Progressive outer retinal necrosis | |
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Other names | Varicella zoster virus retinitis (VZVR), [1] |
The typical “cracked mud" appearance of the fundus in progressive outer retinal necrosis [2] [3] | |
Specialty | Ophthalmology, Infectious diseases |
Progressive outer retinal necrosis (PORN) syndrome is a form of chorioretinitis, an infection in the retina, the back of the eye. The disease is most commonly caused by the varicella zoster virus and is found almost exclusively in patients with HIV/AIDS (acquired immunodeficiency syndrome). Progressive outer retinal necrosis is the second most common opportunistic retinal infection in North America among people with AIDS. [4] The reason this disease process is considered opportunistic is precisely because it only presents in patients with AIDS, a disease that attacks and weakens the immune system, making space for other infections, like Varicella zoster virus (VZV) and Herpes simplex virus (HSV), to attack the body.
The syndrome, PORN, falls under the umbrella of necrotizing herpetic retinopathy, along with Acute retinal necrosis. Although fairly similar processes, the two forms of retinopathy have different presenting symptoms. Acute Retinal Necrosis, or ARN, is damage more central in the retinal portion of the eye with dead or necrotic areas well defined. ARN also presents with inflammation within the eye and is often painful. [5] PORN is a chorioretinitis presenting with multiple lesions in the peripheral retina. Unlike ARN, this disease process has no signs of intraocular inflammation, the hallmark feature, or vascular involvement. [6] [4]
The presentation of the disease is dependent on the patient's AIDS prognosis. If the immune system has been significantly weakened by AIDS, a patient will likely present with worse and faster progressing PORN. [5] Commonly presenting symptoms of PORN include:
The diagnosis of Progressive outer retinal necrosis (PORN) syndrome is made primarily through history and physical exam. A patient's medical history of AIDS increases the likelihood of PORN as the diagnosis. An eye exam will show specific hallmark features, including opacified lesions in the peripheral retina without inflammation.
There are medical tests that can aid in diagnosing the severity of the disease process, however are not necessary for initial diagnosis.
Other possible diseases to consider when a patient presents with symptoms similar to PORN include: CMV retinitis, ARN, Syphilitic retinitis, Toxoplasma retinochoroiditis, tuberculosis, toxocariasis, fungal or bacterial endophthalmitis Inflammatory: Sarcoidosis, Behcet's, other retinal vasculitides, Neoplastic: intraocular lymphoma, leukemia, metastasis. [6]
If left untreated, PORN syndrome can become bilateral, affecting both eyes. The retina can also atrophy, or decay, over time as the blood supply decreases. This leads to retinal detachment, a process where the retina breaks off the back of the eye. Retinal detachments are considered surgical emergencies, as they can lead to blindness if not promptly fixed. [6]
When AIDS first became a diagnosis, ophthalmologists began seeing patients with infectious processes such as Progressive outer retinal necrosis (PORN). With the use of HAART (3 drug regimen standard) treatment for HIV/AIDS in the 1990s, the presentation of these chorioretinitis diseases became less severe and less frequent. [7]
Treatment for Necrotizing Herpetic Retinopathy, including ARN and PORN, includes the anti-viral medications Ganciclovir and Foscarnet. These medications are given as intra-vitreal injections (injected into the fluid of the eye). This treatment has shown success in reversing the disease process and improving vision to an extent. [6]
Inflammation of the geniculate ganglion of the facial nerve is a late consequence of varicella zoster virus (VZV) known as Ramsay Hunt syndrome (RHS), commonly known as herpes zoster oticus. In regard to the frequency, less than 1% of varicella zoster infections involve the facial nerve and result in RHS. It is traditionally defined as a triad of ipsilateral facial paralysis, otalgia, and vesicles close to the ear and auditory canal. Due to its proximity to the vestibulocochlear nerve, the virus can spread and cause hearing loss, tinnitus (hearing noises that are not caused by outside sounds), and vertigo. It is common for diagnoses to be overlooked or delayed, which can raise the likelihood of long-term consequences. It is more complicated than Bell's palsy. Therapy aims to shorten its overall length, while also providing pain relief and averting any consequences.
Diabetic retinopathy, is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries.
Chorioretinitis is an inflammation of the choroid and retina of the eye. It is a form of posterior uveitis. If only the choroid is inflamed, not the retina, the condition is termed choroiditis. The ophthalmologist's goal in treating these potentially blinding conditions is to eliminate the inflammation and minimize the potential risk of therapy to the patient.
Varicella zoster virus (VZV), also known as human herpesvirus 3 or Human alphaherpesvirus 3 (taxonomically), is one of nine known herpes viruses that can infect humans. It causes chickenpox (varicella) commonly affecting children and young adults, and shingles in adults but rarely in children. VZV infections are species-specific to humans. The virus can survive in external environments for a few hours.
Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision. As peripheral vision worsens, people may experience "tunnel vision". Complete blindness is uncommon. Onset of symptoms is generally gradual and often begins in childhood.
Shingles, also known as zoster or herpes zoster, is a viral disease characterized by a painful skin rash with blisters in a localized area. Typically the rash occurs in a single, wide mark either on the left or right side of the body or face. Two to four days before the rash occurs there may be tingling or local pain in the area. Other common symptoms are fever, headache, and tiredness. The rash usually heals within two to four weeks; however, some people develop ongoing nerve pain which can last for months or years, a condition called postherpetic neuralgia (PHN). In those with poor immune function the rash may occur widely. If the rash involves the eye, vision loss may occur.
This is a partial list of human eye diseases and disorders.
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 includes the iris, ciliary body, and choroid. Uveitis is described anatomically, by the part of the eye affected, as anterior, intermediate or posterior, or panuveitic if all parts are involved. Anterior uveitis (iridocyclitis) is the most common, with the incidence of uveitis overall affecting approximately 1:4500, most commonly those between the ages of 20-60. Symptoms include eye pain, eye redness, floaters and blurred vision, and ophthalmic examination may show dilated ciliary blood vessels and the presence of cells in the anterior chamber. Uveitis may arise spontaneously, have a genetic component, or be associated with an autoimmune disease or infection. While the eye is a relatively protected environment, its immune mechanisms may be overcome resulting in inflammation and tissue destruction associated with T-cell activation.
This is a list of AIDS-related topics, many of which were originally taken from the public domain U.S. Department of Health Glossary of HIV/AIDS-Related Terms, 4th Edition.
Electroretinography measures the electrical responses of various cell types in the retina, including the photoreceptors, inner retinal cells, and the ganglion cells. Electrodes are placed on the surface of the cornea or on the skin beneath the eye to measure retinal responses. Retinal pigment epithelium (RPE) responses are measured with an EOG test with skin-contact electrodes placed near the canthi. During a recording, the patient's eyes are exposed to standardized stimuli and the resulting signal is displayed showing the time course of the signal's amplitude (voltage). Signals are very small, and typically are measured in microvolts or nanovolts. The ERG is composed of electrical potentials contributed by different cell types within the retina, and the stimulus conditions can elicit stronger response from certain components.
Cytomegalovirus retinitis, also known as CMV retinitis, is an inflammation of the retina of the eye that can lead to blindness. Caused by human cytomegalovirus, it occurs predominantly in people whose immune system has been compromised, 15-40% of those with AIDS.
The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells.
Retinitis is inflammation of the retina in the eye, which can permanently damage the retina and lead to blindness. The retina is the eye's "sensing" tissue. Retinitis may be caused by a number of different infectious agents. Its most common form, called retinitis pigmentosa, has a prevalence of one in every 2,500–7,000 people. This condition is one of the leading causes that leads to blindness in patients in the age range of 20–60 years old.
Acute retinal necrosis (ARN) is a medical inflammatory condition of the eye. The condition presents itself as a necrotizing retinitis. The inflammation onset is due to certain herpes viruses, varicella zoster virus (VZV), herpes simplex virus (HSV-1 and HSV-2) and Epstein–Barr virus (EBV).
Chickenpox, or chicken pox, also known as varicella, is a highly contagious, vaccine-preventable disease caused by the initial infection with varicella zoster virus (VZV), a member of the herpesvirus family. The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It usually starts on the chest, back, and face. It then spreads to the rest of the body. The rash and other symptoms, such as fever, tiredness, and headaches, usually last five to seven days. Complications may occasionally include pneumonia, inflammation of the brain, and bacterial skin infections. The disease is usually more severe in adults than in children.
White dot syndromes are inflammatory diseases characterized by the presence of white dots on the fundus, the interior surface of the eye. The majority of individuals affected with white dot syndromes are younger than fifty years of age. Some symptoms include blurred vision and visual field loss. There are many theories for the etiology of white dot syndromes including infectious, viral, genetics and autoimmune.
Retinal vasculopathy with cerebral leukocencephalopathyand systemic manifestations is an inherited condition resulting from a frameshift mutation in the C-terminal region of the TREX1 gene. This disease affects small blood vessels, leading to damage of multiple organs including but not limited to the retina and the white matter of the central nervous system. Patients with RVCL develop vision loss, brain lesions, strokes, brain atrophy, and dementia. Patients with RVCL also exhibit other organ involvement, including kidney, liver, gastrointestinal tract, thyroid, and bone disease. Symptoms of RVCL commonly begin between ages 35 and 55, although sometimes disease onset occurs earlier or later. The overall prognosis is poor, and death can sometimes occur within 5 or 10 years of the first symptoms appearing, although some patients live more than 20 years after initial symptoms. Clinical trials are underway, as are efforts to develop personalized medicines for patients with RVCL.
Autoimmune retinopathy (AIR) is a rare disease in which the patient's immune system attacks proteins in the retina, leading to loss of eyesight. The disease is poorly understood, but may be the result of cancer or cancer chemotherapy. The disease is an autoimmune condition characterized by vision loss, blind spots, and visual field abnormalities. It can be divided into cancer-associated retinopathy (CAR) and melanoma-associated retinopathy (MAR). The condition is associated with retinal degeneration caused by autoimmune antibodies recognizing retinal proteins as antigens and targeting them. AIR's prevalence is extremely rare, with CAR being more common than MAR. It is more commonly diagnosed in females in the age range of 50–60.
Sickle cell retinopathy can be defined as retinal changes due to blood vessel damage in the eye of a person with a background of sickle cell disease. It can likely progress to loss of vision in late stages due to vitreous hemorrhage or retinal detachment. Sickle cell disease is a structural red blood cell disorder leading to consequences in multiple systems. It is characterized by chronic red blood cell destruction, vascular injury, and tissue ischemia causing damage to the brain, eyes, heart, lungs, kidneys, spleen, and musculoskeletal system.