Diabetes and the Eye

Karen B. Saland, M.D.August 18, 2008

Diabetes and Eye Disease: Learning Objectives

Identify Systemic Risk FactorsDifferentiate Clinical StagesDescribe treatment strategies and screening guidelines Recognize importance of team approach

Diabetes Mellitus: Epidemiology

135 million people with diabetes worldwide (90% type 2)300 million with diabetes projected by 2025

Diabetes Mellitus: Epidemiology

16 million Americans affected800,000 new cases per year (type 2)2X greater risk in African-Americans, Latinos and Native Americans

Diabetic Retinopathy

Retinal complications of DiabetesLeading cause of blindness in working age Americans

DCCT Findings:

No Baseline Retinopathy

DCCT Findings:

Mild to Moderate Retinopathy

DCCT Findings:

Intensive Glucose Control, No baseline retinopathy

27% reduction in developing retinopathy76% reduction in risk of developing progressive retinopathy

DCCT FINDINGS

Intensive Glucose Control, Mild to Moderate Retinopathy

54 reduction in progression of retinopathy47% reduction in development of severe NPDR or PDR59% reduction in need for laser surgeryPre-existing retinopathy may worsen in early stages of treatment

UKPDS FindingsType 2 Diabetes

Increased glucose and BP control decreases progression of retinopathy

UKPDS FindingsResults

Hemoglobin A1C reduced from 7.9 to 7.0 = 25% decrease in microvascular complicationsBP reduced to <150/85 mm Hg = 34% decrease in retinopathy progression

UKPDS Findings

Hypertension ControlAs important as glucose control in lowering risk of diabetic retinopathyACE inhibitor or beta blocker decreases microvascular complications

DCCT/UKPDS Lessons

Professional and patient educationGood glucose and BP controlRegular examination

Additional Systemic Controls

Proteinuria is a risk factor for macular edemaLisinopril may benefit the diabetic kidney and retina even in normotensive patients

Lowering cholesterol may lead to decreased

hard exudates and improved vision.

WESDR Findings

Diabetic Retinopathy and Cardiovascular Disease

PDR a risk indicator for MI, stroke, amputationPDR elevates risk of developing nephropathy

Diabetic Retinopathy:Clinical Stages

Nonproliferative diabetic retinopathy (NPDR)Preproliferative diabetic retinopathyProliferative diabetic retinopathy (PDR)

NPDR: Early Clinical Signs

MicroaneurysmsHard ExudatesIntraretinal hemorrhages

Patients may be asymptomatic.

Diabetic Macular Edema

Diabetes < /= 5 years = 5% prevalenceDiabetes >/= 15 years =15% prevalence

PDR: Clinical Signs

NeovascularizationVitreous hemorrhage and tractionNPDR features, including macular edema

Vitreous Hemorrhage:Symptoms

FloatersSevere visual loss

Requires immediate ophthalmologic consultation

Review of Clinical Stages

Nonproliferative diabetic retinopathyPatients may be asymptomatic

Preproliferative retinopathyLaser therapy at this stage may help prevent long-term visual loss

Proliferative retinopathyMajor cause of severe visual loss

Panretinal Photocoagulation (PRP)

Outpatient procedureApproximately 1000-2000 burns1 to 3 sessions

PRP: Side Effects

Decreased night visionDecreased peripheral vision

Vitrectomy

Remove vitreous hemorrhageRepair retinal detachmentAllow treatment with PRP

Treatment options: SummaryLaser photocoagulation surgery

Focal macular laser for CSMEPanretinal photocoagulation for PDR

VitrectomyMay be necessary for vitreous hemorrhage or retinal detachment

New Therapies

Anti-VEGF agents decrease capillary permeability and angiogenesisUseful as adjuvant treatment to laser therapy for diabetic retinopathy

Screening Guidelines:Patients with Type 1 Diabetes

Annual ophthalmologic exams starting years after diagnosis and not before puberty

Patients with Type 2 Diabetes

Annual ophthalmologic exams starting at time of Dx

Diabetes and Pregnancy

Ophthalmologic exam before conceptionOphthalmologic exam during first trimesterFollow-up depends on baseline grade

WESDR FindingsPatients’ Access and

Compliance36% missed annual ocular exam60% missed laser surgery

Goals for Success

Timely screening reduces risk of blindness from 50% to 5%100% screening estimated to save $167 million annually

Goals for Success

Better systemic control of:Hemoglobin A1cBPKidney statusSerum Lipids

Reducing the Risk of Blindness

Team approach: primary care physician, nutritionist, endocrinologist, ophthalmologistAccess to eye careSystemic control