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Genetics Fellowship > Hereditary Retinal dystrophies > Flashcards

Hereditary Retinal dystrophies Flashcards

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1
Q

Nwhat is OMIM?

A

the online mendelian Inheritance in Man (website)

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2
Q

how many genetic disorders affect the retina and choroid?

A

nearly 750 according to OMIM

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3
Q

name 2 websites to look for genetic information on retinal diseases?

A

OMIM and RetNet

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4
Q

most retinal hereditary disease are unilateral or bilateral?

A

most are bilateral if unilateral please suspects -infections or inflammatory

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5
Q

name a reversible cause of retinal degeneration?

A

vitamin A

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6
Q

what are the mendelian patterns of inheritance?

A

AD AR X-linked recessive x-linked dominant mitochondrial

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7
Q

if a patient has a retinal degeneration but no family history …

A

the patient may have a ne novo mutation or the family members may have a mild form of disease making them asymptoatic

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8
Q

within a same gene there could be different mutations

A

and each of these can give a different phenotypes for example mutation in the RDS/peripherin can cause: - RP - cone-rod dystrophy - pattern dystrophy mutations in rhodopsin gene cause: -CSNB -RP mutations in CRX (cone-rod homeobox containing gene) can cause: -LCA -cone-rod dystrophy mutaions in Stargardt gene cause: -stargardt disease -severe progressive cone-rod dystrophy -RP

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9
Q

what percentage of patients with the Usher sd mutation have usher without hearing loss?

A

5%

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10
Q

tell me about Autosomal dominant inheritance

A

the disease presents in each generation there is 50% chance of passing the disease to offspring no sex predilection

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11
Q

tell me about autosomal recessive inheritance

A

the affected individual passes the disease to 25% of offspring not every generation affected no sex predilection

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12
Q

what is the inheritance in Stargardts disease?

A

most common is AR ( stARgardts) with most common gene ABCA4 BUT… it can also be AD with the gene ELOV4

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13
Q

what is the inheritance in RP?

A

all forms… AR, AD, x-linked to remember it is also like stargardts in a way because th emost common inheritance is AR (70%) then AD (15%) ad x-linked (15%) the most common genes for RP are: if: AR (ABCA4 and Ush2A AD (30% by rhodopsin) x-linked (80% RPGR - most severe so remember RP grrrrrr angry) and RP2 10%

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14
Q

most common genes in RP

A

the most common genes for RP are: if: AR (ABCA4 and Ush2A AD (30% by rhodopsin) x-linked (80% RPGR - most severe so remember RP grrrrrr angry) and RP2 10%

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15
Q

RPE functions

A

Absorption -of scattered light -of energy and heat Phagocytosis - of photoreceptor outer segment discs TRansport - of photreceptor waste products to choroid - of nutrients fro choroid to photoreceptors Blood retina barrier Retinal adhesion

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16
Q

so doctor….. why do I need the genetic testing?

A

well… if we know the precise diagnosis… - we can give you a more definitive prognosis - we can rule out syndromes or systemic diseases (important in LCA) - it will give you peace of mind - give you better genetic counseling - identify if we need to test your family - keep you posted on clinical trials MY JOB IS TO ORDER the most specific gene testing so you don’t waste money ALSO I will give you a copy of the report.

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17
Q

PPRCA Pigmented paravenous retinochoroidal atrophy

A

rare disease unknown etiology PIGMENT accumulation along the retinal vessels WITH sectors of NORMAL retina in between. usually, vision is normal First described on 1937 no genes found more common in males involves the RPE and choroid

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18
Q

what is the name of the contact lens electrode used for ERG?

A

Burian-Allen

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19
Q

How many genetic disorders affect the eye?

A

750

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20
Q

How many retina degenerations with an identified gene are listed in RetNet?

A

Over 200

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21
Q

If disease is unilateral what should you think?

A

Infection inflammation cancer

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22
Q

Depending on where the mutation lies on the gene…

A

The phenotype will be different

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23
Q

Different mutations in the RDS/peripherin can cause…

A

Cone-rod dystrophy RP Pattern dystrophy

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24
Q

Different mutations in the rhodopsin gene can cause

A

RP CSNB

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25
Q

Different mutations in the CRX (cone-rod homeobox containing gene) can cause…

A

LCA Cone-rod dystrophy

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26
Q

Different mutations in the USH2A an cause…

A

Usher Usher type 3 (no hearing loss) 5%

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27
Q

Different mutations in the ABCA4 gene can cause

A

Stargardts RP Mike cone-rod Severe cone-rod

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28
Q

How to classify the Hereditary dystrophies?

A

1) macular dystrophies 2) diffuse photoreceptor dystrophyies 3) choroidal dystrophies 4) VR or inner retinal

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29
Q

Which are the diffuse photoreceptor dystrophies?

A

1) RP 2) RP variants - sectorial RP - central RP - pericentral RP - unilateral RP - retinitis punctata albescence 3) LCA 4) cone dystrophies 5) cone-rod dystrophies

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30
Q

Which are the choroidal dystrophies?

A

1) choroideremia 2) gyrate 3) regional - central areolar choroidal dystrophy - NC macular dystrophy m

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31
Q

Which are the VR/inner retina dystrophies?

A

XLRS Goldman-Favre syndrome

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32
Q

what are purines?

A

ATP, ADP

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33
Q

what is the muller cell function?

A

They regular the extracellular fluid balance.give homestotic and metabolic support to retinal neurons.

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34
Q

mullers cellc can be activated by?

A

any pathogenict mechanism

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35
Q

when are Purines release in the retina?

A

in the dark

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36
Q

muller cells have lots of which purine receptor?

A

P2X7

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37
Q

what happend to muller cells in hepatic or renal failure?

A

there is muller cell edemabecause the blood beomes diluted (hypoosmotic) and thus the fuid goes from extracellular space in to muller cells.

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38
Q

what happens to muller cel in diabetic retinopathy?

A

the ischemia and hypoxia downregulat and inactivate Kir 2.1 and Kir 4.1 (potassium channels).these Kir channels mediate K influx in to muller cellsAll these results in osmotic imbalance and edema of muller cells

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39
Q

how can steroids help in macular edema?

A

they can help in the non-leaking edema by stimulating clearance by muller cells.Triamcinolone inhibit Triamcinolone activates the final steps in the swellinginhibitorypurinergic signaling cascade

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40
Q

tell me the role of the purinergic system in macular edema?

A

the purinergic system inhibits swelllingtriamcinolone activates the purinergic system,

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41
Q

what is juvenile retinoschisis?

A

* x-linked * inherited VR disorder * of retinal splitting at the macula * 50% have the periphery affected affecting VF * affects 1:5K males in the Us and 1 in 25K worldwide

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42
Q

history of XLRS?

A

* first described by Haas in 1898 * names sex-linked Juvenile retinoschisis by Deutman in 1971

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43
Q

XLRS is a disease of…

A

BOYS BOYS BOYS

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44
Q

which is the pathognomonic findings in XLRS?

A

a spoke-wheel patternstarts at the fovea and radiates 1-1.5 DD

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45
Q

XLRS natural history

A

* starts early infancy * kids cant see at distance * get glasses for hyperopic astigmatism * later cant be corrected to 20/20 * fundus shows spoke wheel pattern * OCT confirms diagnosis * history in males in the family * peripheral retina affected in 2/3 peripheral retina appears as vitreous veils * it is an stationary condition as vision stays in the 20/60-20/100 but later macular atrophy develops and they become legally blind

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46
Q

what kind of scotoma does the peripheral schisis cause?

A

* ABSOLUTE scotoma * because the transmission of signal is interrupted by splitting

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47
Q

does XLRS present varied phenotypes?

A

the variabiloity is lowso the PENETRANCE is highas high as 95%meaning that 95% will have the macular splitting

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48
Q

what is the Mizuo-Nakamura phenomenon?

A

* the fundus appearance is different in the light adapted condition as compared to the dark adapted condition * in XLRs patients can have a macular sheen or beaten-bronze appearance in light adapted that dissapears in dark adapted

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49
Q

in XLRS * what is the affected gene? * what is the affected protein * what is the function of the protein?

A

* RS1 * RS retinoschisin * adhesion/stabilization

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50
Q

what happens in females with XLRS?

A

* its a disease for BOYS * females are carriers * they do not have retinopathy (except few case reports) * they can have mild ERG changes * even in those cases if the prtein RS is low, a little amount is enought to function. This is because they contain a combo o normal a mutant products * this means that for therapy, probably we only need to make the retin aproduce a little bit of the protein and not reach a normal level

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51
Q

which are the two forms of XLRS by age?

A

* <25 yo = cystic form * >25 yo atrophic form

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52
Q

what do you see in XLRS in: visual acuity HVF ​color test ERG

A

* decreased but stationary * normal except if peripheral schisis causing absolute scotoma * normal except in atrophic disease where you can see triptanopia. “electronegative form” with * normal a wave * reduced b-wave. This b-wave does not reach the baseline level. Yes, you can also see an electronegative wave in CSNB

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53
Q

differential diagnosis of electronegative wavemeaning:b wave that does not reach the baseline

A

CSNB * XLRS This si because the b wave is for bipolar and muller cells so its conduction and the conduction is afected in these two diseases.But CSNB causes nyctalopia and XLRS does not cause nyctalopia

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54
Q

XLRS differential diagnosis

A

acquired retinoschisis (both sex, bilateral, asymptomatic, older than 50, NFL splitting) Goldman-Favre (also VR, both sex, macular schisis, NO VEILS, severe ERG depression, and is AUTOSOMAL RECESSIVE) Wagner disease (autosomal DOMINANT, vitreous syneresis, macular pigment clumps and cataracts) Norrie Disease (also also x-linked bilateral in babies but bilateral retinal detachments and mental retardation and deafness) nicotinic acid maculopathy (bilateral CME that resolves after medication discontinuation)

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55
Q

where is the peripheral schisis more common in XLRS?

A

infero-temporal

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56
Q

who discovered the RS1 gene and when?

A

* Sauer in 1997 * the are more than 150 mutations identified * mutations in RS1 gene are present in 95% of XLRS patients *

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57
Q

what is heterogeneity?

A

Heterogeneity is a word that signifies diversity. A classroom consisting of people from lots of different backgrounds would be considered having the quality of heterogeneity.

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58
Q

name 4 syndromic IRDs?

A
  • Bardet-Biedl
  • Kearns-Sayre
  • Usher
  • Ahlstrom
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59
Q

name 5 vitreoretinopathies

A
  • Sticklers
  • Norriers
  • XLRS
  • Wagner
  • FEVR
  • ADNIV
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60
Q

name 2 choriodopathies

A

choroideremia

gyrate atrophy

61
Q

name 3 systemic retinal degenerations

A
  • abetalipoproteinemia
  • Batten
  • Refsum
62
Q
A
63
Q

RPE funcitons

A
  1. Visual pigment regeneration
  2. Phagocytosis of shed photoreceptors OS discs
  3. absorption of scattered light
  4. Transport
    1. nutrients from choroid to Ps
    2. waste products from Ps to choroid
  5. Retinal adhesion
  6. Blood -retinal barrier
  7. Elaboration of humoral and growth factors
64
Q

in the dark are the photoreceptors polarized or depolarized and what is the voltage?

A

in the dark the Ps are DEPOLARIZED

at 40 mv

65
Q

in th ephotoreceptors there are chanels. Are they open or close in dark and in light?

A
  • in the dark - they remain open (keeps current at -40mv
  • in the light the channels are closed: (sodium channels) to hyperpolarize the cell so the
    • 11-cis-retinal converts to
    • all-trans-retinal
      *
66
Q

what are the benefits for the patient to do genetic testing?

A
  1. Confirm diagnosis
  2. r/o syndromic disease
  3. Determine inheritance and decide if family needs to be tested.
  4. Have an idea of prognosis
  5. Characterization for possible enrollement in CT.
67
Q

Tips for ordering genetic testing

A
  • Dont test asymptomatic minors with untreatable diseases
  • Offer testing to patients with findings suggestive of mendelian disease
  • Provide a copy of each report to patient
  • order the most specific testing based on patient’s findings
    *
68
Q
A
69
Q

what is the group with the highest incidence of RP?

A

the Navajo indians (largest native-american indian tribe (many states)

70
Q

first person who described RP?when?

A

Donders in 1855

71
Q

when does nyctalopia appear in RP patients?

A
  1. 7 years median in AR
  2. 4 years in AD

by Tanino and Ohba study

72
Q

disorders causing nyctalopia?`

A
  1. RP
  2. CSNB
  3. AMD
  4. myopia
73
Q

what visual fields is affected first in RP?

A

the supeiror VF

because the inferior retina gets affected first

Although this is not always true and other fields can go first

74
Q

what is the average rate of VF progression? by Berson et al.

A
  • Berson et al
  • 4.6% per year
  • this means that will loose 100% in 20 years…
  • Massof et al
  • 50% in 4.5 years in most forms of RP
  • this means 100% in 10 years
75
Q

what is the 2-stage hypothesis for RP progression?

A

Massof an dFlinkelstein

  • PREDISPOSITION stage (genetic and enviromental factors act here)
  • DEGENERATION stage
76
Q

is VF loss symmetric? in all RPs?

A

yes EXCEPT for females carriers of XL-RP

the distribution of mutant photoreceptor is determined by lyonization (x-chromosome inactivation) This is a random process that determines which chromosomes act on each cell.

77
Q
  • does central vision remain good until the VF is gone?
    • CME
    • pre-retinal fibrosis - ERM
    • RPE deffects
A

not true. Central VA can be affected by:

78
Q

what are predictive factors of retaining good central vision and what of loosing central vision?

A
  • Retain good central vision
    • sectorial RP
    • adRP
  • Poor central vision
    • AP
    • XL-RP (usually blind by age 30-40)
  • Good prognostic sign to have ERG amplitudes >100 uV
79
Q

color vision affected in RP?

A

not until central vision worse than 30/40

80
Q

what % of RP can have photopsias? are they always benign? what is the reson for them?

A

35% but some of them could be RD so have to examine eanywas

the photopsias subside with time as they are located at the edge of scotomas ans once they grow the phootpsias disapear.

81
Q

is RP sine pigmento a different disease or subtype?

A

NO

all RP patients pass through this at one point of their life

82
Q

what are the first funduscopic changes in RP?

A

vessel attenuation

and

RPE granularity

83
Q

what is the pathophysiology of bone spicules?

A

they are the desintegration of RPE

that migrate to the superficial retina

and accumulate in the perivascular intersticial spaces (that is why they are spicules (in between arborization of capillaries)

84
Q
A
85
Q

DDx of CME?

A
  1. DME
  2. Irvine-Gass
  3. Vein occlusions
  4. RP
  5. Pars-planitis
  6. Meds
    1. epinephrine
    2. prostaglandines
    3. nicotinic acid
86
Q

DDx of negative ERG?

causes of non-pathologica decreased ERG?

A

ELECTRONEGATIVE ERG:

  1. CSNB
  2. XLRS
  3. CRAO/CRVO
  4. myotonic dystrophy
  5. Duchene dystrophy
  6. Quinine

NON-PATHOLOGIC DECREASED ERG

  1. High myopia
  2. decreases with age
87
Q

which are the stationary Rod disorders?

which the stationary cone disorders?

A

STATIONARY ROD DISORDERS

  • CSNB
  • fundus albinopuntatus
  • Oguchi disease

STATIONARY CONE DISORDERS

  • achromatopsia
  • rod monochromatism
  • blue-cone monochromatism
88
Q

what is a nice classification of retinochoroidal dystrohies?

A
  1. STATIONARY
    1. ROD
    2. CONES
  2. PROGRESSIVE
    1. ROD
    2. CONES
  3. CHOROIDAL & RPE DISORDERS

STATIONARY ROD DISORDERS

  • CSNB
  • fundus albinopuntatus
  • Oguchi disease

STATIONARY CONE DISORDERS

  • achromatopsia
  • rod monochromatism
  • blue-cone monochromatism
  • LCA

PROGRESSIVE ROD DISORDERS

  • RP
  • RP variants
    • Sectorial
    • Inverse
    • RPA albescens
    • RP sine pigmento
  • RP with systemic
    • Hereditary abetalipoproteinemia (Bassen-Kornzweig)
    • Refsum disease
    • NCL neuronal ceroid lipofuscinosis
    • Bardet-Biedl
    • Usher syndrome
    • CPEOP/Kearns-Sayre

PROGRESSIVE CONE DISORDERS

  • Cone dystrophy
  • Goldman-Favre Syndrome
  • ESCS
  • Retinoschisis
  • Stargardts
  • RPE dystrophies
    • Best
    • AOFMVD
    • Pattern dystrophies
    • NC Macular dystrophy
    • Sorsby Dystrophy

CHOROIDAL AND RPE DYSTROPHIES

  • Familial dominant drusen
  • Central Areolar Choroidal dystrophy
  • Gyrate atrophy
  • Choroideremia
89
Q

NAME THE STATIONARY RETINAL DYSTROPHIES

A

STATIONARY ROD DISORDERS

  • CSNB
  • fundus albinopuntatus
  • Oguchi disease

STATIONARY CONE DISORDERS

  • achromatopsia
  • rod monochromatism
  • blue-cone monochromatism
  • LCA
90
Q

NAME THE PROGRESSIVE ROD AND CONE RETINAL DYSTROPHIES

A

PROGRESSIVE ROD DISORDERS

  • RP
  • RP variants
    • Sectorial
    • Inverse
    • RPA albescens
    • RP sine pigmento
  • RP with systemic
    • Hereditary abetalipoproteinemia (Bassen-Kornzweig)
    • Refsum disease
    • NCL neuronal ceroid lipofuscinosis
    • Bardet-Biedl
    • Usher syndrome
    • CPEOP/Kearns-Sayre

PROGRESSIVE CONE DISORDERS

  • Cone dystrophy
  • Goldman-Favre Syndrome
  • ESCS
  • Retinoschisis
  • Stargardts
  • RPE dystrophies
    • Best
    • AOFMVD
    • Pattern dystrophies
    • NC Macular dystrophy
    • Sorsby Dystrophy
91
Q

name the choroidal and RPE dystrophies

A

CHOROIDAL AND RPE DYSTROPHIES

  • Familial dominant drusen
  • Central Areolar Choroidal dystrophy
  • Gyrate atrophy
  • Choroideremia
92
Q

what is the flynn phenomenon?

A
  • its a paradoxical CONSTRICTION of the pupils in THE DARK
  • seen in:
    • CSNB
    • achromatopsia
    • LCA
    • DOA
93
Q
  • which disease is caused by prolonged recovery of rhodopsin after light exposure?
  • inheritance?
  • what are the symptoms
  • clinical findings?
  • ERG findings?
  • types?
  • Variants?
A
  • CSNB
  • X-linked but… there are variants:
    • Autosomal dominant
      • Nougaret (no rods)
    • Autosomal Recessive
      • Oguchi disease (CSNB+AR+Mizuo-nakamura)
      • Fundus albinopunctatus (CSNB+AR+white dots)
      • Riggs (some rods)
  • Symptoms?
    • nyctalopia
    • delayed dark adaptation
  • normal fundus
  • ERG sctoopic abnormal but recovers if DA x 2-3 h
  • ERG photoopic normal
94
Q

what is this?

A
  • ist FUNDUS ALBINOPUNCTATUS
    • variant of CSNB
    • AR
    • Due to slow visual pigment regeneration
    • produces:
      • nyctalopia
      • DELAY in DARK ADAPTATION
        • detected by dark-adaptation curve and ERG
    • multiple discrete, round, white lesions at RPE (similar to RPA)
    • ERG scotopic abnormal
    • ERG photopic normal
    • abnormal EOG
    • if oyu leave patient in darg x 2-3 h then ERG scotopic will be normal
    • cones can be affected in some cases with a bull’s eye maculopathy
      *
95
Q

what is and where do you see the

Mizuo-Nakamura phenomenon?

A

ita a Gold or silver looking retina in LIGHT

that turns normal after dark adaptation

Seen in:

Oguchi disease

XLRS

cone-rd dystrophy

96
Q

a kid with nyctalopia and decreased scotopic ERG?

is the inheritance important?

A
  • CSNB
  • X-linked but… there are variants:
    • Autosomal dominant
      • Nougaret (no rods)
    • Autosomal Recessive
      • Oguchi disease (CSNB+AR+Mizuo-nakamura)
      • Fundus albinopunctatus (CSNB+AR+white dots)
      • Riggs (some rods)
  • Symptoms?
    • nyctalopia
    • delayed dark adaptation
  • normal fundus
  • ERG sctoopic abnormal but recovers if DA x 2-3 h

ERG photoopic normal

97
Q

what is funduc albinopuntatus?

what is a similar looking disease?

A

Fundus albinopunctatus looks similar to RPA

FAP is stationary but RPA is progressive

  • variant of CSNB
  • AR
  • Due to slow visual pigment regeneration
  • produces:
    • nyctalopia
    • DELAY in DARK ADAPTATION
      • detected by dark-adaptation curve and ERG
  • multiple discrete, round, white lesions at RPE (similar to RPA)
  • ERG scotopic abnormal
  • ERG photopic normal
  • abnormal EOG
  • if oyu leave patient in darg x 2-3 h then ERG scotopic will be normal
  • cones can be affected in some cases with a bull’s eye maculopathy
98
Q

patient with achromatopsia?

is this good news or bad news?

A

well…. its kind of good news

because its stationary

  • Achromatopsia
    • poor central vision
    • nystagmus
    • photophobia
    • poor color perception
    • NORMAL FUNDUS
    • paradoxical pupil constriction in Dark
    • SUBTYPES:
      • Rod monochromatism
        • AR (CNGA3, CNGB3, GNAT2, PDE6C)
        • No cone function at all
        • Rods normal
        • Sees gray
        • Flat photopic response
      • Blue cone monochromatism
        • XR (OPN1W, OPN1MW)
        • Only blue cones functional
        • Slightly better than rod monochromatism
99
Q

what disease is related to CNGA3?

A

achromatopsia!!!!!!!

CNGA3, CNGB3 and GNAT2

  • Achromatopsia
    • poor central vision
    • nystagmus
    • photophobia
    • poor color perception
    • NORMAL FUNDUS
    • paradoxical pupil constriction in Dark
    • SUBTYPES:
      • Rod monochromatism
        • AR (CNGA3, CNGB3, GNAT2, PDE6C)
        • No cone function at all
        • Rods normal
        • Sees gray
        • Flat photopic response
      • Blue cone monochromatism
        • XR (OPN1W, OPN1MW)
        • Only blue cones functional
        • Slightly better than rod monochromatism
100
Q

what gene is related to blue cone monochromatism?

A

OPN1W and OPN1MW

  • Achromatopsia
    • poor central vision
    • nystagmus
    • photophobia
    • poor color perception
    • NORMAL FUNDUS
    • paradoxical pupil constriction in Dark
    • SUBTYPES:
      • Rod monochromatism
        • AR (CNGA3, CNGB3, GNAT2, PDE6C)
        • No cone function at all
        • Rods normal
        • Sees gray
        • Flat photopic response
      • Blue cone monochromatism
        • XR (OPN1W, OPN1MW)
        • Only blue cones functional
        • Slightly better than rod monochromatism
101
Q

what is the inheritance for

achromatopsia

Rood monochromatism

blue cone monochromatism

A

achromatpsia AR

rod monochromatism AR

blue conce monochromatosm X-linked

102
Q

how is this inherited?

  • achromatopsia
  • rod monochromatism
  • bluie cone monochromatism
  • protanopia/deuteranopia
  • tritanopia
A
  • achromatopsia AR
  • rod monochromatism AR
  • bluie cone monochromatism XR
  • protanopia/deuteranopia XR
  • tritanopia AD
103
Q

comment about color tests, what are they good for?

  • Ishihara
  • D-15
  • Anomaloscope
  • Hardy-Rand
A
  • Ishihara (pseudochromatic plates) - detects red-green defect
    • only good for protanopia/deuteranopia
    • to be color defficient you need to miss >4 plates
  • D-15 - detects protan, deutan AND TRITAN (aquired is blue-yellow)
    • distinguishes acquired vs inherited
  • Anomaloscope - detects only red defect
    • luminosity matching
    • good for protanopia/deuteranopia
  • Hardy-Rand
    • like ishihara but detects all 3 color deficits.
104
Q

color defficiency is more common in males or females?

why?

which is the most common form of color deff?

can they see colors?

what are the 3 main deffects?

color test available?

A
  • more common in males 8% vs 0.5%
  • this is because its an X-linked disease so boys are affected
  • red-green is the most common
  • yes they can see colors but they have different shades
  • 3 types:
    • 1) monochromatism
    • 2) dichromatism
    • 3) Anomalous trichromatism
  • color test:
    • The best to distinguish color deficiencies is theAnomaloscope
      • Most accurate
      • Looks like a manual lensometer
    • Most famous:
      • Ishihara pseudochromatic plates
      • Only to detect red-green deficiencies
      • 14 plates
        *
105
Q

how many rods we have?

how many cones?

how many cone types? how do you call their coolor axis?

which is the best test for color defficiencies?

which is the most famous color test? what CD detects?

what CD is detected by D-15?

which test distinguishes inherited vs aquired color defficiencies?

A
  • 120 million rods
  • 6-7 million cones
  • 3 types fo cones (remember PDT - red-green-blue)
    • P Protan Red
    • D Deutan Green
    • T Triptan Blue
  • best color test ia anomaloscope - NOW the COMPUTER COLOR TESTS
  • most famous Ishihara
    • detects only red-green defficiencies
  • D-15 detects red,gree, blue (protan, deutan, tritan axis)
  • D-15 is the only that detects the blue tritan so the only that detects aquired color defficiencies because aquired are blue defficiencies
  • secondary aquired causes are:
    • alcohol abuse
    • trauma
    • glaucoma
    • aginig
106
Q

what is the practical difference between Ishihara and D-15?

A

ishihara detects red-green defficiencies

D-15 red-green-blue

107
Q

are rods or cones affected in LCA?

inheritance?

what is the triad?

A

rods and cones

AR

  • triad
    • nystagmus
    • flat ERG
    • poor pupillary responses
    • poor vision
    • others
      • oculodigital reflex
      • PARADOXIC PUPILS
108
Q

inheritance and behaviour of

LCA

CSNB

A
  • LCA: AR ; stationary - severe
  • CSNB: X-linked - stationary
109
Q

in RP patients;

  • what is th ecolor defficiency?
  • what is the classical HVF?
  • how much does ERG progresses ini 7 years?
  • what refractive error?
  • inheritance?
A
  • tritan!!!!!!!!!!!
  • mid-peripheral scotomas lead to RING scotoma
  • ERG decreased by 50% in 7 years
  • myopia
  • AD: least severe
      • Rhodopsin - Ch3 - most common
    • RDS/peripherin
    • P23H
  • X-lilnkedR:
    • least common
    • earliest onset, fastest progression
    • worse prognosis
110
Q

what refractive erros is associated with RP?

which with LCA?

A

RP with high myopia

LCA with high hyperopia

111
Q

what is the least severe inherited form of RP?

A

AD by rho mutation

tritan!!!!!!!!!!!

mid-peripheral scotomas lead to RING scotoma

ERG decreased by 50% in 7 years

myopia

AD: least severe

  • Rhodopsin - Ch3 - most common

RDS/peripherin

P23H

X-lilnkedR:

least common

earliest onset, fastest progression

worse prognosis

112
Q

What is Refsum disease?

wat do you find in LABS?

exam findings?

inheritance?

systemic finidings?

treatment

A
  • Its an RP variant
    • RP + phytanic acid oxidase deficiency
  • high phytanic acid, cooper and ceruloplasmin
  • NO BONE SPICULES but enlarged corneal nerves
  • AR (Ch7 - PEX1)
  • systemic
    • ataxia
    • deafness
    • anosmia
    • ichtyosis
    • cardiomiopathy
    • short 4rth toe
  • treatment: low phytanic acid (avoid fats and milk)
113
Q

what could this be?

A

short 4rth toe in REFSUM DISEASE (AR)

RP + phytanic acidemia!

114
Q

what is the earliest appearing inherited form of RP?

A

X-linked and also the one with worse prognosis

tritan!!!!!!!!!!!

mid-peripheral scotomas lead to RING scotoma

ERG decreased by 50% in 7 years

myopia

AD: least severe

  • Rhodopsin - Ch3 - most common

RDS/peripherin

P23H

X-lilnkedR:

least common

earliest onset, fastest progression

worse prognosis

115
Q

what is RP + Phytanic acidemia?

A
  • Refsum disease (AR)
    • High phytanic acid
    • No bone spicules
    • Enlarged K nerves
    • Ataxia
    • Deafness
    • Anosmia
    • Cardiomyopathy
    • Short 4th toe
116
Q

what is the name for hereditary abetalipoproteinemia?

what is the inheritance?

A
  • Bassen Kornzqeig
  • is RP + hereditary abetalipoproteinemia
  • has ataxia and acanthocytosis
  • Also AR
  • treatment:
    • low fat diet
    • Vitamin A + E supplementation
117
Q

name the RP variants (RP + something)

A
  • RP + Phytanic acidemia = Refsum disease
  • RP + inherited abetalipoproteinemia = Bassen-Korn
  • RP + neuronal ceroid lipofuscinosis = Batten disease
  • RP + polydactyly + obesity = Bardet-Biedl
  • RP + Spactic paresis = Lawrence moon
  • RP + deafness = Usher Sydnrome
  • RP + Deafness + obesity + endocrine problems = Alstrom
  • RP + CPEO + Ptosis = Kearns-Sayre
118
Q

RP + neuronal ceroid lipofuscinosis

A
  • Batten disease (AR)
    • Lipofuscin accumulates in lysosomes
    • Seizures
    • Dementia
    • Ataxia
    • Vacuolization of peripheral lymphocytes
119
Q

whic disease is RP + retinoschisis?

how is the EOG different form XLRS?

A

Goldman-Favre/ ESCS

  • AR
  • no rods
  • only cones and 92% are S-cones
  • nyctalopia
  • numular yellow lesions
  • macular cysts
  • OPTICALLY-EMPTY vitreous

EOG is normal in XLRS

EOG is abnormal in ESCS

120
Q

how is XLRS different from Senile retinoschisis?

A
121
Q

Bardet-Biedl (AR)

A
  • RP + polydactyly + obesity = Bardet-Biedl (AR)
    • Short stature
    • Hypogonadism
    • Mental retardation
    • Urethral reflux/pyelonephrosis
122
Q

what is the inheritance for the syndromeic RPs?

A

All are AR

  • RP + Phytanic acidemia = Refsum disease (AR)
    • High phytanic acid
    • No bone spicules
    • Enlarged K nerves
    • Ataxia
    • Deafness
    • Anosmia
    • Cardiomyopathy
    • Short 4th toe
  • RP + inherited abetalipoproteinemia = Bassen-Korn
    • Low vitamin A
      • RP + neuronal ceroid lipofuscinosis = Batten disease (AR)
    • Lipofuscin accumulates in lysosomes
    • Seizures
    • Dementia
    • Ataxia
    • Vacuolization of peripheral lymphocytes
  • RP + polydactyly + obesity = Bardet-Biedl (AR)
    • Short stature
    • Hypogonadism
    • Mental retardation
    • Urethral reflux/pyelonephrosis
  • RP + Spactic paresis = Lawrence moon
  • RP + deafness = Usher Sydnrome
  • RP + Deafness + obesity + endocrine problems = Alstrom syndrome
    • Alstrom Syndrome (DM, hypertriglyceridemia)
  • RP + CPEO + Ptosis = Kearns-Sayre
123
Q

which are the progressive cone disorders?

A

PROGRESSIVE CONE DISORDERS

  • Cone dystrophy
  • Goldman-Favre Syndrome
  • ESCS
  • Retinoschisis
  • Stargardts
  • RPE dystrophies
    • Best
    • AOFMVD
    • Pattern dystrophies
    • NC Macular dystrophy
    • Sorsby Dystrophy
124
Q

are the vessels attenuated in cone dystrophy?

how about in cone-rod dystrophy?

A

normal vessels in cone-dystrophy

attenuated vessels in CRD because its a type of RP

125
Q

difference XLRS and senile retinoschisis

A
126
Q

what is the phenotypical difference between these?

how to tell difference?

A
  • NC and Sorsby look VERY SIMILAR!!
  • both are AD

THE DIFFERENCES:

  • NC mac dyst
    • Ch 6 - MCDR1
    • Non-progressive
    • STAPHYLOMATOUS
    • suprisinigly good vision
  • Sorsby Dystrophy
    • Ch 22q - TIMP3 gene
    • Poor prognosis :(
    • god vision until 40’s then down the hill
    • BILATERAL CNVs
    • pseudoinflammatory appearance - dark pigment
127
Q

what is the differential when you see a large central macular atrophic lesion in a

relatively YOUNG patient?

A
  • NCMacular dystrophy - AD
  • Sorsby - AD
  • Central areolar Choroidal dystrophy - AD
  • Stargardts - AR
  • Familial dominant drusen AKA Doyne Honeycome dystrophy
128
Q

choroidal dystrophies? name the only TWO

inheritance?

are they enzymatic deffects?

symptoms?

treatment for any?

A
129
Q

where is the splitting in XLRS and adult retinoschisis

A
  • XLRS: splitting at NFL (young people watch NFL0
  • adult senile schisis: at OPL (old people)
130
Q

what is the inheritance and enzimatic defect of choroideremia?

A

XR

CHM gene

Geranyl transferase

131
Q

DDx of

1) salt and peper fundus
2) cherry red spot
3) RDS/peripherin

A
132
Q

if you see schisis at the infero-temporal region in an adult what to think?

A

senile retinoschisis

at OPL

many times bilateral

progression to RD 3%

has ABSOLUTE scotoma (relative in RD) so this si reverse from what one would think

Blanches with laser

hyperopia

dome shaped

133
Q
A

gyrate atrophy

  • AR
  • Ch10
  • Ornithine aminotransferase
  • nyctalopia
  • young
  • VF loss
  • peripheral pavinstone
  • decreased EOG but normal ERG
  • TTM:
    • restrict arginine!!!
    • vit B6
134
Q

which is a disease of increased ORNITINE?

A

gyrate atrophy (OAT gene) AR Ch10

Tmt: restirct arginine!!!!!!!!!!

135
Q

what is this?

A

choroideremia

  • X-liked recessive
  • Geranyl transferase
  • nyctalopia, photophobia
  • young
  • constricted VF
  • central VA good
  • decreased ERG and EOG
  • feale carriers: SLAT and PEPPER
136
Q

what scotoma do you see in RD and

senile retinoschisis?

A

RD : Relative scotoma

retinoschisis: ABSOLUTE

137
Q

best disease inheritance and mutation?

A

AD

Ch 11

Best1 - bestrophyn

Arden ration <1.2 diagnostic; <1.5 borderline

139
Q

which are the pattern dystrophies?

A
  • they all are:
    • AD
    • due to RDS/peripherin
    • age 20-40
    • CNV rare
    • yellow deposits
  • they are:
    • AOVFMV
    • betterfly
    • reticular
    • Fundus pulvurilentus
      *
141
Q

what is the inheritance in NC macdyst and sorsby?

A

both are AD

THE DIFFERENCES:

NC mac dyst

  • Ch 6 - MCDR1
  • Non-progressive
  • STAPHYLOMATOUS
  • suprisinigly good vision

Sorsby Dystrophy

  • Ch 22q - TIMP3 gene
  • Poor prognosis :(
  • god vision until 40’s then down the hill
  • BILATERAL CNVs
  • pseudoinflammatory appearance - dark pigment
144
Q

what is the defect and treatemtn for gyrate atrophy?

A
  • gyrate atrophy
    • Ornithine aminotransferase
    • AR - Ch 10
    • treatment :
      • Vit B6 supplement
      • restirct arginine
147
Q
A
151
Q

DDx of cherry red spot?

A

tay-chachs

CRAO

trauma

152
Q

DDx of RDS peripherin

A
  • RP
  • pattern dystrophy
  • central areolar choroidal dystrophy
  • cone-rod dystrophy
153
Q

albinism inheritance? OA and OCA

A

OCA —- AR

OA ——-AR & XR

154
Q

name the syndromic RPs

A
  1. RP+ Hx of malnutrition or colon problems =Hereditary abetalipoproteinemia (Bassen-Kornzweig)
  2. RP+hearing loss+anosmia+ataxia = Refsum disease
  3. RP+seizure = NCL neuronal ceroid lipofuscinosis
  4. RP+Obesity+hypogonadism = Bardet-Biedl
  5. RP+hearinig loss+ balance issues= Usher syndrome
  6. RP+CPEO+Ptosis = CPEOP/Kearns-Sayre
155
Q
  • how many degrees of the field of view are tested with the following:
    • Amsler
    • HVF 10-2
    • HVF 24-2
    • HVF 30-2
    • Tangent scree:
    • GVF
A
  • Amsler ———-> central 20
  • HVF 10-2 ———-> 20 degrees
  • HVF 24-2 ———-> 48 degrees (48 in vertical but 54 in horizontal)
  • HVF 30-2 ———-> 60 degrees
  • Tangent scree:———-> 30 degrees sitting at 1m
  • GVF———-> 180 degrees
156
Q
  • ON HVF:
  • which patient is the trigger happy on HVF?
  • sleepy, slow, unmotivated patient
  • patient presses button on the blind spot
  • marker of retinal sensitivity
    *
A
  • trigger happy is FALSE POSITIVES
  • FALSE NEGATIVES
  • fixation losses
  • the MD is a marker of retinal sensitivity
157
Q

how can you tell a patient on HVF is a trigger happy?

A
  • due to HIGH FALSE POSITIVES
158
Q

how can you tell the patient was falling asleep or was desmotivated ot tired during HVF?

A

due to HIGH FALSE NEGATIVES

Genetics Fellowship (22 decks)

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