title: Accommodative changes produced in response to overnight orthokeratology.
abstract: BACKGROUND
  To evaluate short-term (3 months) and long-term (3 years) accommodative changes produced by overnight orthokeratology (OK).
  
  
  METHODS
  A prospective, longitudinal study on young adult subjects with low to moderate myopia was carried out. A total of 93 patients took part in the study. Out of these, 72 were enrolled into the short-term follow-up: 21 were on a control group, 26 on a Paragon CRT contact lenses group, and 25 on a Seefree contact lenses group. The other 21 patients were old CRT wearers on long-term follow-up. Accommodative function was assessed by means of negative and positive relative accommodation (NRA / PRA), monocular accommodative amplitude (MAA), accommodative lag, and monocular accommodative facility (MAF). These values were compared among the three short-term groups at the follow-up visit. The long- and short-term follow-up data was compared among the CRT groups.
  
  
  RESULTS
  Subjective accommodative results did not suffer any statistically significant changes in any of the accommodative tests for any of the short-term groups when compared to baseline. There were no statistically significant differences between the three short-term groups at the follow-up visit. When comparing the short- and long-term groups, only the NRA showed a significant difference (p = 0.0006) among all the accommodation tests.
  
  
  CONCLUSIONS
  OK does not induce changes in the ocular accommodative function for either short-term or long-term periods.
authors.affiliation: Department of Optics II (Optometry & Vision) Faculty of Optics & Optometry, Complutense University of Madrid, Madrid, Spain, gemafelipe@gmail.com.
authors.forename: Gema
authors.initials: G
authors.lastname: Felipe-Marquez
authors.forename: María
authors.initials: M
authors.lastname: Nombela-Palomo
authors.forename: Isabel
authors.initials: I
authors.lastname: Cacho
authors.forename: Amelia
authors.initials: A
authors.lastname: Nieto-Bona
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D003261:Contact Lenses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D054158:Orthokeratologic Procedures; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult