The Challenge Continues: Diabetic Blindness

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The Challenge Continues Diabetic Blindness

• Barbara Davis Center Eye (BDCi)
• William Jackson, M.D.
• Garrett Mitchell, B.A.
• Lynne Bentsen, M.A.
• Chris Orgon, B.S.

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Goal Prevention of Blindness
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Prevention of Diabetic Blindness

• Diabetes is the leading cause of blindness in
  adults in the united states (ages 20-74)
• Over 90 percent is preventable

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Why Do We Need to Stage Diabetic Retinopathy (DR)?

• Almost all diabetic patients will eventually
  develop retinopathy
• This DR is
• orderly
• slowly progressive
• reversible
• chronic
• frequently asymptomatic until end stage

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Why Do We Need to Screen for Diabetic Retinopathy?

• If you cant see it, you cant treat it
• early detection is a vital plank in the campaign
  to prevent diabetic blindness
• DR is very highly amenable to detection
• is responsive to medical/surgical therapies
• Different diagnostic methods exist

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The Human Cost of Not Screening

• History
• 29 year old patient IDDM 18 yrs
• Over 5 years without any health care
• Patients vision at first visit was counting
  fingers at 2 feet in the right eye and 20/100 in
  the left eye

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The Human Cost of Not Screening

• Pathology
• severe neovascular glaucoma IOPgt80(OD)
• rubeosis (OD)
• corneal edema (OD)
• marked diabetic macular edema (OU OD more than
  OS) and
• proliferative diabetic retinopathy (OU OD more
  than OS)

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Example of Rubeosis
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Retinal Images The Human Cost of Not Screening
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Reasons to Screen

• Patient 2 History
• 27 years old
• Patient had been having regular dilated eye exams
  and she was told that she did not have any
  diabetic damage
• Patient had a non-dilated screening at the
  Barbara Davis Center

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Reasons to Screen

• Pathology
• Vision Threatening Proliferative DR (OU)
• Retinal Neovascularization (OU)
• Vitreous Hemorrhage OS

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Retinal Images Patient 2
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Diabetic Retinal Staging

• Diagnostic methods are changing and challenging

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Instruments

• Direct ophthalmoscope
• Non-Mydriatic digital retinal camera

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Retinal Imaging Systems

• Canon
• Zeiss
• Topcon
• Aris
• EyeTel
• Inoveon

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ADA Guidelines for Retinal Exam in Diabetic
Patients

• Annual dilated eye exam after at least 5 years of
  diabetes in patients 10-29 yr old
• Annual dilated eye exam regardless of duration
  in patients older than 30
• Immediately if visually symptomatic
• Pregnant or planning to get pregnant

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Classification Systems

• Early Treatment Diabetic Retinopathy Study
  (ETDRS)
• Complex, landmark diabetic retinopathy study with
  a most challenging classification system
• Airlie-House
• Complex grades given to each diabetic lesion
  depending upon severity

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Classification Systems (Continued)

• Modified Airlie-House Classification System (used
  at the Barbara Davis Center)
• Relatively user friendly simplified scale images
  graded from 1 (no retinopathy) to 6
  (proliferative retinopathy)
• New simplified International Clinical Diabetic
  Retinopathy (ICDR)
• Further simplified scale five levels of disease
  severity from No apparent DR to Proliferative DR

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Classification Systems (Continued)

• Simplified Classification System
• Simple classification systems grades images as
  mild, moderate or severe.

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Retinal Staging at the BDC
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Newer Alternative Therapies for Diabetic
Retinopathy

• 1 - Vitrectomy
• 2 - Steroid - intravitreol
• retroseptal
• intravitreol implants
• (variable duration - up to 3
• years of sustained release)
• Complications
• Glaucoma, cataract

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Vasoendothelial Growth Factors VEGF

• Permeability Factors
• Angiogenic Factors
• Survival Factor
• Proinflammatory Factor
• Neuroprotectant Factor
• Fenestration Factor
• Thrombosis Factor
• Vasodilator Factor

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New Compounds

• Avastin
• Macugen
• Lucentis

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Diabetic Retinopathy Risk Factors

• Duration, Glucose Control and Waist-to-Hip Ratio
  Porta M, et al. EURODIAB Prospective
  Complications Study Group. Diabetologia.
  2001442203
• Type of Diabetic Treatment Giuffre G, et al.
  Prevalence and risk factors of diabetic
  retinopathy in adult and elderly subjectsThe
  Casteldaccia Eye Study. Graefes Arch Clin Exp
  Ophthalmol. 2004 Feb 18
• Age, Puberty, Obesity (in Type 2 DM), Ballard
  DJ, et al. Risk factors for diabetic
  retinopathya population-based study in
  Rochester, Minnesota. Diabetes Care. 19869334
• Blood Pressure, Pregnancy Neely KA, et al
  Diabetic Retinopathy. Med Clin N Amer, 199882847

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Diabetes Control Complications TrialRetinopathy
risk is not completely explained by HbA1c
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The Barbara Davis Experience withNon-dilated
Imaging in Type 1 DM

• 1999-2004
• Nearly 4,000 non-dilated retinal images captured
  in 632 patients

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Methods

• Non-Mydriatic Retinal Camera CR6-45NM
• Three-field fundus photography
• Modified Airlie-House Grading System
• Images captured by a technician and graded by an
  Ophthalmologist

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Methods

• Additional data
• age, sex, duration of diabetes, current HbA1C
• blood pressure, serum creatinine, AER
• lipids (LDL, HDL, triglycerides), obesity (BMI)
• smoking, pregnancy, medications

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Initial Results (N632)
Grade patients
Age yr
Duration yr
A1c
Smokers
20.4
7.5
8.9
12.8
1 (68)
2 (16)
26.3
14.1
9.0
16.5
3 (6)
27.6
15.2
8.7
20.7
34.3
19.1
9.3
18.5
4 (5)
29.8
20.8
9.0
0
5 (1)
35.7
25.0
9.0
19.0
6 (4)
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Summary of Results

• Older age was significantly associated with
  higher DR grade (ANOVA, plt0.0001)
• Longer duration of diabetes was significantly
  associated with higher DR grade (plt0.0001)
• Current HbA1c was not associated with DR grade
  (p0.9)
• Smoking was not associated with DR grade

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Discussion

• As expected, age and duration were associated
  with DR
• Current HbA1c and smoking may not reflect
  cumulative long-term effect of these exposures
• The next step in these analyses will include
  prospective evaluation of these and additional
  risk factors

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Its About Time

• We are all on the diabetic blindness prevention
  team
• Coordinate and Cure