Vision researchers at Mass. Eye and Ear/Harvard Medical School (HMS) Department of Ophthalmology have taken a first step in solving a vexing problem: how to preserve photoreceptor cells and avoid irreversible vision loss in patients following retinal detachment.
Degeneration of photoreceptors, the major light-sensing cells in the eye, is a primary cause of vision loss worldwide. Identifying the underlying causes surrounding photoreceptor cell death is paramount in order to develop new treatment strategies to prevent their loss. Retinal detachment and subsequent degeneration of the retina can lead to progressive visual decline due to photoreceptor cell death. Since photoreceptors are non-dividing cells, their loss results in irreversible visual impairment even after successful retinal reattachment surgery.
New research led by Kip M. Connor and colleagues analyzed innate immune system regulators in the eyes of human patients with retinal detachment and correlated their findings in an experimental model. They discovered that there was a significant increase in the immune system’s “alternative complement pathway” following retinal detachment, and that this pathway facilitated early photoreceptor cell death after injury. Injured photoreceptors lose important proteins that normally protect them from complement-mediated cell death, allowing for selective targeting by the alternative complement pathway. Additionally, by blocking the alternative complement pathway, through both genetic and pharmacologic means, photoreceptors were protected from cell death.
Their findings were published on July 22 in the journal, Science Translational Medicine.