GENERALIZED PHOTORECEPTOR DYSTROPHIES

Question 1

Retinitis pigmentosa - cone or rod

Answer 1

rod-cone dystrophy

Question 2

most common hereditary fundus dystrophy

Answer 2

Retinitis pigmentosa

Question 3

prevalence RP

Answer 3

1:5000

Question 4

RP gene

Answer 4

rhodopsin gene

Question 5

RP - least common form

Answer 5

XLR

Question 6

most severe form of RP

Answer 6

XLR

Question 7

best prognosis of RP

Answer 7

AD

Question 8

atypical / syndromic RP - %

Answer 8

20-30%

Question 9

atypical / syndromic RP - genetics

Answer 9

AR or mitochondrial inheritance

Question 10

RP - triad

Answer 10

bone-spicule retinal pigmentation, arteriolar attenuation and ‘waxy’ disc pallor

Question 11

RP first affects (which test)

Answer 11

contrast sensitivity

Question 12

RP - ancillary tests

Answer 12

Full-field ERG - reduced scotopic rod and combined responses; photopic responses reduce with progression. Multifocal ERG may provide more specific information. EOG is subnormal. DA is prolonged

Question 13

RP - who benefit from lutein

Answer 13

Patients with mutations in gene RHO1

Question 14

RP - lutein, in whom avoided

Answer 14

in patients with ABCA4 mutations

Question 15

syndromic RP

Answer 15

(5) Usher syndrome, Kearns–Sayre syndrome, Bassen–Kornzweig syndrome or abetalipoproteinaemia, Refsum disease, Bardet-Biedl syndrome

Question 16

Usher syndrome - genetics

Answer 16

AR

Question 17

Kearns–Sayre syndrome - genetics

Answer 17

mitochondrial inheritance

Question 18

Kearns–Sayre syndrome

Answer 18

chronic progressive external ophthalmoplegia with ptosis. salt and pepper appearance most striking at the macula; less frequent findings are typical RP or choroidal atrophy similar to choroideremia

Question 19

Bassen–Kornzweig syndrome or abetalipoproteinaemia - genetics

Answer 19

AR

Question 20

Bassen–Kornzweig syndrome or abetalipoproteinaemia

Answer 20

fat and fat-soluble vitamin (A,D,E,K) absorption is dysfunctional, severe spinocerebellar ataxia, ‘thorny’ red cells (acanthocytosis), RP-like changes developing towards the end of the first decade

Question 21

Refsum disease - genetics

Answer 21

AR

Question 22

Refsum disease

Answer 22

Phytanic acid accumulates, similar to RP or take on a salt and pepper appearance

Question 23

Bardet–Biedl syndrome - genetics

Answer 23

genetically heterogeneous

Question 24

Bardet–Biedl syndrome

Answer 24

polydactyly and mental handicap. typically a bull’s-eye maculopathy due to cone-rod dystrophy and less frequently typical RP, RP sine pigmento and retinitis punctata albescens

Question 25

Leber congenital amaurosis

Answer 25

severe rod-cone, ERG non-recordable ○ 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.

Question 26

Pigmented paravenous chorioretinal atrophy

Answer 26

(AD) asymptomatic, non-progressive, ERG normal, bone-spicule together with sharply outlined zones of chorioretinal atrophy that follow the course of the major retinal veins