title: Anterior segment changes during accommodation in eyes with a monofocal intraocular lens: high-frequency ultrasound study.
abstract: OBJECTIVE
  To analyze anterior segment structure changes during accommodative stimuli after monofocal intraocular lens (IOL) implantation using 2 ultrasound biomicroscopy (UBM) systems.
  
  
  METHODS
  Department of Ophthalmology, University of Verona, Verona, Italy.
  
  
  METHODS
  Twenty-six eyes (23 patients) with 1 of 4 monofocal IOL types were studied. Five to 9 months postoperatively, the patients were examined by high-frequency UBM using the HiScan system (Optikon 2000 SpA) and UBM 840 system (Carl Zeiss Meditec). Anterior chamber depth (ACD), iris-zonule distance, anterior chamber angle (ACA), scleral-ciliary process angle, and iris-ciliary process angle were measured using both systems. The iris-ciliary process distance and scleral spur perpendicular-sulcus distance were measured with the UBM 840 system and the sulcus-sulcus distance and capsular bag-IOL position with respect to ciliary process apex, with the HiScan system. Two experienced examiners performed all measurements.
  
  
  RESULTS
  All parameters except the horizontal iris-ciliary process distance and vertical ACA measured by the UBM 840 system and horizontal ACA by the HiScan system showed significant variation during accommodation. An anterior shift of the IOL-capsular bag ciliary processes--sulcus-zonular iris complex was observed. A simultaneous centripetal shift of ciliary bodies and processes, shown by a reduction in sulcus and capsular bag diameter, was also observed.
  
  
  CONCLUSIONS
  Anterior segment structures demonstrated accommodative movement on UBM after implantation of standard monofocal IOLs.
authors.affiliation: Eye Clinic, Department of Neurological and Visual Science, University of Verona, Verona, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Marchini
authors.forename: Emilio
authors.initials: E
authors.lastname: Pedrotti
authors.forename: Marina
authors.initials: M
authors.lastname: Modesti
authors.forename: Silvia
authors.initials: S
authors.lastname: Visentin
authors.forename: Roberto
authors.initials: R
authors.lastname: Tosi
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D033401:Microscopy, Acoustic; D018918:Phacoemulsification; D011305:Presbyopia / Q000503:physiopathology*; D011474:Prosthesis Design; D019591:Pseudophakia / Q000000981:diagnostic imaging / Q000503:physiopathology*