Download - VASCULAR AND HEREDITARY RETINAL DISEASE
VASCULAR AND HEREDITARY RETINAL
DISEASE
Dr Russell J Watkins
Hypertension Affects 15-20% of the population Asymptomatic (if essential) Morbidity arises from complications
Ischaemic heart disease Cerebrovascular disease Renal failure
Appropriate treatment prevents complications
Hypertension Definitions (WHO & ISH)
Normotension systolic <140mmhgdiastolic <90mmhg
Borderline systolic >140 to <160diastolic >90 to <95
Hypertension systolic >160diastolic >95
Hypertension Essential hypertension
95% of hypertension is idiopathic Secondary hypertension
5% is due to other medical conditions• Mainly renal disease• Other causes very rare
Hypertension Both essential & secondary hypertension can be
subclassified as Benign Malignant or accelerated
Hypertension The spectrum of hypertensive eye disease
[Arteriosclerotic retinopathy] Hypertensive retinopathy CRVO/BRVO CRAO/BRAO AION Cranial neuropathies
Hypertensive Retinopathy Grading
Grade 1: arteriolar silver wiring Grade 2: grade 1 changes + AV nipping Grade 3: grade 2 changes + haemorrhage,
exudate & cotton wool spots Grade 4: grade 3 changes + disc swelling
Macular star Occurs if exudates collect in Henle’s layer
Arteriosclerotic Retinopathy NOTE not ATHEROsclerosis
Usually associated with hypertension Accelerated by DM
Arteriosclerotic Retinopathy Signs
AV nipping (Salus’ sign) Dilated vein distal to AV crossing (Bonnet’s sign) Tapering of vein either side of AV crossing (Gunn’s
sign) Right angle deflection of vein Arteriolar “silver wiring” Ischaemic choroidal infarcts (Elschnig bodies) Retinal arterial macroaneurysm Ischaemic optic neuropathy
Retinal Macroaneurysm Occurs in
Elderly hypertensive patients Arteriosclerotic patients
Single or multiple Usually at posterior pole
Retinal Macroaneurysm Outcomes:
May occlude spontaneously May bleed - trilayer haemorrhage May leak → circinate exudate ±macular
oedema Management
Refer as priority Either managed conservatively or undergo
focal/grid photocoagulation
Retinal Vein Occlusion Causes
Pressure on the vein• AV nipping, ↑IOP
Vessel wall disease• DM, periphlebitis
Hyperviscosity• Hyperlipdaemia, polycythaemia, myeloma,
leukaemia
Retinal Vein Occlusion Clinical signs
Dilated veins Flame shaped haemorrhages Retinal oedema CWS Venous sheathing (occasionally arterial) Exudates
Retinal Vein Occlusion Complications
Macular oedema NVD & NVE
• Tractional RD• Rubeosis (100-day glaucoma)
Optometric management Referral as priority for investigation of
underlying cause Photocoagulation if marked ischaemia/NV
Retinal Artery Occlusion Causes
External pressure• CAG, RD surgery
Vessel wall disease• Atheroma, arteritis (GCA, PAN, SLE)
Embolisation• Carotid, cardiac wall or valve
Retinal Artery Occlusion Types of embolus
Cholesterol (Hollenhorst plaques) Fibrinoplatelet (amaurosis fugax) Calcific (usually permanent occlusion)
Retinal Artery Occlusion Clinical features
Sudden painless loss of vision Field defect if BRAO APD White, oedematous retina with reflex from
choroidal vessels visible at fovea (cherry red spot)
~20% develop rubeosis Optic atrophy with no other features
Retinal Artery Occlusion Optometric management
Refer as emergency• May be GCA, though this is less likely than
embolus• Recovery unlikely (but possible)
Possible measures• Ocular massage in supine position• IV acetazolamide• AC paracentesis• CO2 rebreathing
Retinopathy of Prematurity A cicatrising or proliferative retinopathy affecting
premature babies ? Exposure to high levels of oxygen In the UK, all neonates <32/40 gestation are
screened Severe ROPs are treated with photocoagulation
or cryotherapy Classification depends on degree of peripheral
retinal changes, fibrovascular proliferation & vitreoretinal traction
The most severe ROP causes total RD & 2° ACG
Hereditary retinal disease…
Retinitis Pigmentosa Group of progressive bilateral disorders of retinal
photoreceptor/RPE complex Triad of
Night blindness Visual field defect Typical fundal appearance
RP may be familial RP may be associated with other defects & may
be the result of a syndrome
Retinitis Pigmentosa Symptoms
Night blindness Visual difficulties because of field loss Photophobia & glare
Patients with RP may have Myopia PSCLO Keratoconus Optic disc drusen Glaucoma CMO
Retinitis Pigmentosa Early signs
↓dark adaptation Annular scotoma Equatorial patchy RPE atrophy & hypertrophy Attenuated retinal vessels
Retinitis Pigmentosa Late signs
Tubular fields (2-3°) Bone corpuscle pigmentation Choroidal atrophy Retinal venous sheathing Drusen Waxy optic atrophy
Retinitis Pigmentosa Inheritance (varies with geographical location)
AR 51% AD 26% XLR 23%
Prognosis 25% maintain adequate reading vision LVAs usually required
Retinitis Pigmentosa Atypical variations
Sine pigmento Macular type (preceding macular changes) Pericentric (possible rod-cone dystrophy) Sectoral (symmetrical, bilateral, commonly
inferonasal) Fundus albipunctatus
Choroidal Degenerations
Central areolar sclerosis (AD/AR) Onset 20-40yrs Bilateral central
atrophy Progressive visual loss Normal
electrophysiology
Choroidal Degenerations Gyrate atrophy (AR)
Treatable biochemical abnormality
Onset 10-30yrs Night blindness &
tunnel vision Progressive, patchy,
equatorial atrophy Myopia & cataract Abnormal
electrophysiology
Choroidal Degenerations Choroideraemia (XLR)
Onset 5-15yrs Progressive night
blindness Eventual total
blindness Progressive granular
pigmentary changes Late - total choroidal
atrophy Carrier state exists
Albinism Failure of melanocyte/melanosomes Variable deficiency of melanin Enzyme defects are
Tyrosinase positive Tyrosinase negative
Types of albinism Generalised (oculocutaneous) - AR Ocular - XLR
Albinism Oculocutaneous albinism
T-pos• Mild, improves with age• Iris transillumination• Nystagmus• Poor vision• Refractive errors
Albinism Oculocutaneous albinism
T-neg• Severe disease• Photophobia• Poor vision & large refractive errors• Nystagmus• Iris transillumination• No fundal pigmentation or foveal reflex• Abnormal chiasmal decussation →
abnormal architecture of LGN
Albinism Ocular albinism (XLR)
Confined to eyes Giant melanosomes in RPE Carriers have iris transillumination & granular
RPE