Background: Studies indicate that electrical stimulation of retinitis pigmentosa (RP) retina is beneficial. Quantum dots (QDs) can convert light to electrical stimulus and therefore may have therapeutic potential for RP. Methods: This was an open-label, fellow eye-controlled, first-in-human safety study. Five adults with end-stage (arm A) and 15 with severe (arm B) RP received one or two intravitreal injections of 0.2 or 2μM cadmium/selenium 655 Alt QDs. Results: No adverse events were attributed to QDs. In arm A, median best corrected visual acuity was unchanged. In arm B, mean best corrected visual acuity improved from 6/398 to 6/177, versus 6/147 to 6/144 in the fellow eye. Conclusion: Intravitreal QDs can be safely administered to patients with RP. Vision appears to benefit and further validating studies are justified.
Keywords: device; electrical stimulation; intravitreal injection; nanotechnology; quantum dots; retinitis pigmentosa.
Lay abstract This study investigated the use of quantum dots (QDs) to treat very advanced retinitis pigmentosa (RP), a disease characterized by progressive loss of peripheral and then central vision. QDs are sometimes called ‘artificial atoms’. If they are injected into the eye, they settle in the retina, the light-sensing layer of cells that is damaged by RP. When light enters the eye, it is absorbed by the QDs in the retina, and the light energy is converted to electrical energy. Electrical stimulation has been shown to benefit degenerating retina, as occurs in RP, and hence QDs may have the potential to improve or preserve vision in people with RP. This preliminary study recruited 20 people with very severe RP and injected QDs into their eyes. We aimed to see whether the QDs were safe. No adverse reactions were attributed to the QDs, and the average vision of treated eyes improved, whereas the participants’ untreated fellow eyes showed no real change in vision. Although encouraging, these results are only preliminary, and a larger study is planned to explore these findings.