The TEK Gene: Responsible for Primary Congenital Glaucoma?

Researchers have identified a new genetic cause for childhood glaucoma. Primary congenital glaucoma is a severe form of glaucoma and a significant cause of childhood blindness. It currently has no cure, tends to occur in both eyes and is observed across Western and Asian countries alike.

Primary congenital glaucoma exhibits elevated intraocular pressure, enlarged eye globes, oedema, corneal opacification, photophobia, excessive tearing and optic neuropathy.

In a healthy eye, a water-like fluid called aqueous humour is produced and fills the anterior part of the eye. It is then drained into a small blood vessel called Schlemm’s canal. Schlemm’s canal thus controls the pressure within the eye. Defects or absence of Schlemm’s canal leads to increased intraocular pressure, which leads to glaucoma and subsequent vision loss.

Recently, a US study has identified a gene called TEK or Tie2, such that its mutations could cause primary congenital glaucoma. In 10 of 189 unrelated families with children who suffer from primary congenital glaucoma, TEK mutations were identified as the main cause. This finding validates similar findings in mice published in 2014. Deletion of TEK in very young mice results in developmental loss of Schlemm’s canal, extremely raised intraocular pressure, rapid and complete loss of retinal ganglion cells and glaucoma. Thus, TEK plays a critical role in the development and formation of Schlemm’s canal in mice. It was an exciting ‘eureka’ moment for the researchers to discover the similarities in the role TEK play between humans and mice.

A new therapeutic target?

With scientists now knowing the signalling pathways of TEK, this could offer a new therapeutic target for severe glaucoma and other forms of glaucoma. Scientists are aiming to develop eye drops, which could potentially fix the faulty blood vessel by repairing the TEK pathway.

The full research article is available at https://www.jci.org/articles/view/85830