Glaucoma refers to a group of conditions that usually cause pressure to build up inside the eye. This increase in pressure can damage the optic nerve and the photo-sensitive cells on the retina at the back of the eye. Damage to these structures causes impaired vision, which cannot be repaired or reversed and can ultimately lead to blindness if left untreated.
Opticians assess intra-ocular pressure as part of routine eye tests. The most common form of glaucoma – open angle glaucoma – generally occurs slowly over many years, with pressure gradually building, but there may be no detectable damage to vision at first. If regular eye tests are missed or badly performed, then glaucoma may not be diagnosed until perceptible loss of vision has already started to occur. Treatment can stop or slow further damage, so most patients retain useful vision, but those who lose any sight will not regain it.
Early diagnosis of glaucoma is therefore key to avoiding or minimising visual loss. Now researchers at University College London report a breakthrough that may enable the diagnosis of glaucoma between five and ten years before any symptoms occur.
The test involves a dye that attaches to certain retinal cells. As the cells die, their chemical make-up changes, causing certain structures to move to the outer parts of the cell and to which the dye then attaches. The dye is fluorescent and can be seen on clinical examination at the back of the eye, revealing the extent of the damage as it develops far earlier than is currently possible. Earlier treatment can then follow, which should result in very substantial improvement in the outcome for patients.
There are separate suggestions of potentially wider application of this research, to identify decay in other types of cells, specifically those affected by neurodegenerative diseases, such as dementia, multiple sclerosis and Parkinson’s Disease.
Welcoming this report, Andrew Clayton of Penningtons Manches’ clinical negligence team, who specialises in ophthalmic claims, explains: “Glaucoma affects around 60 million people globally, most of whom will lose a third of their sight before being diagnosed. Monitoring intra-ocular pressure to diagnose and treat glaucoma in the UK is relatively advanced and effective in retaining useful vision for most people. For those affected, however, the impact can be a life-changing disability. The sample population tested in the latest research is very small and more work needs to be commissioned to evaluate this development, but it carries the hope of transforming glaucoma diagnosis and management.”