Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an acquired inflammatory

uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and ...

that belongs to the heterogenous group of

white dot syndromes White dot syndromes are inflammatory diseases characterized by the presence of white dots on the fundus, the interior surface of the eye.retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

. Early in the course of the disease, the lesions cause acute and marked

vision loss Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficul ...

(if it interferes with the optic nerve) that ranges from mild to severe but is usually transient in nature. APMPPE is classified as an inflammatory disorder that is usually bilateral and acute in onset but self-limiting. The lesions leave behind some pigmentation, but

visual acuity Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye ...

eventually improves even without any treatment (providing scarring doesn't interfere with the optic nerve). It occurs equally between men and women with a male to female ratio of 1.2:1. Mean onset age is 27, but has been seen in people aged 16 to 40. It is known to occur after or concurrently with a systemic infection (but not always), showing that it is related generally to an altered

immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

. Recurrent episodes can happen, but are extremely rare.

Signs and symptoms

The onset of ocular symptoms are usually preceded by episode of viral or flu-like symptoms such as fever, cough or sore throat (however this is not always the case). Patients can typically present

erythema nodosum Erythema nodosum (EN) is an inflammatory condition characterized by inflammation of subcutaneous fat tissue, resulting in painful red/blue lumps or nodules that are usually seen symmetrically on both shins, on the thighs, arms, and elsewhere. I ...

livedo reticularis Livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin. The discoloration is caused by reduction in blood flow (ischemia) through the arter ...

, bilateral

, and sudden onset of marked visual loss associated with the appearance of multiple lesions in the retina. These lesions may be colored from grey-white to cream-shaded yellow. Other symptoms include scotomata and

photopsia Photopsia is the presence of perceived flashes of light in the Visual field, field of vision. It is most commonly associated with: * posterior vitreous detachment * migraine aura (ocular migraine / retinal migraine) * acephalgic migraine, migrain ...

. In weeks to a month times the lesions begin to clear and disappear (with prednisone) leaving behind areas of retinal pigment epithelial atrophy and diffuse fine pigmentation (scarring). Rarely

choroidal neovascularization Choroidal neovascularization (CNV) is the creation of new blood vessels in the choroid layer of the eye. Choroidal neovascularization is a common cause of neovascular degenerative maculopathy (i.e. 'wet' macular degeneration) commonly exacerbated ...

occur as a late onset complication.

Cause

The cause of the inflammation remains unknown. It is hypothesized that it may occur as an autoimmune response to a mild infection, or it may be viral in nature, as evidenced by the preceding flu-like illness that generally accompanies it. It is associated with an increased incidence of both

HLA-B7 HLA-B7 (B7) is an HLA- B serotype. The serotype identifies the more common HLA-B*07 gene products. (For terminology help see: HLA-serotype tutorial) B7, previously HL-A7, was one of the first 'HL-A' antigens recognized, largely because of the f ...

and

HLA-DR2 HLA-DR2 (DR2) of the HLA- DR serotype system, is a broad antigen serotype that is now preferentially covered by HLA-DR15 and HLA-DR16 serotype group. This serotype primarily recognizes gene products of the HLA-DRB1*15 and HLA-DRB1*16 allele gro ...

. The underlying etiology of APMPPE continues to cause debate. The term 'Pigment Epitheliopathy' was chosen by Gass to reflect what he thought was the tissue most significantly affected. Van Buskirk et al., and Deutman et al. proposed choriocapillaris ischemia as the more likely primary etiology.

Indocyanine green angiography Indocyanine green angiography (ICGA) is a diagnostic procedure used to examine choroidal blood flow and associated pathology. Indocyanine green (ICG) is a water soluble cyanine dye which shows fluorescence in near-infrared (790–805 nm) rang ...

(ICGA), and OCT angiography (OCTA) studies have provided support for choriocapillaris involvement. However, a novel hypothesis was proposed implicating a direct neurotropic infection as a possible underlying cause given the dynamic changes observed along the neuronal pathway of the retina 1. Steptoe PJ, Pearce I, Beare NAV, Sreekantam S, Mohammed BR, Barry R, Steeples LR, Denniston AK. Proposing a Neurotropic Etiology for Acute Posterior Multifocal Placoid Pigment Epitheliopathy and Relentless Placoid Choroidopathy. Investigative Ophthalmology & Visual Science (2021) 62:3447–3447. doi:10.3389/fopht.2021.802962 https://www.frontiersin.org/articles/10.3389/fopht.2021.802962/full

Diagnosis

Diagnosis is usually made on clinical appearance alone on

fundoscopy Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part ...

and/or retinal imaging. Supplementary tests such as Optical coherence tomography(OCT) and fundus fluorescein angiography/Indocyanine angiography together with OCT-Angiography are commonly performed to help aid diagnosis and monitoring.

Fundus photography Fundus photography involves photographing the rear of an eye, also known as the fundus (eye), fundus. Specialized fundus cameras consisting of an intricate microscope attached to a flash (photography), flash enabled camera are used in fundus pho ...

is useful to document the appearance of APMPPE lesions.

Management

The original description categorized APMPPE as a self-limiting condition with a good prognosis, but the disease can be recurrent and result in significant visual loss. 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 Prednisone is a glucocorticoid medication mostly used to immunosuppressive drug, suppress the immune system and decrease inflammation in conditions such as asthma, COPD, and rheumatologic diseases. It is also used to treat high blood calcium ...

is prescribed, but in recurrent disease an

antimetabolite An antimetabolite is a chemical that inhibits the use of a metabolite, which is another chemical that is part of normal metabolism. Such substances are often similar in structure to the metabolite that they interfere with, such as the antifolat ...

agent may be indicated.

Prognosis

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 Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both artery, arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily c ...

may cause neurological complications. These occurrences can start with mild headaches that steadily worsen in pain and onset, and can include attacks of

dysesthesia Dysesthesia is an unpleasant, abnormal sense of touch. Its etymology comes from the Greek word "dys," meaning "bad," and "aesthesis," which means "sensation" (abnormal sensation). It often presents as pain but may also present as an inappropriate, ...

. This type of deterioration happens usually if the lesions involve the fovea.

References

External links

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