Purpose: To explore the use of adult human photoreceptor transplantation as a treatment for advanced retinitis pigmentosa (RP).
Design: Prospective noncomparative case series.
Participants: Eight patients with advanced RP.
Intervention: Transplantation of adult human cadaver photoreceptor sheets harvested with the excimer laser. No immunosuppression was used postoperatively. Patients were followed for 12 months postoperatively.
Main outcome measure: Visual acuity and retinal function measured by psychophysical, electrophysiologic, and clinical testing.
Results: Best-corrected visual acuity (Bailey-Lovie chart), median reading speed, contrast sensitivity, and visual fields for the operated eye were not statistically significantly improved postoperatively. The amplitude and latency of the maculoscope electroretinogram, as well as the log threshold for dark adaptation, did not change between the operated and control (unoperated) eye. There was no detectable homograft reaction on slit-lamp biomicroscopy or fluorescein angiography. The only adverse effect observed was one patient who complained of monocular diplopia after retinal transplantation and subsequent cataract surgery.
Conclusions: Allogeneic adult human photoreceptor transplantation is feasible in RP but was not associated with rescue of central vision or a delay in visual loss. However, any possible slowing in the rate of retinal degeneration will take many years to determine.