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Diagnosis of PIC can be difficult because the appearance may be similar to other conditions and types of posterior uveitis, especially other forms of the so called white dot syndromes. The diagnosis is made by eliminating all the other possibilities by careful examination by an experienced ophthalmologist, aided with visual field testing and Fluorescein angiography (an intra-venous dye used to show the blood vessels at the back of the eye).
It is important that the correct diagnosis is made because treatment may be quite different for apparently similar conditions.
Diagnosis of AIR can be difficult due to the overlap of symptoms with other disorders. Examination of the fundus (inner surface of eye) can show no results or it can show narrowing of the blood vessels, abnormal colouration of the optic disc, and retinal atrophy. Fundus examination results are not indicative of autoimmune retinopathy but they are used to initiate the diagnostic process. An electroretinogram (eye test used to see abnormalities in the retina) is used to detect AIR. An abnormal electroretinogram (ERG) with respect to light and dark adaptations indicates AIR. The ERG also allows differentiation between cancer-associated retinopathy and melanoma-associated retinopathy. If the ERG shows cone responses, CAR can be prematurely diagnosed. If the ERG shows a significant decrease in b-wave amplitude, MAR can be prematurely diagnosed. To confirm, analysis for anti-retinal antibodies through Western blotting of serum collected from the patient is done.
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.
What happens with PIC depends a lot on the presence or absence of an important complication, Choroidal neovascularization (known as CNV).
Often, the inflammation in PIC is self limiting, not always requiring treatment.
However treatment is advised if there are many active or central lesions, or if there are signs of CNV.
Immunoglobulin samples are obtained from a large pool of healthy, matched donors (10000 - 20000). The immunoglobulin mixture is then administered through IV at a rate of 0.4g/kg/day for 5 days. Antibodies in the IVIG mixture interact with binding sites of the disease-associated antibodies (such as anti-recoverin antibodies). This prevents binding to proteins targeted as antigenic and reduces disease activity. Responses to this treatment can vary and are impacted if the patient is diagnosed with any type of cancer. Patients who respond positively show improvement in the clarity of their vision and their visual field.
The erosion may be seen by an eye doctor using the magnification of a biomicroscope or slit lamp. Usually fluorescein stain must be applied first and a cobalt blue-light used, but may not be necessary if the area of the epithelial defect is large. Optometrists and ophthalmologists have access to the slit lamp microscopes that allow for this more-thorough evaluation under the higher magnification. Mis-diagnosis of a scratched cornea is fairly common, especially in younger patients.
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.
MEWDS is a self limited disease with excellent visual recovery within 2-10 weeks. However residual symptoms including photopsia may persist for months.
One cause of the White Dot Syndromes as suggested by Gass involves viral or infectious agents. Specifically pertaining to the ‘AZOOR complex,’ Gass has postulated that a virus may enter the retina at the optic head and the infection may spread from one photoreceptor to another. Some unexplained features include the development of more than one disease in the same patient and the majority of cases occurring in females.
According to Becker’s common genetic hypothesis, “unlike mendelian genetic disorders, common autoimmune and inflammatory diseases arise from combinatorial interactions of common non-disease specific loci, disease specific loci, and specific environmental triggers.” An important aspect of this hypothesis pertains to the existence of common non-disease genes that predispose patients to autoimmune diseases. Jampol and Becker insinuate that ‘common susceptibility genes’ are present in patients affected by white dot syndromes. The presence of environmental triggers, such as viral infections, immunizations, and stress, and interactions with other genes contribute to the development of the white dot syndromes. Additionally, Jampol and Becker hypothesize that the predisposing genetic loci can be identified.
Gass points to a lack of evidence in support of the Becker theory. Instead, Gass highlights that although evidence indicates that patients with AZOOR have a greater chance of developing autoimmune diseases, this does not mean that the AZOOR complex of disorders are themselves autoimmune diseases. This is supported by the difficulty in detecting “retinal autoantibodies” in AZOOR patients.
Two other diseases which also present with white dots on the fundus are retinitis punctata albescens and fundus albipunctatus. These diseases are not white dot syndromes, but have much more defined etiology. Retinitis punctata albescens is caused by mutations in RLBP1, the gene for retinaldehyde binding protein 1. In comparison, fundus albipunctatus is caused by mutations in RDH5 gene for an 11-cis-RDH in RPE cells.
Specific characteristics regarding the white dots and predicted etiology are presented of selected diseases.
Diagnosis includes dilated fundus examination to rule out posterior uveitis, which presents with white spots across the retina along with retinitis and vasculitis.
Laboratory testing is usually used to diagnose specific underlying diseases, including rheumatologic tests (e.g. antinuclear antibody, rheumatoid factor, angiotensin converting enzyme inhibitor <-- error) and serology for infectious diseases (Syphilis, Toxoplasmosis, Tuberculosis).
Major histocompatibility antigen testing may be performed to investigate genetic susceptibility to uveitis. The most common antigens include HLA-B27, HLA-A29 (in birdshot chorioretinopathy) and HLA-B51 (in Behçet disease).
Radiology X-ray may be used to show coexisting arthritis and chest X-ray may be helpful in sarcoidosis.
Generally speaking, people diagnosed with photic retinopathy recover visual acuity completely within two months, though more severe cases may take longer, or not see complete recovery at all.
Given that episodes tend to occur on awakening and managed by use of good 'wetting agents', approaches to be taken to help prevent episodes include:
- Environmental:
- ensuring that the air is humidified rather than dry, not overheated and without excessive airflow over the face. Also avoiding irritants such as cigarette smoke.
- use of protective glasses especially when gardening or playing with children.
- General personal measures:
- maintaining general hydration levels with adequate fluid intake.
- not sleeping-in late as the cornea tends to dry out the longer the eyelids are closed.
- Pre-bed routine:
- routine use of long-lasting eye ointments applied before going to bed.
- occasional use of the anti-inflammatory eyedrop FML (prescribed by an ophthalmologist or optometrist) before going to bed if the affected eye feels inflamed, dry or gritty
- use of a hyperosmotic (hypertonic) ointment before bed reduces the amount of water in the epithelium, strengthening its structure
- use the pressure patch as mentioned above.
- use surgical tape to keep the eye closed (if Nocturnal Lagophthalmos is a factor)
- Waking options:
- learn to wake with eyes closed and still and keeping artificial tear drops within reach so that they may be squirted under the inner corner of the eyelids if the eyes feel uncomfortable upon waking.
- It has also been suggested that the eyelids should be rubbed gently, or pulled slowly open with your fingers, before trying to open them, or keeping the affected eye closed while "looking" left and right to help spread lubricating tears. If the patient's eyelids feel stuck to the cornea on waking and no intense pain is present, use a fingertip to press firmly on the eyelid to push the eye's natural lubricants onto the affected area. This procedure frees the eyelid from the cornea and prevents tearing of the cornea.
Photic retinopathy generally goes away on its own over time, but there is no specific treatment known to be reliable for speeding recovery. One path sometimes attempted, which has unclear results, is to treat the initial macular edema with corticosteroids.
The prognosis is generally good for those who receive prompt diagnosis and treatment, but serious complication including cataracts, glaucoma, band keratopathy, macular edema and permanent vision loss may result if left untreated. The type of uveitis, as well as its severity, duration, and responsiveness to treatment or any associated illnesses, all factor into the outlook.
Multiple evanescent white dot syndrome (MEWDS) is an uncommon inflammatory condition of the retina that typically affects otherwise healthy young females in the second to fourth decades of life.
The typical patient with MEWDS is a healthy middle aged female age 15-50. There is a gender disparity as women are affected with MEWDS four times more often than men. Roughly 30% of patients have experienced an associated viral prodrome. Patients present with acute, painless, unilateral change in vision.
Because CAPS is extremely rare and has a broad clinical presentation, it is difficult to diagnose, and a significant delay exists between symptom onset and definitive diagnosis. There are currently no clinical or diagnostic criteria for CAPS based solely on clinical presentation. Instead, diagnosis is made by genetic testing for "NLRP3" mutations. Acute phase reactants and white blood cell count are usually persistently elevated, but this is aspecific for CAPS.
Phototherapeutic keratectomy (PTK) done by an ophthalmologist can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies including EBMD.
Acute zonal occult outer retinopathy (AZOOR) is an inflammatory retinopathy in the category of white dot syndromes typified by acute loss of one or more zones of outer retinal function associated with photopsia, minimal funduscopic changes and abnormal electroretinography findings.
Diagnosis for "type 1" of this condition for example, sees that the following methods/tests are available:
- Endoscopic
- CT scan
- Histologic test
Immunosuppressive therapy may be used in "type I" of this condition, ketoconazole can be used for "autoimmune polyendocrine syndrome type I" under certain conditions The component diseases are managed as usual, the challenge is to detect the possibility of any of the syndromes, and to anticipate other manifestations. For example, in a person with known Type 2 autoimmune polyendocrine syndrome but no features of Addison's disease, regular screening for antibodies against 21-hydroxylase may prompt early intervention and hydrocortisone replacement to prevent characteristic crises
Patients may complain of severe problems with dry eyes, or with visual obscurations. It can also be asymptomatic, and only discovered because of subtle lines and marks seen during an eye exam.
EBMD is a bilateral anterior corneal dystrophy characterized by grayish epithelial fingerprint lines, geographic map-like lines, and dots (or microcysts) on slit-lamp examination. Findings are variable and can change with time. While the disorder is usually asymptomatic, up to 10% of patients may have recurrent corneal erosions, usually beginning after age 30; conversely, 50% of patients presenting with idiopathic recurrent erosions have evidence of this dystrophy.
Since interleukin 1β plays a central role in the pathogenesis of the disease, therapy typically targets this cytokine in the form of monoclonal antibodies (such as canakinumab), binding proteins/traps (such as rilonacept), or interleukin 1 receptor antagonists (such as anakinra). These therapies are generally effective in alleviating symptoms and substantially reducing levels of inflammatory indices. Case reports suggest that thalidomide and the anti-IL-6 receptor antibody tocilizumab may also be effective.
Screening generally only takes place among those displaying several of the symptoms of ABCD, but a study on a large group of institutionalized deaf people in Columbia revealed that 5.38% of them were Waardenburg patients. Because of its rarity, none of the patients were diagnosed with ABCD (Waardenburg Type IV). Nothing can be done to prevent the disease.
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.