Dear colleagues hope this material will help you in your fast revision on ophthalmology. regards DR M HASSAN

1. Retinitis Pigmentosa
Presenter
DR M hassan

2. Def.
It is a clinically and genetically heterogeneous group of inherited
retinal disorders ch.ch by :-
a) diffuse progressive dysfunction of predominantly rods.
b) subsequent degeneration of cones & (RPE).
What is the etiology ?
Since RP is a collection of many different genetic disorders, the
etiology is quite variable.
the final common pathway appears to be (photoreceptor cell death
by apoptosis ).
What we mean by ( apoptosis ) ?
It is a Greek word means drooping / falling off used to describe
normal death of cells in sequence.

3. Pathology : ( in order )
a) Degeneration of rods 1st
b) Start @ equator
c) Peripheral extension
d) Degeneration of cones
NB :-
Pathologic findings of an enucleated eye in a patient with autosomal
recessive RP showed that:-
1. the rod and cone outer segments were shortened and
disorganized in the patient’s best field of vision.
2. while in the area of visual loss there was a total loss of outer
segments and a decrease in photoreceptors number.

4. What is most common inheritance of RP ?
AR
What is the best inheritance prognosis in RP ?
AD
What is the worst inheritance prognosis in RP ?
XLR ( X LINKED RECESSIVE )
What is the most common gene involved in RP ?
RDS ( peripherin gene)

5. symptoms ( bilateral )
1. Night blindness ( Rods)
2. Loss of peripheral vision 1st .
3. Later on , Loss of central vision (cones)

8. Signs :
 main signs :-
Fundus : ( triad )
1) Arteriolar narrow ( threads like )
2) Waxy pallor optic disc
3) Pigmentation in retina & vitreous (bony spicules)

10.  Others :-
1. Keratoconus .
2. PSCC
3. Vitreous cells
4. RPE atrophy
5. CME
What are the commonest refractive errors in RP ?why?
1. Myopia ??
2. Hyperopia ??
3. Non of above ??

11. What are investigations needed?
VF ( findings) /
1) Peripheral scotoma
2) Ring scotoma
3) Progressive constricted field
4) Tubular vision .
What is scotoma ?
It is the area of obscurity of VF surrounded by normal VF
( normal retinal sensitivity)

13. ERG (electroretinogram)
it measures the electrical potential generated by rods and
cones after a light stimulus.
Findings :-
1) Subnormal a wave ( photoreceptors) = negative
2) Subnormal b wave ( bipolar & mullers cells) = positive.
Electrooculogram (EOG) :-
It is a measurement of the function of the RPE and
photoreceptors by measuring the standing potential
between the cornea and the retina

15. Is there any roles of OCT , FFA in RP? Discuss in brief.
Yes ,
It is mainly to diagnose other associations of RP such as ;-
1. CME ( OCT , FFA ).
2. Early deterioration in RPE ( FFA ).
Is there any role of lab. tests in RP diagnosis ?
Yes ,
Genetic test is important in diagnosis of atypical cases of RP.
Ornithine-lysine ratio (for gyrate atrophy of the retina)

16. From previous mentioned tests , what is the main
diagnostic test & main prognostic test ?
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17. What is DD of RP ?
1. gyrate atrophy.
2. Chorideremia ( rare , X-linked recessive form of hereditary retinal
degeneration)
3. cone-rod dystrophy.
4. cone dystrophy.
5. Lebers congenital amaurosis.
6. Drug toxicity from thioridazine hydrochloride (Mellaril) (can lead
to diffuse pigmentary and RPE atrophy).
7. diffuse unilateral subacute neuroretinitis (DUSN) can cause
similar pigmentary retinopathy seen in patients with RP.

18. How to DD between DUSEN & RP ?
 DUSEN Ch. Ch. by /
1. Unilateral.
2. Caused by parasite.
3. The worm can be seen by fundus examination.

19. What are the causes of pseudo-RP ?
1. Trauma
2. Congenital Syphilis (leopard skin retinopathy).
3. Congenital rubella.
4. Drug induced: Thioridazine streaks, chloroquine, quinine
5. Laser scars
6. Chronic RD.
7. Chronic uveitis
8. Cancer-associated retinopathy

20. What are the criteria of Atypical RP ?
1) Cone –rod dystrophy ( starts @ cones)
2) Sectorial RP ( affect one sectors of the retina)
3) Peri-centric RP ( around the macula)
4) Punctate RP (scattered white spots without
pigmentation)

21. Can we prevent RP ?
Since RP is a genetic disorder, there is currently no intervention that
would prevent manifestations of RP.
Treatment
Usually ,, No treatment but new trials Can be done /
1) Sub retinal injection of RPE 65 ( gene therapy)
2) Retinal implant .
3) Retinal transplantation
4) Stem cells
5) Vitamin therapy ( Vit. A)
6) Psychological and visual rehabilitation
NB : DON’T FORGET Examination of other family members of the
affected person is recommended

25. Fast revision

26.  Can a pt. with RP be legally blind in spite of having good central
vision?
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 What are the Types of Sunglasses preferred in RP ?
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27.  Can an RP patient be legally blind in spite of having good central
vision?
Yes, visual field of less than 10 degrees even with VA of 6/6.
 What are the Types of Sunglasses preferred in RP ?
Some clinicians prefer :-
1. orange photochromic sunglasses with tinted side shields.
2. dark amber sunglasses with tinted side shields.
 NB :-
Sunglasses should be selected for outdoor use that provide maximal
comfort to the vision without compromising vision.

28. What is the Mechanism of glaucoma in RP. ?
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29. What is the Mechanism of glaucoma in RP. ?
RP can be associated with both angle closure and open angle
glaucoma.
Angle closure glaucoma:-
There is increased zonular instability with anterior shifting of iris lens
diaphragm resulting in angle narrowing and angle closure
glaucoma.
POAG, NTG :-
a) attributed to the mutation of gene for retinitis pigmentosa
b) GTPase regulator-interacting protein 1 (RPGRIP1) on
chromosome 14q11.
c) ++ IOP

30. What is the difference ( ) Amsler grid chart &
Amsler Dubois chart ?

36. What is DD of night blindness ?
1. ------------
2. ----------------
3. ------------------
4. -----------------------

37. What is DD of night blindness ?
1. Idiopathic
2. RP
3. Gyrate disease
4. Vit. A deficiency

38. Which of the following not associated with RP ?
1. CME
2. PSCC
3. ERM
4. Endophthalmitis

43. Thanks for attention