DR and vein occlusions Flashcards
Severe NPDR
4 (DBH &/or MAs)-2 (venous beading)-1 (IRMA)
very severe npdr: 2+ NPDR critiera
Severe NPDR - chance to progress 15% to PDR in 1 year
Very severe NPDR - 45% chance to progress to PDR in 1 year
CWS have no impact on progression
When to f/u:
minimal NPDR: 1 year
mid-moderate NPDR: 6-12 mo
Severe NPR, high risk or inactive PDR, CSME : 2-4 mo
Measuring retinal artery pressure
Ophthalmodynamometry can be used to measure retinal artery pressure. It will show a NORMAL artery pressure in CRVO but a LOW artery pressure in carotid occlusive disease.
FIPTS (focal intraretinal periarteriolar transudates)
different from CWS (superficial radial capillary net)
FIPTs (precapillary level) and deeper, smaller, and more gray than CWS.
exclusively occur in malignant hypertension, unlike CWS which may occur in a variety of ocular diseases.
On FA: FIPTs appear as punctate foci of leakage while CWS typically hypofluoresce due to nonperfusion.
Focal vs grid laser settings
Parameters for focal and grid laser are very similar (i.e. 50 to 100 micron spot / 0.1 sec or less duration).
Difference: on what is actually photocoagulated.
For focal, all discrete (FOCAL) leaking microaneurysms are lasered between 500 and 3000 microns from the fovea.
For grid, all areas of DIFFUSE leakage are lasered >500 microns from the fovea and >500 microns from the temporal margin of the disc.
CRAO
cilioretinal-sparing central retinal artery occlusion (CRAO).
retinal whitening but with preservation of perfusion in the foveal area
FA: absence of dye in the majority of the retinal blood vessels except for a few vessels feeding the fovea
The blood supply to the inner layers of the retina is typically derived entirely from the central retinal artery. Exception: ~15-30% of eyes have a cilioretinal artery which is a branch most directly from the posterior ciliary arteries.
> two-thirds of cases VA < 20/400.
Vision of NLP typically does not occur in CRAO, but can occur with simultaneous choroidal infarction (e.g. ophthalmic artery occlusion).
Leading cause of blindness in Americans age 20-64
Leading cause of blindness in U.S. patients aged 20-64 years= diabetic retinopathy.
From WHO leading causes of blindness worldwide (in descending order) = cataract, glaucoma, AMD, corneal opacities, diabetic retinopathy, childhood blindness, trachoma, and onchocerciasis.
From BSC leading causes of blindness: cataract, onchocerciasis, and glaucoma.
CRVO and BRVO risk factors
BRVO: unique = BMI (increased). B for BRVO and BMI
CRVO: unique = DM (ischemic type). ABCD (C and D are close together)
Both BRVO AND CRVO: HTN and glaucoma and CV dz (ischemic type)
Order of focal and PRP
Mnemonic: Focal FIRST (always)
Perform focal or grid PRIOR to PRP
perform focal prior to CE/IOL in CSME
CRVO vs carotid artery occlusive disease
retinal veins dilated in BOTH CRVO and carotid occlusive disease BUT
CRVO - tortuous retinal veins only with CRVO and NORMAL ophthalmodynamometry retinal artery pressure measurement
low ophthalmodynamometry retinal artery pressure measurement in carotid occlusive disease
Which of the following statements accurately describes the routine evaluation of patients with diabetes mellitus?
DR usually is not seen until the patient has diabetes for 6-7 years.
initial ophthalmic examination on Dx w/DM and annually thereafter
pregnant diabetic women: examinations performed in the first trimester and, at a minimum, q3 months until delivery.
branches of the ophthalmic artery.
central retinal artery
posterior ciliary arteries
lacrimal artery
CPL
retinal arterial macroaneurysm (RAM).
HTN in 2/3 of RAM pts
if no macular edema, may be observed without treatment
if visually-significant macular edema, the RAM may be lightly treated with photocoagulation using a larger spot size (e.g. 200 to 500 microns).
BUT,must always remember that photocoagulation of the RAM may induce retinal arterial thrombosis and subsequent infarction of the distal retina.
branch retinal vein occlusion most commonly occurs where?
most commonly occurs (>60%) in the superotemporal quadrant
Hypertensive Retinopathy
Scheie classification?
Grade 0: no change
Grade 1: trace arterial narrowing
Grade 2: frank arterial narrowing + focal irregularities
Grade 3: grade 2 + retinal hemorrhages/exudates
Grade 4: grade 3 + disc swelling
Can cause BRAO, BRVO, CRVO
Treatment? Laser if macula involved Macroaneurysms 2/3 from HTN retinopathy; also CRVO Tx: laser
Hypertensive Choroidopathy
Usually occurs w/ acute HTN: Preeclampsia or eclampsia Renal disease Pheochromocytoma Malignant HTN
Findings?
Elschnig spots
Siegrist streaks
Serous RD
FA?
early focal choroidal hypoperfusion
late subretinal leakage
DDx?
Vaso-occlusive dx (TTP, ITP, DIC)
Inflammatory dx (GCA, Wegener’s)
