title: The effect of phacoemulsification cataract surgery on polarimetry and tomography measurements for glaucoma diagnosis.
abstract: OBJECTIVE
  To assess whether optical coherence tomography (OCT)Stratus 3000, confocal laser scanning ophthalmoscopy (HRT3), and scanning laser polarimetry (GDx-VCC) results show parameter differences between presurgery and postsurgery in patients with cataracts and suspected glaucoma.
  
  
  METHODS
  Glaucoma Service in the Department of Ophthalmology at the Miguel Servet University Hospital, Zaragoza, Spain.
  
  
  METHODS
  Forty-six eyes of 46 patients were enrolled in this cross-sectional study and examined with OCT, HRT3, and GDx-VCC before and after phacoemulsification. Differences between presurgery and postoperative measurements were calculated using nonparametric test.
  
  
  RESULTS
  The most significant difference between the study groups was in the OCT image quality; the signal-to-noise ratio improved from presurgery to postsurgery. All of the statistically significant sectors reflected measurements in the nasal region and the maximum superior and average nasal retinal nerve fiber layer (thickness (Smax/Navg). Almost all parameters of the HRT area remained unchanged after the surgery, but important differences were observed in cup depth, volume parameters, and image quality. The Glaucoma Progression Score feature may not be helpful in the presence of lens opacity. Temporal incision during the surgery affected most of the nasal GDx-VCC parameters and the image quality.
  
  
  CONCLUSIONS
  OCT image quality was reduced preoperatively in the eyes with cataracts and retinal nerve fiber layer thickness in the nasal sectors was increased in these eyes postoperatively. Cup depth, volume parameters, Glaucoma Progression Score, and the image quality of HRT measurements were all influenced by cataract removal. In our study temporal incision during surgery affected the nasal parameters in GDx-VCC. Our results suggest that the examiner should consider obtaining a new baseline measurement after cataract surgery.
authors.affiliation: Applied Physics, Faculty of Science, University of Zaragoza, Zaragoza, Spain. anaisa@unizar.es
authors.forename: Ana
authors.initials: A
authors.lastname: Sánchez-Cano
authors.forename: Luis E
authors.initials: LE
authors.lastname: Pablo
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Larrosa
authors.forename: Vicente
authors.initials: V
authors.lastname: Polo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000473:pathology*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D019654:Lens Implantation, Intraocular; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D018918:Phacoemulsification; D012165:Retinal Ganglion Cells / Q000473:pathology; D057109:Scanning Laser Polarimetry; D041623:Tomography, Optical Coherence