Chronic Visual Loss Emil Kurniawan SHMO Royal Melbourne Hospital.

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

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

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)


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)

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

Summary

• Causes of chronic visual loss

• Cataract

• Glaucoma

• Age-related macular degeneration

• Refractive error

• Retinitis pigmentosa

• Diabetic retinopathy

Chronic Visual Loss Emil Kurniawan SHMO Royal Melbourne Hospital.

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