Retinal vasculitis is inflammation of the vascular branches of the retinal artery, caused either by primary ocular disease processes, or as a specific presentation of any systemic form of vasculitis such as Behçet's disease, sarcoidosis, multiple sclerosis, or any form of systemic nectrozing vasculitis such as temporal arteritis, polyarteritis nodosa, and granulomatosis with polyangiitis, or due to lupus erythematosus, or rheumatoid arthritis. Eales disease, pars planitis, birdshot retinochoroidopathy (autoimmune bilateral posterior uveitis), and Fuchs heterochromic iridocyclitis (FHI) can also cause retinal vasculitis. Infectious pathogens such as "Mycobacterium tuberculosis", visceral larva migrans ("Toxocara canis" & "Toxocara cati") can also cause retinal vasculitis.

Retinal vasculitis presents as painless, decrease of visual acuity (blurry vision), visual floaters, scotomas (dark spot in vision), decreased ability to distinguish colors, and metamorphopsia (distortion of images such as linear images).

Birdshot chorioretinopathy may show resistance to treatment. Immunosuppressant therapy along with oral corticosteroid has been somewhat effective in slowing down the progressive inflammation associated with the disorder, preserving visual integrity as much as possible. Long-term use of such medications must be closely monitored, however, due to the discomforting and potentially debilitating and life-threatening side-effects.

Immunosuppressive drugs such as the therapeutic monoclonal antibody daclizumab, ciclosporin and methotrexate have proven to be effective treatment options for birdshot chorioretinopathy. Substantial reduction and even stabilization of both vitreous inflammation and retinal vasculitis have been evident via electroretinography, during daclizumab (IL-2 receptor blocker) therapy. This is also supported by the observation of elevated levels of IL-2 in the eyes of patients. Loss of visual acuity unrelated to the inflammation caused by the disorder, however, often remains unchanged despite usage of the drug. This is reflected by the lack of difference in visual acuity and the vision-related quality of life among various treatment categories in birdshot patients. Contraindications and adverse side-effects are always a factor, as well.

Quick determination of the cause may lead to urgent measures to save the eye and life of the patient. High clinical suspicion should be kept for painless vision loss in patients with atherosclerosis, deep venous thrombosis, atrial fibrillation, pulmonary thromboembolism or other previous embolic episodes. Those caused by a carotid artery embolism or occlusion have the potential for further stroke by detachment of embolus and migration to an end-artery of the brain. Hence, proper steps to prevent such an eventuality need to be taken.

Retinal arterial occlusion is an ophthalmic emergency, and prompt treatment is essential. Completely anoxic retina in animal models causes irreversible damage in about 90 minutes. Nonspecific methods to increase blood flow and dislodge emboli include digital massage, 500 mg IV acetazolamide and 100 mg IV methylprednisolone (for possible arteritis). Additional measures include paracentesis of aqueous humor to decrease IOP acutely. An ESR should be drawn to detect possible giant cell arteritis. Improvement can be determined by visual acuity, visual field testing, and by ophthalmoscopic examination.

At a later stage, pan-retinal photocoagulation (PRP) with an argon laser appears effective in reducing the neovascular components and their sequelae.

The visual prognosis for ocular ischemic syndrome varies from usually poor to fair, depending on speed and effectiveness of the intervention. However, prompt diagnosis is crucial as the condition may be a presenting sign of serious cerebrovascular and ischemic heart diseases.

In 2009, the Undersea and Hyperbaric Medical Society added "central retinal artery occlusion" to their list of approved indications for hyperbaric oxygen (HBO). When used as an adjunctive therapy, the edema reducing properties of HBO, along with down regulation of inflammatory cytokines may contribute to the improvement in vision. Prevention of vision loss requires that certain conditions be met: the treatment be started before irreversible damage has occurred (over 24 hours), the occlusion must not also occur at the ophthalmic artery, and treatment must continue until the inner layers of the retina are again oxygenated by the retinal arteries.

The treatment method used depends on the cause of the hemorrhage. In most cases, the patient is advised to rest with the head elevated 30–45°, and sometimes to put patches over the eyes to limit movement prior to treatment in order to allow the blood to settle. The patient is also advised to avoid taking medications that cause blood thinning (such as aspirin or similar medications).

The goal of the treatment is to fix the cause of the hemorrhage as quickly as possible. Retinal tears are closed by Laser treatment or cryotherapy, and detached retinas are reattached surgically.

Even after treatment, it can take months for the body to clear all of the blood from the vitreous. In cases of vitreous hemorrhage due to detached retina,long-standing vitreous hemorrhage with a duration of more than 2–3 months, or cases associated with rubeosis iridis or glaucoma, a vitrectomy may be necessary to remove the standing blood in the vitreous.

Several options exist for the treatment of BRVO. These treatments aim for the two of the most significant complications of BRVO, namely macular edema and neovascularization.

- Systemic treatment with oral Aspirin, subcutaneous Heparin, or intravenous thrombolysis have not been shown to be effective treatments for CRVO and for BRVO no reliable clinical trial has been published.

- Laser treatment of the macular area to reduce macular edema is indicated in patients who have 20/40 or worse vision and did not spontaneously improve for at least 3 months (to permit the maximum spontaneous resolution) after the development of the vein occlusion. It is typically administered with the argon laser and is focused on edematous retina within the arcades drained by the obstructed vein and avoiding the foveal avascular zone. Leaking microvascular abnormalities may be treated directly, but prominent collateral vessels should be avoided.

- The second indication of laser treatment is in case of neovascularization. Retinal photocoagulation is applied to the involved retina to cover the entire involved segment, extending from the arcade out to the periphery. Ischemia alone is not an indication for treatment provided that follow-up could be maintained.

- Preservative-free, nondispersive Triamcinolone acetonide in 1 or 4 mg dosage may be injected into the vitreous to treat macular edema but has complications including elevated intraocular pressure and development of cataract. Triamcinolone injection is shown to have similar effect on visual acuity when compared with standard care (Laser therapy), However, the rates of elevated intraocular pressure and cataract formation is much higher with the triamcinolone injection, especially the higher dosage. Intravitreal injection of Dexamethasone implant (Ozurdex; 700,350 μg) is being studied, its effect may last for 180 days. The injection may be repeated however with less pronounced effect. Although the implant was designed to cause less complications, pressure rise and cataract formation is noted with this treatment too.

- Anti-VEGF drugs such as Bevacizumab (Avastin; 1.25 -2.5 mg in 0.05ml) and Ranibizumab (lucentis) injections are being used and investigated. Intravitreal anti-VEGFs have a low incidence of adverse side effects compared with intravitreal corticosteroids, but are currently short acting requiring frequent injections. Anti-VEGF injection may be used for macular edema or neovascularization. The mechanism of action and duration of anti-VEGF effect on macular edema is currently unknown. The intraocular levels of VEGF are increased in eyes with macular edema secondary to BRVO and the elevated VEGF levels are correlated to the degree and severity of the areas of capillary nonperfusion and macular edema.

- Surgery is employed occasionally for longstanding vitreous hemorrhage and other serious complications such as epiretinal membrane and retinal detachment.

- Arteriovenous sheathotomy has been reported in small, uncontrolled series of patients with BRVO. BRVO typically occurs at arteriovenous crossings, where the artery and vein share a common adventitial sheath. In arteriovenous sheathotomy an incision is made in the adventitial sheath adjacent to the arteriovenous crossing and is extended along the membrane that holds the blood vessels in position to the point where they cross, the overlying artery is then separated from the vein.

Retinal haemorrhages, especially mild ones not associated with chronic disease, will normally resorb without treatment. Laser surgery is a treatment option which uses a laser beam to seal off damaged blood vessels in the retina. Anti-vascular endothelial growth factor (VEGF) drugs like Avastin and Lucentis have also been shown to repair retinal haemorrhaging in diabetic patients and patients with haemorrhages associated with new vessel growth.

Treatment consists of Anti-VEGF drugs like Lucentis or intravitreal steroid implant (Ozurdex) and Pan-Retinal Laser Photocoagulation usually. Underlying conditions also require treatment. Non-Ischemic CRVO has better visual prognosis than Ischemic CRVO.

A systematic review studied the effectiveness of the anti-VEGF drugs ranibizumab and pagatanib sodium for patients suffering from non-ischemic CRVO. Though there was a limited sample size, participants in both treatment groups showed improved visual acuity over 6 month periods, with no safety concerns.

There is no good evidence for any preventive actions, since it appears this is a natural response to aging changes in the vitreous. Posterior vitreous detachment (PVD) has been estimated to occur in over 75 per cent of the population over age 65, that PVD is essentially a harmless condition (although with some disturbing symptoms), and that it does not normally threaten sight. However, since epiretinal membrane appears to be a protective response to PVD, where inflammation, exudative fluid, and scar tissue is formed, it is possible that NSAIDs may reduce the inflammation response. Usually there are flashing light experiences and the emergence of floaters in the eye that herald changes in the vitreous before the epiretinal membrane forms g

Owing to the self-limiting nature of the disease, treatment is generally not required. In cases where lesions appear to be interfering with the optic nerve, methyl prednisone is prescribed.

In terms of the treatment of cytomegalovirus retinitis, oral valganciclovir, intravenous ganciclovir, IV foscarnet, and IV cidofovir are all efficient in the treatment of this condition. Also intravitreal injections, an injection of medicine into the vitreous near the retina, of foscarnet in concomitance with oral valganciclovir can be used for treatment as well.

Often individuals with CMV retinitis will need surgery for either retinal detachment or intravitreal instillation of ganciclovir. Retinal detachment occurs in up to 29% of affected eyes, repair being most effective with endolaser and silicone oil endotamponade.Intravitreal ganciclovir implant has the benefit of less systemic toxicity. An adverse effect of this is retinal detachment (and vitreous hemorrhage), also there is no systemic beneficial effect for cytomegalovirus organ disease.

Treatment of Eales’ disease comprises:

1. Medical treatment:

A course of oral corticosteroids for extended periods is the main stay of treatment

during active inflammation. A course of antitubercular therapy has also been

recommended in selective cases.

2. Laser photocoagulation of the retina is indicated in stage of neovascularizion.

3. Vitreoretinal surgery is required for nonresolving vitreous haemorrhage and tractional retinal detachment.

•If active TB present - treat with ATT

•otherwise manage the vitreous hemorrhage -

Partial h’ge - postural management with propped up position

Total h’ge - Pars Plana Vitrectomy

In the early stages, there are a few treatment options. Laser surgery or cryotherapy (freezing) can be used to destroy the abnormal blood vessels, thus halting progression of the disease. However, if the leaking blood vessels are clustered around the optic nerve, this treatment is not recommended as accidental damage to the nerve itself can result in permanent blindness. Although Coats' disease tends to progress to visual loss, it may stop progressing on its own, either temporarily or permanently. Cases have been documented in which the condition even reverses itself. However, once total retinal detachment occurs, sight loss is permanent in most cases. Removal of the eye (enucleation) is an option if pain or further complications arise.

If the diagnostic workup reveals a systemic disease process, directed therapies to treat that underlying cause should be initiated. If the amaurosis fugax is caused by an atherosclerotic lesion, aspirin is indicated, and a carotid endarterectomy considered based on the location and grade of the stenosis. Generally, if the carotid artery is still patent, the greater the stenosis, the greater the indication for endarterectomy. "Amaurosis fugax appears to be a particularly favorable indication for carotid endarterectomy. Left untreated, this event carries a high risk of stroke; after carotid endarterectomy, which has a low operative risk, there is a very low postoperative stroke rate." However, the rate of subsequent stroke after amaurosis is significantly less than after a hemispheric TIA, therefore there remains debate as to the precise indications for which a carotid endarterectomy should be performed. If the full diagnostic workup is completely normal, patient observation is recommended.

In general, BRVO has a good prognosis: after 1 year 50–60% of eyes have been reported to have a final VA of 20/40 or better even without any treatment. With time the dramatic picture of an acute BRVO becomes more subtle, hemorrhages fade so that the retina can look almost normal. Collateral vessels develop to help drain the affected area.

This ocular pathology was first described by Iwanoff in 1865, and it has been shown to occur in about 7% of the population. It can occur more frequently in the older population with postmortem studies showing it in 2% of those aged 50 years and 20% in those aged 75 years.

Birdshot chorioretinopathy is a rare form of posterior uveitis and accounts for 1-3% of uveitis cases in general. Birdshot chorioretinopathy is thought to be an autoimmune disease. The disease has strong association with the Human leukocyte antigen haplotype (HLA)-A29, which is the strongest association between a disease and HLA class I documented (>99% of patients are HLA-A29 positive by molecular testing and HLA-A29-negative cases are controversial). This indicates a role for T-lymphocytes in the pathogenesis. Birdshot chorioretinopathy is associated with IL-17, a hallmark cytokine of TH17 cells that play an important role in autoimmunity . The disease affects typically middle-aged or elderly caucasians. HLA-A29 is less prevalent in Asia and no birdshot chorioretinopathy cases have been reported in Asia. When birdshot chorioretinopathy is suspected, a person is usually tested to determine if they are HLA-A29 positive. Although previously HLA-A29 testing was not considered necessary for definitive diagnosis, because HLA-A29 is also common in the general healthy population (7%). An increasing number of specialists consider the presence of HLA-A29 critical for diagnosis. Additional (genetic or environmental) or unknown factors may be associated with HLA-A29 in the pathogenesis.

In 2014, Kuiper et al. conducted a genome-wide association study in birdshot chorioretinopathy and studied the entire genome of Dutch, Spanish and English patients. This large genetic study ascertained HLA-A29:02 as the primary risk factor and identified the "endoplasmic reticulum aminopeptidase (ERAP) 2" gene strongly associated with birdshot chorioretinopathy. Genetic variants near "ERAP2" on chromosome 5 resulted in high mRNA and protein expression of this aminopeptidase in BSCR patients. ERAP2 is an aminopeptidase that, together with the closely related ERAP1, trims peptides in the endoplasmic reticulum and loads these peptides on HLA molecules for presentation to T cells of the immune system. ERAP-HLA associations have also been reported in Ankylosing spondylitis and Behcet's disease, suggesting shared pathogenic pathways among these diseases.

Several treatments have been attempted for CRAS; however, none show definitive improvement in outcomes. The Undersea and Hyperbaric Medical Society lists Central Retinal Artery Occlusion (CRAO) as an approved indication for Hyperbaric Oxygen Therapy. This a treatment for CRAO that is covered by medical insurance in North America. Other treatments include ocular massage, anterior chamber paracentesis, and inhalation therapy of a mixture of 5% carbon dioxide and 95% oxygen.

With respect to embolic and hemodynamic causes, this transient monocular visual loss ultimately occurs due to a temporary reduction in retinal artery, ophthalmic artery, or ciliary artery blood flow, leading to a decrease in retinal circulation which, in turn, causes retinal hypoxia. While, most commonly, emboli causing amaurosis fugax are described as coming from an atherosclerotic carotid artery, any emboli arising from vasculature preceding the retinal artery, ophthalmic artery, or ciliary arteries may cause this transient monocular blindness.

- Atherosclerotic carotid artery: Amaurosis fugax may present as a type of transient ischemic attack (TIA), during which an embolus unilaterally obstructs the lumen of the retinal artery or ophthalmic artery, causing a decrease in blood flow to the ipsilateral retina. The most common source of these athero-emboli is an atherosclerotic carotid artery. However, a severely atherosclerotic carotid artery may also cause amaurosis fugax due to its stenosis of blood flow, leading to ischemia when the retina is exposed to bright light. "Unilateral visual loss in bright light may indicate ipsilateral carotid artery occlusive disease and may reflect the inability of borderline circulation to sustain the increased retinal metabolic activity associated with exposure to bright light."

- Atherosclerotic ophthalmic artery: Will present similarly to an atherosclerotic internal carotid artery.

- Cardiac emboli: Thrombotic emboli arising from the heart may also cause luminal obstruction of the retinal, ophthalmic, and/or ciliary arteries, causing decreased blood flow to the ipsilateral retina; examples being those arising due to (1) atrial fibrillation, (2) valvular abnormalities including post-rheumatic valvular disease, mitral valve prolapse, and a bicuspid aortic valve, and (3) atrial myxomas.

- Temporary vasospasm leading to decreased blood flow can be a cause of amaurosis fugax. Generally, these episodes are brief, lasting no longer than five minutes, and have been associated with exercise. These vasospastic episodes are not restricted to young and healthy individuals. "Observations suggest that a systemic hemodynamic challenge provoke[s] the release of vasospastic substance in the retinal vasculature of one eye."

- Giant cell arteritis: Giant cell arteritis can result in granulomatous inflammation within the central retinal artery and posterior ciliary arteries of eye, resulting in partial or complete occlusion, leading to decreased blood flow manifesting as amaurosis fugax. Commonly, amaurosis fugax caused by giant cell arteritis may be associated with jaw claudication and headache. However, it is also not uncommon for these patients to have no other symptoms. One comprehensive review found a two to nineteen percent incidence of amaurosis fugax among these patients.

- Systemic lupus erythematosus

- Periarteritis nodosa

- Eosinophilic vasculitis

- Hyperviscosity syndrome

- Polycythemia

- Hypercoagulability

- Protein C deficiency

- Antiphospholipid antibodies

- Anticardiolipin antibodies

- Lupus anticoagulant

- Thrombocytosis

- Subclavian steal syndrome

- Malignant hypertension can cause ischemia of the optic nerve head leading to transient monocular visual loss.

- Drug abuse-related intravascular emboli

- Iatrogenic: Amaurosis fugax can present as a complication following carotid endarterectomy, carotid angiography, cardiac catheterization, and cardiac bypass.

Vision improves in almost all cases. In rare cases, a patient may suffer permanent visual loss associated with lesions on their optic nerve.

Rarely, coexisting vasculitis may cause neurological complications. These occurrences can start with mild headaches that steadily worsen in pain and onset, and can include attacks of dysesthesia. This type of deterioration happens usually if the lesions involve the fovea.

Telemedicine programs are available that allow primary care clinics to take images using specially designed retinal imaging equipment which can then be shared electronically with specialists at other locations for review. In 2009, Community Health Center, Inc. implemented a telemedicine retinal screening program for low-income patients with diabetes as part of those patients annual visits at the Federally Qualified Health Center.

As one gets older, pockets of fluid can develop in the vitreous. When these pockets develop near the back of the eye, the vitreous can pull away from the retina and possibly tear it. Posterior vitreous detachment accounts for 3.7–11.7% of vitreous hemorrhage cases.

Retinopathy is any damage to the retina of the eyes, which may cause vision impairment. Retinopathy often refers to retinal vascular disease, or damage to the retina caused by abnormal blood flow. Age-related macular degeneration is technically included under the umbrella term retinopathy but is often discussed as a separate entity. Retinopathy, or retinal vascular disease, can be broadly categorized into proliferative and non-proliferative types. Frequently, retinopathy is an ocular manifestation of systemic disease as seen in diabetes or hypertension. Diabetes is the most common cause of retinopathy in the U.S. as of 2008. Diabetic retinopathy is the leading cause of blindness in working-aged people. It accounts for about 5% of blindness worldwide and is designated a priority eye disease by the World Health Organization.

Severe ipsilateral or bilateral carotid artery stenosis or occlusion is the most common cause of ocular ischemic syndrome. The syndrome has been associated with occlusion of the common carotid artery, internal carotid artery, and less frequently the external carotid artery. Other causes include:

- Takayasu's arteritis

- Giant cell arteritis

- Severe ophthalmic artery occlusion, due to thromboembolism.

- Surgical interruption of anterior ciliary blood vessels supplying the eye, particularly during extensive strabismus surgery on 3 or more rectus muscles, leading to an anterior segment ischemic syndrome.

To date, there is no known effective treatment for the non-proliferative form of macular telangiectasia type 2.

Treatment options are limited. No treatment has to date been shown to prevent progression. The variable course of progression of the disease makes it difficult to assess the efficacy of treatments. Retinal laser photocoagulation is not helpful. In fact, laser therapy may actually enhance vessel ectasia and promote intraretinal fibrosis in these individuals. It is hoped that a better understanding of the pathogenesis of the disease may lead to better treatments.

The use of vascular endothelial growth factor (VEGF) inhibitors, which have proven so successful in treating age-related macular degeneration, have not proven to be effective in non-proliferative MacTel type 2. Ranibizumab reduces the vascular leak seen on angiography, although microperimetry suggests that neural atrophy may still proceed in treated eyes.In proliferative stages (neovascularisation), treatment with Anti-VEGF can be helpful.

CNTF is believed to have neuroprotective properties and could thus be able to slow down the progression of MacTel type 2. It has been shown to be safe to use in MacTel patients in a phase 1 safety trial.