Diabetic Retinopathy in Pregnancy

1
Diabetic Retinopathy in Pregnancy

• Chukwuma I. Onyeije, M.D.
• Director of Education
• Lenox Hill Hospital

2
Scope of the Problem

• 6 of American public has diabetes
• Only one half have been diagnosed
• 150,000 deaths per year from diabetes related
  complications
• 12,000 people lose their sight each year due to
  diabetes

3
Scope of the Problem

• Diabetic retinopathy is the leading cause of
  blindness in women between the ages of 24 and 65.

4
Other Ocular Manifestations of Diabetes

• Senile cataracts
• Transient cataracts
• Rubeosis iridis
• Glaucoma

5
Anatomy of the Eye

• Pupil
• Regulates the entry of light
• Constrictor pupilae
• Dilator pupilae
• Lens
• Vitreous Humor
• 99 Water
• Also contains hyaluronic acid and collagen
• Retina

6
Anatomy of the Eye

• The Retina
• Innermost layer of the eyeball
• Posterior portion is photosensitive
• Anterior portion is not photosensitive
• Composed of a chain of three neurons in ten layers

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Classification of Diabetic Retinopathy

• Background Retinopathy
• Earliest lesion
• Preproliferative Retinopathy
• Ischemic Lesions
• Proliferative Retinopathy
• Neovascularization

Nonproliferative Diabetic Retinopathy (NPDR)
Proliferative Diabetic Retinopathy (PDR)
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Background Retinopathy

• First lesion of diabetic retinopathy seen with an
  opthalmoscope
• Retinal microaneurysms
• Outpouching of retinal capillaries appear as red
  dots
• Can be seen as early as two years after the onset
  of IDDM
• Blot hemorrhages
• Hard exudates

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Background Retinopathy
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Preproliferative Retinopathy

• Lesions related to ischemia
• Cotton wool spots
• Infarcted areas of the nerve fiber layer
• Venous bleeding and duplication
• Dilated veins with irregular caliber
• Intraretinal microvascular abnormalities
• Earliest signs of neovascularization
• Caused with shunt and collateral vessel formation

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Preproliferative Retinopathy
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Preproliferative Retinopathy
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Proliferative Retinopathy

• Growth of abnormal blood vessels
• Retinal neovascularization is likely stimulated
  by retinal ischemia
• Untreated neovascular proliferation may lead to
  vitreous hemorrhage and retinal detachment

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Neovascularization in Proliferative Retinopathy

• NVD Neovascularization of the disc
• BAD Prognosis
• NVE Neovascularization elsewhere
• Prognosis is not as bad

15
Severity and Duration

• Microaneurysms as early as two years after onset
  of IDDM
• After 15 years- 98 of patients will have at
  least background retinopathy
• After 25 years- virtually 100 of patients will
  have some form or retinopathy

16
Severity and Duration

• Negligible risk of retinopathy in women with
  gestational diabetes
• Minimal risk of retinopathy in women with IDDM
  for less than 5 years

17

• Diabetic Retinopathy is no longer a
  contraindication to pregnancy

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Pathophysiology

• Primary etiologic factor Chronic hyperglycemia
  producing microvascular lesions.
• Structural changes are identical in both pregnant
  and non-pregnant patients

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Pathophysiology

• The Paradox of Diabetes
• Lack of intracellular glucose for glycolysis in
  spite of excessive glucose in the serum
• (Insufficient glucose transport in the absence of
  insulin)

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The Polyol Pathway

• Activated by excessive extracellular glucose
• Minimal activity in euglycemic patients
• Aldose reductase converts glucose to D-sorbitol
• Sorbitol is converted into D-fructose
• D-sorbitol and D-fructose are trapped
  intracellularly
• Intracellular polyol sugars increase osmotic
  gradient
• Osmotic insult causes thickening of the basement
  membrane and cellular damage

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The Polyol Pathway

• Prolonged activation of the polyol pathway leads
  to pericyte death from osmotic damage
• Pericyte loss leads to weakening of the capillary
  wall
• Weakened capillary walls cause microaneurysm and
  closure
• New blood vessels bud in areas of pericyte
  deterioration setting the stage for
  neovascularization

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Therapy for Diabetic Retinopathy

• Laser photocoagulation is now the standard of
  care
• Reduces the risk of severe visual loss by 50
  compared to no treatment
• Mechanism of action not clearly understood
• Photocoagulation may reduce the level of Vascular
  Endothelial Growth Factor (VEGF) elaborated by
  the peripheral, poorly perfused retina
• SAFE IN PREGNANCY

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Management of Diabetic Retinopathy

• Pre-pregnancy counseling
• Planned pregnancy
• Opthalmologic protocol
• Baseline exam by retinal specialist at the
  beginning of pregnancy
• Patients with minimal disease re-examination
  every trimester and 3 to 6 months postpartum
• Monthly follow-up for severe NPDR or early PDR
• Closer follow-up of patients with minimal disease
  and proteinuria, hypertension or nephropathy.

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Controversies

• Does retinopathy worsen in pregnancy?
• Is rapid glycemic control dangerous?
• Retinopathy and the valsalva maneuver?
• Impact of hypertension on retinopathy.