Factors Associated With Dropout From Silicone Hydrogel Contact Lens Daily Wear

Victoria E Evans, Nicole A Carnt, Thomas J Naduvilath, Brien A Holden

Introduction:

• Discomfort, dryness, redness, poor vision and shorter wear time are
  associated with drop out from low Dk soft lens daily wear (Pritchard et al
  1999, Young et al 2002)
  
• Refitting with silicone hydrogel lens can alleviate some of these problems
  (Riley et al 2006, Dumbleton et al 2006)
  
• However, drop out from silicone hydrogel lens wear still occurs so we
  investigated to see if the same factors were leading to discontinutation in
  silicone hydrogel lens daily wear (SiHy DW).

Purpose:

To examine factors related to discontinuation in SiHy DW to see if they
differed from those reported in the literature for low Dk lenses.


Methods:

• This was a retrospective, case-control analysis of five SiHy lenses and four
  lens care solutions
  
• 20 clinical trials were included in the analysis, one for each lens solution
  combination.
  
• Lenses/solutions were used for 3 months by approximately 40 participants
  per combination.
  
• Lenses: lotrafilcon A, lotrafilcon B, galyfilcon A, senofilcon A, balaficon A
  
• Solutions: ClearCare/AOSept Plus, AQuify MPS/Focus AQUA, Opti-Free
  Express, Opti-Free Replenish
  
• Participants who discontinued after baseline (DC) were compared to those
  who completed each trial (controls).
  
• Data from scheduled study visits and a 2 month telephone questionnaire
  were analysed using chi-square tests and linear mixed model analyses.

Results:

• 84.8% of participants who attended visits after baseline successfully
  completed the 3 month trial (Figure 1). The non-adverse event related
  discontinuation rate was 10.7% in the first three months.
  The additional 4.5% of participants who discontinued after an adverse event
  were excluded from the case control analysis.
• Reasons for non-adverse event related discontinuation are shown in Figure 2.
• Compared to those completing each trial, a greater proportion of DC
  participants were less than 20 years old (p=0.027), and were new to lens
  wear or SiHy lenses (p=0.001).
• There was no difference in gender, ethnicity, lubricating drop usage, no
  clinical difference in over-refraction sphere, uncorrected cylinder, visual acuity
  or slit lamp ocular physiology between the two groups.
• Subjective ratings and symptoms that were significantly different between the
  DC participants and controls are presented in Figures 3, 4, 5 and 6.