Retinitis pigmentosa is a group of inherited retinal diseases characterized by progressive degeneration of the photoreceptors. It initially affects rods, resulting in night blindness and peripheral vision loss, and later involves cones leading to tunnel vision. Symptoms include nyctalopia and peripheral field defects. Signs include bone spicule pigmentation, arteriolar attenuation, and disc pallor. It can be inherited in autosomal dominant, recessive or X-linked patterns. Investigations include electroretinography to detect photoreceptor dysfunction and optical coherence tomography. There is currently no cure or treatment to stop progression.

1. RETINITIS PIGMENTOSA
Othman Al-Abbadi, M.D

2. Retinitis Pigmentosa
• Inherited diffuse retinal degenerative diseases
• Most common hereditary fundus dystrophy
(1/5.000)
• Initially predominantly affecting the rod
photoreceptors, with later degeneration of cones
• May occur as
–AD
–AR
–XLR
–Sporadic

3. Modes of inheritence
• XLR is the least common but most severe form,
and may result in complete blindness by the
third or fourth decades
• AR disease can also be severe
• Sporadic cases may have a more favourable
prognosis, with retention of central vision until
the sixth decade or later
• AD disease generally has the best prognosis

4. Symptoms
• Nyctalopia and dark adaptation difficulties are
frequently presenting symptoms
• Mid-peripheral then far-peripheral field loss
• reduced central vision (late)
• Cataract
• Photopsia

5. Signs
• Triad of
• bone-spicule retinal pigmentation
• arteriolar attenuation
• ‘waxy’ disc pallor

6. Progression
• Bilateral mid-peripheral intraretinal perivascular
‘bone-spicule’ pigmentary changes with
arteriolar narrowing
• Then a gradual increase in density of the
pigment
• Anterior and posterior spread
• Peripheral pigmentation may become severe,
with marked arteriolar narrowing and disc pallor

10. • The macula may show
• Atrophy
• epiretinal membrane formation
• cystoid macular oedema (CMO)
• Myopia is common.
• Optic disc drusen occur more frequently

11. Complications
• PSCC
• OAG
• Keratoconus
• PVD
• Intermediate uveitis
• Exudative RD

12. Investigations
• ERG
• EOG
• Perimetry
• OCT
• Genetic analysis

13. ERG
• ElectroRetinoGram
• Components
• A wave photoreceptors
• B wave muller cells + bipolar cells
• C wave RPE

14. ERG
• Sensitive diagnostic test
• Early  reduced scotopic rod and
combined responses
• With progression  photopic responses
also reduce

16. EOG
• Measurement of standing potential between the
cornea and the retina
measurement of function of the RPE and
photoreceptors
• Abnormal in RP
• However, ERG is considered a more sensitive
test for detection of photoreceptor function and
consequently EOG is not routinely done

17. Visual field
• Characteristically shows a ring scotoma in the
mid-periphery of the visual field
• Start as a group of isolated scotomas around 20
degrees from fixation, and gradually coalesce to
form a partial followed by a complete ring
• Useful in monitoring the progression of disease
and document the status of legal blindness

18. OCT
• to detect
• CMO
• Epiretinal membrane
• vitreomaular traction

19. Treatment
• Many treatments have been explored without
proven benefit
• These include various vitamins and minerals,
vasodilators, tissue therapy with placental
extract, cortisone, cervical sympathectomy,
injections of a hydrolysate of yeast RNA,
ultrasound, transfer factor, dimethyl sulfoxide,
ozone, muscle transplants, and subretinal
injections of fetal retinal cells

20. Atypical retinitis pigmentosa
• Syndromic
• Usher syndrome
• Kearns–Sayre syndrome
• Bassen–Kornzweig
syndrome
• Refsum disease
• Bardet–Biedl syndrome
• Non-syndromic
• Retinitis pigmentosa sine
pigmento
• Retinitis punctata
albescens
• Sector retinitis pigmentosa
• Leber congenital
amaurosis
• Pigmented paravenous
chorioretinal atrophy

21. Usher syndrome
• About 15% to 20% of affected individuals with retinitis
pigmentosa have associated hearing loss
• There are three major types;
• Type I (75%) which features profound congenital
sensorineural deafness and severe RP with an
extinguished ERG in the first decade plus unintelligible
speech & vestibular ataxia
• Type III (2%), with progressive hearing loss, vestibular
dysfunction and relatively late-onset pigmentary
retinopathy

22. Kearns–Sayre syndrome
• Part of chronic progressive external
ophthalmoplegia
• Mitochondrial inheritance
• Abnormalities include
• Ptosis
• diffuse disturbance of the RPE
• ERGs that are usually reduced in amplitude
• respiratory distress
• heart block which may require a pacemaker

23. Bassen–Kornzweig syndrome
• Abetalipoproteinaemia
• Malabsorption of fat and fat-soluble vitamin
• Develops FTT in infancy
• The fundus exhibits scattered white dots
followed by RP-like changes developing towards
the end of the first decade; there may also be
ptosis, ophthalmoplegia, strabismus and
nystagmus

24. Refsum disease
• The patient accumulates exogenous phytanic acid
• Findings include a peripheral neuropathy, ataxia, an increase
in CSF protein with a normal cell count, and retinitis
pigmentosa
• All have elevated serum phytanic acid
• A defect exists in the conversion of phytanic acid to alpha-
hydroxy phytanic acid which results in its accumulation
• Treatment consists of restricting not only animal fats and
milk products (i.e., foods that contain phytanic acid) but also
green leafy vegetables containing phytol

25. Bardet–Biedl syndrome
• Includes RP, mental retardation,
polydactylism, apple-shaped obesity, and
hypogonadism
• Almost 80% have severe changes by the
age of 20 years

26. Retinitis pigmentosa sine
pigmento
• Sine pimento = Without pigment
• Absence or paucity of pigment accumulation
• May subsequently appear with time
• Functional manifestations are similar to typical
RP

28. Retinitis punctata albescens
• Albescens = whitish
• Scattered whitish-yellow spots, most
numerous at the equator, usually sparing
the macula, and associated with arteriolar
attenuation
• Nyctalopia and progressive field loss occur

30. Sector retinitis pigmentosa
• Sectoral RP
• AD
• Characterized by involvement of inferior
quadrants only
• Progression is slow (many cases are
apparently stationary)
• Unilateral RP can also occur

32. Leber congenital amaurosis
• Severe rod-cone dystrophy
• The commonest genetically defined cause of
visual impairment in children
• ERG is usually non-recordable even in early cases
• Systemic associations include
• mental handicap, deafness, epilepsy, central
nervous system and renal anomalies, skeletal
malformations and endocrine dysfunction

33. • Presentation
• Blindness at birth or early infancy
• associated with roving eye movements or
nystagmus
• Photoaversion
• Cataract
• Hypermetropia
• Nestagmus

34. • Signs are variable but may include:
• Absent or diminished pupillary light reflex
• The fundi may be normal in early life apart from mild
arteriolar narrowing
• Initially mild peripheral pigmentary retinopathy, salt
and pepper changes, and less frequently yellow flecks
• Severe macular pigmentation
• Pigmentary retinopathy, optic atrophy and severe
arteriolar narrowing in later childhood
• Oculodigital syndrome: constant rubbing of the eyes
may cause orbital fat atrophy with enophthalmos, and
subsequent keratoconus or keratoglobus

37. Pigmented paravenous
chorioretinal atrophy
• Pigmented paravenous chorioretinal atrophy
• Usually asymptomatic and non-progressive
• ERG is normal
• Paravenous bone-spicule pigmentation together
with sharply outlined zones of chorioretinal atrophy
that follow the course of the major retinal veins
• Changes may also encircle the optic disc
• The optic disc and vascular calibre are usually
normal