Retinal Dystrophies 1 Flashcards
Retinal Dystrophies
hereditary disorders that affect outer retina- photoreceptors and RPE
both eyes
Retinitis Pigmentosa
rods affected before cones
atypical forms can be associated with systemic disorders
Symptoms of Retinitis Pigmentosa
night blindness
Appearance of Retinitis Pigmentosa
retinal bone spicule pigmentary changes
narrowing of retinal arteries
waxy optic disc pallor
possible macular changes- ERM, CME, atrophy
RP Sine Pigmento
atypical RP
pigmentary changes initially absent or minimal
Sector RP
atypical RP
pigmentary changes only in 1 or 2 quadrants
Retinitis Punctata Albescens
atypical RP
scattered whitish spots, mostly near equator
Ocular Associations of Retinitis Pigmentosa
cataracts myopia optic nerve drusen glaucoma keratoconus PVD
Usher’s Syndrome
hearing loss + RP
Diagnosis of RP
visual fields
ERG
dark adaptometry
Leber’s Congenital Amaurosis
affects both rods and cones at birth- born legally blind
babies with wandering eyes- nystagmus
associated with neurological, renal, bone, endocrine abnormalities
Diagnosis of Leber’s Congenital Amaurosis
suspected for babies born with wandering eyes/ nystagmus
pupils show little or no response to light
ERG severely reduced
fundus initially normal
Presentation of Leber’s Congenital Amaurosis
progressive RPE degeneration and narrowing of retinal arterioles
severe macular pigmentation or atrophy
optic nerve atrophy
oculodigital syndrome causing enophthalmos
Albinism
abnormal synthesis of melanin
affects eyes alone or eyes and skin and hair
Tyrosinase Negative Oculocutaneous Albinism
no melanin production
white hair and pale skin
iris and fundus have no pigmentation
Tyrosinase Positive Oculocutaneous Albinism
reduced melanin production
lighter hair and skin
iris translucency and iris hypopigmentation
Ocular Albinism
melanin deficiency limited to eyes
skin and hair normal
males show iris and fundus hypopigmentation, females normal
Ocular Presentation of Albinism
light sensitivity reduced VA from foveal hypoplasia high refractive error iris translucency fundus shows choroidal vessels reduced/ absent stereopsis
Ocular Mx of Albinism
correct refractive error
tinted lenses
low vision services
Systemic Problems of Albinism
increased risk of basal and squamous cell carcinoma
Stargardt’s Disease
abnormal acumulation of lipofuscin within RPE
Presentation of Stargardt’s Disease
in children
unexplained gradual vision loss
macula appears beaten bronze, progresses to bull’s eye atrophy
light colored flecks in mid periphery- fundus flavimaculatus
Diagnosis of Stargardt’s Disease
macular changes with surrounding flecks
FA shows dark choroid from lipofuscin accumulation blocking florescence
fundus autofluorescence
abnormal EOG
Mx of Stargardt’s Disease
no tx
poor prognosis- 20/200
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