GP Lens Management Guide – 9

General Problem-Solving

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Flexure

Symptoms

  • Vision varies with blink or poor initial vision

Causes

  • High astigmatism
  • Steep BCR
  • Thin design
  • Large OZD

Diagnosis

  • Toricity with over-keratometry but spherical on radiuscope

Management

  • Flatter BCR
  • Increase CT
  • Reduce OZD
  • Switch to lower Dk material

Decentration


Inferior Decentration

Superior Decentration


Lateral Decentration

Symptoms

  • Vision varies with blink
  • Lens awareness

Causes

  • Decentered corneal apex or ATR astigmatism
  • Tight or loose lid tension
  • Thick lens design
  • High specific gravity material
  • Unusual corneal topography. (Beware of superior flattening and inferior steepening shown in topography for long-term wear of superior positioning GP.)

Diagnosis

  • Biomicroscopic evaluation during and after blink: see excessive movement with blink or simply stays in a decentered position. Patient views through non-optical periphery of lens, often intermittently.

Management

Inferior Decentration

  • (+) lenticulate if power >-5.00
  • (-) lenticulate if power <-1.50
  • (-) lenticulate all + lens
  • Bitoric for >2.50 cylinder
  • Lid attachment design
  • Flatter BCR
  • Minimize CT
  • Lower specific gravity material

Superior Decentration

  • Plus lenticular
  • Increase CT
  • Steepen BCR

Lateral Decentration

  • Larger overall diameter
  • Steeper BCR
  • Aspheric design

Corneal Dessication 3 & 9 Staining


Symptoms

  • Lens awareness
  • Occurs in more than 50% of rigid lens wearers

Causes

  • Dryness
  • Lid margin disease (meibomianitis) and blepharitis can compromise tear film

Diagnosis

  • Phenol Red Thread
  • 3 and 9 o’clock punctate staining
  • Severity range from diffuse punctate staining to corneal opacification and neovascularization

Management

  • If staining coalesced, improve centration
  • Decrease edge lift (consider aspheric design or steepen PCR & PCW)
  • Change to F-S/A material
  • Ensure proper blinking & frequency
  • Frequent use of rewetting drops
  • Lid hygiene
  • Hot compresses with gentle lid massage for meibomian gland dysfunction
  • Humidifier

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