Lecture 19 Therapeutic contact lenses

Question 1

What are the 2 main categories of therapeutic contact lenses?

Answer 1

*Bandage contact lenses:
- lenses used for treatment of ocular discomfort or to support the cornea during healing after surgery/disease.
- Protect cornea from the environment or mechanical interaction from lids.

-Rehabilitative contact lenses:
- lens prescribed for conditions that prevent a patient from achieving adequate visual function with spectacles because of high, irregular, asymmetric refractive error.
- Partially or completely occlusive lenses that improve function or cosmesis after trauma, surgery, or stroke.

Question 2

What are the types of therapeutic contact lenses?

Answer 2

1. Bandage
2. Lens for chronic conditions
3. Light reducing
4. Cosmetic

Question 3

What is an amniotic lens?

What is it used for?

Answer 3

*Produced from the amniotic sac during pregnancy
*It is sectioned and sterilised
*Can be sutured onto px own eye or under a soft contact lens

*Used for severe, common reoccurring corneal erosions
*When amniotic lens is on eye, the amniotic membrane allows the epithelial to regenerate by proving scaffolding structure
*After 2 weeks when the lens is removed, the amniotic membrane will dissolve and px corneal erosion will completely heal

Question 4

What chronic conditions may a therapeutic lens be needed for?

Answer 4

-graft vs host syndrome
-sjogren’s syndrome
-steven’s johnson syndrome
-filamentary keratitis

Question 5

What type of lens do chronic conditions benefit from and why?

Answer 5

rigid scleral contact lenses

*Scleral lenses protect corneal surface and prevent further corneal erosion, trauma
*The fluid layer keeps the corneal surface hydrated
*In severe cases, the lenses can be work overnight to help re-epithelialisation

Question 6

What are the indications for prosthetic lens?

Answer 6

1.To improve the cosmetic appearance of the px’s eye e.g., corneal opacification
2.They can reduce the amount of light entering the eye e.g., for albinism

Question 7

What are the types of prosthetic lenses?

Answer 7

Tinted lenses
*Solid colours with no iris details
*Come in range of tint and densities
*Diameter of pupil and iris can be varied
*Can be solid colour with clear pupil or black out pupil

Screen printed lenses
*Fine mesh screen with iris detail
*Allows iris detail in a reproducible way
*Each lens looks like the one previously
*Lens come in different densities with clear or black pupil

Hand painted lens
*Matched to existing iris colour
*Picture of iris sent to artist

Question 8

How can prosthetic lenses be used to correct the appearance of strabismus?

Answer 8

*Cosmetic lens can correct the appearance
*Place a DATAC lens on the eye (dot and top and centre)
*A picture is taken of where the dots align
*Sent to laboratory so they have match of iris and position of iris on relation to dot
*Lab can produce an accurate iris pattern (artist decentres pattern)
*Lens will also stop visual disturbances as no sight in strabismus eye with lens in