A team of scientists has recently discovered a gene that can damage the cells of the eye by gradual degeneration of the retina, causing vision loss in middle age.
According to the researchers, chemical changes in the eye can lead to blindness in middle age.
Their findings help to understand a genetic condition that causes vision loss for one in 3,000 people in the UK.
The team looked at how changes in a gene – known as RPGR – can damage eye cells to cause a condition known as X-linked pigmentary retinitis – an inherited chronic ocular disease characterized by black pigmentation and gradual degeneration of the retina.
The condition is incurable and affects night vision and peripheral vision before gradually causing blindness in middle age.
The team at the University of Edinburgh took skin samples from two patients and transformed stem cells – which can become any cell type – into light-sensitive cells known as photoreceptors.
They compared these cells to healthy relatives of patients.
Photoreceptors – which deteriorate in patients with retinitis pigmentosa – differ in their fundamental structure compared to those of the family members.
Monitoring studies in mice identified key molecules that interact with RPGR to maintain the structure of the photoreceptors.
When RPGR is defective, the structure is compromised and the photoreceptors can not function properly, resulting in loss of vision.
Principal investigator Roly Megaw said that by promoting understanding of the RPGR gene and its effects on photoreceptor cells, they hope that these findings will bring them closer to developing a possible treatment for this devastating disease.
The research, which is being presented on Sept. 5 at the Edinburgh Eye Development and Degeneration conference in Edinburgh, appears in the journal Nature Communications.