chronic visual loss emil kurniawan shmo royal melbourne hospital
TRANSCRIPT
Chronic Visual LossEmil 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%
• Drusen
• Geographic atrophy
• Photoreceptor degeneration
• Gradual over years
• Often asymptomatic
• More obvious scotoma when light adapting
Exudative – 10%
• Choroidal (sub-retinal) neovascularisation
• Pre-retinal hemorrhage
• Elevation of retina
• Subretinal fibrosis
• Metamorphopsia
• Central scotoma
• Rapidly progressive (weeks)
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