Glaucoma

Glaucoma is one of the leading causes of blindness world-wide. Although an increase in intraocular pressure is often associated with this disease, it is marked by the progressive death of retinal ganglion cells. Previous studies in Dr. Rob Nickells' laboratory and others have shown that ganglion cell death occurs by a mechanism that is characteristic of apoptosis - a form of programmed cell death that is regulated by a successive activation of genes from within the dying cell.

Hypothetically, neuronal cell death can be blocked or prevented by agents that interrupt key biochemical pathways that are controlled by these genes. This form of treatment, termed "neuroprotection" may provide important avenues of therapy for many neurodegenerative disorders which includes glaucoma.

Dr. Nickells' laboratory studies some of the earliest events that occur in retinal ganglion cells during the cell death process. For these studies they make use of mice lacing genes critical for the cell death process. Their current focus is on epigenetic changes that lead to silencing of normal gene expression well in advance of the committed step in the apoptotic pathway.

Dr. Michael Nork’s research focuses on the mechanisms by which various ocular diseases affect the outer retina (especially the rods and cones) and how injury to the outer retina might, in turn, affect disease pathogenesis.

For example, Dr. Nork and his colleagues have found selective blue cone loss in retinal detachment and diabetic retinopathy. They have also found evidence that the retinal cones may are injured in glaucoma--a disease that is not traditionally associated with the outer retina.

Working with other members of the Department, they have described morphologic changes in the photoreceptors in post-mortem human eyes that were donated by people who carried a diagnosis of glaucoma. Further confirmatory studies with animal models of glaucoma have shown anatomic, biochemical and functional effects on the cones. His lab is currently studying the role that photoreceptor injury may play in the pathogenesis of vision loss in glaucoma.