Disease

1. RETIONOBLASTOMA
• Retinoblastoma is an eye cancer that begins in the retina — the
sensitive lining on the inside of your eye. Retinoblastoma most
commonly affects young children, but can rarely occur in adults.
• A rare form of eye cancer, retinoblastoma is the most common form
of cancer affecting the eye in children. Retinoblastoma may occur in
one or both eyes.

2. Causes
• Retinoblastoma occurs when nerve cells in the retina develop genetic
mutations. These mutations cause the cells to continue growing and
multiplying when healthy cells would die. This accumulating mass of
cells forms a tumor. Alterations in RB1 or MYCN can give rise to
retinoblastoma.
• Retinoblastoma cells can invade further into the eye and nearby
structures. Retinoblastoma can also spread (metastasize) to other
areas of the body, including the brain and spine.
• For most instances of retinoblastoma, it's not clear what causes the
genetic mutation that leads to cancer. However, it's possible for
children to inherit a genetic mutation from their parents.

3. During the early stages of a baby's development, retinal eye cells grow very quickly and then stop
growing.
But in rare cases, 1 or more cells continue to grow and form a cancer called retinoblastoma.
In about 4 out of 10 (40%) cases, retinoblastoma is caused by a faulty gene, which often affects both
eyes (bilateral).
The faulty gene may be inherited from a parent, or a change to the gene (mutation) may occur at an
early stage of the child's development in the womb.
It's not known what causes the remaining 6 out of 10 (60%) retinoblastoma cases. In these cases,
there's no faulty gene and only 1 eye is affected (unilateral).

5. Symptoms
• Because retinoblastoma mostly affects infants and small children,
symptoms aren't common. Signs you may notice include:
• A white color in the center circle of the eye (pupil) when light is shone
in the eye, such as when someone takes a flash photograph of the
child
• Eyes that appear to be looking in different directions
• Poor vision
• Eye redness
• Eye swelling

6. Retinoblastoma that is inherited
• Gene mutations that increase the risk of retinoblastoma and other
cancers can be passed from parents to children.
• Hereditary retinoblastoma is passed from parents to children in an
autosomal dominant pattern, which means only one parent needs a
single copy of the mutated gene to pass the increased risk of
retinoblastoma on to the children. If one parent carries a mutated
gene, each child has a 50% chance of inheriting that gene.

9. Complications
• Children treated for retinoblastoma have a risk of cancer returning in
and around the treated eye. For this reason, your child's doctor will
schedule follow-up exams to check for recurrent retinoblastoma.
• Additionally, children with the inherited form of retinoblastoma have
an increased risk of developing other types of cancers in any part of
the body in the years after treatment, especially pine blastoma, a
type of brain tumor. For this reason, children with inherited
retinoblastoma may have regular exams to screen for other cancers.

11. TREATMENT
• The priority of retinoblastoma treatment is to preserve the life of the child, then
to preserve vision, and then to minimize complications or side effects of
treatment. The exact course of treatment depends on the individual case and is
decided by the ophthalmologist in discussion with the paediatric oncologist.
• The various treatment modalities for retinoblastoma includes
• Thermotherapy involves the application of heat directly to the tumor,
usually in the form of infrared radiation. It is also used for small tumors.
• Laser photocoagulation is recommended only for small posterior tumors.
An argon or diode laser or a xenon arc is used to coagulate all the blood
supply to the tumor.
• Cryotherapy induces damage to the vascular endothelium with secondary
thrombosis and infarction of the tumor tissue by rapidly freezing it. It may
be used as primary therapy for small peripheral tumors or for small
recurrent tumors previously treated with other methods.

13. Retinitis pigmentosa
• Retinitis pigmentosa (RP) is a group of rare eye diseases that affect the
retina (the light-sensitive layer of tissue in the back of the eye). RP makes
cells in the retina break down slowly over time, causing vision loss.
• Also known as hereditary retinal dystrophy
• RP is a genetic disease that people are born with. Symptoms usually start in
childhood, and most people eventually lose most of their sight.
• There’s no cure for RP. But vision aids and rehabilitation (training) programs
can help people with RP make the most of their vision.

14. What causes RP?
• Most of the time, RP is caused by changes in genes that control cells in the retina. These
changed genes are passed down from parents to children.
• RP is linked to many different genes and can be inherited in different ways .Its
transmission is Autosomal recessive in most cases. Other modes of transmission include
autosomal dominant and X-linked
• Retinal cells may contain a variety of mutations and this depends o the underlying
genetic cause
• Mutations can trigger apoptosis (programmed cell death) of retinal photoreceptors.
• Apoptosis of some cells can trigger apoptosis of surrounding cells
• Retinal pigment epithelial cells can detach and deposit into perivascular areas, leaving
bony spicule –shaped melanin deposits..
• Sometimes RP happens as part of other genetic conditions, like Usher syndrome. Usher
syndrome causes both vision and hearing loss.

16. symptoms of RP
• The most common early symptom of RP is loss of night vision —
usually starting in childhood. Parents may notice that children with RP
have trouble moving around in the dark or adjusting to dim light.
• RP also causes loss of side (peripheral) vision — so you have trouble
seeing things out of the corners of your eyes. Over time, your field of
vision narrows until you only have some central vision (also called
tunnel vision).
• Some people with RP lose their vision more quickly than others.
Eventually, most people with RP lose their side vision and their central
vision.

17. Other symptoms of RP
include:
•Sensitivity to bright light
•Loss of color vision

19. How will my eye doctor check for RP?
• Eye doctors can check for RP as part of a comprehensive dilated eye exam. The exam is
simple and painless — the doctor will give you some eye drops to dilate (widen) your
pupil and then check your eyes for RP and other eye problems. The exam includes a
visual field test to check peripheral (side) vision.
• Other tests for RP include:
• Electroretinography (ERG). ERG lets the eye doctor check how well your retina responds
to light.
• Optical coherence tomography (OCT). This test uses light waves to take a detailed picture
of your retina.
• Fundus autofluorescence (FAF) imaging. In this test, the eye doctor uses blue light to take
a picture of the retina.
• Genetic testing. Your doctor may suggest a genetic test to learn more about the type of
RP they have. This can tell you how your RP symptoms may change over time.

20. treatment for RP
• here’s no cure for RP, but low vision aids and rehabilitation (training)
programs can help people with RP make the most of their vision.