The genetics of a rare form of glaucoma that affects younger men

Research details

  • Type of funding: PhD Studentship
  • Grant Holder: Professor Chris Hammond
  • Institute: Kings College London
  • Region: London
  • Start date: October 2016
  • End Date: September 2019
  • Priority: Causes
  • Eye Category: Glaucoma

Overview

Pigmentary glaucoma is a rare form of the condition in which the optic nerve is damaged by high pressure in the eye that’s due to scattered pigment from the coloured part of the eye (the iris). The scattered pigment ends up blocking the eye so that fluid can’t flow out (which usually happens at the same rate that fluid is produced so that the eye stays at a constant pressure and the eyeball holds its shape.)

There are no symptoms in the first stages and patients are much younger than in other types of glaucoma so it’s often diagnosed only after permanent damage to the optic nerve has been done.

We yet don’t know what caused pigmentary glaucoma but it runs in families so genes are likely to be important. So in this study the student and team are looking for any genetic variations in people’s DNA that are linked to pigmentary glaucoma and whether there are any genetic links to other common eye conditions. They will also try to establish what any genetic changes they find actually do. In the shorter term results from the study could lead to earlier diagnosis, before sight loss happens. And in the longer term it could lead to developing treatment that can prevent permanent damage to vision.
  • Scientific summary

    Identification of the genetic causes of pigmentary glaucoma

    Pigmentary Glaucoma (PG) is a blinding disease that arises as a result of elevated intraocular pressure due to Pigment Dispersion Syndrome, with iris pigment obstructing aqueous outflow. Although a relatively infrequent form of glaucoma, it is disproportionally important because of its early onset. Knowledge about PG is scant and mainly consists of a number of risk factors, all of which point to a largely genetic aetiology. Working under the rationale that finding genes altering susceptibility to a disease can inform about disease pathophysiology, this project seeks to identify genetic factors contributing to PG, to uncover genes participating in mechanisms that concomitantly lead to PG and other ocular conditions (e.g. myopia) as well as characterise the molecular mechanisms by which they do so. It will take advantage of a discovery cohort of at least 375 well-characterised PG patients as well as subsequent replication cohorts. It will try to establish the common genetic basis between PG and other eye traits (pigmentation, refraction, IOP and others) and will take advantage of a large dataset of -omics measurements to explore the potential functional links that the associated variants will have with changes in gene transcription, methylation and eventual interaction with the metabolic environment.