Download - LENS DYNAMICS, INC.. SCLERAL HISTORY Original contact lens Hand ground glass lenses Fit by casting a mold of the cornea.

LENS DYNAMICS, INC.

SCLERAL HISTORY

• Original contact lens

• Hand ground glass lenses

• Fit by casting a mold of the cornea

EARLY SCLERAL PERFORMANCE

• Difficult to fit

• Hard to manufacture and reproduce

• Corneal hypoxia

• Very short wearing times

• Corneal molding – The negative kind

SCLERAL DEFINED

• Mini-Sclerals – 12.5mm to 14.5mm

• Medium Range Sclerals – 15.0mm to 18.0mm

• Full Sclerals – 18.5mm to 28.0mm

SCLERALS – FIRST OR LAST RESORT?

WHY FIT A SCLERAL LENS?

THE PRO:

• To vault highly irregular corneas

• To provide better visual acuity than soft lenses

• To prevent lost lenses

• New Oxygen permeable materials

WHY FIT A SCLERAL LENS?

THE CON:

• Harder to fit

• Harder to insert and remove

• Can reduce metabolic waste removal

• Potential for hypoxia

• Harder to fit

THE PRACTICAL:

• First or Last Resort as a design?

• Who fits sclerals at all?

• Who fits sclerals as the design of First choice?

• Who fits sclerals as a design of Last resort?

THE DESIGN:

• 13.0mm, 13.5mm, 14.0mm

• Lathe cut on DAC ALM lathes

• Spherical back and front surfaces

• Normally NOT fenestrated

HOW TO FIT

• Start with a base curve close to average Ks

• Trial for best alignment pattern as possible

• Be sure there is NO conjunctival drag

• Do spherical over-refraction

• Need 0.5mm of movement

FITTING TIPS

• Fill concave side with saline/wetting drops into posterior of trial lens

• Dip fluorescein strip into solution

• Insert using 2 fingers to handle the trial lens with patient looking at floor

• Low riding lens – select flatter base curve

• Flatten base curve to solve edge tightening

CASE HISTORIES

48 years old, Caucasian male, OD cornea

• Can’t use bi-toric• Quadrant Specific

base curve not indicated

• Temporal/superior area eliminates reverse curve design

• Select Semi-Scleral 13.5 design

CASE 1

48 years old, Caucasian male, OD cornea

• Average K is 47.00 D. or 7.18mm

• Select 7.20mm BC from trial set, 13.5mm -4.00

• Acceptable fit with -2.25 over-refraction

CASE 1

22 years old, African American male, OS cornea

CASE 2

• Superior, peripheral area too steep for Quadrant Specific base curve

• Bi-toric not indicated• Select Semi-Scleral

13.5 design



• Select 7.20 BC from trial set, 13.5mm

• Lens too tight at edge and too much vaulting

CASE 2


• Select trial lens 0.2mm flatter or 7.40mm

• Acceptable fit• Perform spherical

over-refraction

CASE 2

31 year old Caucasion female, OD cornea

• Bi-toric not indicated• Flatter areas too

narrow for Quadrant Specific base curves

• Reverse curve design not indicated

• Select Semi-Scleral 13.5 design

CASE 3



• Select 7.30mm trial lens from trial set

• Low riding lens-select flatter base curve

CASE 3


• Select 7.50mm base curve from trial set

• Acceptable fit with lens properly positioned

• Perform spherical over-refraction

CASE 3

Questions?