Ocular Disease III: Exam 2: Lecture 5: Diabetic Retinopathy Flashcards
Diabetes
- Type 1
- Type 2
- Immune system Ab that attacks the insulin producing BETA CELLS of the pancreas. (lack of Insulin Production, B-Cells of PANCREASES)
- Due to Insulin Resistance; GLUT4 RECEPTORS
Blood Glucose Ranges
- Fasting Blood Glucose: Normal?
a. Over what? - Random Blood Glucose > what?
- A1c > than what?
a. LATEST Recommendation is to keep it BELOW what?
b. It’s a measurement of what?
c. REPRESENTS what? - Normal Glucose Values?
a. Consistent Range over what = HYPERGLYCEMIA?
b. Consistent Range BELOW what = HYPOGLYCEMIA? - TWO MOST IMPORTANT THINGS ABOUT DIABETES?
- 200
- > 6.5
a. Latest Recommendation is TO KEEP IT BELOW 6
- > 6.5
b. of Glycated Hemoglobin
c. the AVG Blood Glucose over the LAST 2-3 MONTHS. MOST IMPORTANT NUMBER!
4. 80-110 mg/dL
a. over 126 mg/dL
b. below 70 mg/dL
5. HOW LONG THEY HAVE HAD IT, and the A1C Number!!!
Diabetes
- Type 1
a. Onset when?
b. Causes? - Type 2
a. Onset
b. % of DM?
c. Causes?
- a. 30 Years
b. 90-95% of DM cases
c. Genetics, OBESITY, Poor Diet, Inactive Lifestyle, UNKNOWN?
*if Idiopathic is an answer, circle it, 90% of the time, that’s the CORRECT ANSWER!
Epidemiology: USA
- What is the LEADING cause of NEW-ONSET BLINDNESS in WORKING-AGE POPULATION (20-74 yrs)
- Less than what % of diabetics receive annual retinal Examinations?
- DIABETES (17 million americans w/DM…probably a lot more than that)
- <50%
* EVERY diabetic needs to receive an Annual Dilated Blood Exam.
Prevalence of DM by race/Ethnicity in USA an %
- Whites?
- Blacks?
- Hispanic/Latino?
- 11.4 million (7.5%)
- 2.8 million (15%)
- 2 million (13%)
* Diabetic…Pretty much an everybody disease…it doesn’t discriminate
DIABETIC EPIDEMIC: What % of Pts with Type 2 are OVERWEIGHT?
- About 80%
Diabetic Epidemic
- About how many NEW CASES of DIABETES is there each year in the US?
- ALARMING INCREASE of INCIDENCE IN TYPE 2 DM among whom?
- 800,000 NEW CASES/YEAR in US
2. Among KIDS and YOUNG ADULTS!
Risk Factors For Development of Diabetic Retinopathy
- IDDM
a. 95% over how many years after being Diagnosed? (*YEARS BEFORE PUBERTY DO NOT COUNT!!) By puberty he means 14 yrs old.
b. 10 Years?
e. >30 years?
- What is the NUMBER 1 REASON that CAUSES the RISK FACTOR FOR DIABETES?
- NIDDM
a. 11-13 years?
b. >15 Years?
c. >10 years?
- a. >30 YEARS w/the Disease, about 95% have Diabetic Retinopathy
b. VERY Rare
c. 27%
d. 71%
e. 30% have PDR - It’s simply the NUMBER OF YEARS YOU HAVE HAD the DISEASE! (regardless of treatment and blood sugar control)
- a. 23%
b. 60%
c. 3% have PDR
Risk Factors for Development of Diabetic Retinopathy
- 4 things?
- Quality of Glucose Control
a. Elevated Glycated Hemoglobin levels
b. Hyperglycemia may cause DR (With High glucose levels, glucose binds to Amino Groups of Proteins and this leads to Tissue Damage) - Hypertension
- Serum Lipid Levels
- Pregnancy
a. 10% progression to NPDR
b. 4% progression to PDR
Diabetes: Causes
- Know that Hyperglycemia causes what?
a. Know that PKC and Angiontensin System will do what?
- Oxidative Stress.
a. Vascular Endothelial Dysfunction
* Know that diabetes issues is a MESS. It’s overwhelming.
Pathophysiology of DR
- Glucose Toxicity from Hyperglycemia will AFFECT WHAT?
- Possible Culprits
a. Aldose Reductase (Converts Sugars to Alcohol): So Aldose Reductase Inhibitors Do what?
b. PKC
c. Increased RBC Aggregation
* b, and c, he won’t ask questions about it. - Other possible Culprits?
- CAPILLARY ENDOTHELIUM
a. It has tight junctions, so blood doesn’t perforate, but if it breaks, that’s what causes the Leakage of Blood. - a. reduce cataract formation, PERMEABILITY of SMALL VESSELS, and PERICYTE LOSS (KEY thing is Pericyte Loss)
- Platelets and Elevated Prostaglandin (this is inflammation!)
* Causes Adhesion, Secretion, Aggregation
Diabetic Retinopathy: Pathophysiology
- Is Cause of DIABETIC RETINOPATHY Single or Multi Factorial?
a. But it all leads to what?
- MULTI FACTORIAL (multiple things cause it)
a. VASCULAR ENDOTHELIAL DYSFUNCTION is CENTRAL to ALL of the MECHANISMS of DAMAGE!
**KNOW THIS
Decreased Tissue Oxygenation
- CHRONIC VASODILATION does 3 things: what?
- BASEMENT Membrane THICKENING
- Pericyte DEGENERATION
- Endothelial CELL PROLIFERATION
Diabetes is the Disease of the Capillaries (1)
- What happens to the CAPILLARY BM?
a. What does this prevent? - What happens to Pericytes?
- The first HEME in DR is due to what?
- THICKENING (may lead to closure)
a. Prevents Pericytes from being in Contact w/Endothelial Cells (They form the Tight Junction) which may increase LEAKAGE Potential - PERICYTE DROPOUT (lining capillaries)
a. Increases leakage potential and leads to breakdown of BLOOD-RETINA BARRIER.
b. FOCAL Loss leads to Bulging of Capillaries and MICROANEURYSM FORMATION
3. Due to Capillary leakage from Pericyte loss.
Diabetes is the Disease of the Capillaries (2)
- Weakened Capillaries!
a. 1st CHANGE that OCCURS in RETINOPATHY?
b. Dot and Blot Hemes
c. Flame Shaped Hemes
d. MACULAR EDEMA: what is it?
e. THIS IS THE MOST COMMON CAUSE of WHAT in DR?
f. What is Fluid leakage & Lipid Accumulation?
g. What happens with Capillary Closure?
- a. Aneurysm formation and LEAKAGE from WEAKENED CAPILLARIES
b. INL and OPL (Deep)
c. NFL (superficial)
d. LEAKING ANEURYSMS & CAPILLARIES in MACULAR AREA
e. of VISUAL REDUCTION! (but, it’s not the Most common cause of severe, Irreversible Visual Reduction: That would be NEO, NVG and Tractional RD)! KNOW THIS!
f. Exudate!
g. Hypoxia and Progression
* Macular Edema will NEVER Cause Comprehensive Drastic Vision loss.