title: Objective measurement of intraocular lens movement and dioptric change with a focus shift accommodating intraocular lens.
abstract: OBJECTIVE
  To objectively measure the shift and refractive change of the 1CU accommodating intraocular lens (IOL) (HumanOptics) and compare them to that of a monofocal AcrySof MA30 IOL (Alcon Laboratories) in the fellow eye.
  
  
  METHODS
  Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom.
  
  
  METHODS
  Thirty patients who had bilateral cataract surgery 18 to 24 months previously with a 1CU IOL prospectively randomly allocated to 1 eye and an AcrySof MA30 monofocal IOL to the other eye were examined. Distance correction, near vision, reading fluency, near point, and defocus to minus spheres were measured. Intraocular lens shift to an accommodative stimulus following instillation of pilocarpine 4% was measured with the ACMaster. Refractive change between distance and near was measured with the Tracey wavefront analyzer.
  
  
  RESULTS
  Of the original 30 patients recruited, complete measurements could only be obtained for 20. There was no significant difference in near visual function with either IOL. A small anterior movement of the 1CU was seen with accommodation 0.010 mm +/- 0.028 (SD). After pilocarpine 4% instillation, a forward movement of 0.220 +/- 0.169 mm was seen with the 1CU compared to a backward movement of 0.028 +/- 0.095 with the MA30. There was no significant correlation between distance corrected near visual acuity and IOL movement. No change in spherical equivalent between distance and near was seen on wavefront analysis of either IOL.
  
  
  CONCLUSIONS
  Small forward movement of the 1CU IOL was seen with accommodation and increased following pilocarpine, compared to the posterior movement of the MA30 IOL. The amount of the IOL shift was not sufficient to provide useful near vision, but the difference suggests that the engineering concept behind the 1CU IOL is valid.
authors.affiliation: Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom. johancox@doctors.org.uk
authors.forename: Joanne
authors.initials: J
authors.lastname: Hancox
authors.forename: David
authors.initials: D
authors.lastname: Spalton
authors.forename: Catherine
authors.initials: C
authors.lastname: Heatley
authors.forename: Hari
authors.initials: H
authors.lastname: Jayaram
authors.forename: John
authors.initials: J
authors.lastname: Marshall
mesh_terms: D000065:Accommodation, Ocular / Q000187:drug effects / Q000502:physiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008875:Middle Aged; D008916:Miotics / Q000008:administration & dosage; D010862:Pilocarpine / Q000008:administration & dosage; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D008916:Miotics; D010862:Pilocarpine