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
RGP vs. Hydrogel
RGP |
Hydrogel |
Oxygen transmission |
Convenience to patient |
A. Good candidates
B. Poor candidates
O3/O4 (B&L), Cooper Clear & Vantage Thin(CooperVision), CSI Clarity FW (WJ)
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)
CW 79 (B&L), Permaflex Natural & Permalens (CooperVision), LL-70 (Lombart Lenses)
Zero 4 (Ocular Sciences), Optima FW (B&L), Vantage Thin FW (CooperVision), CSI FW (WJ) Custom, Revolution (Sunsoft), Durasoft 3 Litetint D3LT (WJ)
O3/O4 Natural Tints (B&L), Vantage Thin Accents FW (CooperVision), Hydron Versa-scribe tints (Ocular Sciences)
Durasoft 3 Colors - D3OP & Durasoft 3 Complements D3CO (WJ)
B. Extended Wear Torics
Hydrasoft Toric XW (Coast Vision), Hydrocurve 3 (WJ), Sunsoft Eclipse & Sunsoft Toric,
C. Disposable Extended Wear Sphericals
D. Frequent Replacement Sphericals
E. Silicone-Hydrogels
F. Multifocals
A. Silicone/Acrylates- Do not use
B. Fluoro-Silicone/Acrylates
*UV absorber available in the above three lens materials
• Deposit Resistance
• Increased Wettability
• Stable
• Durable
• Oxygen Permeability
• UV absorber?
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
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
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
F. Corneal Ulcers
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
H. Myopic Creep
I. Treatment of Edema &/or Edema-related symptoms & signs
J. CLARE - CL induced Acute Red Eye
X. RGP EW Complications
A. Lens Stability
B. Limbal Desiccation
C. Vascularized Limbal Keratitis
• 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
• Inferior positioning
• Fluorescein pooling at lens periphery
• Trapped debris under lens
• Upon removal, an indentation ring is present
• Corneal ulcer possible
• 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)
XI. Patient Education
Do my eyes look good?
Can I see well?
XII. Progress Examinations
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
If not disposable:
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.