title: Postoperative intraocular lens rotation: a randomized comparison of plate and loop haptic implants.
abstract: OBJECTIVE
  To compare the postoperative rotation of plate and loop haptic implants of spherical power to ascertain the optimal design appropriate for toric intraocular lenses (IOLs).
  
  
  METHODS
  Randomized, controlled trial.
  
  
  METHODS
  Forty-eight patients attending for routine cataract surgery by phacoemulsification.
  
  
  METHODS
  Patients with cataract as the only ocular disease were randomly implanted with plate or loop haptic implants after uncomplicated phacoemulsification. The baseline position of the IOL was determined from a video frame acquired at the conclusion of surgery. Postoperative IOL position was documented using digital retroillumination images at 2 weeks and 6 months after surgery. Capsular fusion patterns were recorded using slit-lamp biomicroscopy. Correlation of IOL rotation with axial length, capsular contraction, and fusion was attempted.
  
  
  METHODS
  Early IOL rotation, occurring between surgery and 2 weeks after surgery, was graded as mild (<10 degrees), moderate (10 degrees < to <30 degrees), or severe (>30 degrees) by a semiobjective online comparison of the images. Late IOL rotation, occurring between 2 weeks and 6 months, was measured more precisely using software developed specifically for the study.
  
  
  RESULTS
  Twenty-three patients were allocated the loop haptic and 25 the plate haptic IOL. The groups were comparable for demographic variables and numbers of patients excluded from analysis (P > 0.05). Five (24%) of 21 of plate haptic IOLs underwent severe early rotation compared to 2 (9%) of 22 loop haptics (P = 0.36). The median late rotation was 6.8 degrees for loop haptics compared to 0.6 degrees for plate haptics (P = 0.0073). Between 2 weeks and 6 months, anticlockwise rotation had occurred in 16 (89%) of 18 loop haptic IOLs compared to 11 (52%) of 21 plate haptic IOLs (P = 0.0081).
  
  
  CONCLUSIONS
  Plate haptic IOLs show greater rotational stability than do loop haptics made from polypropylene once capsular fusion has taken place. Loop haptics invariably rotate anticlockwise after 2 weeks.
authors.affiliation: Oxford Eye Hospital, Radcliffe Infirmary, England. ckpatel@ukgateway.net
authors.forename: C K
authors.initials: CK
authors.lastname: Patel
authors.forename: S
authors.initials: S
authors.lastname: Ormonde
authors.forename: P H
authors.initials: PH
authors.lastname: Rosen
authors.forename: A J
authors.initials: AJ
authors.lastname: Bron
mesh_terms: D019923:Capsulorhexis; D005548:Foreign-Body Migration / Q000209:etiology*; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D018918:Phacoemulsification; D011183:Postoperative Complications; D011446:Prospective Studies; D011474:Prosthesis Design; D012399:Rotation; D012826:Silicone Elastomers; D013997:Time Factors
chemical_list: D012826:Silicone Elastomers