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