Have you worn contact lenses before?
Have you ever experienced any complications with contact lens wear?
What is your average wearing time?
How do you care for your present contact lenses?
Do you have spectacles you wear as a back-up?
What is your occupation and hobbies?
Do you have any current medical or ocular conditions?
Are you taking any medications?Do you experience allergies, seasonal or chronic?
Have you experienced dryness of the eyes with or without contact lens wear

2. Preliminary Tests

Visual Acuity
Subjective Refraction
Keratometry
Slit Lamp Examination
Lid Eversion
Tear Break-up TimeFluorescein Evaluation
Slit lamp examination of any current lenses

VII. Material Selection

A. Hydrogels

•Disposable
•Full-time EW
•Occasional EW
•Solution-free system

B. RGP’s Moderate Dk F-S/A RGP(i.e., 60)

• Durability
• PMMA refit
• Flexible Wear

C. High Dk F-S/A RGP ( i.e., 90 & above)

• Hyperopes
• Those exhibiting edema
• Full-time Extended Wear

VIII. Fitting Tips for RGP’s

1. Fitting techniques identical to DW RGP fitting
2. Fit the same material as to be ordered
3. Center thickness should increase 0.02mm for high Dk materials (Refer back to RGP Fitting outline)

IX. Hydrogel EW Complications - are caused by the long-term lens wear and the continuous corneal edema

A. Neovascularization

1. Treatment

a. Higher Dk/L lens
b. Reduce wearing time from 7 days to 3 days
c. Reduce wearing time to flexible or occasional EW
d. Reduce wearing time to DW with EW material
e. Refit in RGP

B. Giant Papillary Conjunctivitis (GPC)

1. Symptoms and signs previously discussed in Hydrogel Troubleshooting Outline
2. Occurs more frequently in EW
3. Treatment-Return to DW &/or discontinue lens wear

C. Microcysts

1. Occur 3 weeks to 6 months after EW initiated
2. Occur generally in the mid-peripheral corneal epithelium
3. Trapped metabolic debris
4. With the biomicroscope, appear as tiny bubbles or vacuoles in the cornea
5. Treatment

a. Less than 50 microcysts may be tolerated; however, this signals a problem
b. Over 50 microcysts requires lens wear to be discontinued
c. Decrease by increasing oxygen-try a higher oxygen transmissable lens
d. If severe, discontinue lens wear and wait for the microcysts to disappear. It may take 5-10 weeks.

D. Striae-folds at Descemet’s level (See Hydrogel Troubleshooting handout)

E. Infiltrates

1. Typically near the limbus
2. One or more fluffy white spots in stroma
3. Does not stain with fluorescein or may have overlying defect
4. Composed of inflammatory cells lying within the stroma
5. Discontinue lens wear until infiltrate disappears (may take up to 2 months)
6. Treat infection
7. May treat prophylactically with antibiotic/steroid combination to reduce inflammatory response

F. Corneal Ulcers

1. Result of abrasion, epithelial disruption, area of staining, mechanical trauma, edema
2. Patient should remove the lens at the beginning of mild discomfort or pain
3. Characterized by stromal infiltration in the area of epithelial defect surrounded by edema
4. Compliance important to prevent contamination of the solutions & case
5. Requires lens wear to be discontinued (save lenses) and aggressive treatment
6. Treatment:

a. Culture or not?

b. Initial treatment should be broad and intensive and treatment can be altered once the result of the culture comes back.

c. Do not hesitate in referring, especially if near the visual axis

d. Follow closely

e. RTC 24 hrs.

f. Melton & Thomas regimen: (Ciloxan or Ocuflox) 1 drop every 15-60 minutes for several hrs., hourly for 1-2 hrs., every 2 hrs. for 2-3 days, qid for a few more days. Use Polysporin ointment at bedtime

g. Catania regimen: (Ciloxan or Ocuflox) Drop in office. 1 drop every 5 minutes for 5 doses, 3 drops every 1-2 hrs. for 24 hrs., wake every 2 hrs. at night, 2 drops every hr. for 2 days, 1 drop every 4 hrs. for 10-14 days.

h. Cycloplege Homatropine 2%. (Ciloxan or Ocuflox) 1 drop every 15 minutes for 6 hrs., 1 drop every 30 min. for 18 hrs., Second day:1 drop every hr., 1 drop every 4 hrs. for 3-14 days, Polysporin ointment at night.

i. Cycloplege 5% Homatropine. (Ciloxan or Ocuflox) 1-2 drops every 15 minutes for 1 hr., 1-2 drops every 30 min. for next 4 hrs., 1 drop every hr. for next 24 hrs., qid for 10-14 days

 Differential Dx of a Sterile Infiltrate -vs-Infectious Keratitis (taken from Catania and other sources)

Sx/Sign	Infiltrate	Ulcer
Pain	Mild	Mod.-severe
Size	<2mm	>2mm
Defect	no stain	Stain Raised/ excavated
Discharge	absent	present
Location	peripheral	central-mid peripheral
AC	absent or mild	mild-severe
Culture	-	+
IOP	normal	possibly elevated
Photophobia	present/absent	present
Lids	minimal/faint red	ptosis/red
Conjunctiva	pink-red, lacrimation	crimson,mucous
Edges of defect	defined	fuzzy
Lucency	haze	white-opaque
Edema	surround-island	50% surface
Infiltration	superficial	full stromal
Pupils	PERRLA	miotic
VA	unaffected	<20/50

G. Endothelial Changes

1. Resulting from hypoxia
2. Must look to see, will see in any CL wearer to some degree
3. Polymegethism - different sizes of endothelial cells
4. Polymorphism - different shapes of cells
5. Blebs - Pits or elevations in endothelium
6. Bedewing - Clusters of leukocytes which look like droplets or spots

H. Myopic Creep

1. Progressively more myopic prescription due to corneal edema
2. Occurs approximately 1-6 months after beginning EW

I. Treatment of Edema &/or Edema-related symptoms & signs

1. Reduce wearing time (EW to FW/EW to DW)
2. Refit with a lens which will provide greater oxygen to the cornea (i.e., EW hydrogel worn DW, RGP)
3. Discontinue lens wear in moderate to severe cases until edema clears then refit or change wearing time
4. May use a topical hyperosmotic agent such as Muro-128 ointment, which will increase the tonicity of the tear film and enhance fluid removal from the cornea

J. CLARE - CL induced Acute Red Eye

1. Breakdown of trapped contaminants, tight lens, solution sensitivity, dehydration, tear film changes
2. Discontinue lens wear for 2-3 days, treat problem and refit if necessary.

X. RGP EW Complications

A. Lens Stability

1. Decreases as Dk/L increases
2. Flexure
3. Warpage
4. Power change

B. Limbal Desiccation

C. Vascularized Limbal Keratitis

1. Clinical Signs:

• Former PMMA & S/A wearer
• Elevated limbal epithelial lesion
• Diffuse, ill defined border
• Semi-opaque
• Conjunctival injection
• Edema & staining
• Corneal vascularization

D. Lens Adhesion- absence of movement on the blink

1. Symptoms: Absent or minimal
2. Clinical Signs:

• Inferior positioning
• Fluorescein pooling at lens periphery
• Trapped debris under lens
• Upon removal, an indentation ring is present
• Corneal ulcer possible

3. Management

• Reduce flexure
• Polish back surface
• Increase use of rewetting drops
• Massage lens with lid
• Reduce WT to DW
• Hydrogels

E. Foreign Body Abrasion

F. Epithelial Wrinkling - Transient folds, noticed upon awakening

G. Ptosis (Fonn/Holden)

1. Unilateral ptosis observed in REW vs HEW study
2. Resolution after 5 weeks

XI. Patient Education

1. Extended wear has the potential of causing a vision threatening condition if the patient is not compliant with proper wearing schedule, care and progress visits.
2. Thoroughly educate the patient
3. The patient should not delay removing the lenses and calling the practitioner is there is any problem.
4. Back-up spectacles required
5. Informed Consent
6. Preferred wearing schedule is flexible or occasional EW (Can even wear lenses DW)
7. Yamane triad - Do my eyes feel good?

Do my eyes look good?

Can I see well?

XII. Progress Examinations

1. 1 week DW, 24 hour EW, 3-7 days EW, 2 weeks EW, 1 month EW, 3 months EW and every 3 months thereafter (For patients progressing normally)
2. Procedures to perform at progress visits

1. Subjective comments or complaints
2. Visual acuity
3. Over-refraction
4. SLE with & without lenses
5. Fluorescein evaluation
6. Lid eversion
7. Keratometry
8. Subjective refraction
9. For RGP’s - Over K’s, Fluorescein evaluation with lenses on

XIII. Lens Care for Hydrogel

1. Use lens lubricants am & pm
2. Throw old, expired solution away - Be cautious about solution contamination
3. Clean lenses upon each and every lens removal
4. Wash hands thoroughly upon lens removal

If not disposable:

5. Lenses with greater than 55% water content can not be heat disinfected.
6. Enzyme time may be reduced - check instructions
7. Enzyme at minimum weekly
8. Disinfect upon lens removal after cleaning

Lens Care for RGP’s

A. Wetting & Soaking Solution to be used at every lens removal

B. Surfactant cleaning to be performed upon lens removal prior to disinfecting

C. Weekly enzyme cleaning if needed

D. Lens lubricant to be used at minimum upon awakening and before going to sleep

E. Use of Laboratory cleaners if necessary, in office only

XIV. Cases

Hydrogel EW Cases:

Case 1 - Patient comes in to the office with pain, photophobia and tearing. He has discontinued lens wear on his own. He first noticed a minor discomfort at 4:00pm the day before which seemed to slightly improve with the use of an old bottle of lens lubricant. He did not remove the lens until the following morning when his eye became extremely uncomfortable. Staining reveals a small (1mm) circular area of staining surrounded by haziness in the cornea.

Solution - Think Ulcer

Case 2 - Patient comes in for a 1 month EW progress visit. There are considerable bubble-like areas that do not move with the lens. Upon lens removal, these areas do not stain with fluorescein.

Solution - Think Microcysts

Case 3 - The patient calls for an emergency visit. She has not been in for 2 months. She is a very compliant patient. She has not been able to wear her lenses for the past 2 days. She has mild discomfort which has gotten worse and is at its peak when she awakes. Slit lamp examination reveals numerous defects in the cornea with punctate staining.

Solution - Microcystic edema, Microcysts erupting on the corneal surface in the morning

Case 4 - The patient has been wearing extended wear lenses for 6 months. He has been known to overwear his lenses at times. He complains that his glasses aren’t as good anymore. His last spectacle prescription was given to him 6 months ago at his primary care visit. He is taking -0.50D more OD and -1.00D more OS.

Solution - Myopic Creep

RGP EW Cases:

Case 1 - A myopic patient is a former long-term PMMA wearer desiring extended wear. The practitioner refit the patient into a lower Dk (i.e., 50-60) RGP extended wear material. The patient has experienced improved vision and decreased spectacle blur with the new lenses; however, some central corneal clouding is still present with mild spectacle blur. Examination of the lenses reveals scratches and slight (i.e., 0.50D) warpage.

Solution - Re-educate Patient on care & handling, Consider refitting to a higher Dk

Case 2 - A patient wears 9.0mm Polycon II (PBH) lenses with a base curves equal to 7.81mm, center thickness of 0.10mm, Dk of 12 and a power equal to -4.75D. Although the patient is very satisfied with the present lenses and an optimum lens-to-cornea fitting relationship exists, she is highly motivated for extended wear.

Solution - Try Fluorocon lenses as they are the exact design but in an extended wear material. Diagnostic fitting is recommended.

Case 3 - A patient desires RGP EW lenses. The patient is a good candidate with the following prescription: OD +2.50 OS +4.00. What type of lens material might you select for her?

Solution - High Dk material like Fluoroperm 92 or 151

Case 4 - Mary has been successfully wearing Paraperm EW lenses for approximately 6 years. She is about 48 years old and has recently been noticing more ocular dryness than usual. In addition, you have noticed 3 & 9 staining increased from a very minimal amount to a Grade 1+. What would you suggest?

Solution - Fluoro-Silicone/Acrylate material to enhance wettability, like Fluoroperm 60

Case 5 - On dispensing of new RGP EW lenses, a patient’s visual acuity is 20/25-2 OU. Over-refraction is +0.25-1.00 X 180 OU with over-K’s 43/44 @ 090. The diagnostic fit was done with Polycon II trial lenses of Dk=12. The patient has 2D of corneal toricity. The best fit was 0.75D steeper than K. The visual acuity was 20/20 OU at the fit. What is the problem?

Solution - Lens flexure, Should have been fit in the material to be ordered, not a low Dk Polycon lens.

V.A.H. 2000

Some excellent sources to read: Chap. 9 of Contact Lens Problem Solving by ES Bennett

Chapter 10 of Specialty Contact Lenses: A Fitter’s Guide by C Schwartz

Chapter 15 of Clinical Manual of Contact Lenses by Bennett & Henry or Chapter 16 2nd Edition.