A rare condition with an uncertain etiology, Vogt-Koyanagi-Harada disease affects numerous body organs, including the eyes, hearing, skin, brain, and spinal cord. Rapid vision loss is the most typical sign. Neurological symptoms may also accompany a syndrome, such as headaches, vertigo (dizziness), nausea, and sleepiness. Alopecia, and loss of skin, hair, and eyelash color are further symptoms of this illness. Although the precise etiology is unknown, genetic factors or an aberrant immune system response to viral infection can both contribute to this condition.

 

Introduction:

 

Vision is at risk from Vogt-Koyanagi-Harada disease (VKH), a genetic disorder that affects multiple systems. The visual, auditory, neurological, and integumentary symptoms of VKH are typically present in stages. Bilateral diffuse uveitis, which causes pain, redness, and blurred vision, is the disease’s defining feature. The physical manifestations of the Vogt-Koyanagi-Harada sickness can be divided into four stages: prodromal, acute uveitic, convalescent, and chronic recurrent.

• The prodromal phase is characterized by flu-like symptoms that normally last a few days and may be asymptomatic or mimic a non-specific viral illness.
• A few days later, the acute uveitic phase starts, and it normally lasts for many weeks. Bilateral panuveitis, which causes vision blurring, marks the beginning of this phase.
• The gradual tissue removal of pigment of the outermost layer of skin caused by vitiligo, polio, hair loss, and widespread fundus greying during the convalescent stage is what gives the skin it’s recognizable orange-red coloring.
• The chronic recurrent phase may be characterized by recurring episodes of uveitis, however, it is more frequently described by chronic, low-grade, frequently asymptomatic uveitis that can cause cataracts, glaucoma, ocular pressure, and granulomatous anterior inflammation.

 

Causes of Vogt-Koyanagi-Harada Disease:

 

It is still unknown what the true etiology and pathophysiology of Vogt-Koyanagi-Harada disease are. However, important developments in a wide range of fields of fundamental research have allowed for enormous advancement in recent decades. Viruses found in patients with Vogt-Koyanagi-Harada disease support the theory that the sickness is caused by a microbial infection. Meningismus, headaches, and fever in the prodromal stage of the disease have led to the hypothesis that a viral infection is the cause of Vogt-Koyanagi-Harada sickness.

According to antigenic and pathologic research, Vogt-Koyanagi-Harada disease is assumed to be an aggressive degenerative condition that is brought on by CD4+ T cells that target melanocytes. These activated T cells are expected to initiate the inflammatory process by releasing cytokines like IL 17 and IL 23 in patients who lack T regulatory cells and have a lower tolerance to melanocytes. It is unknown what specifically changed the tolerance to melanocytes. In people who express HLA DRB1*0405, genetic susceptibility, and viral infection may work together to trigger the autoimmune process.

 

Signs and Symptoms

 

Initial symptoms of Vogt-Koyanagi-Harada disease include nausea, vertigo, migraines, and intense eye pain. These symptoms are typically followed within a few weeks by uveitis, inflammation of the eye, and vision impairment. This could happen in one or both eyes at once, or it could start in one eye and spread to the other a few days later. Hearing loss may become noticeable and the retina may detach. In the coming weeks, the chronic stage will begin. The eyes as well as the skin are changing throughout this stage.

The choroid, the outermost layer of the eye loaded with vessels of blood that feed the retina, may lose color as a result of alterations in the eyes, and some regions of the retina may acquire microscopic yellow nodules. The loss of cells that produce pigment can result in the development of seamless, white patches on the skin (vitiligo). The head, eyelids, and body are typically covered in these white spots. From a few months to several years, the phase of chronic illness can last.

Treatment often results in vision and hearing improvements in patients. However, some issues, such as eyesight and hearing impairments, hair loss with a corresponding loss of hair, eyelash, and skin color, and permanent hair loss are possible. Secondary glaucoma and cataract development are potential long-term visual damage.

 

Diagnosis of Vogt-Koyanagi-Harada Disease:

 

• FFA (Fundus Fluorescein Angiography): is a test to determine the blood flow to the choroid and retina. FFA initially reveals uneven focal or patchy choroidal circulation fluorescence. The size of the hyperfluorescent patches grows as the illness worsens. The telltale sign of Vogt-Koyanagi-Harada sickness is a moth-eaten appearance.
• ICG (indocyanine green angiography): is a diagnostic technique used to look at pathology and choroidal blood flow. During the early stages of the disease, ICG exhibits hyper fluorescence and hyperfluorescent black areas.
• Fundus Autofluorescence (FAF): FAF is used to assess the disease’s state. FAF will exhibit both hyper and hypo autofluorescence during the active stage. Additionally, several patterns, including diminished autofluorescence, enhanced autofluorescence, and normal autofluorescence, can be found during the chronic stage.
• Laboratory tests: A spinal fluid study is performed to detect the illness, and the early stages show an elevated protein level.
• The disease is also assessed using optical coherence tomography (OCT), which also aids in determining whether subretinal fluid is present.
• Ultrasonography is used to assess a disease’s acute phases.
• The persistent stage of the disorder is identified when electroretinography is performed.

 

Treatment for Vogt-Koyanagi-Harada Disease:

 

• To effectively manage the condition, an early diagnosis is crucial.
• Corticosteroids are used aggressively in the treatment of the illness.
• Treatment for Vogt-Koyanagi-Harada disease requires a neurological and ophthalmological evaluation.
• According to certain beliefs, immunosuppressants should be used as the initial form of therapy. Due to the numerous negative effects of steroids, immunosuppressants are used. The treatment of the condition has also included the use of Rituximab, Azathioprine, Cyclosporine A, and Mycophenolate Mofetil.
• Surgery is performed as glaucoma therapy.
• Laser iridotomy involves making a tiny hole in the iris and using a laser to remove the fluid.
• Surgical iridectomy – A surgical procedure is used to remove a portion of the iris.
• Trabeculectomy: This procedure involves making a flap in the sclera and draining fluid through the flap to lower pressure and treat glaucoma.