This is the first problem to consider as it represents a causative factor for the other two problems.

• Causes:
  • • Thick lens design
    • High edge clearance
    • Low corneal apex
    • High corneal astigmatism
• Management:¹
  • • Reduce the center thickness of the lens (i.e., ultrathin design)
    • Make sure to have proper edge design (- lenticular for all plus and ≤ – 1.50D powers; + lenticular for ≥ -5.00D)
    • Design a bitoric GP for ≥ 2.50D corneal astigmatism
    • Strive for lid attachment with a low-medium edge clearance design

(3 & 9 o’clock staining)

Corneal desiccation or drying/desiccation of the exposed peripheral 3 & 9 o’clock areas of the cornea (Figure 1) has several causes but the incidence is much less today due to the management options listed below.²

• Causes:
  • • Inferior decentration of the lens resulting from the causes listed under #1.
    • Poor surface wettability of the lens/ocular surface disease
•  Management:
  • • Optimize centration through aforementioned methods (i.e., reduce center thickness, lenticular if applicable, reduce edge clearance, bitoric if high corneal astigmatism)
    • Reorder with Tangible Hydra-PEG coating
    • Manage ocular surface disease if present

This can be both initial and acquired.

• Initial poor surface wettability.
  • • Causes:
      • • Residual laboratory polish on lens
        • Other residues from manufacturing process
    • Management:
      • • Use of laboratory/extra-strength cleaner (assuming coatings not present)
• Acquired poor surface wettability:
  • • Causes:
      • • Poor compliance with daily care and cleaning
        • Ocular surface disease
        • Use of lanolin-containing hand creams and/or soft soaps prior to handling the lenses
    • Management:
      • • Patient education: importance of cleaning in the palm of the hand upon removal every night and soaking in the recommended solution. Also, not to use a lanolin-containing soap or lotion prior to handling lenses
        • Recommend a hydrogen peroxide disinfection system
        • Reorder lenses with coatings and prescribe boost solutions for monthly refreshing of the lens coating.