Understanding genetics
There are hundreds of different types that can affect any part of the eye. Accurate diagnosis helps our patients understand their prognosis, their risk to other family members and is essential in entering novel treatment trials.
Every cell of our body contains 3.1 billion pieces of DNA, the code that tells our body how to work. Sections of DNA form genes and we have two copies of every gene. More than 1000 genes are known to be vital in how our eyes work.
A mutation (spelling mistake) in the DNA can cause a genetic eye disease. Some conditions can run in families but for many there is no family history.
How does it present
Patients can be born with genetic eye disease such as congenital cataract or glaucoma or develop symptoms later in life. Any part of the eye can be affected including eyelids, eye muscles, cornea, lens, retina and optic nerve.
The commonest type of genetic eye disease is retinitis pigmentosa (known as rod-cone dystrophy) where the light-sensing cells in the back of the eye slowly stop working. Patients develop poor night vision (nyctalopia), reduced peripheral visual fields and eventually poor central vision. There are many different subtypes of rod-cone dystrophy that can present at any age. Other types of retinal dystrophy can present with altered colour vision and blurring.
Sometimes patients do not have any symptoms but their optometrist spots the changes or patients are referred for a check as other family members are known to be affected.
Diagnoses
A detailed history including family history and the latest retinal and optic nerve imaging cameras give vital clues as to the type of genetic eye condition. Your genetic eye specialist has exceptional experience and expertise in these rare conditions to help achieve an accurate diagnosis.
Genetic testing can be arranged directly from Auckland Eye and the interpretation and counselling of these results help families understand their condition and the risk to other family members. Vitally, across the world, extensive research is ongoing to find treatments for these disorders and an accurate diagnosis is the first step for future treatment trials.
Resources
Further information on types of genetic eye disease and sources of support can be found here:
- Parent of Vision Impaired NZ https://pvi.org.nz
- Blind Low Vision NZ https://blindlowvision.org.nz
- The Blind and Low Vision Education Network NZ (BLENNZ) https://www.blennz.school.nz
- Retina NZ Inc https://retina.org.nz
- Foundation Fighting Blindness https://www.fightingblindness.org
Specialists
Dr Sarah Hull
MBBS, MA, FRCOphth, PhD
If you have a question or would like to book an appointment, please contact our friendly specialist team
