Children
&
Retinitis Pigmentosa
The eye is a sort of a cavity containing eyelid, eye ball, fluid in both parts of eye ball to maintain its shape, muscles, nerves, Fluid called aqueous humor in the area from inner surface of cornea to front of lens for nourishing inner structure, blood vessels, cornea, pupil, Retina, Jelly like fluid called Vitreous humor in posterior chamber from back surface of lens to Retina, and structure that forms and draining of tears. Each orbit is plump shaped formed by several tiny bones.
Cornea is a clear curved layer in front of pupil. It plays a
role of protective cover for Retina
which is placed at the back of eye.
Light after passing through cornea enters in pupil which is a black dot
in center of eye. Pupil is surrounded by a circular-colored area which controls
level of light before its entrance in eye.
Here we will discuss in detail the function of Retina the
most complicated part of eye in context of “Retinitis Pigmentosa” an incurable
disease in children.
The retina is a thin layer of tissue at the back of the eye
that acts like the film in a camera. It is located near the optic nerve and is
about the size of a postage stamp. It is curved in shape and looks like an
interior of a sphere. The material of the retina is mostly made up of
specialized cells and nerve fibers. The peculiar shape enables it to receive
and focus light from different angles.
Retina contains specialized cells called photoreceptors,
bipolar cells and ganglion cells. These
all work together and create a complexed network of multiple connections which
ultimately help in having accurate vision.
The most sensitive part of Retina is a very small area called
“Macula” having millions of tightly packed
natural photoreceptors and are of two types.
1)Rods
2)Cones
Rods are abundant as compared to cones and are located along
outer line of Retina. They are very sensitive to light and work at low level of
light. They do not contribute in color generation but provide good quality
night vision. On the other hand, Cones
are responsible for color vision and are mainly used in bright light or day.
Light on touching eye, passes through cornea and lens before
reaching Retina. The photoreceptors in
the retina on detecting the light get in action. They immediately generate
electrical signals for onward transmission to brain through optic nerve. The
brain within no time n reads signals and converts them in pictures or visuals.
Another important function of Retina is its ability to adopt
different conditions of light making life comfortable. On entering a place with
comparatively less or no light, our Retina dilates while on going to place with
bright light or open sun light our Retina reacts and shrinks automatically
letting less light in eye.
Retina has many important features which enable to have clear
view of world around. Scientists and Doctors are still trying to have knowhow
of the remaining functions. One thing is confirmed that all these features are
developed in childhood and early years of life. It has also been established
that Retina constantly goes through a
generation and renewal n process throughout life to maintain quality of vision.
Retinitis Pigmentosa (RP)
RP is
one of the diseases that is related to Retina and is commonly found in children
or diagnosed in childhood. RP is a rare genetic disorder of eye which leads to
poor functioning of Retina, slow vision loss and then ends to blindness. It is
said to be most commonly inherited Retinal disorders.
In this disease, some or many of photoreceptor cells are
damaged or destroyed which affects structure and Network. The high density of
cones in Macula naturally designed to work like high resolution Digital camera
with more pixels is thus affected thus sending poor signals to brain. It all
results in poor or dead vision in one or both eyes.
The first symptom of RP is usually the complaint from
children of not being able to see in dark or in places with less light. At the
later stages the patient might not be able to see objects at side or notice
things which are not directly in front of them. At that stage vision is limited
to center of eye. Overtime, central vision may also be affected, which is the
ability to see things clearly straight ahead. This can make it hard to read,
watch television, or recognize faces.
There are several genes involved in development and
maintenance of healthy Retina. Any mutation in any of the genes can become a cause of RP. The role of genes in RP will be discussed in some later article.
Till today no cure or treatment is available in any part of
world. On diagnosis of disease, ophthalmologists recommend regular checkup and
advise supplements like Vitamin A. Regular intake of Vitamin A have shown good
results in some patients and has slowed down progress. Regular eye examination
and Genetic testing are also advised of patients with family history of RP or
inherited Retina disorder. Parents should also have a close eye on children’s
daily movements and should consult doctors on priority basis on doubts of any
symptoms described above. Children should also avoid activities having risk of
injuries. Some slight lifestyle changes should also be adopted like usage of
eye covers while playing sports and to save themselves from flying
objects.
Important notes of some leading ophthalmologists regarding
Retinitis Pigmentosa are being quoted here.
