CASE STUDY I - Dr. Rinehart

• 38-year-old white female
• The patient was displeased with the short life of her soft contact lenses.
• The entering unaided distance acuity for this patient is 20/70 for each eye.

Baseline Data

• Subjective refraction:
       OD -1.50 - 0.50 x 090
       OS -1.75 sphere
• Keratometer reading:
       OU 43.00/43.00 @ 090
• Eccentricity:
       OD 0.54
       OS 0.65
• HVID:
       OU 11.3 mm

Best Fit Diagnostic Lens

• Base curve = 8.54 (39.50 D)
• Alignment curve = 7.94 (42.50 D)
• Lens diameter = 10.0 mm
• Sagittal depth = 1.462

Patient's Lens

Day 1 Results

• The unaided distance acuity is 20/20 with each eye.
• Subjective refraction:
       OD + 0.25 sphere
       OS + 0.50 sphere
• Keratometer readings:
       OD 42.00/42.50 @ 090
       OS 42.00/42.00 @ 090
• Topography shows well centered treatment zones OU.

After 2 Months of Nighttime Lens Wear

• Unaided distance acuity:
       OD 20/20
       OS 20/20
• Subjective refraction:
       OD plano sphere
       OS Pl - 0.50 x 090
• Keratometer readings:
       OD 42.00/42.25 @ 090
       OS 42.50/42.25 @ 090
• Topography continues to be well centered.

 
CASE STUDY II - Dr. Rinehart

• 38-year-old white female
• Has worn soft lenses for 17 years.
• Does not like becoming more nearsighted.

Baseline Data

• Unaided DVA:
       OD 20/80
       OS 20/80
• Subjective refraction:
       OD -1.75 -0.25 x 090 20/20
       OS -2.00 sphere 20/20
• Keratometer readings:
       OD 43.75/43.75 @ 090
       OS 44.00/44.00 @ 090

Prefit Topography

Day 1 Results

• Unaided DVA:
       OD 20/20
       OS 20/20
• Subjective refraction:
       +0.25 sphere 20/20
       +0.50 sphere 20/20
• Keratometer readings:
       OD 41.50/42.00 @ 090
       OS 41.50/42.00 @ 090

No changes were made since everything except topography looked good. Is this the right decision?

10 Day Results

• Unaided DVA:
       OD 20/40
       OS 20/30
• Subjective refraction:
       OD + 1.50 - 1.75 x 065 20/20
       OS + 1.75 - 1.25 x 125 20/20
• Keratometer readings:
       42.50/43.00 @ 090
       42.50/44.00 @ 090

Sagittal depth of the lens was increased by 9 microns.

Results After 1 Week of Wearing the New Lens

• Unaided DVA:
       OD 20/20
       OS 20/20
• Subjective refraction:
       OD + 0.25 sphere 20/20
       OS plano sphere 20/20
• Keratometer readings:
       42.75/42.75 @ 090
       42.75/42.75 @ 090

Results After 2 Months of Overnight Wear

• Unaided DVA:
       OD 20/20
       OS 20/20
• Subjective refraction:
       OD + 0.75 sphere 20/20
       OS + 0.75 sphere 20/20
• Keratometer readings:
       41.75/42.00 @ 090
       42.00/42.00 @ 090

 
CASE STUDY III - Dr. Rinehart

• 13-year-old female
• Has worn daily wear soft lenses for about one year.
• No medications.

Baseline Data

• Unaided DVA:
       OD 20/250
       OS 20/250
• Subjective refraction:
       OD -3.25 sphere 20/20
       OS -3.25 -0.50 x 070 20/20
• Keratometer readings:
       OD 45.50/45.00 @ 090
       OS 45.50/45.50 @ 090

Topography After One Night of Lens Wear

With the above topography, what must be considered when deciding whether or not to make a fit change?

How do you decide whether to wait or refit now?

What fit change is indicated?

Any other tests you would perform to rule out that the topographer was fooled and this really isn't a central island.

Topography After Refit