Optical modulation of transgene expression in retinal pigment epithelium

D. Palanker, D. Lavinsky, T. Chalberg, Y. Mandel, P. Huie, R. Dalal, M. Marmor

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Over a million people in US alone are visually impaired due to the neovascular form of age-related macular degeneration (AMD). The current treatment is monthly intravitreal injections of a protein which inhibits Vascular Endothelial Growth Factor, thereby slowing progression of the disease. The immense financial and logistical burden of millions of intravitreal injections signifies an urgent need to develop more long-lasting and cost-effective treatments for this and other retinal diseases. Viral transfection of ocular cells allows creation of a "biofactory" that secretes therapeutic proteins. This technique has been proven successful in non-human primates, and is now being evaluated in clinical trials for wet AMD. However, there is a critical need to down-regulate gene expression in the case of total resolution of retinal condition, or if patient has adverse reaction to the trans-gene products. The site for genetic therapy of AMD and many other retinal diseases is the retinal pigment epithelium (RPE). We developed and tested in pigmented rabbits, an optical method to down-regulate transgene expression in RPE following vector delivery, without retinal damage. Microsecond exposures produced by a rapidly scanning laser vaporize melanosomes and destroy a predetermined fraction of the RPE cells selectively. RPE continuity is restored within days by migration and proliferation of adjacent RPE, but since the transgene is not integrated into the nucleus it is not replicated. Thus, the decrease in transgene expression can be precisely determined by the laser pattern density and further reduced by repeated treatment without affecting retinal structure and function.

Original languageEnglish
Title of host publicationOphthalmic Technologies XXIII
StatePublished - 2013
Externally publishedYes
Event23rd Conference on Ophthalmic Technologies - San Francisco, CA, United States
Duration: 2 Feb 20133 Feb 2013

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


Conference23rd Conference on Ophthalmic Technologies
Country/TerritoryUnited States
CitySan Francisco, CA


  • age related macular degeneration
  • gene therapy
  • retinal pigment epithelium
  • selective laser therapy
  • vascular endothelial growth factor


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