title: The effect of two novel lubricant eye drops on tear film lipid layer thickness in subjects with dry eye symptoms.
abstract: OBJECTIVE
  Because the lipid layer of the tear film is recognized as a critical component in dry eye disease, this study was designed to determine if a single eye drop of either Soothe or Systane produces a significant increase in lipid layer thickness (LLT) for subjects reporting symptoms indicative of dry eyes.
  
  
  METHODS
  A double-blind, internally paired study was performed. A custom-built lipid layer interferometer, enabling characterization of lipid layer interference patterns, was used to quantify baseline LLT (OU) of eligible subjects. Inclusion criteria included: 1) presence of dry eye symptoms and 2) baseline LLT < or =75 nm. Subjects (n = 40) received a single eye drop of Soothe in one eye and a single eye drop of Systane in the contralateral eye. After the instillation of each test drop, LLT was reanalyzed for all subjects.
  
  
  RESULTS
  The mean +/- standard error baseline LLT pre-eye drop instillation was 60.0 +/- 1.8 nm for eyes treated with Soothe and 61.5 +/- 1.8 nm for eyes treated with Systane. These means were not significantly different (p > 0.5). The mean LLT for eyes treated with Soothe increased to 124.4 +/- 4.9 nm (p < 0.0001). The mean LLT for eyes treated with Systane increased to 71.3 +/- 2.6 nm (p < 0.0001). The LLT increase from Soothe was significantly greater than that from Systane (p < 0.0001).
  
  
  CONCLUSIONS
  In subjects with symptoms indicative of dry eye states and LLT < or =75 nm, one eye drop of Soothe more than doubled LLT, a 107% mean increase, whereas Systane increased LLT by 16%.
authors.affiliation: Korb Associates, Boston, MA 02116, USA. drkorb@aol.com
authors.forename: Donald R
authors.initials: DR
authors.lastname: Korb
authors.forename: Robert C
authors.initials: RC
authors.lastname: Scaffidi
authors.forename: Jack V
authors.initials: JV
authors.lastname: Greiner
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Kenyon
authors.forename: John P
authors.initials: JP
authors.lastname: Herman
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Blackie
authors.forename: Thomas
authors.initials: T
authors.lastname: Glonek
authors.forename: Courtney L
authors.initials: CL
authors.lastname: Case
authors.forename: Victor M
authors.initials: VM
authors.lastname: Finnemore
authors.forename: Teresa
authors.initials: T
authors.lastname: Douglass
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D015352:Dry Eye Syndromes / Q000188:drug therapy / Q000378:metabolism*; D004643:Emollients / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007368:Interferometry; D050356:Lipid Metabolism; D008153:Lubrication; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D013666:Tears / Q000378:metabolism*; D017155:Wettability
chemical_list: D004643:Emollients; D009883:Ophthalmic Solutions