CASE STUDY - Mr. Mike Ward

• 53-year-old male engineering professor
• CC: blurred VA, OS following LASIK
• Hx: HCL x 20 years "wears very well"; desired LASIK for increased sports activity/sailing
• LASIK, OS only; GP, OD

Pre-op refraction: OS: -9.25 +1.50 x 50° ≥ 20/32 Pre-op keratometry: OS: 44.62 / 45.25 (? Axis) Note: Records show stable Ks for > 10 years

• Pre-op VK suggestive of keratoconus
• Risks explained, including possible need for continued GP wear
• Patient decided that the risk was acceptable and would be satisfied if myopia could be decreased

Post-op patient c/o petaloid flower pattern in central vision, blur and multiple images, OS Post-op refraction: OS: -2.75 +1.50 x 80° ≥ 20/63 Post-op keratometry (Sim K): OS: 44.25 / 43.75 x 113°

Post-op SLE: only minimal haze, otherwise WNL Contact lens fitting, OS: dx. GP & MR o/CL ≥ 20/60 PH o/CL ≥ 20/40 DFE: irregular macula; referred

Retina evaluation: Noted self medicated niacin 1000mg/day, PO dx: niacin maculopathy Plan: d/c niacin, proceed with CL fitting

Contact lens fitting (2 months later): aspheric design 7.60/-1.00/9.2 140 AEL VA: 20/25; all day WT Patient continues to complain of deteriorating vision

Topographical Changes Pre-op: 44.62 / 45.25 Post-op: 44.25 / 43.75 113 2 months: 46.5 / 47.3 x 88° 12 months: 50.9 / 49.5 x 27° VK shows relatively steep central island

Discussion

• Pre-op suggestive of KC: topography, oblique cylinder axis, MR & K cyl. not equal
• Post-op: change in central K not equal to reduction in myopia
• Progressive visual loss and steepening K post-operatively
• Latrogenic keratectasia

 
RESEARCH STUDY - Mr. Mike Ward

Visual Rehabilitation with Contact Lenses after Laser in Situ Keratomileusis

• Retrospective chart review
• 35 eyes of 22 patients requiring visual rehabilitation following LASIK
• Four rigid contact lens designs were evaluated for appropriate contact lens to cornea relationship

Figure 1. Normal corneal topography. Circles represent 3, 5 and 7mm zones.		Figure 2. LASIK plus transverse keratotomy with sutures; raised arc in 5mm zone from 140° to 225°. Pt. # 8.
Figure 3. Eccentric LASIK ablation decentered toward 215° meridian with paracentral island. Pt. # 5.		Figure 4. Keratoconus evident following LASIK; the apex is displaced inferiorly toward 330° meridian with an arc-shaped depression in the zone from 80° to 180°. Pt. # 3.

Irregular Astigmatism Correction

• Irregular astigmatism cannot be adequately corrected with either spectacles or soft contact lenses
• GP lenses provide the best opportunity for visual rehabilitation in cases of irregular astigmatism

Contact Lens Radius to Keratometry Relationship

• The average CL radius was: 8.38mm (40.3D)
• Radius range: 9.12 to 7.58mm (37.0 to 44.5D)
• Mean K to radius relationship: negative 2.1D

Final GP Lens Designs Fitted After LASIK

• Aspherical with 0.17mm edge lift (17)
• Spherical myolenticular tricurve (11)
• Custom quadcurve (6)
• Aspherical with 0.14mm edge lift (1)

Base Curve to Cornea Relationship

GP Lens Diameter Range: 9.2 to 10.9mm Mean = 10.2mm Most frequently used (12/35); mode = 10.5

The rigid lens provides a smooth, regular anterior refractive surface for the eye, allowing tears to fill the space between the posterior lens surface and the anterior cornea.

Visual Acuity

• Mean postoperative unaided VA =
  20/100, range: 20/25 to 20/400
• Mean postoperative best spectacle-corrected VA =
  20/40, range: 20/20 to 20/100
• Mean postoperative best contact lens-corrected VA =
  20/20, range: 20/15 to 20/60

Visual Stability

• GP lenses are used to favorably mold (splint) the cornea. This will stabilize topography and vision, and decrease astigmatism.
• SCL lenses will not stabilize topography or vision.

 
 
1) Visual Rehabilitation with Contact Lenses Following LASIK. Ward, Michael A; J. Refractive Surgery, Vol.17(4): 433-440, July-August, 2001.
2) Contact Lens Management Following Corneal Refractive Surgery. Ward MA; Ophthalmol Clin N Am 16 (2003); 395-403

 
CASE STUDY - Dr. Loretta Szczotka

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