Fluorescein angiography is usually performed for diagnosis and follow-up of patients with POHS.

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.

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).

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).

CNV can be detected by using a type of perimetry called preferential hyperacuity perimetry. On the basis of fluorescein angiography, CNV may be described as classic or occult. Two other tests that help identify the condition include indocyanine green angiography and optical coherence tomography.

Diagnosis of age-related macular degeneration rests on signs in the macula, irrespective of visual acuity. Diagnosis of AMD may include the following procedures and tests:

- The transition from dry to wet AMD can happen rapidly, and if it is left untreated can lead to legal blindness in as little as six months. To prevent this from occurring and to initiate preventative strategies earlier in the disease process, dark adaptation testing may be performed. A dark adaptometer can detect subclinical AMD at least three years earlier than it is clinically evident.

- There is a loss of contrast sensitivity, so that contours, shadows, and color vision are less vivid. The loss in contrast sensitivity can be quickly and easily measured by a contrast sensitivity test like Pelli Robson performed either at home or by an eye specialist.

- When viewing an Amsler grid, some straight lines appear wavy and some patches appear blank

- When viewing a Snellen chart, at least 2 lines decline

- Preferential hyperacuity perimetry changes (for wet AMD)

- In dry macular degeneration, which occurs in 85–90 percent of AMD cases, drusen spots can be seen in Fundus photography

- In wet macular degeneration, angiography can visualize the leakage of bloodstream behind the macula. Fluorescein angiography allows for the identification and localization of abnormal vascular processes.

- Using an electroretinogram, points in the macula with a weak or absent response compared to a normal eye may be found

- Farnsworth-Munsell 100 hue test and Maximum Color Contrast Sensitivity test (MCCS) for assessing color acuity and color contrast sensitivity

- Optical coherence tomography is now used by most ophthalmologists in the diagnosis and the follow-up evaluation of the response to treatment with antiangiogenic drugs.

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.

Treatment requires careful consideration of angiographic findings when a choroidal neovascular membrane is suspected which is a condition that responds to treatment. A vitreo-retinal specialist (an ophthalmologist specialized in treatment of retinal diseases) should be consulted for proper management of the case.

Presumed ocular histoplasmosis syndrome and age-related macular degeneration (AMD) have been successfully treated with laser, anti-vascular endothelial growth factors and photodynamic therapy. Ophthalmologists are using anti-vascular endothelial growth factors to treat AMD and similar conditions since research indicates that vascular endothelial growth factor (VEGF) is one of the causes for the growth of the abnormal vessels that cause these conditions.

A 2012 Cochrane review found the use of vitamin and mineral supplements, alone or in combination, by the general population had no effect on whether or not AMD started.

CNV is conventionally treated with intravitreal injections of angiogenesis inhibitors (also known as "anti-VEGF" drugs) to control neovascularization and reduce the area of fluid below the retinal pigment epithelium. Angiogenesis inhibitors include pegaptanib, ranibizumab and bevacizumab (known by a variety of trade names, such as Macugen, Avastin or Lucentis). These inhibitors slow or stop the formation of new blood vessels (angiogenesis), typically by binding to or deactivating the transmission of vascular endothelial growth factor ('VEGF'), a signal protein produced by cells to stimulate formation of new blood vessels. The effectiveness of angiogenesis inhibitors has been shown to significantly improve visual prognosis with CNV, the recurrence rate for these neovascular areas remains high.

CNV may also be treated with photodynamic therapy coupled with a photosensitive drug such as verteporfin (Visudyne). The drug is given intravenously. It is then activated in the eye by a laser light. The drug destroys the new blood vessels, and prevents any new vessels forming by forming thrombi.

A maculopathy is any pathological condition of the macula, an area at the centre of the retina that is associated with highly sensitive, accurate vision.

The most recognized cause of a toxic optic neuropathy is methanol intoxication. This can be a life-threatening event that normally accidentally occurs when the victim mistook, or substituted, methanol for ethyl alcohol. Blindness can occur with drinking as little as an ounce of methanol, but this can be counteracted by concurrent drinking of ethyl alcohol. The patient initially has nausea and vomiting, followed by respiratory distress, headache, and visual loss 18–48 hours after consumption. Without treatment, patients can go blind, and their pupils will dilate and stop reacting to light.

- Ethylene glycol, a component of automobile antifreeze, is a poison that is toxic to the whole body including the optic nerve. Consumption can be fatal, or recovery can occur with permanent neurologic and ophthalmologic deficits. While visual loss is not very common, increased intracranial pressure can cause bilateral optic disc swelling from cerebral edema. A clue to the cause of intoxication is the presence of oxalate crystals in the urine. Like methanol intoxication, treatment is ethanol consumption.

- Ethambutol, a drug commonly used to treat tuberculosis, is notorious for causing toxic optic neuropathy. Patients with vision loss from ethambutol toxicity lose vision in both eyes equally. This initially presents with problems with colors (dyschromatopsia) and can leave central visual deficits. If vision loss occurs while using ethambutol, it would be best to discontinue this medication under a doctor’s supervision. Vision can improve slowly after discontinuing ethambutol but rarely returns to baseline.

- Amiodarone is an antiarrhythmic medication commonly used for abnormal heart rhythms (atrial or ventricular tachyarrythmias). Most patients on this medication get corneal epithelial deposits, but this medication has also been controversially associated with NAION. Patients on amiodarone with new visual symptoms should be evaluated by an ophthalmologist.

- Tobacco exposure, most commonly through pipe and cigar smoking, can cause an optic neuropathy. Middle-aged or elderly men are often affected and present with painless, slowly progressive, color distortion and visual loss in both eyes. The mechanism is unclear, but this has been reported to be more common in individuals who are already suffering from malnutrition.

The inherited optic neuropathies typically manifest as symmetric bilateral central visual loss. Optic nerve damage in most inherited optic neuropathies is permanent and progressive.

- Leber’s hereditary optic neuropathy (LHON) is the most frequently occurring mitochondrial disease, and this inherited form of acute or subacute vision loss predominantly affects young males. LHON usually presents with rapid vision loss in one eye followed by involvement of the second eye (usually within months). Visual acuity often remains stable and poor (around or below 20/200) with a residual central visual field defect. Patients with the 14484/ND6 mutation are most likely to have visual recovery.

- Dominant optic atrophy is an autosomal dominant disease caused by a defect in the nuclear gene OPA1. A slowly progressive optic neuropathy, dominant optic atrophy, usually presents in the first decade of life and is bilaterally symmetrical. Examination of these patients shows loss of visual acuity, temporal pallor of the optic discs, centrocecal scotomas with peripheral sparing, and subtle impairments in color vision.

- Behr’s syndrome is a rare autosomal recessive disorder characterized by early-onset optic atrophy, ataxia, and spasticity.

- Berk–Tabatznik syndrome is a condition that shows symptoms of short stature, congenital optic atrophy and brachytelephalangy. This condition is extremely rare.

Lucio's phenomenon is treated by anti-leprosy therapy (dapsone, rifampin, and clofazimine), optimal wound care, and treatment for bacteremia including antibiotics. In severe cases exchange transfusion may be helpful.

The main pathological features of this disease are a vasculitis affecting all cutaneous vessels.

There are by five characteristic features:

- colonisation of endothelial cells by acid-fast bacilli

- endothelial proliferation and marked thickening of vessel walls to the point of obliteration

- angiogenesis

- vascular ectasia

- thrombosis of the superficial and mid-dermal blood vessels

The likely pathogenesis is endothelial cell injury due to colonization/invasion followed by proliferation, angiogensis, thrombosis and vessel ectasia.

Treatment of migraine-associated vertigo is the same as the treatment for migraine in general.

MAV is not recognized as a distinct diagnostic entity. Lembert and Neuhauser propose criteria for definite and probable migraine-associated vertigo.

A diagnosis of "definite migraine-associated vertigo" includes a case history of:

- episodic vestibular symptoms of at least moderate severity;

- current or previous history of migraine according to the 2004 "International Classification of Headache Disorders";

- one of the following migrainous symptoms during two or more attacks of vertigo: migrainous headache, photophobia, phonophobia, visual or other auras; and

- other causes ruled out by appropriate investigations.

A diagnosis of "probable migraine-associated vertigo" includes a case history of episodic vestibular symptoms of at least moderate severity and one of the following:

- current or previous history of migraine according to the 2004 "International Classification of Headache Disorders";

- migrainous symptoms during vestibular symptoms;

- migraine precipitants of vertigo in more than 50% of attacks, such as food triggers, sleep irregularities, or hormonal change;

- response to migraine medications in more than 50% of attacks; and

- other causes ruled out by appropriate investigations.

Note that, in both of the above criteria, headache is not required to make the diagnosis of migraine-associated vertigo.

They add that, in patients with a clear-cut history, no vestibular tests are required. Other historical criteria which are helpful in making the diagnosis of migraine-associated vertigo are vertiginous symptoms throughout the patient’s entire life, a long history of motion intolerance, sensitivity to environmental stimuli, illusions of motion of the environment, and vertigo that awakens the patient.

Although treatment may be unnecessary, there may be social implications, especially in young children when venturing from a supportive home environment to a public environment (e.g., starting school). Continued support, including monitoring behavior and educating the child about his or her appearance as seen by others, is encouraged. Gradual or sudden withdrawal from interaction with others is a sign that may or may not be related to such behavior. Studies are being conducted to elucidate these implications.

Treatment is usually unnecessary. In severe cases, surgery with a bilateral levator excision and frontalis brow suspension may be used.

A 2014 study classified cases into three types—epidermolysis bullosa simplex (EBS), junctional epidermolysis bullosa (JEB), and dystrophic epidermolysis bullosa (DEB) -- and reviewed their times of death. The first two types tended to die in infancy and the last in early adulthood.

The MRI of patients with VWM shows a well defined leukodystrophy. These MRIs display reversal of signal intensity of the white matter in the brain. Recovery sequences and holes in the white matter are also visible. Over time, the MRI is excellent at showing rarefaction and cystic degeneration of the white matter as it is replaced by fluid. To show this change, displaying white matter as a high signal (T2-weighted), proton density, and Fluid attenuated inversion recovery (FLAIR) images are the best approach. T2-weighted images also displaying cerebrospinal fluid and rarefied/cystic white matter. To view the remaining tissue, and get perspective on the damage done (also helpful in determining the rate of deterioration) (T1-weighted), proton density, and FLAIR images are ideal as they show radiating stripe patterns in the degenerating white matter. A failure of MRI images is their ineffectiveness and difficulty in interpretation in infants since the brain has not fully developed yet. Though some patterns and signs may be visible, it is still difficult to conclusively diagnose. This often leads to misdiagnosis in infants particularly if the MRI results in equivocal patterns or because of the high water content in infants' brains. The easiest way to fix this problem is a follow-up MRI in the following weeks. A potentially similar appearance of MRI with white matter abnormalities and cystic changes may be seen in some patients with hypomelanosis of Ito, some forms of Lowe's (oculocerebrorenal) disease, or some of the mucopolysaccharidoses.

The prognosis for individuals with schizencephaly varies depending on the size of the clefts and the degree of neurological deficit.

Cases of lymphangioma are diagnosed by histopathologic inspection. In prenatal cases, cystic lymphangioma is diagnosed using an ultrasound; when confirmed amniocentesis may be recommended to check for associated genetic disorders.

Epidermolysis bullosa can be diagnosed either by a skin (punch) biopsy at the edge of a wound with immunofluorescent mapping, or via blood sample and genetic testing.

Treatment depends on the anatomy of the malformation as determined by angiography or Magnetic Resonance Imaging (MRI).