title: Changes in ocular physiology, tear film characteristics, and symptomatology with 18 months silicone hydrogel contact lens wear.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the longitudinal changes in ocular physiology, tear film characteristics, and symptomatology experienced by neophyte silicone hydrogel (SiH) contact lens wearers in a daily-wear compared with a continuous-wear modality and with the different commercially available lenses over an 18-month period.
  
  
  METHODS
  Forty-five neophyte subjects were enrolled in the study and randomly assigned to wear one of two SiH materials: lotrafilcon A or balafilcon A lenses on either a daily- (LDW; BDW) or continuous-wear (LCW; BCW) basis. Additionally, a group of noncontact lens-wearing subjects (control group) was also recruited and followed over the same study period. Objective and subjective grading of ocular physiology were carried out together with tear meniscus height (TMH) and noninvasive tear breakup time (NITBUT). Subjects also subjectively rated symptoms and judgments with lens wear. After initial screening, subsequent measurements were taken after 1, 3, 6, 12, and 18 months.
  
  
  RESULTS
  Subjective and objective grading of ocular physiology revealed a small increase in bulbar, limbal, and palpebral hyperemia as well as corneal staining over time with both lens materials and regimes of wear (p < 0.05). No significant changes in NITBUT or TMH were found (p > 0.05). Subjective symptoms and judgment were not material- or modality-specific.
  
  
  CONCLUSIONS
  Daily and continuous wear of SiH contact lenses induced small but statistically significant changes in ocular physiology and symptomatology. Clinical measures of tear film characteristics were unaffected by lens wear. Both materials and regimes of wear showed similar clinical performance. Long-term SiH contact lens wear is shown to be a successful option for patients.
authors.affiliation: Neurosciences Research Institute, Aston University, Aston Triangle, Birmingham, UK. jsantodomingo@menicon-net.co.jp
authors.forename: Jacinto
authors.initials: J
authors.lastname: Santodomingo-Rubido
authors.forename: James S
authors.initials: JS
authors.lastname: Wolffsohn
authors.forename: Bernard
authors.initials: B
authors.lastname: Gilmartin
mesh_terms: D000293:Adolescent; D000328:Adult; D003262:Contact Lenses, Extended-Wear; D003315:Cornea / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020100:Hydrogels; D008297:Male; D009799:Ocular Physiological Phenomena; D011474:Prosthesis Design; D012016:Reference Values; D012828:Silicones; D013666:Tears / Q000378:metabolism*; D013997:Time Factors; D005466:Fluorocarbons
chemical_list: D020100:Hydrogels; D012828:Silicones; C481129:lotrafilcon A; D005466:Fluorocarbons