Central Retinal Vein Occlusion (CRVO)

Central Retinal Vein Occlusion (CRVO)
SYMPTOMS Non-ischemic CRVO: Sudden painless vision loss (typically 20/200 or better)
Ischemic CRVO: Sudden painless vision loss (typically counting fingers or worse)
Patients with a non-ischemic CRVO tend to have Normal peripheral vision while patients with an ischemic CRVO tend to have Abnormal peripheral vision
Patient may also report Mild to severe vision loss in the presence of neovascular glaucoma, an intravitreal hemorrhage, a subhyaloid hemorrhage, and a preretinal hemorrhage, Central vision loss and Metamorphopsia in the presence of cystoid macular edema, Central vision loss and scotoma in the presence of paracentral acute middle maculopathy (PAMM), Central vision loss and Peripheral vision loss in the presence of optic nerve pallor
SIGNS Typically unilateral
Acute occlusion: Dilated and tortuous veins and venules, Vessel sheathing, Extensive intraretinal hemorrhages (Dot/Blot/Flame) that extend from the posterior pole to periphery in all 4 quadrants (most numerous in the periphery) known as "Blood and Thunder", Microaneurysms, Macroaneurysms, Cotton wool spots, Exudates, Retinal capillary nonperfusion, Cystoid macular edema, Paracentral acute middle maculopathy (PAMM), NVD, NVE, NVA, NVI, Preretinal hemorrhages, Subhyaloid hemorrhages, Intravitreal hemorrhages, Neovascular glaucoma, Optic nerve edema
There is increased risk of development and severity of these signs with ischemic CRVOs when compared to non-ischemic CRVOs
The signs seen with an acute central retinal vein occlusion typically resolve in 6-12 months
Chronic/Resolved occlusion: Most intraretinal hemorrhages disappear (some dot/blot/flame hemorrhages will remain for months to years), Cotton wool spots usually disappear, Improvement in the amount of exudates (may remain for months to years), Veins and venules become less tortuous and dilated (due to decrease in pressure against the walls of the vein and venules), Sclerotic retinal vessels, Macular ischemia (enlargement of foveal avascular zone), Collateral vessels, Optocilliary shunt vessels, Optic nerve pallor
WORK-UP Pupils, EOMs, Full eye exam with dilated retinal exam (look closely at the pupillary ruff for NVI especially before dilating), Gonioscopy, OCT analysis of the macula (signs of cystoid macular edema are best seen with an OCT ), OCT analysis of the optic nerve, OCT-Angiography (disruption of the perifoveal capillary plexus correlates with the presence of peripheral retinal ischemia and deep vascular complex nonperfusion), Fluorescein Angiography (it is better to do a widefield fluorescein angiography because capillary nonperfusion typically starts in the periphery and than later involves the posterior pole / greater than or equal to 10DD of capillary nonperfusion is indicative of an ischemic CRVO), Fundus photos, B-scan ultrasound (if unable to view the retina), Electrodiagnostic testing (Multifocal ERG: presence of a B-wave that is 60% of the normal height is indicative of an ischemic CRVO), Watzke-Allen test, Macular photostress test, Amsler grid
TREATMENT Refer to PCP ASAP in order to get any systemic conditions under control and for a full work-up
Give take home Amsler grid in order to monitor for change
Consider starting a topical glaucoma drop in other eye especially if IOP is elevated or patient has glaucoma (potentially prevents a central retinal vein occlusion in the other eye)
Patient needs to use caution with any strenuous exercise or activities in the presence of retinal neovascularization
Patient should sleep with their head elevated in presence of a preretinal, subhyaloid, and/or intravitreal hemorrhage
Non-ischemic or Ischemic CRVO without any evidence of cystoid macular edema and retinal neovascularization: Needs to be monitored closely
Non-ischemic or Ischemic CRVO with evidence of cystoid macular edema and/or retinal neovascularization: Refer to retinal specialist ASAP for treatment
NVI and/or NVA with normal IOP and no evidence of glaucomatous optic nerve damage: Refer to retinal specialist within 48 hours
NVI and/or NVA with elevated IOPs but no evidence of glaucomatous optic nerve damage or with associated secondary open angle glaucoma: Begin treatment with topical and oral glaucoma medications. Refer to retinal specialist within 48 hours
NVI and/or NVA with secondary angle closure with or without glaucoma: The goal is to lower the IOP as quickly as possible in office and then refer to a retinal specialist ASAP. A glaucoma specialist will most likely be involved as well as patient will need a trabeculectomy and/or shunt
FOLLOW-UP Non-ischemic CRVO without any evidence of cystoid macular edema and retinal neovascularization: Should see back in 1-2 months in order to monitor for development of cystoid macular edema, worsening of ischemia, retinal neovascularization, and neovascular glaucoma. If stable, patient should be seen in 3-4 months
Ischemic CRVO without any evidence of cystoid macular edema and retinal neovascularization: Should see back every month for the first 6 months in order to monitor for development of cystoid macular edema, worsening of ischemia, retinal neovascularization, and neovascular glaucoma
Once retinal neovascularization becomes involutional or quiescent and the retina and macula is stable, patient should be seen back every 3-6 months
Neovascular glaucoma: Patient will most likely continue care with a retinal specialist and/or glaucoma specialist. If condition is stable and patient is no longer seeing a retinal specialist and/or glaucoma specialist, the patient should be seen every 2-4 months
ADDITIONAL LAB | TESTS If patient is older (50 years old or more), they need to follow-up with their PCP for additional testing if not already done which includes the following: Blood pressure, Fasting blood sugar, HbA1c, Lipid panel, Thyroid panel, CBC with differential, ESR, Plasma protein electrophoresis, Renal function testing, Carotid duplex, Cardiac evaluation
If patient is younger (less than 50 years old), they need to follow-up with their PCP for additional testing if not already done which includes the following: Blood pressure, Fasting blood sugar, HbA1c, Lipid panel, Thyroid panel, CBC with differential, ESR, Plasma protein electrophoresis, Renal function testing, Carotid duplex, Cardiac evaluation, ANA, ACE, Thrombophilia screening (PT, TT, BT, PTT, INR, Protein C, Protein S, Anticardiolipin antibodies)
ETIOLOGY Blockage of blood flow within the central retinal vein at or near the lamina cribosa. Venous blockage leads to an increase in back pressure to the capillaries, venules, and vein which causes damage and subsequent nonperfusion and leakage
DIFFERENTIAL DX Diabetic retinopathy, Hypertensive retinopathy, Anemia retinopathy, Sickle cell retinopathy, Leukemia retinopathy, Central retinal artery occlusion, Ocular ischemic syndrome
NOTES There are 3 main etiologies of a CRVO
Compression: Sclerosis and hardening of central retinal artery (due to various etiologies including diabetes, hypertension, and high cholesterol) leads compression on the central retinal vein and thrombus formation, Glaucoma (elevated intra-ocular pressure leads to thrombus formation in the central retinal vein due to posterior bowing of the lamina cribosa), Papilledema, Thyroid eye disease, Orbital tumor
Inflammation of the primary vessel walls: Systemic vasculitis (due to various etiologies including tuberculosis, syphilis, and lupus), Localized vasculitis (due to various etiologies such as sarcoids)
Increase in blood stream viscosity: Clotting disorders (due to various etiologies such as antiphospholipid syndrome, protein C deficiency, protein S deficiency, and anticardiolipin antibodies), Drugs such as oral contraceptives, Blood dyscrasias (due to various etiologies such as sickle cell anemia, lymphoma, leukemia, and polycythemia vera)
The highest risk factor for development of a CRVO in older patients is hypertension
About 15-20% of non-ischemic CRVOs will eventually become ischemic (on average, this conversion takes about 4-6 months)
Patients with a CRVO (more so ischemic) have a risk of developing NVI/NVA within 90 days which could lead to neovascular glaucoma. It is important to perform gonioscopy on all patients with a CRVO
A retina with a CRVO that has >75DD of retinal capillary nonperfusion significantly increases the risk of development of neovascularization (in fact, this is considered the highest predictor for development of neovascularization)
A retina with a CRVO that has <30DD of retinal capillary nonperfusion significantly decreases the risk of development of neovascularization
A hemi-central CRVO is a variant of a CRVO (in about 20% of patients, the branches of the central retinal vein retinal vein are present even posterior to the lamina cribosa so when a central retinal vein occlusion occurs at or near the lamina cribosa, only one of these branches will be affected which means only one half of the retina will be affected)
Impending CRVO: Patient is typically asymptomatic with good vision, Mild vein and venule tortuosity and dilation, Few flame/dot/blot hemorrhages , Paracentral acute middle maculopathy (PAMM)
An impending CRVO may eventually resolve on its own or convert to complete obstruction
Treatment for an impending CRVO: Treat the underlying systemic conditions (refer patient to PCP to get any systemic conditions under control and for a full work-up), Consider antiplatelet agents and anticoagulants (should discuss with PCP), Consider starting glaucoma drops in the eye with the impending CRVO especially if IOP is elevated or patient has glaucoma (potentially prevents full obstruction)
Central Retinal Vein Occlusion (CRVO): Fundus photo demonstrating the presence of blood and thunder in the posterior pole https://imagebank.asrs.org/file/968/crvo-with-flame-hemorrhages
Posted in Ocular Conditions, Retina-Vascular