Chronic Visual Loss

Report
Chronic Visual Loss
Emil Kurniawan
SHMO
Royal Melbourne Hospital
Case 1
• A 75 year old woman is seen for an annual physical
examination and complains of mild difficulty in
reading and seeing street signs
• Vision is especially worse at night, and now has
trouble with her knitting
• PHx: HTN, T2DM diet controlled, ex-smoker
• O/E: VA R 6/18 and L 6/12
Case 1
• What is the likely diagnosis?
Cataract
• Symptoms gradual over years
• 1. Reduction in visual acuity
• Worsening of existing myopia
• Correction of hyperopia “second sight of the aged”
• 2. Loss of contrast sensitivity in low light
• 3. Glare in bright light
• Forward scatter of light
Pathophysiology
• Loss of organisation of proteins in lens
• Progressive opacity
• Symptoms due to blockage, aberrant refraction or
forward reflection of light
Causes
• Age-related by far the most common
• Multifactorial
• Environmental factors (UV, radiation, toxins…)
• Diabetes, hypertension, obesity, smoking, …
• Ocular: high myopia, uveitis
• Steroids
• Trauma
• Syndromic
Types
Management
• Surgery
• Timing and indication of surgery
• Driving
• GA, LA, topical
• Importance of complete ophthalmological
assessment
• Post-op follow-up: 1 day, 1 week, 1 month
Management
Complications
• Intraoperative
• Posterior capsule rupture
• Expulsive (choroidal) hemorrhage
• Postoperative
•
•
•
•
•
Endophthalmitis
Cystoid macular edema
Retinal detachment
Posterior capsule opacification
IOL dislocation
Case 2
• A 76 year old man has noted visual distortion from the
RE over the past week
• Straight lines viewed through his right eye dipped down
in the centre
• Round plates seem to have “edges”
• O/E: VA R 6/18 and L 6/6
• What is the likely diagnosis?
• What test are you going to do?
Case 2
Case 2
Case 2
Macular degeneration
• Loss of central vision
• Reading, recognising faces impaired
• Peripheral (navigational) vision preserved
• Leading cause of legal blindness in developed world
• Multifactorial
• Age
• Smoking, vascular disease, UV light, diet, FHx, …
• Atrophic (dry) or exudative (wet)
Macular degeneration
Atrophic – 90%
Exudative – 10%
•
Choroidal (sub-retinal)
neovascularisation
•
Pre-retinal hemorrhage
• Photoreceptor degeneration
•
Elevation of retina
• Gradual over years
•
Subretinal fibrosis
• Often asymptomatic
•
Metamorphopsia
• More obvious scotoma
when light adapting
•
Central scotoma
•
Rapidly progressive (weeks)
• Drusen
• Geographic atrophy
Macular degeneration
Geographic atrophy –
dry AMD
Choroidal neovascularisation –
wet AMD
Macular scarring – wet AMD
Management – dry AMD
• Lifestyle
• Stop smoking, reduce UV exposure, Zinc &
antioxidants
• Low vision aids
• Legal blindness and driving
• Monitoring with Amsler chart
Management – wet AMD
• Observation
• Laser photocoagulation
• Indication: well-demarcated CNV
• Best for extrafoveal lesions (MPS study)
• Induce scotoma, recurrence, complications
• Verteporfin photodynamic therapy (PDT)
• Photosensitizer activated with low light
• Recurrence, needs re-treatment every 3 months
• Anti-VEGF
Anti-VEGF therapies
• VEGF-A stimulates angiogenesis and vascular
permeability
• Intravitreal injection of monoclonal antibodies
• Ranibizumab (Lucentis)
• MARINA and ANCHOR studies
• Off-label Bevacizumab (Avastin)
• SANA and CATT trials
• Combination with other therapy modalities not useful
• Future: silencer RNAs – bevasiranib, …
Case 3
• A 68 year old man was referred from his optometrist
for visual field testing
• He has not reported any problems with vision, but
the test report shows a reduction in peripheral vision
in the RE
Case 3
• What is your likely
diagnosis?
• What further
examination are you
going to do?
Case 3
LE
RE
Glaucoma
• 1. Optic nerve damage (optic disc cupping)
• Cup:disc ratio >0.6
• Loss of neuroretinal rim
• 2. Increased IOP
• 3. Peripheral visual defects
(navigational sight)
The trick of IOP
• Only 10% with IOP>21 have glaucoma
• The rest have ocular hypertension
• Only 50% of glaucoma patients have IOP>21
• The rest have normal tension glaucoma
Glaucoma
• Types
• Primary
• Open angle (90%)
• Closed angle
• Secondary
• Congenital
Primary open angle glaucoma
• “The silent thief of sight”
• Asymptomatic
• Usually detected on routine examination
• Risk factors: IOP, age, FHx, DM, myopia
• Impaired drainage of aqueous humor through
trabecular meshwork
• Due to age-related morphological changes
Primary open angle glaucoma
Management
• Aim to stop progress
• Cannot recover sight already lost
• Medical – reduction of aqueous secretion
•
•
•
•
•
Beta-blockers (Timolol)
Alpha-agonists (Brimonidine)
Prostaglandin analogues (Latanoprost)
Parasympathomimetics (Pilocarpine)
Carbonic anhydrase inhibitors (Brinzolamide)
Management
• Surgical
• Argon and selective laser trabeculoplasty
• Filtering surgery
• Trabeculectomy
• Laser peripheral iridotomy
• Iridectomy
• Canaloplasty
Case 4
• A 13 year old girl is seen for physical examination at
school. She admits to difficulty in reading the
blackboard, but not in reading textbooks. She does
not wear glasses.
• O/E: VA R 6/36 ph 6/6 and L 6/36 ph 6/6
• What is your diagnosis?
Refractive error
• Corrects with pinhole
• Management: glasses, contact lenses, refractive
surgery
Case 5 – spot diagnosis
Retinitis pigmentosa
• Genetically inherited
• Progressive retinal dystrophy
• Night blindness, tunnel vision, legal blindness
• Bony spicules from mottling of RPE
• Incurable
• Future: gene therapy, bionic eye, …?
Case 6 – diabetic retinopathy
• Microvascular retinal changes
• Blindness is progressive, but preventable
• Annual retinal examination
• Tight T2DM control HbA1c 6-7%
• Appropriate laser treatment
• Pre-proliferative retinopathy
• Proliferative retinopathy
• Also predisposes to cataract & glaucoma
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Diabetic retinopathy
Summary
• Causes of chronic visual loss
• Cataract
• Glaucoma
• Age-related macular degeneration
• Refractive error
• Retinitis pigmentosa
• Diabetic retinopathy

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