title: The influence of brightness on functional assessment by mferg: a study on scaffolds used in retinal cell transplantation in pigs.
abstract: To determine the effect of membrane brightness on multifocal electroretinograms (mfERGs), we implanted poly lactic-co-glycolic acid (PLGA) membranes in the subretinal space of 11 porcine eyes. We compared membranes with their native shiny white color with membranes that were stained with a blue dye (Brilliant Blue). Histological and electrophysiological evaluation of the overlying retina was carried out 6 weeks after implantation. Histologically, both white and blue membranes degraded in a spongiform manner leaving a disrupted outer retina with no preserved photoreceptor segments. Multifocal ERG revealed the white membranes to have a significantly higher P1-amplitude ratio than the blue (P = 0.027), and a correlation between brightness ratio and P1-amplitude ratio was found (r = 0.762). Based on our findings, we conclude that bright subretinal objects can produce normal mfERG amplitude ratios even when the adjacent photoreceptors are missing. Functional assessment with mfERG in scaffold implant studies should therefore be evaluated with care.
authors.affiliation: Department of Ophthalmology, Glostrup Hospital, Copenhagen University Hospital, Nordre Ringvej 57, 2600 Glostrup, Denmark.
authors.forename: A T
authors.initials: AT
authors.lastname: Christiansen
authors.forename: J F
authors.initials: JF
authors.lastname: Kiilgaard
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: R
authors.initials: R
authors.lastname: Ejstrup
authors.forename: G E
authors.initials: GE
authors.lastname: Wnek
authors.forename: J U
authors.initials: JU
authors.lastname: Prause
authors.forename: M J
authors.initials: MJ
authors.lastname: Young
authors.forename: H
authors.initials: H
authors.lastname: Klassen
authors.forename: H
authors.initials: H
authors.lastname: Kaplan
authors.forename: M
authors.initials: M
authors.lastname: La Cour