What layers of the retina would you find dot/blot hemes?
Middle layers of the retina (INL + OPL)
What defines Proliferative Diabetic Retinopathy?
Neovascularization
If you see a haziness to a retinal image indicating fibrosis - how do you manage it?
Refer to retinal specialist within a day or two so patient doesn't have a retinal detachment. (i.e. Neovascularization)
What should the normal non-fasting blood sugar be between?
70-150
Why is the type of diabetes important to ask in case history?
Type is important because onset of complications is sooner in type II than type I.
Patients with renal disease will need lab work done. What are you looking for as far as elevated levels?
Proteinuria, elevated blood urea nitrogen (BUN) and creatinine.
If a patient has renal disease, what is this a good indication of?
Renal disease is an excellent predictor of diabetic retinopathy.
In normal aging, how does refractive error shift?
Increase in hyperopia and ATR cylinder.
What kind of refractive error does a nuclear sclerotic cataract cause?
A myopic shift
If your patient has low blood glucose levels in your office, what can you do to help?
Provide a sugar tablet or provide them some orange juice.
What two things would you document as negative in a diabetic exam?
NVI (Neovascularization of Iris)
Diabetic Retinopathy
Diabetic patients are often difficult to dilate. What is the condition called? What do you do about it?
Pupillary autonomic neuropathy
Use all of the agents and may have to use more than 1 drop of each.
How long does it take for diabetic retinopathy to develop with Diabetes Mellitus?
After ~ 8 years.
79% of diabetics have retinopathy after 20 years.
What hormone most likely contributes to the pathophysiology of diabetic retinopathy?
Growth hormone
It used to be treated by a pituitary ablation to prevent diabetic retinopathy.
What is the pathophysiology of pericyte dysfunction?
Hyperglycemia --> aldose reductase pathway --> sorbitol --> pericyte dysfunction.
Pericytes prevent the leakage of vessels. If dysfunctional - causes leakage.
What is the pathology of ischemia?
Clogging of vessels - due to platelets and blood viscosity.
What is the cause of neovascularizaiton?
Hypoxia
What are indications of Intraretinal Microvascular Abnormalitie?
Venous beading, cotton wool spots
(venous beading = sausaging of vessels)
Where in the retina would you see flame hemes?
More inner layers - NFL
Where in the retina do cotton wool spots occur?
NFL
If you see capillary non-perfusion - what can this indicate?
May indicate that neovascularization is close to occurring.
What are some of the findings and characteristics of Non-Proliferative Diabetic Retinopathy?
Microanerurysms - pericyte loss (earliest*)
Dot Heme/Blot Heme/Flame Heme
Exudates
Macular Edema/CSME
Cotton Wool spots
IRMA
Venous Beading
(Increased risk for progressing from NPDR to PDR as you go down the list)
What is the difference between Non-proliferative and Proliferative Diabetic Retinopathy?
NPDR = no neovascularization
PRD = Neovascularization
Define micro aneurysms.
Small bulge in blood vessels due to wearing of the walls/pericytes because of high blood glucose. These are the FIRST to appear.
How would dot/blot hemes show on flouresceine angiography?
Hypoflourescence due to hemes blocking normal choroidal fluorescence.
How would micro aneurysms appear on FA?
Hyperfluorescence - appear as small white dots
Would be difficult to see with the naked eye.
What are signs/characteristics of Proliferative Diabetic Retinopathy?
NVI
NVA
NVD
NVE
Rubeotic Glaucoma
Vitreal Hemorrhages/Pre-retinal hemes - "boat shaped hemes"
Traction RD
In what layers would you find a "boat-shaped" hemorrhage?
Between the potential space of the retina and post-hyaloid space.
What is your management if you have findings of neovascularization?
REFER SAME DAY OR AS SOON AS POSSIBLE.
How is mild non-proliferative diabetic retinopathy defined? How do you manage?
presence of at least one micro aneurysm or hemorrhage. RTC 6 months to 1 year.
How is moderate non-proliferative diabetic retinopathy defined? How do you manage?
Increased hemes and micro aneurysms plus possible cotton wool spots, venous beading in one quadrant. RTC within 6 months
What is the leading cause of visual impairment in patients with diabetic retinopathy?
Macular Edema
If you see IRMA or venous beading, what can this indicate?
Potential capillary non-perfusion which could lead to neovascularization. See sooner or even refer to a retinal specialist.
What test is the best to use to view and measure possible macular edema?
OCT to measure macular thickness. Concern about ME could develop neovascularization sooner than later.
Regarding diabetic retinopathy, what are some threats to vision?
Macular edema
Macular non-perfusion
Proliferative:
Vitreal heme
Neovascular glaucoma (robotic glaucoma)
Traction Retinal detachment
Regarding the threats to vision with diabetic retinopathy, which are treatable?
Macular edema
Vitreal hemorrhage
Neovascular glaucoma
Traction retinal detachment
With maculopathy, what are the threats to vision? Which is treatable?
Edema (treatable)
Non-perfusion (ischemia) - doesn't respond well to treatments as well as edema.
Can you diagnose macular edema based upon visual acuities?
Maybe. An OCT would be best to diagnose ME. A patient could still have good acuities so it shouldn't be the guiding factor.
What are the three rules for diagnosing CSME?
1) Retinal thickening within 1/3 DD of center of fovea
2) Hard exudates within 1/3DD of center of fovea with associated retinal thickening
3) 1DD of thickening - at least part is within 1DD of center of fovea
Just need 1 to diagnose
What 2 things are missing from the rules to diagnosing CSME?
1) OCT - didn't have at the time
2) Hemes - don't really put at risk for macular edema
How is Fluorescein Angiography used in diabetes?
To differentiate between Edema and non-perfusion - shows wehre/how to treat.
What are the 3 best diagnostic tests an optometrist can use to diagnose CSME?
1) OCT
2) BIO and retinal biomicroscopy
3) FLAN if needed
If you have a patient with a vitreous hemorrhage - what test can you use to check for retinal detachments?
B-Scan ultrasound