Retinitis pigmentosa

3. Retinitis Pigmentosa and
Allied Disorders

4. Also known as
“tapetoretinal degeneration” (by Leber in 1916)
“primary pigmentary retinal degeneration,”
“pigmentary retinopathy,”
“Rod cone dystrophy.”

5. PREVALENCE
• Prevalence 1 in 3500 to 1 in 4500
• South India – common retinal cause of blindness
• Andhra Pradesh – prevalence of 0.8% in a population

6. TYPES
• Typical retinitis pigmentosa
• Atypical retinitis pigmentosa

7. • INHERITENCE – SPORADIC or AD,AR or XL
• Mutation of rhodopsin gene
• XL – least common and more severe
• Female carriers - normal fundus or golden-metallic reflex “tapetal” reflex at macula
and/or small peripheral patches of “bone-spicule” pigmentation
TYPICAL RETINITIS PIGMENTOSA

8. Modes of inheritence
• XLR is the least common but most sever e 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

9. SYMPTOMS
Nyctalopia
• Difficulty in dim illumination
• At night, functional field worsen and mobility Increases
• Problem in bright light rather than in dim light (cone – rod variant of RP)
• ERG helps to differentiates

10. Visual field
• progressive loss of peripheral visual field
• ring in mid periphery but unaware
• field loss progresses both centrally and toward sides, results in narrow area of vision
• cone like or tunnel like vision
• blindness

11. • In general, there is a strong tendency for the visual field loss to be symmetric
between the two eyes.
• A notable exception to this is the phenotype expressed in female carriers of X-
linked RP.
• In this situation, the distribution of mutant photoreceptors in the retina is
determined by lyonization (X-chromosomal inactivation).
• This is a random event determining which genes of the two X chromosomes (the
normal or mutant copy) are expressed in a particular cell.
• This leads not only to unusual, irregular patterns of visual field loss in individual
eyes but also to quite striking differences in field loss between the two eyes.

12. LIGHT AND GLARE PROBLEMS
• Photopsia or photophobia
• Photopsias are described as tiny, blinking or shimmering lights or as a coarse, sparkling
graininess to vision
• As the scotomas become denser over the years, the photopsia decrease and finally
disappear
• The cellular or tissue correlates that underlie photopsia in RP are unknown but may
include photoreceptor dysfunction, neural sprouting, aberrant synapse formation, and
secondary remodeling of the retina, all of which occur as sequelae of photoreceptor
degeneration.

13. Central vision loss
• Cystoid macular edema (CME)
• diffuse retinal vascular leakage
• macular preretinal fibrosis
• retinal pigment epithelial (RPE) defects in the macula or fovea
• frequent fluctuations in vision “good days and bad days”

14. Fundus Appearance
• attenuated retinal vessels,
• mottling and granularity of the RPE,
• bone spicule intraretinal pigmentation,
• optic nerve head pallor

15. • Patients who have very early RP without fundus pigmentary abnormalities are
often diagnosed as having RP sine pigmento or pauci pigmentary RP.
• This is no longer considered a specific subtype of RP but a stage through which
many, if not most, patients with RP pass.
• The sine pigmento stage may exist for decades before typical RP signs appear.

16. • Intraretinal, bone spicule pigment formations represent migration of pigment from disintegration
of RPE cells with accumulation in the interstitial spaces surrounding retinal vessels.
• This process occurs most prominently at the junctions of vessels producing perivascular pigmentary
cuffing and spicule-shaped deposits.
• The loss of pigment within the pigment epithelial cells often produces an overall gray, desaturated
appearance to the retina with greater visibility of underlying choroidal vessels through the more
transparent pigment epithelium.
• Eventually, the normal salmon-pink color of the entire mid- and far peripheral fundus is replaced by
dense bone spicule pigmentary formations

17. GRADUAL INCREASE IN DENSITY OF THE
PIGMENTARY CHANGES WITH ANTERIOR AND
POSTERIOR SPREAD

18. RPE atrophy
Sheaths of pigments
RPE retinal layers
Choroidal vessels visualized
Tesselated fundus
PIGMENT SPOTS

19. Ganglion cell degeneration
Increase in optic atrophy
Wax like yellowish appearance
Consecutive atrophy with macular atrophy
Epiretinal
Membrane

20. The optic disc may be normal in early RP, show a waxy fullness with hyperemia,
or appear waxy and pale A “golden ring” or yellowish-white halo
Golden ring
Waxy pallor
Peripappilary drusen-common
in Ushers syndrome

21. Vitreous abnormality
• presence of fine, dust-like pigmented cells released from degeneration of the
RPE.
• complete posterior detachment of the vitreous
• “cotton-ball” opacities
• interwoven filaments in the retrocortical space
• spindle shaped vitreous condensations

22. Severe and generalized pigmentary changes throughout the macula and periphery as
well as inferior exudate and a serous retinal detachment .
The patient received laser photocoagulation leading to resolution of the subretinal
fluid.

23. • Posterior subcapsular cataract
• Open angle glaucoma
• Myopia common
• Keratoconus uncommon
• Vitreous changes – post. Vitreous Detachment
• Optic disc drusen very frequent
ANTERIOR SEGMENT COMPLICATION

24. INVESTIGATIONS
HISTORY – Rate of progression, functional difficulties, systemic associations,
family history, allergic , psychosocial and educational history
VISUAL ACUITY – Helps to know the extent of the disease
Early stage – partial or complete annular or ring
scotoma seen corresponding to degenerated zone
of retina.
Late stage – field becomes smaller, reduces to restricted area
around the fixation point
Long duration Central Vision remains a.k.a “Tubular Vision”

25. • COLOUR VISION –
 Good Central Vision – Normal colour vision
 Involvement of CONES – colour vision impaired
• AMSLER GRID – for any distortion/scotoma in central 10 degree of visual field
• Flash light evaluation – squint, ptosis(kearns-sayre syndrome), nystagmus, pupillary
reactions.
• S.L.E – Conjunctival or Corneal deposits ( e.g in cystinosis) with Lens Status
• Anterior Chamber Depth and Gonioscopy I.O.P
• I.D.O and 90D/78D examination
• Systemic evaluation

26. ERG IN RETINITIS PIGMENTOSA
• In Diagnosis of RP.
• Distinguish some types of RP.
• Screening of Relatives of patient of RP.
• Follow up of disease .
• D D from other similar dystrophies.

27. DIAGNOSIS
AMPLITUDE
• Usual ERG findings (Wide Field ERG) in RP include general reduction in the amplitude(a
& b waves) of ERG responses .
• Reduction of scotopic rod response is the first ERG sign.
• Maximum response which reflects rod and cone activity may be affected after scotopic
responses become abnormal.
• Visual electrophysiologists usually concentrate on scotopic and mesopic results for early
detection of RP.

28. 2) Implicit Time:
• RP patients often show prolonged b-wave implicit times.
• However, in the early stages of the disease, ERG may show normal amplitude and
implicit time values.

29. MERG IN DIAGNOSIS OF RP
MERG from a
patient with RP. No
activity is recorded
in the periphery.
Responses are
obtained centrally,
but are abnormal in
both amplitude and
implicit time

30. DISTINGUISH SOME TYPES OF RP
 Rod responses to dim blue light under dark-adapted conditions are reduced in all
genetic types and, when detectable, are delayed in b- wave implicit times.
 In the dominant with reduced penetrance, X-linked, and autosomal recessive forms of
RP,cone b-wave implicit times, are so delayed
 The subnormal responses with delayed b-wave implicit times seen in the widespread
progressive forms of RP contrast with the subnormal responses with normal b-wave
implicit times seen in self- limited sector RP

31. Electroretinographic
responses for a normal
subject and four patients with
retinitis pigmentosa (ages 13,
14, 14, and 9).
Responses were obtained after
45 minutes of dark adaptation
to single flashes of blue light
(left column) and white light
(middle column). Responses
(right column) were obtained
to 30- cycles-per-second (or
30-Hz) white flickering light

32. SCREENING OF RELATIVES OF PATIENT OF RP
 Full-field ERGs can be used not only to detect which patients are affected with the early
stages of RP but also to determine which relatives are normal. In families with RP,
patients age 6 and older with normal full-field ERGs with normal cone and rod
amplitudes and normal cone and rod b- wave implicit times have not been observed to
develop RP at a later time.

33. MANAGEMENT
• REFRACTIVE ERROR
 Refractive correction
 HIGH HYPERMETROPIA -leber’s congenital amaurosis
 RP and keratoconus could coexist.
• CATARACT –
 Develops in early stages
 VA decrease and glare increase

34. MACULAR EDEMA and EPIRETINAL MEMBRANES
• Affect of Central Vision by C.M.E
• best detected by O.C.T and F.F.A
• Thin Epiretinal Membrane in front of
Macula causes Central Vision Loss
• Vitreous Surgery to peel the membrane
also removes Vitreous opacities
• Systemic Acetazolamide

35. GENETIC STUDY –
• Modes - AD,AR,XL
• Closed relative marriage increase risk
• Pedigree tree drawn for all patients
• Genetic counseling
VISUAL REHABLITATION IN END STAGE

36. 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

37. RETINITIS
PIGMENTOSA
HYPOGONADI
SM
MENTAL
RETARDATI
ON
OBESITY
POLYDACTYLY
LAURENCE
- MOON-
BIEDL
SYNDROM
E
MENTAL
RETARDATI
ON
INFANTI
LE
DEAFNE
SS
DWARFISM
NYSTAGM
US ATAXIACOCKAY
NE
SYNDRO
ME
PERIFERAL
NEUROPAT
HY
CEREBEL
LAR
ATAXIA
REFSUM
SYNDRO
ME
LABYRINTHI
NE
DEAFNESS
USHER
SYNDRO
ME
VESTIBUL
O-
CEREBEL
LAR
ATAXIA
CONGENIT
AL
DEAFNES
S
MENTAL
DEFICIENC
Y
HALLGR
EN
SYNDRO
ME

38. Usher syndrome
• About 15% to 20% of affected individuals with retinitis pigmentosa
have associated hearing loss
three major types
Type I (75%) - 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

39. 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

40. Bassen–Kornzweig syndrome
• Abetalipoproteinaemia
• Malabsorption of fat and fat-soluble vitamin
• Failure to thrive in infancy, acanthocytosis
• Spinocerebelar ataxia
• 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

41. Refsum disease
• The patient accumulates exogenous phytanic acid
• Findings include a peripheral neuropathy, ataxia, an increase in CSF protein with a
normal cell count, retinitis pigmentosa ,ichtyosis
• 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

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

44. 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

45. 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

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

47. 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

48. • Presentation
• Blindness at birth or early infancy
• associated with roving eye movements
• Photoaversion
• Cataract
• Hypermetropia
• Nystagmus

49. • 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

51. 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