Diagnosis commonly occurs later in childhood and often occurs incidentally in asymptomatic patients or as a cause of visual impairment. The first symptoms are commonly found during routine vision screenings.

A number of examinations can be used to determine the extent of the syndrome and its severity. Fluorescein angiography is quite useful in diagnosing the disease, and the use of ultrasonography and optical coherence tomography (OCT) are helpful in confirming the disease. Neuro-ophthalmic examinations reveal pupillary defects (see Marcus Gunn Pupil). Funduscopic examinations, examinations of the fundus of the eye, allow detection of arteriovenous malformations. Neurological examinations can determine hemiparesis and paresthesias. Malformations in arteriovenous connections and irregular functions in the veins may be distinguished by fluorescein angiographies. Cerebral angiography examinations may expose AVMs in the cerebrum. MRIs are also used in imaging the brain and can allow visualization of the optic nerve and any possible atrophy. MRI, CT, and cerebral angiography are all useful for investigating the extent and location of any vascular lesions that are affecting the brain. This is helpful in determining the extent of the syndrome.

Diagnosis is made by an ophthalmologist during eye examination. Further tests such as fluorescein angiography or lumbar puncture are usually performed to confirm the diagnosis.

Neurosarcoidosis is a similar autoimmune disorder that can be confused with APMPPE.

The treatment for Bonnet–Dechaume–Blanc syndrome is controversial due to a lack of consensus on the different therapeutic procedures for treating arteriovenous malformations. The first successful treatment was performed by Morgan et al. They combined intracranial resection, ligation of ophthalmic artery, and selective arterial ligature of the external carotid artery, but the patient did not have retinal vascular malformations.

If lesions are present, they are watched closely for changes in size. Prognosis is best when lesions are less than 3 cm in length. Most complications occur when the lesions are greater than 6 cm in size. Surgical intervention for intracranial lesions has been done successfully. Nonsurgical treatments include embolization, radiation therapy, and continued observation. Arterial vascular malformations may be treated with the cyberknife treatment. Possible treatment for cerebral arterial vascular malformations include stereotactic radiosurgery, endovascular embolization, and microsurgical resection.

When pursuing treatment, it is important to consider the size of the malformations, their locations, and the neurological involvement. Because it is a congenital disorder, there are not preventative steps to take aside from regular follow ups with a doctor to keep an eye on the symptoms so that future complications are avoided.

Macular telangiectasia type 1 must be differentiated from secondary telangiectasis caused by retinal vascular diseases such as retinal venous occlusions, diabetic retinopathy, radiation retinopathy, sickle cell maculopathy, inflammatory retinopathy/Irvine–Gass syndrome, ocular ischemic syndrome/carotid artery obstruction, hypertensive retinopathy, polycythemia vera retinopathy, and localized retinal capillary hemangioma. In addition, Macular telangiectasia type 1 should be clearly differentiated from dilated perifoveal capillaries with evidence of vitreous cellular infiltration secondary to acquired inflammatory disease or tapetoretinal dystrophy. Less commonly, macular telangiectasis has been described in association with fascioscapulohumeral muscular dystrophy, incontinentia pigmenti, and familial exudative vitreoretinopathy with posterior pole involvement.

Macular telangiectasia type 2 is commonly under-diagnosed. The findings may appear very similar to diabetic retinopathy, and many cases ave been incorrectly ascribed to diabetic retinopathy or age-related macular degeneration. Recognition of this condition can save an affected patient from unnecessarily undergoing extensive medical testing and/or treatment. MacTel should be considered in cases of mild paramacular dot and blot hemorrhages and in cases of macular and paramacular RPE hyperplasia where no other cause can be identified.

Treatment is based

on the stage of the disease. Stage 1 does not

require treatment and

should be observed. 4

Neovascularization

(stage 2) responds well

to laser ablation or

cryotherapy.2,4 Eyes

with retinal detachments (stages

3 through 5) require surgery, with

earlier stages requiring scleral

buckles and later stages ultimately

needing vitrectomy. 2,4

More recently, the efficacy of

anti-VEGF intravitreal injections

has been studied. In one study,

these injections, as an in adjunct

with laser, helped early stages

achieve stabilization, but further

investigation is needed.6

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

Patients and their primary care physicians must be made fully aware of the ophthalmic risks and the need for regular screening examinations to detect retinal toxicity at an early stage.

Baseline evaluation for patients beginning treatment with a chloroquine derivative should include a complete eye examination by an eye care professional, retinal photography for follow-up comparisons, and Visual field testing with a white pattern. Central visual field assessment should test the central 10° of vision with a white test target (such as Humphrey 10-2 program).

In patients at risk or those with unclear presentation, optical coherence tomography (loss of IS/OS junctions), fundus autofluorescence (focal hyper or hypoautofluorescence), and multifocal electroretinography (paracentral depressions) may be obtained.

Profound abnormalities detected with visual field and multifocal electroretinography testing can be observed in the presence of a normal retinal appearance. Retinal examinations are advised for documentation, but visible bull's-eye maculopathy is a late change, and the goal of screening is to recognize toxicity at an earlier stage. Annual screening should begin after 5 years (or sooner if there are unusual risk factors).

FEVR is, as its name suggests,

familial and can be inherited in an

autosomal dominant, autosomal

recessive or X-linked recessive pattern.1-3 It is caused by mutations in

FZD4, LRP5, TSPAN12 and NDP

genes, which impact the wingless/

integrated (Wnt) receptor signaling

pathway. 3 Disruption of this path

way leads to abnormalities of vascu-

lar growth in the peripheral retina. 2,3

It is typically bilateral, but asymmetric, with varying degrees of

progression over the individual’s

lifetime. Age of onset varies, and

visual outcome can be strongly

influenced by this factor. Patients

with onset before age three have a

more guarded long-term prognosis

whereas those with later onset are

more likely to have asymmetric

presentation with deterioration of

vision in one eye only. 2-3 However,

because FEVR is a lifelong disease,

these patients are at risk even as

adults.2 Ocular findings and useful

vision typically remain stable if the

patient does not have deterioration

before age 20.2,4 Due to the variability and unpredictability of the

disease course, patients with FEVR

should be followed throughout

their lifetime.

Clinical presentation can vary

greatly. In mild variations, patients

may experience peripheral vascular

changes, such as peripheral avascular zone, vitreoretinal adhesions,

arteriovenous anastomoses and a

V-shaped area of retinochoroidal

degeneration. 4 Severe forms may

present with neovascularization,

subretinal and intraretinal hemorrhages and exudation. 4 Neovascularization is a poor prognostic

indicator and can lead to retinal

folds, macular ectopia and tractional retinal detachment. 2,4 Widefield FA has been crucial in

helping to understand this disease,

as well as helping to confirm the

diagnosis. An abrupt cessation

of the retinal capillary network

in a scalloped edge posterior to

fibrovascular proliferations can

be made using FA.2,3,5 Patients can

also show delayed transit filling on

FA as well as delayed/patchy choroidal filling, bulbous vascular terminals, capillary dropout, venous/venous shunting and abnormal

branching patterns. 2,3,5 The staging of FEVR is similar

to that of retinopathy of prematurity. The first two stages involve an

avascular retinal periphery with or

without extraretinal vascularization (stage 1 and 2, respectively). 4 Stages three through five delineate

levels of retinal detachment; stage 3

is subtotal without foveal involvement, stage 4 is subtotal with foveal

involvement and stage 5 is a total

detachment, open or closed funnel.4

Because there was neovascularization in the absence of retinal detachment, our patient was

considered to have

stage 2.

Although MacTel is uncommon, its prevalence is probably higher than most physicians believe. The early findings are subtle, so the diagnosis is likely often missed by optometrists and general ophthalmologists. MacTel was detected in 0.1% of subjects in the Beaver Dam study population over age 45 years, but this is probably an underestimate because identification was made based only on color photographs.

No major new biomicroscopic features of MacTel have been identified since the early work of Gass and colleagues.

The advent of optical coherence tomography (OCT) has allowed better characterization of the nature of the inner and outer lamellar cavities. Loss of central masking seen on autofluorescence studies, apparently due to loss of luteal pigment, is now recognized as probably the earliest and most sensitive and specific MacTel abnormality.

The key fundus findings in macular telangiectasia type 2 involve retinal crystalline—fine, refractile deposits in the superficial retinal layers—may be seen within the affected area.a focal area of diminished retinal transparency (i.e. "greying") and/or small retinal hemorrhages just temporal to the fovea. Dilated capillaries may also be noted within this area, and while this is often difficult to visualize ophthalmoscopically, the abnormal capillary pattern is readily identifiable with fluorescein angiography.

Areas of focal RPE hyperplasia, i.e.pigment plaques, often develop in the paramacular region as a response to these abnormal vessels. Other signs of macular telangiectasia type 2 include right angle venules, representing an unusual alteration of the vasculature in the paramacular area, with vessels taking an abrupt turn toward the macula as if being dragged.

Diagnosis of MacTel type 2 may be aided by the use of advanced imaging techniques such as fluorescein angiography, fundus autofluorescence, and OCT. These can help to identify the abnormal vessels, pigment plaques, retinal crystals, foveal atrophy and intraretinal cavities associated with this disorder.

Fluorescein angiography (FA) is helpful in identifying the anomalous vasculature, particularly in the early stages of Type 2 disease. Formerly, FA was essential in making a definitive diagnosis. However, the diagnosis can be established with less invasive imaging techniques such as OCT and fundus autofluorescence. Some clinicians argue that FA testing may be unnecessary when a diagnosis is apparent via less invasive means.

The natural history of macular telangiectasia suggests a slowly progressive disorder. A retrospective series of 20 patients over 10 to 21 years showed deterioration of vision in more than 84% of eyes, either due to intra-retinal edema and serous retinal detachment (Type 1) or pigmented RPE scar formation or neovascularisation (Type 2).

In a recent analysis (Susac et al., 2003), MRI images from 27 patients fulfilling the diagnostic criteria of Susac's syndrome were reviewed. Multifocal supratentorial lesions were present in all patients. Most lesions were small (3 to 7 mm), though some were larger than 7 mm. All 27 patients had corpus callosum lesions. These all had a punched-out appearance on follow up MRI. Though most commonly involving white matter, many patients also had lesions in deep grey matter structures, as well as leptomeningeal enhancement. Multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM) can mimic the MRI changes seen in patients with Susac's syndrome. However, the callosal lesions in Susac's syndrome are centrally located. In comparison, patients with MS and ADEM typically have lesions involving the undersurface of the corpus callosum. Deep gray matter involvement commonly occurs in ADEM but is very rare in MS. Leptomeningeal involvement is not typical of either MS or ADEM. What this means is that if 10 lesions are found in the brain of an MS patient, a lesion may be found in the corpus callosum. If you have 10 lesions in a Susac patient, more than half will be in the corpus callosum.

A concern about this illness is that it mimics multiple sclerosis when looking at the vision loss and brain lesions. If close attention is not paid to the retina of a patient with vision loss and brain lesions, their symptoms may be mistaken for MS instead of Susac's syndrome. This may account for the low prevalence of the illness. There is also a pathological similarity between the endotheliopathy in Susac's syndrome with that seen in juvenile dermatomyositis.

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.

Based on the presence of extraocular findings, such as neurological, auditory and integumentary manifestations, the "revised diagnostic criteria" of 2001 classify the disease as complete (eyes along with both neurological and skin), incomplete (eyes along with either neurological or skin) or probable (eyes without either neurological or skin) . By definition, for research homogeneity purposes, there are two exclusion criteria: previous ocular penetrating trauma or surgery, and other concomitant ocular disease similar to VKH disease.

Patients typically present with low frequency hearing loss detectable via an audiogram. Headaches are frequently present in addition to roaring tinnitus and often some degree of paranoia. Partial vision loss is often present and caused by branch retinal artery occlusions. The presence of refractile or non-refractile yellow Gass plaques in the retinal arterioles is near pathognomonic for the disease. Fluorescein angiography may demonstrate leakage in areas remote from the retinal infarctions.

Diagnosis is based on the demonstration of vascular lesions in large and middle-sized vessels on angiography, CT scan, magnetic resonance angiography or FDG PET. FDG PET can help in diagnosis of active inflammation not just in patients with active Takayasu arteritis prior to treatment but also in addition in relapsing patients receiving immunosuppressive agents.

Contrast angiography has been the gold standard. The earliest detectable lesion is a local narrowing or irregularity of the lumen. This may develop into stenosis and occlusion. The characteristic finding is the presence of "skip lesions," where stenosis or aneurysms alternate with normal vessels. Angiography provides information on vessel anatomy and patency but does not provide information on the degree of inflammation in the wall.

The age at onset helps to differentiate Takayasu's arteritis from other types of large vessel vasculitis. For example, Takaysu's arteritis has an age of onset of 60 years.

Takayasu arteritis is not associated with ANCA, rheumatoid factor, ANA, and anticardiolipin antibodies.

Controversies exist around eliminating this disorder from breeding Collies. Some veterinarians advocate only breeding dogs with no evidence of disease, but this would eliminate a large portion of potential breeding stock. Because of this, others recommend only breeding mildly affected dogs, but this would never completely eradicate the condition. Also, mild cases of choroidal hypoplasia may become pigmented and therefore undiagnosable by the age of three to seven months. If puppies are not checked for CEA before this happens, they may be mistaken for normal and bred as such. Checking for CEA by seven weeks of age can eliminate this possibility. Diagnosis is also difficult in dogs with coats of dilute color because lack of pigment in the choroid of these animals can be confused with choroidal hypoplasia. Also, because of the lack of choroidal pigment, mild choroidal hypoplasia is difficult to see, and therefore cases of CEA may be missed.

Until recently, the only way to know if a dog was a carrier was for it to produce an affected puppy. However, a genetic test for CEA became available at the beginning of 2005, developed by the Baker Institute for Animal Health, Cornell University, and administered through OptiGen. The test can determine whether a dog is affected, a carrier, or clear, and is therefore a useful tool in determining a particular dog's suitability for breeding.

Cessation of the drug at the first sign of toxicity is recommended. No treatment exists as yet for this disorder, so it is imperative that patients and their ophthalmologists be aware of the best practices for minimizing toxic damage.

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 detection of tumours specific to VHL disease is important in the disease's diagnosis. In individuals with a family history of VHL disease, one hemangioblastoma, pheochromocytoma or renal cell carcinoma may be sufficient to make a diagnosis. As all the tumours associated with VHL disease can be found sporadically, at least two tumours must be identified to diagnose VHL disease in a person without a family history.

Genetic diagnosis is also useful in VHL disease diagnosis. In hereditary VHL, disease techniques such as southern blotting and gene sequencing can be used to analyse DNA and identify mutations. These tests can be used to screen family members of those afflicted with VHL disease; "de novo" cases that produce genetic mosaicism are more difficult to detect because mutations are not found in the white blood cells that are used for genetic analysis.

Brain MRI shows vermis atrophy or hypoplasic. Cerebral and cerebellar atrophy with white matter changes in some cases.

There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery

Genetic counseling and screening of the mother's relatives is recommended.

Despite the temporary nature of the vision loss, those experiencing amaurosis fugax are usually advised to consult a physician immediately as it is a symptom that may herald serious vascular events, including stroke. Restated, “because of the brief interval between the transient event and a stroke or blindness from temporal arteritis, the workup for transient monocular blindness should be undertaken without delay.” If the patient has no history of giant cell arteritis, the probability of vision preservation is high; however, the chance of a stroke reaches that for a hemispheric TIA. Therefore, investigation of cardiac disease is justified.

A diagnostic evaluation should begin with the patient's history, followed by a physical exam, with particular importance being paid to the ophthalmic examination with regards to signs of ocular ischemia. When investigating amaurosis fugax, an ophthalmologic consult is absolutely warranted if available. Several concomitant laboratory tests should also be ordered to investigate some of the more common, systemic causes listed above, including a complete blood count, erythrocyte sedimentation rate, lipid panel, and blood glucose level. If a particular cause is suspected based on the history and physical, additional relevant labs should be ordered.

If laboratory tests are abnormal, a systemic disease process is likely, and, if the ophthalmologic examination is abnormal, ocular disease is likely. However, in the event that both of these routes of investigation yield normal findings or an inadequate explanation, noninvasive duplex ultrasound studies are recommended to identify carotid artery disease. Most episodes of amaurosis fugax are the result of stenosis of the ipsilateral carotid artery. With that being the case, researchers investigated how best to evaluate these episodes of vision loss, and concluded that for patients ranging from 36–74 years old, "...carotid artery duplex scanning should be performed...as this investigation is more likely to provide useful information than an extensive cardiac screening (ECG, Holter 24-hour monitoring, and precordial echocardiography)." Additionally, concomitant head CT or MRI imaging is also recommended to investigate the presence of a “clinically silent cerebral embolism.”

If the results of the ultrasound and intracranial imaging are normal, “renewed diagnostic efforts may be made,” during which fluorescein angiography is an appropriate consideration. However, carotid angiography is not advisable in the presence of a normal ultrasound and CT.

Cerebral angiography and magnetic resonance imaging, family medical history, symptoms, a complete physical examination, and ultimately biopsy of the brain, are often required for the diagnosis. Also, many lab tests must be done for the diagnosis; tests may reveal anemia (a shortage of red blood cells), a high white blood cell count, a high platelet count, allergic reactions, immune complexes, antibodies (tools the body uses to fight off threats) and elevation of inflammatory markers. Another crucial part in the diagnosis of cerebral vasculitis is the use of imaging techniques. Techniques such as conventional digital subtraction angiography (DSA) and magnetic resonance imaging (MRI) are used to find and monitor cerebral involvement.

Eales disease most commonly affects healthy young adults. Male predominance (up to 97.6%) has been reported in a majority of the series. The predominant age of onset of symptoms is between 20 and 30 years. The disease is now seen more commonly in the Indian subcontinent.

If tested in the prodromal phase, CSF pleocytosis is found in more than 80%, mainly lymphocytes. This pleocytosis resolves in about 8 weeks even if chronic uveitis persists.

Functional tests may include electroretinogram and visual field testing. Diagnostic confirmation and an estimation of disease severity may involve imaging tests such as retinography, fluorescein or indocyanine green angiography, optical coherence tomography and ultrasound. For example, indocyanine green angiography may detect continuing choroidal inflammation in the eyes without clinical symptoms or signs. Ocular MRI may be helpful and auditory symptoms should undergo audiologic testing. Histopathology findings from eye and skin are discussed by Walton.

The diagnosis of VKH is based on the clinical presentation; the diagnostic differential is extensive, and includes (almong others) sympathetic ophthalmia, sarcoidosis, primary intraocular B-cell lymphoma, posterior scleritis, uveal effusion syndrome, tuberculosis, syphilis, and multifocal choroidopathy syndromes.

Checking the eyes for signs of papilledema should be carried out whenever there is a clinical suspicion of raised intracranial pressure, and is recommended in newly onset headaches. This may be done by ophthalmoscopy or fundus photography, and possibly slit lamp examination.