Corneal electroretinographic function rescued by normal retinal pigment epithelial grafts in retinal degenerative Royal College of Surgeons rats.
OBJECTIVE
This study was designed to examine whether retinal function can be rescued by allogeneic normal retinal pigment epithelial (RPE) grafts in Royal College of Surgeons (RCS) with retinal degeneration and, if so, whether this rescued function can be measured and followed by recording the corneal electroretinogram (ERG).


METHODS
RPE donors were RCS-Long Evans crossbred F1 rats with phenotypically normal retinas. Half an RPE sheet was implanted in the subretinal space of RCS rats at postnatal day 20. The fundi of the recipients' eyes were examined, and the corneal ERGs were recorded. The eyes were also examined histologically.


RESULTS
The RPE grafts were identified by fundus examination in all 21 recipients. No clinical or histologic evidence of inflammation was detected in the media or the retina of the host eye. Eighteen of 21 (86%) recipients showed rescued corneal ERG function. In nine recipients, the PIII response in the grafted eye was significantly greater than in the nongrafted eye. In the other nine recipients, the ERG in the grafted eye showed a b-wave and an a-wave, whereas no b-wave was detected in the nongrafted eye. Recipients of the sham operation (n = 13) revealed no ERG function rescue. To determine long-term corneal ERG function in RPE recipients, 8 of 18 animals in which ERG function was rescued were randomly selected for continued observation. These recipients sustained rescued ERG function for 16 to 17 weeks, at which time the experiment ended.


CONCLUSIONS
Results indicate that retinal function of degenerative RCS rats, as measured by corneal ERG, can be rescued by implantation of allogeneic normal RPE into the subretinal space of the eye. Furthermore, this rescued function can be followed up over a relatively long period of time, thus providing a useful model for studying the functional changes of RPE allografts resulting from either immunologic or neurobiologic influences.
Jiang
L Q
LQ
Schepens Eye Research Institute, Boston, MA 02114.
Hamasaki
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D000818:Animals; D003315:Cornea / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D008297:Male; D010857:Pigment Epithelium of Eye / Q000473:pathology / Q000502:physiology* / Q000637:transplantation*; D051381:Rats; D011922:Rats, Mutant Strains; D012160:Retina / Q000502:physiology; D012162:Retinal Degeneration / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D014184:Transplantation, Homologous