Medical Retina and Macular Diseases

Dr. Timothy Y. Y. LaiMBBS, MMedSc, MRCSEd, FCOphthHK, FHKAM(Ophth)

Department of Ophthalmology and Visual Sciences

The Chinese University of Hong Kong

Medical Retina• A specialty that deals with the investigation and

non-surgical treatment of retinal disorders

• Retinal diseases associated with systemic diseases– Diabetic Retinopathy– Hypertensive Retinopathy

• Vascular retinopathies• Medical macular diseases

– Age-related Macular Degeneration

Retinal Diseases Associated with

Systemic Diseases

Diabetic Retinopathy

• One of the leading causes of blindness• Risk factors

– Duration of diabetes• 80% of type I and 70% of type II diabetics have

retinopathy after 15 yrs

– Type of diabetes mellitus– Control of hyperglycemia– Hypertension– Associated renal disease– Pregnancy

Diabetic Retinopathy

• Classification– Non-proliferative (NPDR)

• Mild• Moderate• Severe

– Proliferative (PDR)

• Pathogenesis– Microvascular disease causing capillary

damage– Leakage of blood constituents into the retina

• Retinal hemorrhages• Retinal edema• Lipid exudation

Non-proliferative Diabetic Retinopathy (NPDR)

Non-proliferative Diabetic Retinopathy (NPDR)

• Dot and blot hemorrhage

• Hard exudate

• Cotton-wool spots

• Venous beading

• Venous loops

Non-proliferative Diabetic Retinopathy (NPDR)

  

Progression from NPDR to PDR

Stage Progression to PDR

in 1 year

Mild NPDR <5%

Moderate NPDR 20%

Severe NPDR 50%

Proliferative Diabetic Retinopathy (PDR)

• Pathogenesis– Retinal ischemia causing neovascularization

• May be asymptomatic if only neovascularization without hemorrhage

Neovascularization at Disc(NVD)

Neovascularization elsewhere(NVE)

Causes of Visual Loss in DR

• Macular Edema

• Complications of PDR– Vitreous hemorrhage– Fibrous tissue proliferation– Retinal detachment

MicroaneurysmsCircinate exudateRetinal edema

Vitreous Hemorrhage Tractional Retinal Detachment

CombinedRetinal Detachment

Diabetic Retinopathy

• Treatment– Laser photocoagulation

• Focal or grid: for macular edema • Pan-retinal photocoagulation: for PDR

– Control of systemic disease• Hyperglycemia• Hypertension• Renal disease

– Vitreous surgery

Laser PhotocoagulationOutpatient procedureTopical AnesthesiaMultiple Sessions

In PDR, laser should be performed before vitreous hemorrhage and retinal detachment develops

Diabetic Retinopathy

• Early identification of the disease and prompt referral to the ophthalmologist

• Dilate your patients for examination with ophthalmoscope regularly

• Prompt treatment reduces risk of visual loss by 50%

• Patients may be asymptomatic but still have advanced PDR

Hypertensive Retinopathy

• Focal or generalized narrowing of retinal arteries associated with hypertension

• Clinical features– Cotton-wool spots– Hard exudates– Macular star– Macular edema– Retinal hemorrhage– Optic disc swelling

Hypertensive Retinopathy

Grade Ophthalmoscopy Features

1 Mild arteriolar narrowing (copper-wiring)

2 Marked arteriolar narrowing with deflection of veins at AV crossing (silver wiring and AV nipping)

3 2 + Flame-shaped hemorrhage, cotton-wool spots

4 3 + Disc swelling

Severe Hypertensive Retinopathy

Macular star Disc swelling

Hypertensive Retinopathy

• Management– Rule out secondary hypertension– Control of hypertension

Vascular Retinopathies

Retinal Vascular Occlusions

• Venous occlusion more common than arterial occlusion

• Pathogenesis– Arterial occlusion – embolus

• Central retinal artery occlusion (CRAO)• Branch retinal artery occlusion (BRAO)

– Venous occlusion – abnormal blood flow• Central Retinal Vein Occlusion (CRVO)• Branch Retinal Vein Occlusion (BRVO)

Retinal Arterial Occlusions

• Symptoms– Sudden, painless, marked loss of vision– Immediate treatment within 24-48 hours may

be beneficial in some patients

• Systemic Associations– Cardiovascular disease– Carotid artery disease– Temporal arteritis / inflammatory arteritis– Coagulopathies

Central Retinal Artery Occlusion

Branch Retinal Artery Occlusion

Afferent Pupillary DefectCherry Red SpotRetinal Edema

Retinal Venous Occlusions

• Symptoms– Sudden painless loss of vision– Various extent of visual loss

• Systemic Associations– Diabetes Mellitus– Hypertension– Hematological diseases– Vasculitis

Central Retinal Vein Occlusion

Branch Retinal Vein Occlusion

Macular edema Neovascular glaucoma

Laser photocoagulation

Macular Diseases

Where is the macula?

視網膜Retina

脈絡膜Choroid鞏膜

Sclera角膜Cornea

晶體Lens

Iris 虹膜

Cilliary body睫狀體

視神經Optic nerve

黃斑區Macula

Fovea

Macula

Macular Diseases

• Common surgical macular diseases– Macular hole– Epiretinal membrane

• Common medical macular diseases– Age-related macular degeneration (AMD)– Myopic maculopathy – Central serous chorioretinopathy (CSC)

Age-related Macular Degeneration (AMD)

• Leading cause of severe vision loss in people > 50 years in the western world

• Visual loss due to drusens / RPE degeneration or development choroidal neovascularization (CNV)

Age-related Macular Degeneration (AMD)

• Two forms– Dry (non-neovascular) AMD (80% to 90%)

– Wet (neovascular) AMD (10% to 20%)

• 90% of vision loss is caused by wet form of AMD

Decrease in color and contrast sensitivity

Symptoms of AMD – Early

Impairment of central visual function

Symptoms of AMD – Intermediate

Metamorphopsia, distortion of central image

Symptoms of AMD – Intermediate

Central Scotoma

Symptoms of AMD – Late

Bruch’sBruch’sMembraneMembrane

Bruch’sBruch’sMembraneMembrane

DrusenDrusenDrusenDrusen

Hallmark of AMDDevelopment of Drusen

Early Dry AMD

• Asymptomatic

• Examination reveals several small drusen or a few medium-sized drusen (63-124m)

Intermediate Dry AMD• Many medium-

sized drusen or 1 large drusen (>125m)

• Vision may be impaired

Advanced Dry AMD

• More severe visual impairment

• Presence of drusen with degeneration of RPE

• Geographic atrophy

ChoroidalChoroidalNeovascularizatioNeovascularizationn

ChoroidalChoroidalNeovascularizatioNeovascularizationn

Dry AMD Wet AMDFormation of New Vessels

Diagnosis

• Vision function testing–Visual acuity

–Amsler grid

• Ophthalmolscopy

• Fluorescein angiography

• Amsler Grid • Adequate lighting• Wear reading glasses • Hold the Amsler grid at

normal reading distance (about 30cm)

• Cover one eye at a time • Stare at the center dot

• Ask the following questions:

• Are any of the lines wavy, missing, blurry, or discolored?

• Are any of the boxes different in size or shape from the others?

Early Diagnosis

5mm squares10 cm x 10 cm

Self monitoring with Amsler Grid

Normal Abnormal

Intravenous injection

Uptake of fluorescein dye at the site of abnormal vessels

- Size, Location, Activity

Fluorescein angiography

Management of AMD• Treatment for neovascular AMD

– Laser photocoagulation– Submacular surgery– Photodynamic therapy (PDT) with Verteporfin– Anti-angiogenesis therapy (Anti-VEGF)

• Prevent progression to advanced AMD– Antioxidants– Quit smoking

• Low-vision aids

Laser Photocoagulation

• Non-selective thermal laser photocoagulation– Destroy CNV– Irreversible damage to the

overlying retina and RPE– Side effects of immediate

scotoma or drop in central vision

– CNV persist or recur in 50% of patients

Step 1:Step 1:InfusionInfusion

Step 2:Step 2:Nonthermal LaserNonthermal Laser

ApplicationApplication

PDT with Verteporfin

Mechanisms of action

• Chain of reactions vessel thrombosis

Non-thermal Laser

Drug infusion1

2

..

High dose AREDS supplements

• Beta-carotene• Vitamin A• Vitamin C• Vitamin E• Zinc • Copper

• Decrease risk of progression from dry to wet AMD

• Most important risk factors for AMD• Smokers have 300% to 400% more risk in

developing AMD than non-smokers• Even passive smoking increase the risk of AMD by

30% to 40%

Smoking and AMD

Prevention is better than cure

• Increasing prevalence of AMD due to aging and western life-style

• Recognize and correct risk factors– Quit smoking– Healthy diet

• Self screening test in high-risk group• Regular dilated fundus examination to

evaluate AMD findings

Early diagnosis is the key to save vision

Thank You