• 29-year-old white male with a history of high myopia and astigmatism corrected with corneal gas permeable (GP) lenses with a wearing time of 10 hours/day x one month. He has been wearing spectacles since age two and previously wore soft contact lenses starting at age 12.
• CC: distorted vision including ghosting, glare with headlights, and blurred vision for 10 years. Significant improvement in quality of vision with corneal GP lenses without complete resolution of ghosting.
• Secondary CC: discomfort and irritation with current GP lenses.
• MHx: anxiety, depression, headaches, seasonal allergies. He quit smoking five years ago. Daily use of a nicotine vape.
• Medications: aripiprazole, trazodone, sertraline, hydroxyzine to treat anxiety and depression, and ibuprofen and sumatriptan to treat migraines.

• Entering visual acuities (VAs) with habitual corneal GP lenses
  • • OD 20/30
    • OS 20/40
    • OU 20/30 NVA: OU 20/30
• Habitual corneal GP (keratoconic design) lens assessment OU:
  • • Over-refraction plano OD and OS
    • SLE: OD: Inferiorly decentered interpalpebral flat fit with central bearing, fluorescein pooling surrounding area of bearing, excessive mid-peripheral bearing, and adequate edge lift 360 (Figure 1a).
      OS: Inferiorly decentered inter-palpebral flat fit with a central band of bearing, fluorescein pooling greater above than below the area of bearing, excessive mid-peripheral bearing, and adequate edge lift 360 (Figure 1b).
      Excessively flat fit bearing on cone apex OU

• Refraction:

OD -8.25 -9.25 x 163, 20/40⁺
OS -7.25 -8.75 x 011, 20/30^–

• Slit Lamp Examination OU:

• Corneal Tomography OD, OS (Figure 2)

• Interpretation:
  • • Front surface axial map: inferior corneal steepening
    • Elevation greater on the posterior float compared to the anterior float corresponding with the area of steepening.
    • Pachymetry map: thin area of less than 500um corresponding to the inferior elevated area.
• Diagnosis:
  • • The patient was diagnosed with bilateral keratoconus more advanced OD than OS.
    • Treatment and Management: Patient referred for corneal collagen crosslinking to decrease progression of corneal thinning. Scleral lenses were advised for improved comfort, lower risk of corneal scarring, and better corneal stabilization.

• Scleral lens diagnostic fitting with toric peripheral curve
  • • Initial diagnostic lens selection:

• • • Diagnostic lens assessment:

• Ordered lens parameters: Peripheral corneal zone was steepened by 100um to increase central clearance by 100um. The over-refraction was vertexed and incorporated into the new power.
• Dispense visit:

The patient reported good comfort, excellent quality of vision, and no obvious ghosting or distortion.

• Complete a comprehensive evaluation for patients with unknown history. Early keratoconus diagnosis is crucial to allow for a prompt referral for crosslinking to slow progression of the disease.
• Don’t hesitate to attempt a new lens design when there is an issue with another design. This patient was re-fit from a corneal GP to a scleral design for increased stability and comfort.
• Initiating a lens fit prior to crosslinking may be needed to improve vision and, in this case, corneal health. The lens fit typically remains stable following crosslinking; however, educate the patient that modifications may be needed.