title: Comparison of the optical image quality in the periphery of phakic and pseudophakic eyes.
abstract: OBJECTIVE
  The natural lens may provide some compensatory optical effect in the periphery. When it is substituted by an IOL during cataract surgery, the quality of the peripheral optics will be modified. We compared the peripheral image quality in the eyes of patients with one eye implanted with a monofocal IOL and the fellow eye still with the natural precataract lens.
  
  
  METHODS
  We used a scanning peripheral Hartmann-Shack wavefront sensor to measure the central 80° of visual angle along the horizontal meridian. Twelve patients with ages ranging between 65 to 81 years were evaluated. The results of the phakic and pseudophakic eyes were compared using the spherical equivalent, astigmatism, higher order aberrations, and the Strehl ratio. The statistical differences at each angle between the two eyes were evaluated.
  
  
  RESULTS
  In the eyes implanted with IOLs, the peripheral mean spherical equivalent was slightly more myopic than in the phakic eyes, although the differences were only significant for some angles. Astigmatism increased much faster in the periphery for the pseudophakic eyes as compared with the phakic eyes. The mean values were significantly different from 9° and 17° outwards at the temporal and nasal retina, respectively. As an example, at 30°, eyes implanted with IOLs presented 1.5 diopters (D) of additional astigmatism. The higher order aberrations were not significantly different between the two groups.
  
  
  CONCLUSIONS
  Eyes implanted with monofocal IOLs present more astigmatism in the periphery than the healthy older eyes. This suggests that the crystalline lens provides a beneficial effect to partially compensate off-axis astigmatism. The degradation of the peripheral retinal image may reduce the pseudophakic patient's performance in common visual tasks.
authors: Laboratorio de Óptica, Instituto Universitario de investigación en Óptica y Nanofísica (IUiOyN), Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain.
authors: Bart
authors: B
authors: Jaeken
authors: Sandra
authors: S
authors: Mirabet
authors: José María
authors: JM
authors: Marín
authors: Pablo
authors: P
authors: Artal
mesh_terms: D000368:Aged; D001251:Astigmatism / Q000503:physiopathology*; D002387:Cataract Extraction; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D054120:Phakic Intraocular Lenses / Q000009:adverse effects; D011474:Prosthesis Design; D019591:Pseudophakia / Q000503:physiopathology*; D012030:Refractive Errors / Q000503:physiopathology*; D014785:Vision, Ocular / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology
keywords: aberrations; intraocular lenses; peripheral optics; refractive errors