title: Influence of cataract surgery on optical coherence tomography and neurophysiology measurements in patients with retinitis pigmentosa.
abstract: OBJECTIVE
  To evaluate the effect of uncomplicated cataract phacoemulsification on the measurements of visual evoked potentials (VEP), pattern electroretinogram (PERG), and macular and retinal nerve fiber layer (RNFL) using 2 spectral-domain optical coherence tomography (OCT) instruments, the Cirrus OCT (Carl Zeiss Meditech) and Spectralis OCT (Heidelberg Engineering), in patients with retinitis pigmentosa (RP), and to assess the reliability of the OCT measurements before and after cataract surgery.
  
  
  METHODS
  Observational cross-sectional study.
  
  
  METHODS
  Thirty-five eyes of 35 patients with RP (20 men and 15 women, 45-66 years) who underwent cataract phacoemulsification were studied. At 1 month before and 1 month after surgery, visual acuity, VEP, PERG, and 3 repetitions of scans using the RNFL and macular analysis protocols of the Cirrus and Spectralis OCT instruments were performed. The differences in measurements between the 2 visits were analyzed. Repeatability of OCT measurements was evaluated by calculating the coefficients of variation.
  
  
  RESULTS
  VEP amplitude, RNFL thicknesses provided by Cirrus and Spectralis, and macular measurements provided by Cirrus OCT differed between the 2 visits. VEP latency, PERG measurements, and macular thicknesses provided by the Spectralis OCT before surgery did not differ significantly from those after surgery. The OCT repeatability was better after surgery, with lower coefficients of variation for scans performed after surgical removal of the cataract. The nuclear, cortical, and posterior subcapsular types of cataracts did not show different repeatability.
  
  
  CONCLUSIONS
  The presence of cataracts affects VEP amplitude, RNFL, and macular measurements performed with OCT in eyes with RP. Image repeatability significantly improves after cataract phacoemulsification.
authors.affiliation: Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain. egmvivax@yahoo.com
authors.forename: Elena
authors.initials: E
authors.lastname: Garcia-Martin
authors.forename: Diego
authors.initials: D
authors.lastname: Rodriguez-Mena
authors.forename: Isabel
authors.initials: I
authors.lastname: Dolz
authors.forename: Carmen
authors.initials: C
authors.lastname: Almarcegui
authors.forename: Laura
authors.initials: L
authors.lastname: Gil-Arribas
authors.forename: Maria P
authors.initials: MP
authors.lastname: Bambo
authors.forename: Jose M
authors.initials: JM
authors.lastname: Larrosa
authors.forename: Vicente
authors.initials: V
authors.lastname: Polo
authors.forename: Luis E
authors.initials: LE
authors.lastname: Pablo
mesh_terms: D000368:Aged; D002386:Cataract / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009482:Neurophysiology; D018918:Phacoemulsification; D011446:Prospective Studies; D012160:Retina / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology