title: The effect of cataract surgery on blue-yellow and standard-pattern visual-evoked potentials.
abstract: OBJECTIVE
  Blue-yellow visual-evoked potentials (BY-VEPs) may be used for diagnostics of functional ganglion cell damage in glaucoma and other ocular diseases. In this study we investigated the impact of lenticular opacities on BY- and standard pattern reversal VEPs by examining patients before and after cataract surgery.
  
  
  METHODS
  Eighteen patients with moderate cataract were included in a prospective study. Transient on/off isoluminant blue-yellow 2° checks were used for short-wavelength stimulation (BY-VEP), transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs. VEPs were acquired before (24 ± 30 days) and after cataract surgery (14 ± 16 days). The contralateral eye was used as a control.
  
  
  RESULTS
  Amplitude and latency of M1 and M2 peaks did not change significantly from before to after surgery. The amplitude of the BY-VEPs did not change significantly after cataract surgery (pre-surgery, -7.42 ± 3.43 μV, post-surgery, -7.93 ± 3.65 μV, p = 0.42), yet the latency of the main negative peak showed a significant decrease (pre-surgery, 143.9 ± 12.9 ms, post-surgery, 133.2 ± 7.7 ms, p = 0.0006). The BCVA improvement was significant from before to after cataract surgery (pre-surgery, 0.344 ± 0.125 LogMAR, post-surgery, 0.224 ± 0.179 LogMAR, p = 0.013) yet not correlated to the absolute decrease in latency of the BY-VEP after surgery (r = 0.309, p = 0.22). No significant changes were found in the contralateral eye.
  
  
  CONCLUSIONS
  The BY-VEP is sensitive to lenticular opacities of the human lens, presumably due to the increased short-wavelength absorption in the aging eye. This fact should be considered when applying BY-VEPs for diagnostics.
authors.affiliation: Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany, mfuest@ukaachen.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Fuest
authors.forename: Niklas
authors.initials: N
authors.lastname: Plange
authors.forename: Sarah
authors.initials: S
authors.lastname: Jamali
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schwarzer
authors.forename: Gernot
authors.initials: G
authors.lastname: Roessler
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Babac
authors.initials: B
authors.lastname: Mazinani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000503:physiopathology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D010865:Pilot Projects; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D014795:Visual Pathways / Q000503:physiopathology