Ocular Ischemic Syndrome (OIS)

Ocular Ischemic Syndrome (OIS)
SYMPTOMS Decrease in vision is the most common symptom as it occurs in 91% of patients with OIS (vision loss is gradual 67% of the time and about 66% of patients with OIS end up seeing 20/60 or worse)
Eye pain (typically a dull ache over brow) due to ischemia occurs in 40% of patients with OIS (this pain tends to be worse when patient is sitting up as opposed to lying down where the eye pain improves due to improvement in blood flow). This is called ocular angina
Amaurosis Fougax is reported 10-15% of the time
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 Peripheral vision loss in the presence of optic neuropathy
SIGNS Typically unilateral
Anterior segment signs: Conjunctival and episcleral injection, Asymmetric corneal arcus, Corneal edema, Iris atrophy, Fixed mid-dilated pupil with decreased light response, EOM restrictions, Ptosis, Ocular hypotony, NVI, NVA, Neovascular glaucoma, Uveitis (flare more so than cells)
Posterior segment signs: Narrow retinal arteries and arterioles, Dilated but not tortuous veins and venules, Mid-peripheral dot/blot hemorrhages, Microaneurysms, Cotton wool spots, Capillary nonperfusion, Chorioretinal atrophy, Cherry red spot especially if associated with retinal artery occlusions, Optic neuropathy, Asymmetric retinopathies such as diabetic retinopathy, Cystoid macular edema, NVD, NVE, Subhyaloid hemorrhage, Preretinal hemorrhage, Intravitreal hemorrhage
Posterior segment signs are more common to see in patients with OIS than anterior segment signs
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, Fluorescein Angiography, Indocyanine Green Angiography, Fundus photos, Infrared photos, B-scan ultrasound (if unable to view the retina), Electrodiagnostic testing (Multifocal ERG: presence of a diminished A and B wave), Watzke-Allen test, Macular photostress test, Amsler grid
TREATMENT Refer to PCP/ER STAT (patient has an increased mortality rate with the leading cause of death being a myocardial infarction)
Give take home Amsler grid in order to monitor for change
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
Ocular ischemic syndrome without any significant complications: Needs to be monitored closely. There is no ocular treatment
Ocular ischemic syndrome with corneal edema: Treat with a topical steroid (Prednisolone acetate or Durezol) and a topical hyperosmotic (Muro 128)
Ocular ischemic syndrome with a uveitis: Treat with a topical steroid (Prednisolone acetate or Durezol) and a topical cycloplegic
Ocular ischemic syndrome with evidence of cystoid macular edema and/or retinal neovascularization: Refer to retinal specialist ASAP for treatment
Ocular ischemic syndrome with an associated central retinal artery occlusion: Typically irreversible damage occurs 90-100 minutes after the initial onset of the CRAO and any treatment should be done within 24 hours of the initial onset of the CRAO
Treatments that can be attempted in office
Ocular massage (needs to be done for at least 1 hour) while patient lies in a supine position
Begin Diamox 250mg QID for the first 24 hours along with topical glaucoma agents (Beta blockers and Alpha-2 Agonists) in order to quickly lower IOP (Always keep in mind the contraindications and side effects before prescribing these medications). Should not be done if hypotony is present
Have patient breath in a paper bag
Other treatments to consider include paracentesis and a hyperbaric oxygen therapy
There is no particular order to all the treatment options. These are treatments that can be attempted but there is no definitive proof that any of the treatments actually work. Visual prognosis is still will be poor despite any treatment
Refer to a retinal specialist ASAP after attempting in office treatments especially if there is retinal neovascularization, subhyaloid hemorrhages, preretinal hemorrhages, intravitreal hemorrhages, and/or cystoid macular edema
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 Ocular ischemic syndrome without any significant complications: Should see back every 1-2 months for the first 6 months in order to monitor for development of corneal edema, uveitis, cystoid macular edema, worsening of ischemia, retinal neovascularization, and neovascular glaucoma. If stable, follow-up in 4-6 months
Ocular ischemic syndrome with corneal edema and/or a uveitis: Patient should be seen back in 1-2 weeks for a follow-up until resolution
Acute central retinal artery occlusion associated with ocular ischemic syndrome without evidence of retinal neovascularization, neovascular glaucoma, subhyaloid hemorrhages, preretinal hemorrhages, intravitreal hemorrhages, and/or cystoid macular edema: 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 3-4 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 The patient needs 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, CBC with differential, ESR, ANA, Plasma protein electrophoresis, Thrombophilia screening (PT, TT, BT, PTT, INR, Protein C, Protein S, Anticardiolipin antibodies), Carotid duplex, Cardiac evaluation, MRA/CTA of the carotid arteries
ETIOLOGY Severe carotid artery stenosis or occlusion leads to ocular hypoperfusion and ischemia. Typically occurs when there is >90% internal carotid artery stenosis or common carotid artery stenosis at the bifurcation (leads to a 50% reduction in ipsilateral perfusion pressure)
DIFFERENTIAL DX Central retinal vein occlusion, Diabetic retinopathy, Hypertensive retinopathy, Anemia retinopathy, Sickle cell retinopathy, Leukemia retinopathy
NOTES Only about 4% of patients with carotid artery disease develop ocular ischemic syndrome
If there is good collateral circulation between the two internal carotid arteries or between the internal and external carotid arteries, ocular ischemic syndrome is less likely to develop.
Reversal of blood flow may be seen in the ophthalmic artery as intracranial blood vessels may steal or shunt blood away from the ophthalmic artery
The systemic disease most commonly associated with ocular ischemic syndrome is hypertension
Retina-vascular disease associated with ocular ischemic syndrome is also called Venous Stasis Retinopathy
Iris and/or angle neovascularization is seen in about 67-87% of all ocular ischemic syndrome cases
Neovascular glaucoma in patients with ocular ischemic syndrome may actually have lower than expected IOPs if there is concurrent ocular hypotony
Ocular Ischemic Syndrome (OIS): Fundus photo demonstrating mid-peripheral intraretinal hemorrhages which are commonly seen in patients with ocular ischemic syndrome https://imagebank.asrs.org/file/3344/ocular-ischaemic-syndrome-colour-2
Posted in Ocular Conditions, Retina-Vascular