Glaucoma, Vision Loss, and Lab Mice – Is There Hope for a Cure?
Contrary to what most believe, glaucoma does not typically present with severe symptoms. Notoriously dubbed the “silent thief of sight”, many forms of glaucoma have no warning signs. By the time symptoms such as hazy vision and eye pain become noticeable, there may already be significant damage done. The root of this condition lies in the optic nerve, whose deterioration over time leads to the development of blind spots in the visual field. Such nerve damage is typically linked to increased pressure in the eye due to the build-up of aqueous humour in the eye. Think of water running from a tap into a kitchen sink. The sink overflow hole serves to prevent the basin from overflowing, but it may not be effective in draining a large amount of fluid quickly. Similarly, aqueous humour inside the eye is typically drained through a tissue called the trabecular meshwork, but the rate of fluid drainage is drastically reduced when the drainage system malfunctions or the aqueous humour is overproduced. If left untreated, glaucoma may eventually lead to vision loss and blindness within 20 years of diagnosis, coupled with a host of symptoms in the likes of blurred vision, severe headaches, and eye redness.
Sounds terrifying, but surely there is a cure for this eye disease, one so prevalent amongst the elderly and those with risk factors such as diabetes and hypertension? Unfortunately, the answer is not right now, but there is much promising research underway that may alter this state in the future.
Current Treatment Methods
Though vision loss from glaucoma cannot be fully restored, leaps and bounds have been made in the race to obtain a cure for glaucoma. If detected in the early stages, treatment and regular check-ups can significantly aid in preventing and slowing loss of eyesight. The aim behind glaucoma treatment is to reduce intraocular pressure, which is achieved through several methods such as laser treatment, prescription eye drops, surgery in later stages.
The first stage in clinical glaucoma treatment is the application of eye drops that help improve the drainage of fluid (aqueous humour) from the eye, and controlling fluid production. This is followed by oral medications that are generally aimed at inhibiting fluid production. Alternative treatment methods include surgical procedures and laser therapy, aimed at opening up clogged channels in the trabecular meshwork.
It may seem disheartening that even with such treatment, eyesight lost to the nerve damage caused by glaucoma can never be fully recovered, but it may help to keep in mind that 15 years ago, researchers thought it was impossible to restore glaucoma-induced vision loss to even a small extent. Besides, glaucoma treatment may soon be revolutionised with the development of novel procedures: one in particular that may be tested on glaucoma patients within the next two years.
A Milestone in Glaucoma Treatment Research
Scientists from Harvard Medical School have successfully restored vision in mice, returning the retinal ganglion cells of their eyes to youthful gene function. This treatment has been developed based on a new theory on the causative factors leading to age-related diseases. Since different cells of the body have vastly varied functions that occur based on the same genetic code, different levels of specialisation become necessary, whereby cells only express genes specific to their form and function. It has been postulated that the regulatory functions which control gene expression in various cells may be impaired over time as ageing occurs, thereby increasing the likelihood of many age-related conditions presenting over time.
Building on the work of Nobel Prize winner Shinya Yamanaka’s ground-breaking work on induced pluripotent stem cells (iPS cells), the team delivered specific transcription factors, known as Yamanaka factors, to the retina, which led to improved nerve regeneration of damaged optic nerves, and the restoration of vision loss in mice with a condition similar to glaucoma.
The implications of these findings are far-reaching. Representing a novel treatment modality in regenerative medicine, these results are a clear sign of a new era that has arrived; one where the understanding of neural developmental processes have provided invaluable tools in repairing the aged brain.
More importantly, this research has definitely fuelled hope that one day, glaucoma and its resultant vision loss may become things of the past.
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