Scleral lens is a large rigid contact lens with a diameter range of 15mm to 25mm. Its resting point is beyond the
corneal borders, and are believed to be among the best vision correction options for irregular corneas. Wearing scleral lens also can postpone or even prevent surgical intervention as well as decrease the risk of corneal scarring.
3. Scleral Lens
Also known as: Haptic lens
‘haptic’ = se nse o f to uch
A large diameter rigid contact lens that cover the
entire surface & rest on sclera.
Diameter: 15.0mm to 25.0mm
Minimum or no contact on the cornea
7. When it starts?
Scleral lens is used to fit on corneal diseases
(irregular corneas)
Two forms of manufacturing lens
(a) Spin cast - mold
(b) Lathe cut – custom made
Scleral lenses are lathe cut
High cost making it unpopular
8. Why is Scleral Lens not popular?
Expensive
Large lens diameter
Difficult to fit
Fragile
Lack of expertise to fit
Complications when patient wear it overnight
10. Indications
1. Vision Improvement
Mainly for corneal ectasia cases
Primary : Keratoconus, keratoglobus, PMD
Secondary : Post refractive surgery (LASIK,LASEK, PRK)
Other conditions: post trauma, corneal scar due to
infection
To restore and improve vision
11. Indications
2. Corneal protection
In 2 conditions:
Severe ocular disease (Sjogren, Steven Johnson, Graft versus
host dx)
Incomplete lid closure (eyelid coloboma, ectropion,
exophthalmos, nerve palsies)
Help by reducing corneal exposure to air (not to close the
eye)
Benefits:
To relieve symptoms of pain & discomfort
Keep ocular surface moist in severe dry eyes by fluid reservoir
retention
Slow the progression of corneal disease and delay the need for
surgery
Decrease risk of scarring
12. Indications
3. Cosmetic
In prosthetic eye (not widely use in Malaysia due to its cost)
Full ocular prostheses
Partially prostheses
Use on: aniridia (reduce glaring), albinism,
trauma,nanophthalmos
4. Sport
More secured – reduce risk of loss
Provides stable vision and comfort
13. Indications
5. Drug delivery
Scleral lens has tear reservoir
Instill drug onto bowl of scleral lens
RGP is not suitable for drug delivery, due to lens movement
5. Normal eyes
Very common in other country
Corneal lens cannot fit well
It gives less complication
15. Design of scleral lens
1. Optical zone
Minimal/not contact with cornea (RGP: contact)
Large size (RGP: smaller)
Give optical effect
Surface:
Anterior surface: Aspheric design to reduce photophobia and aberration
Posterior surface: Same shape as cornea
Sagittal height of scleral lens is higher than RGP sagittal height
Available in toric (but not available in Malaysia)
16. Design of scleral lens
2. Transitional zone
Only scleral lens has transitional zone
Connect sclera and sclera
It set the sagittal height
Changing sagittal height means change the transitional zone (flatter or
steeper)
Depends on the shape of the sclera
The transitional zone for small diameter ScCL may rest on limbal
area, not for larger diameter ScCL.
Range of transition zone: 0.5mm to 2.0mm.
17. Design of scleral lens
2. Transitional zone
Scle ralshape
Referring to cornea, limbus and sclera
Affect the ScCL fitting
Involve the transitional and landing zone
The sclera can be evaluated using:
Pentacam
Anterior segment OCT
Type of limbal profile:
1. Gradual convex
2. Gradual tangential (common)
3. Convex concave
4. Marked convex (common)
5. Marked tangential
1 2 3 4 5
18. Design of scleral lens
2. Transitional zone
Lim balang le and scle ralang le
What: This is angle between iris & cornea
Temporal angle larger than nasal angle (T≠N)
ScCL easily decentred to the nasal
However, it would not affect vision because the optical zone is large.
19. Design of scleral lens
3. Landing zone (Haptic zone)
Area of ScCL that rest on the sclera
Important to know:
Size of landing zone
Angle of landing zone
Landing zone as back surface toric: change the thickness at one
side
Can make peripheral toric by thinning the edge like prism ballast.
Increase diameter of landing zone, make it more comfortable to wear
as less movement produced
22. Scleral lens fitting
1. Optical/Clearance zone diameter
Optical zone important to provide good optical
outcome and corneal clearance
Clearance zone = optical zone + transition zone
Usually 0.2mm larger than HVID
Size depends on lens designs
Can be altered to improve corneal and limbal
clearance
24. Scleral lens fitting
2. Central and limbal clearance
Up to 600 microns of corneal clearance can be easily
achieved if needed centrally.
Clearance of 200–300 microns is usually considered
sufficient, but this can easily go up to 500 microns if desired
with the end stage large diameter lenses.
The terms “flat” and “steep” are substituted with increase or
decrease in sagittal height instead.
Increasing the sagittal height of the lens causes the lens to “lift” off the eye,
increasing the clearance or vault of the lens.
Sagittal depth differs with the condition:
Ectasia needs larger than post-corneal grafts
Ocular surface disease management requires large sagittal height
25. Scleral lens fitting
Central and limbal clearance evaluation
Start with low sagittal height and gradually increase height to desired clearance
A green fluorescein pattern will be visible.
Use a thin optical section with brightest illumination setting at a 45 degree angle
If CCT known, compare corneal thickness to tear layer thickness to estimate clearance
If CCT not know, assume a 530micron central cornea and 650 micron at periphery
(Doughty 2000) and compare to the slit.
26. Scleral lens fitting
Limbal clearance
Complete and generous limbal clearance is necessary to
ensure tear circulation and prevent erosive damage to the
limbal epithelial cells.
If very little fluorescein observed in the limbal area of the lens,
then the lens is too small and should select a larger diameter.
Scleral lens with inadequate limbal clearance
Scleral lens with complete limbal
clearance
27. Scleral lens fitting
3. Landing zone alignment
The landing zone should rest evenly on the scleral conjunctiva with the
edge appearing just above the conjunctival epithelium.
The lens should not move with blinking. Moving lens cause discomfort
to the patient. Can correct by tightening the landing zone.
No fluorescein will be visible under a well-fit landing zone except at the
edge.
A ring of bearing on the inner part of the landing zone indicates a flat landing
zone
A ring of bearing on the outer part of the landing zone indicates a steep
landing zone
Increasing the size of the landing zone relieves pressure if needed.
28. Scleral lens fitting
4. Lens edge lift
Assess lens edge lift after 30 minutes of lens installation during fitting
process.
Also assess lens edge after 3-4 hours of lens wear.
Too much edge lift :
Cause lens awareness and discomfort
Action: Decrease the edge lift by changing the landing zone angle or by choosing
a smaller landing zone radius of curvature.
Low edge lifts:
Leave a full or partial impingement ring on the conjunctiva after lens removal
Two easy methods
Observe the edge lift with white light & how much it “sinks” into the
conjunctiva
Push-in method -preferred if the lens showed some mobility
Remove lens and evaluate surface with fluorescein staining
32. Patient compliance
Patient compliance:
1. Hygiene
Cleaning kit same as RGP, must using protein cleaner.
If deposit on lens present, first see Giant papillary
Conjunctivitis.
1. Sleeping with Scleral CL
Pt love to wear lens overnight.
Advice patient not to wear scleral lens extendedly to avoid
complications.
33. Future Scleral Lens
Would you consider scleral lens in future?
YES.
Good alternative for irregular cornea
Less complications
Better corneal health