| Date post: | 17-Jan-2016 |
| Category: |
Documents |
| Upload: | polly-greene |
| View: | 225 times |
| Download: | 0 times |
Diabetic Retinopathy
Alan D. Letson, MDProfessor & William H. Havener Chair in Ophthalmology
Department of Ophthalmology
Part I: Introduction and The History of Treatment for Diabetic Retinopathy
Learning Objectives
Primary Learning Objective: Apply knowledge of risk factors and retinal findings to screening and management of diabetic retinopathy
Secondary Learning Objectives:
differentiate the lesions of non-proliferative and proliferative retinopathy
describe screening, diagnosis and management of the various causes of vision loss related to diabetic retinopathy
Acknowledgment
Several of the slides used in this presentation come from slide sets prepared for diabetes education by: Pennsylvania Diabetes Association
American Academy of Ophthalmology
Why are we talking about this specific ophthalmic disease? Diabetic Retinopathy is the most common cause of blindness Diabetic Retinopathy is a “model” for many other retinal vascular diseases Ocular lesions and complications seen in Diabetic Retinopathy are not
unique to Diabetes, and can be seen as a result of many other systemic vascular diseases such as hypertension, vaso-occlusive diseases, and collagen-vascular diseases.
The treatments used for DR are the same as treatments for many other retinal vascular diseases.
Non-ophthalmologists can play an important role in the screening and detection of retinopathy and can help their patients by making sure they benefit from early detection and treatment.
Non-ophthalmologists are key players in the treatment of diabetic eye disease by knowing about and managing the medical risks that contribute to this disease.
Prior to 1974
No known effective treatments Blindness common outcome Pituitary ablation
1976 Diabetic Retinopathy Study
Demonstrated effectiveness of pan retinal photocoagulation (PRP) for proliferative retinopathy
Late 1970’s – Early 1980’s
Refinement of laser procedures
Development of vitreo-retinal microsurgical instrumentation and procedures
1982: Early Treatment Diabetic Retinopathy Study
Demonstrated effectiveness of focal photocoagulation for macular edema.
2005 – to date
First use of VEGF inhibitors in 2005 Pharmaceutical Industry Sponsored Trials August 2012 ranibizumab (Lucentis)
became FDA approved for treating Diabetic macular Edema
2014 – DRCR.net trial comparing aflibercept to ranibizumab showed superiority of aflibercept.
Currently
Diabetic Retinopathy remains one of the most significant complications of diabetes and continues to be the leading cause of blindness.
Early detection and early treatment are crucial for the prevention of blindness
Diabetic Retinopathy
Diabetic Retinopathy
Alan D. Letson MDProfessor & William H Havener Chair in Ophthalmology
Department of Ophthalmology
Part 2: Risk Factors and Lesions
A 66 year old woman presents with decreased vision in her right A 66 year old woman presents with decreased vision in her right eye. What additional information is important? What will you do to eye. What additional information is important? What will you do to evaluate and manage her complaint?evaluate and manage her complaint?
A 35 year man , 25 year Hx of IDDM, A 35 year man , 25 year Hx of IDDM, previously visually asymptomatic previously visually asymptomatic with 20/20 vision , now presents with with 20/20 vision , now presents with a sudden onset of floatersa sudden onset of floaters
58 year old woman 58 year old woman
CC: gradual blur of vision, getting worse for 6 monthsCC: gradual blur of vision, getting worse for 6 months
PMH: NIDDM 11 years, HgbA1C = 8.7PMH: NIDDM 11 years, HgbA1C = 8.7
BP 158/90BP 158/90
Va: 20/80 OD, 20/25 OSVa: 20/80 OD, 20/25 OS
Who Gets Retinopathy?
Factors include Age of onset Duration of disease Degree of control Hypertension
Prevalence of Retinopathy
Duration of Diabetes (years)
100
75
50
25
00 5 10 15 20
%
Prior to Age 30
Duration less than 5 years 17% have some retinopathy Macular edema unusual, PDR rare
Duration greater than 15 years 98% have some retinopathy Approximately 1/3 have macular edema Approximately 1/3 have PDR
Age of Onset and Duration
Age of Onset and Duration
After Age 30 Duration less than 5 years
29% have some retinopathy. Macular edema unusual, PDR 2%
Duration greater than 5 years 78% have some retinopathy Approximately 28% have macular edema Approximately 16% have PDR
DCCT and UKPS
Intense glucose control reduced rates of progression of retinopathy
Blood Pressure control reduced progression of retinopathy
Diabetes Control and Complications Trial
Intensive glucose control
No baseline retinopathy 76% reduction in the risk of developing
significant retinopathy
Diabetes Control and Complications Trial
Intensive glucose control Mild to moderate retinopathy
54% reduction in progression 47% reduction in development of severe
NPDR or PDR 56% reduction in need for laser surgery.
Hypertension and Diabetes
There is a positive correlation between elevated systolic blood pressure and the development of exudative complications of retinopathy
Pathophysiology
Known
Hyperglycemia > loss of pericytes
Loss of pericytes > loss of capillary endothelia and capillaries
Loss of capillaries > hypoxia and ischemia
Hypoxia > release of VEGF
Pathophysiology
Known VEG-F
Stimulates proliferation of new vessels Increases vascular permeability Has pro-inflammatory action
Other Possible Mechanisms
Aldose reductase: glucose to sorbitol causing osmotic cell damage
Protein Kinase C with VEGF upregulation, enhanced by hyperglycemia
Reactive oxygen species causes oxidative damage – increased VEGF
Growth hormone plays permissive role for VEGF, reduction in GH prevents neovascularization
Classification and Lesions of Diabetic Retinopathy
NonProliferative Diabetic Retinopathy (NPDR)
Proliferative Diabetic Retinopathy (PDR)
Early NonProliferative Diabetic Retinopathy
Microaneurysms
Hard exudates
Intraretinal hemorrhages
Macular edema*
Advanced NonProliferative Diabetic Retinopathy
Cotton wool spots
IntraRetinal Microvascular Abnomalities (IRMA)
Venous Beading
Courtesy PDA
Advanced NonProliferative Diabetic Retinopathy
High risk of imminent PDR
No immediate treatment
Patient needs re-evaluated in 2-4 months
Proliferative Diabetic Retinopathy
Signs of NPDR including macular edema
Neovascularization of disc (NVD) or retina (NVE)
Vitreous hemorrhage
Fibrous proliferation with retinal detachment
Courtesy PDA
Diabetic Retinopathy
Alan D. Letson MDProfessor & William H Havener Chair in Ophthalmology
Department of Ophthalmology
Part 3: Vision loss in Diabetic Retinopathy and how do we treat it?
What Causes Vision Loss?
Maculopathy can occur in NPDR or PDR
Vitreous hemorrhage PDR
Traction Retinal Detachment PDR
Diabetic Maculopathy Includes
Macular edema(retinal swelling)
Lipid exudation(hard exudates)
Ischemia(capillary nonperfusion)
What Are Symptoms of Maculopathy?
None
Gradual progressive loss of central vision
Vision is “smeared”, “oily”, “filmy”, “scum”, “dirty glasses”
Central scotoma
When is Maculopathy Treated?
Retinal edema within 1/3 disc diameter from the center of the fovea
Hard exudate within 1/3 DD associated with edema
Edema greater than 1 DD in area within 1 dd from fovea
How do We Treat Macular Edema?
Treatment guided by Fluorescein angiography
Focal laser coagulation of microaneurysms
Anti-VEGF drugs
Video 1
Video 2
Results of Treatment for Macular Edema
50% reduction in rate of vision loss
20% improved vision
60% stable vision
20% will show progressive vision loss in spite of treatment
AntiVEGF Treatment for Diabetic Macular Edema RIDE study 2007-2012: Ranibizumab safe
and effective for DME FDA approval August 2012 DRCR.net: laser plus Ranibizumab
superior to laser alone or ranibizumab alone for DME
DRCR.net ( OSU is a member) aflibercept superior to ranibizumab 2014
What are Symptoms of Proliferative Diabetic Retinopathy?
None
Floaters and cobwebs
Rapid dramatic vision loss
Visual field loss
When is Proliferative Diabetic Retinopathy Treated?
Pan Retinal Photocoagulation for High Risk PDR:
NVD
NVD or NVE with preretinal bleeding
Vitrectomy for non-clearing vitreous hemorrhage or TRD
Pan Retinal Photocoagulation (PRP)
Outpatient procedure
1000-2000 laser burns
1 to 3 sessions
Side effects: Decreased night vision
Decreased peripheral vision
Decreased central vision
Courtesy PDA
Courtesy PDA
FiberopticilluminationFiberoptic
illumination
InfusionLine
InfusionLine
Suction/Cutting tipSuction/
Cutting tipAAO
Results of Treatment for Proliferative Diabetic Retinopathy
Laser reduces risk of severe vision loss by 60%
Vitrectomy restores pre-hemorrhage vision in 85% and allows completion of treatment with laser
Vitrectomy restores vision in 65% for repair of TRD
Diabetic Retinopathy
Alan D. Letson MDProfessor & William H Havener Chair in Ophthalmology
Department of Ophthalmology
Part 4: The Role of the Non Ophthalmologist
Medical Management: Hgb A1C < 7.0
Good Glucose controlBoth DCCT and UK study show reduction in ocular complications.
Medical Management: Hypertension
A significant risk factor for development and progression of retinopathy.
Systolic < 130 mmHg Risk reduction similar for ACE inhibitors or
other agents (Beta-blockers)
Medical Management: Lipid Abnormality
Increased retinal exudation with: Elevated serum cholesterol Elevated triglycerides Manage lipid abnormalities
Medical Management: Anemia
Frequently overlooked Significant effects on retina Hgb < 12gms = 2x risk for retinopathy Increased risk of macular edema.
Medical Management: Anemia
Low hematocrit is an independent risk factor for developing PDR and severe vision loss.
Frequently related to renal disease and associated lack of erythropoeitin production.
Correction reduces retinal exudation and edema.
Medical Management: Medication FAQs
Aspirin – no increase in severity or frequency of hemorrhage
ASA did decrease death from Cardiovascular disease by 17%
Anti-oxidants - ? Benefit of Vitamins C, E, beta-carotene
Medical Management: When to refer?
Situations requiring referral: Macular edema NVD/NVE Vitreous bleeding Sudden unexplained vision loss
Medical Management: Screening Criteria
Pregnancy: discussion risk before conception Existing retinopathy may worsen Retinopathy may develop Retinal evaluation before conception or in first
trimester.
Medical Management: Screening Criteria
Diabetes Dx < age 30: Annual ophthalmologic exams beginning 5
years after diagnosis. Ophthalmoscopy by PCP at other intervals.
Medical Management: Screening Criteria
Diabetes Dx > age 30: Annual ophthalmologic exams beginning at
the time of diagnosis. Ophthalmoscopy by PCP for signs at other
intervals.
Final Comment
Team Event: patient, ophthalmologist and physician managing diabetes.
With good team play, the prognosis for maintaining functional sight is good.
Summary
describe the risk factors for developing diabetic retinopathy
describe the lesions of non-proliferative retinopathy
describe the lesions of proliferative retinopathy
classify the stages of diabetic retinopathy
describe the indications and options for ophthalmic treatment of non-proliferative retinopathy
describe the indications and options for treatment of proliferative retinopathy
describe the medical management of persons with diabetes that will impact retinopathy
list screening criteria for ophthalmic examination in person with diabetes
Survey
We would appreciate your feedback on this module. Click on the button below to complete a brief survey. Your responses and comments will be shared with the module’s author, the LSI EdTech team, and LSI curriculum leaders. We will use your feedback to improve future versions of the module.
The survey is both optional and anonymous and should take less than 5 minutes to complete.
Survey
