February 28 is Rare Disease Day. This event aims to raise awareness and to generate change for the 300 million people worldwide living with a rare disease and their families and carers.
From 1 April 2023, Vision Foundation is merging with leading sight loss charity, Fight for Sight. Fight for Sight fund ground-breaking research into sight loss, investing nearly £8 million to fund over 100 projects at leading universities and hospitals across the UK. Together, we will combine breakthrough research and life-changing services to build a better world for blind and partially sighted people.
Let’s explore how Fight for Sight’s funding advances research into 5 types of rare disease that cause sight loss.
Retinitis Pigmentosa (RP) is a group of related inherited eye conditions affecting the retina – the light-sensitive tissue at the back of the eye. RP affects roughly one in 4,000 people worldwide. Night blindness is one of the earliest symptoms, typically appearing in adolescence. It gets progressively worse and can lead to blindness.
Due to being an inherited eye condition, the cause of RP is genetic – 60 different causative faults in genes have been identified so far. One of the most common causes of RP is a fault in the genes which produce proteins called splicing factors; why this happens is unknown.
Fight for Sight recently funded a project investigating a gene (ARL13B), which is critical for the correct function of a structure in the retina. It could advance the discovery of potential future therapies, such as gene therapy introducing the correct form of ARL13B into individuals with splicing factor RP. The grant was awarded to Dr Kathryn Hentges from the University of Manchester.
Tanzanian Endemic Optic Neuropathy (TEON)
Tanzanian Endemic Optic Neuropathy (TEON) causes irreversible vision loss in young people, resulting in significant disability and substantial educational and economic implications. Centred around Dar es Salaam in East Africa, the condition affects up to 40,000 people under 40 years old.
The cause of TEON is relatively unknown. However, we know it is caused by damage to the optic nerve, which connects the eye to the brain. This nerve needs a substantial amount of energy to work properly. Therefore, optic nerve cells are very susceptible to damage to mitochondria, the portion of a cell that produces energy.
Based on existing research, researchers have hypothesised that TEON results from damage to mitochondria via lifestyle (diet) and environmental (low sunlight exposure) factors in individuals with genetic susceptibility. Dr Frederick Burgess from the University of St Andrews aims to understand more about the environmental, lifestyle and genetic causes of TEON. Fight for Sight have co-funded his research alongside the Royal College of Ophthalmologists.
Gene faults leading to coloboma
Coloboma is a condition where the eye doesn’t form correctly as an embryo develops, leaving a gap that can cause severe sight loss. Specific genetic faults in a gene called YAP lead to coloboma in humans, but we don’t know why.
Fight for Sight have funded Professor Stephen Wilson with a PhD studentship. He used high-resolution imaging to study the process as the eye develops in zebrafish, as the condition can also be demonstrated in this animal
Inherited retinopathies (CRB-1)
Inherited retinopathies are a group of eye diseases that affect the retina, the light-sensitive tissue at the back of the eye. They are all caused by at least one gene that is not working properly. In people with inherited retinopathies, the light-sensing cells (photoreceptors) in the retina stop working and eventually die – causing progressive sight loss, often leading to blindness.
Faults in the CRB1 gene can cause different inherited retinopathies. It is not understood why specific faults in the CRB1 gene can cause different retinopathies with such varied patterns of sight loss – meaning healthcare professionals cannot predict both the severity and how quickly a person’s sight loss will progress.
Professor Mariya Moosajee at the UCL Institute of Ophthalmology aims to improve our understanding of inherited retinopathies’ natural history (or progression) caused by faults in the CRB1 gene. Fight for Sight are co-funding her research alongside Moorfields eye charity. Her research could help determine which patients might benefit from novel gene therapies and other innovative treatments in the future.
British Ophthalmological Surveillance Unit
A newly revamped UK-wide research platform could be the key to understanding, preventing, diagnosing, and eventually treating rare eye diseases.
The British Ophthalmological Surveillance Unit (BOSU) enables investigators to identify patients newly diagnosed with specific rare eye conditions through a monthly reporting (active surveillance) system involving all senior ophthalmologists across the UK.
With recent funding awarded from Fight for Sight, BOSU will transform into a new integrated digital system, which will be more reflective of the changing digital landscape in healthcare, and the changing framework post-GDPR and will be a more efficient system in a post-COVID-19 world.