title: Short-term clinical comparison of two dual-disinfection multipurpose disinfecting solutions.
abstract: OBJECTIVE
  To compare the short-term clinical performance of two dual-disinfectant multipurpose disinfecting solutions (MPDS) when used in conjunction with two silicone hydrogel contact lenses.
  
  
  METHODS
  Participants wore galyfilcon A and balafilcon A lenses, randomly allocated one type to each eye. Multipurpose disinfecting solutions were double-masked and allocated using a randomized crossover design. Lenses were presoaked overnight in the allocated MPDS, containing either polyquaternium-1/alexidine dihydrochloride (PQ-alexidine) or polyquaternium-1/myristamidopropyl dimethylamine (PQ-MAPDA). Lenses were worn daily for 4 days and disinfected with the same MPDS in which they had been soaked. Clinical assessments occurred immediately after insertion, 2 hours after insertion, and after 2 hours of wear on day 4. Subjective ratings were collected at each assessment and after 6 hours of wear on days 1 to 3. Linear mixed models were used for statistical analysis.
  
  
  RESULTS
  Solution-induced corneal staining (SICS) incidence was significantly different between MPDS lens combinations (P=0.01) with PQ-MAPDA-balafilcon A showing the highest incidence (27.8%). The incidence of SICS was significantly higher when balafilcon A lenses were worn compared with galyfilcon A (19.4% vs. 2.8%; P=0.04). There was no significant difference in SICS incidence between MPDS (PQ-alexidine=5.6%, PQ-MAPDA=16.7%; P=0.08). Polyquaternium-1/alexidine dihydrochloride was associated with significantly fewer symptoms of burning/stinging (9.7±0.6 vs. 9.1±2.2; P=0.03) and self-assessed redness (9.8±0.5 vs. 9.2±1.9; P=0.03) on initial lens insertion. There were no significant differences between MPDS for comfort ratings (P>0.05).
  
  
  CONCLUSIONS
  These short-term clinical results provide an initial indication that PQ-alexidine is associated with fewer symptoms on insertion but no significant difference in ocular comfort compared with PQ-MAPDA. Longer studies are required to provide further evidence.
authors.affiliation: Brien Holden Vision Institute (D.T., P.L.d.l.J., R.W., T.N.), Sydney, New South Wales, Australia; and School of Optometry and Vision Science (P.L.d.l.J., M.D.P.W.), University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tilia
authors.forename: Percy
authors.initials: P
authors.lastname: Lazon de la Jara
authors.forename: Rebecca
authors.initials: R
authors.lastname: Weng
authors.forename: Thomas
authors.initials: T
authors.lastname: Naduvilath
authors.forename: Mark D P
authors.initials: MD
authors.lastname: Willcox
mesh_terms: D000293:Adolescent; D000328:Adult; D001645:Biguanides / Q000009:adverse effects*; D018639:Contact Lens Solutions / Q000009:adverse effects*; D003263:Contact Lenses, Hydrophilic; D003316:Corneal Diseases / Q000139:chemically induced*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D020100:Hydrogels; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011437:Propylamines / Q000009:adverse effects*; D011446:Prospective Studies; D017155:Wettability; D055815:Young Adult
chemical_list: D001645:Biguanides; D018639:Contact Lens Solutions; D020100:Hydrogels; D011437:Propylamines; C001570:alexidine; C401661:myristamidopropyl dimethylamine