Retinitis pigmentosa is a group of inherited eye diseases characterized by the gradual degeneration of photoreceptor cells in the retina. This causes vision loss that gets worse over time, with symptoms including trouble seeing at night and developing tunnel vision. It is a genetic disorder, where mutations in any of several genes can cause the photoreceptor cells to deteriorate. The progression and severity of vision loss varies between individuals. While there is no cure, treatments aim to slow the progression and help manage symptoms through methods like vitamin supplements, sunglasses, low vision aids, and retinal implants.

1. Retinitis Pigmentosa

2. treatment of rp
Inheritance of RP
Cause of RP
Symptoms of rp
diagnosis of rp
type of rp

3. Retinitis pigmentosa
A group of chronic hereditary eye diseases
characterized by dark pigmentation and
gradual degeneration of photoreceptor cells in
the retina, causing visual impairment.
✘ General feature of RP:-
✘ Classic bone spiculing in the peripheral retina.
✘ Trouble seeing at night with tunnel vision.
✘ Retinitis pigmentosa is one of the most common
inherited diseases of the retina (retinopathies),
which affects roughly 1 in 4,000 people.

4. Photoreceptor cells
Retinal cells that absorb and convert light into electrical signals,
which eventually transmit to the brain, where they are processed into
the images we see. There are two types of cell present in retina.
✘ Rod cells: present on the outer regions of the retina, and allow us to see
in dim and dark light.
✘ Cone cells: reside in the central part of the retina, and allow us to see
fine visual detail and color.

5. Cause of RP

6. ✘ Researchers have discovered over 100 genes which play essential role in the
structure and function of photoreceptor cells.
✘ A disease-causing mutation in one of these genes can send faulty messages
to retinal cells that cause their progressive degeneration and damage to
photoreceptor cells whch cause vision impairment with black pigments, a
condition known as RP.
✘ Which initially and mainly affects the rod photoreceptor Cells with
subsequent degeneration of the cones.
✘ First signs of RP in affected children can be seen as early as age 10, with
progression of the disease continuing throughout the individual's life. But
due to the involvement of so many genes, the progression and severity of
RP varies greatly for the individuals.
✘ Eventually, most individuals with RP will lose most of their sight but still
complete blindness is uncommon.
Cause and progression

7. ✘ Disruption of molecular chaperones and misfolding of rhodopsin
proteins, the pigment of the rod cell that plays an essential role in the
visual-transduction cascade that enables vision in low-light conditions,
gives rise to autosomal dominance forms of RP.
✘ More than 100 mutations have been identified in the RHO gene such as
Pro23His, which causes about 25% of the autosomal dominant form of
RP.
✘ Mutations in pre-mRNA splicing factors such as PRPF3, PRPF8, PRPF31
and PAP1 can cause autosomal dominant form of RP.
✘ A mutation on the USH2A gene causes 10–15% of all autosomal
recessive and a syndrome form of RP known as Usher's syndrome.
✘ RPGR and RP2 genes are 6 of 2 genes that cause the X-linked form of RP
in their mutated state.
Mutated gene

8. Inheritance of RP

9. Being an inherited disorder RP can potentially affect another member of
the family.
✘ According to family history inheritance patterns of RP can be described as:-
✘ Simplex inheritance:- In 30-40% of all cases, RP affect a person without any
family history. This can result from de-novo mutation.
✘ Other cases of RP, where family history has been determined, fall into three
main categories depends on the location and type of mutated gene:-
✘ Gene present on autosomes:-
✘ Autosomal recessive inheritance.
✘ Autosomal dominant inheritance.
✘ Gene present on X chromosome:-
✘ X-linked inheritance.

10. Autosomal recessive
inheritance:-
✘ These types of inheritance pattern of RP have been
identified in at least 45 genes. It takes two copies of the
mutant gene to give rise to the disorder. Person with
single copy of mutated gene is unaffected carrier.
✘ Two unaffected individuals who are carriers of the same
RP-inducing gene mutation can produce offspring with:-
✘ 25% chance the child will have the disorder.
✘ 50% chance the child will be a unaffected carrier.
✘ 25% chance the child will be normal.

11. Autosomal dominant
inheritance
✘ In this kind of inheritance only one mutated copy of
gene in cell is sufficient to cause the disorder.
✘ Most people with autosomal dominant RP have an
affected parent and other family members with the
disorder.
✘ When a dominant gene mutation occurs in one of the
parents, there is a 50% chance that any children will
inherit this mutation and the disorder.

12. X-linked inheritance
✘ If the genes associated with X-linked retinitis pigmentosa are located on
the X chromosome disease shows X-linked inheritance.
✘ In males, one altered copy of the gene in each cell is sufficient to cause
the condition.
✘ In females, mutations usually have to occur in both copes of the gene to
cause the disorder.
✘ If the father is affected, all sons will be unaffected and all daughters will
be carriers. If the mother is the carrier:-
50% chance of having a son with the disorder
50% chance of having a daughter who is a carrier
✘ However, at least 20 percent of females who carry only one mutated copy
of the gene develop mild symptoms of retinal pigmentosa.

13. Symptoms of rp

14. Symptoms
✘ Due to loss of rod cells:-
✘ Night blindness: when you cannot see anything in the dark which makes it
hard to adjust in darkness.
✘ Tunnel vision: Due to the gradual loss of rod cells people tend to lose more
of the peripheral visual field, developing tunnel vision.
✘ Development of bone spicules in the fundus.
✘ visual field:- the area of space that is visible at a given instant without
moving the eyes.
Non-syndromic RP usually presents a variety of the
following symptoms:

16. ✘ Poor color separation: In later stages, cone degradation makes it
difficult to see different colors clearly.
✘ Loss of central vision: Some people also have problems with central
vision.
✘ Latticework vision (due to loss of peripheral vision).
✘ Photopsia; (blinking/swirling/shimmering lights).
✘ Photophobia: aversion to bright lights
✘ Macular edema; Swelling of retina.
✘ Loss of depth perception.
✘ Blurring of vision.
✘ Cataracts.
Symptoms

17. diagnosis of rp

18. ✘ Ophthalmoscope: a tool that allows for a wider, clear view of the
retina. This typically reveals abnormal, dark pigment deposits that
streak the retina. These pigment deposits are in part why the
disorder was named retinitis pigmentosa.
✘ Visual field testing: it helps measure side vision and finds any blind
spots that may be developing.
✘ Genetic testing: It can also help determine the likely course or
severity of a disease and whether gene therapy to replace the faulty
gene may be helpful.
✘ Optical coherence tomography (OCT): it takes highly detailed
pictures of retina and help in diagnose RP and find out how it is
affecting your retina.
Fundus photo of RP patient
Normal photo of Fundus
Tools and techniques

19. ✘ An ERG measures the electrical response of the retinal photoreceptor
cells to photic stimulation.
✘ People with RP have a decreased electrical activity, reflecting the
declining function of photoreceptors.
✘ This test uses gold foil or a contact lens with electrodes attached. A flash
of light is sent to the retina and the electrodes measure rod and cone cell
responses.
Electroretinogram/ Electroretinography(ERG)
The basic waveform of ERG

20. The two components that are most often
measured are the a- and b-waves. The a-wave is
the first large negative component, followed by
the b-wave which is corneal positive and usually
larger in amplitude.
Electroretinogram

21. treatment
of rp

22. There is no known cure for retinitis pigmentosa.
✘ Due to involvement of over 100 genes there are so many forms of RP,
Which makes it difficult to predict how any one patient will respond to any
treatment.
✘ However, doctors are working hard to find few new treatment options
such as orientation and mobility training, light avoidance and/or the use
of low-vision aids to slow down the progression of RP.
✘ Such as;-
✘ Acetazolamide: This medication can ease swelling called macular edema
and improve your vision.
✘ Vitamin A palmitate: High doses (15,000 IU/day) of vitamin A palmitate
may slow down progression of the RP in adults a little each year.
✘ Sunglasses: To protect eyes from harmful ultraviolet rays that may speed
vision loss.

23. Research is also being conducted in areas such as gene therapy
research, transplant research, and retinal prosthesis.
✘ Gene therapy: -
✘ Since RP is usually the result of a defective gene, gene therapy can be
used to put healthy genes in damaged cell or tissue.
✘ Transplantation: -
✘ Transplantation of healthy retinal cells into sick retinas could be a
potential treatment of RP.
✘ But these treatments have not yet been considered as clinically safe and
successful.
Potential treatment
One type of RP, caused by mutation with a gene RPE65, can be treated.

24. Retinal implant: -
✘ A device called “artificial retina” or the ARGUS II, developed by Second
Sight, is a prosthetic device that functions in place of lost photoreceptor
cells and may be helpful for some patients with severe vision loss due to RP.
✘ It consists of a light-sensitive electrode that is surgically implanted into a
single eye and paired with glasses equipped with a camera. Images are
converted to electrical pulses that are sent to the retina.

25. type of rp

26. ✘ Non-syndromic RP: when it occurs alone, without any other clinical
findings.
✘ Retinitis pigmentosa sine pigmento
✘ Retinitis punctata albescens
✘ Sector retinitis pigmentosa
✘ Leber congenital amaurosis
✘ Pigmented paravenous chorioretinal atrophy.
Type of RP
✘ Cone-rod dystrophy:- when cones degradation takes prior to rods, so
daylight and color vision are affected before night vision.
✘ Syndromic RP: with other neurosensory disorders, developmental
abnormalities etc.

28. ✘ Sine pimento means without pigment.
✘ Absence or paucity of pigment
accumulation.
✘ May subsequently appear with time.
✘ Functional manifestations are similar to
typical RP.
Retinitis pigmentosa sine pigmento

29. ✘ Albescens means whitish.
✘ Scattered whitish-yellow spots, most
numerous at the equator, usually sparing
the macula, and associated with arteriolar
attenuation.
✘ Nyctalopia (night blindness) and
progressive field loss occur.
Retinitis punctata albescens

30. ✘ Bone spicule pigmentation in specific area
only.
✘ Mainly involvement of inferior quadrants
only.
✘ Progression is slow (many cases are
apparently stationary)
✘ Unilateral RP can also occur.
Sector retinitis pigmentosa

31. ✘ Usher syndrome: RP combined with deafness (congenital or
progressive).
✘ Kearns–Sayre syndrome (Ragged Red Fiber Myopathy): RP combined
with ophthalmoplegia, dysphagia, ataxia, and cardiac conduction
defects.
✘ Nephrotic syndrome: RP associated with Alport's syndrome .
✘ McLeod syndrome: RP is in association with muscular dystrophy or
chronic granulomatous disease.
✘ Bardet–Biedl syndrome: RP associated with hypogonadism.
✘ Other conditions include neurosyphilis, toxoplasmosis and Refsum's
disease.
Syndromic RP

32. ✘ Children with RP may benefit from low vision aids that maximize existing
vision.
✘ For example, there are special lenses that magnify central vision to expand
visual field and eliminate glare.
✘ Computer programs that read text are readily available.
✘ Portable lighting devices can adjust a dark or dim environment.
✘ Mobility training can teach people to use a cane or a guide dog,
✘ Eye scanning techniques can help people to optimize remaining vision.
✘ Once a child is diagnosed, he or she will be referred to a low vision
specialist for a comprehensive evaluation. Parents may also want to meet
with the child's school administrators and teachers to make sure that
necessary accommodations are put in place.
Living with RP

33. Thank you
By; Anshul kushwaha
anshul.mhg.nhu@gmail.com