POSNER SCHLOSSMAN SYNDROME
It is also known as: “Glaucomato-cyclitic Crisis”
It is an uncommon type of open-angle glaucoma.
First described by Posner and Schlossman in 1948.
It is characterized by: Recurrent episodes of mild, non-granulomatous anterior uveitis and markedly elevated intra-ocular pressure (IOP).
It is usually a self-limited condition.
It has been associated with a number of systemic disorders including:
- Gastrointestinal (Especially peptic ulcer).
- Allergic disorders (HLA-Bw54 was discovered in 41% patients in a study, suggesting a role for immunogenetic factors).
- Infection (Herpes simplex DNA was found in aqueous specimens of 3 patients with PSS; evidence of Cytomegalovirus [CMV] infection as the inciting agent has also been reported).
Usually seen in young-middle aged individuals, 20-50 years of age (though may occur in elderly also).
Commoner in males.
Slight ocular discomfort or pain.
Colored halos. (Halos last several hours to a few weeks or even longer. Usually recur on monthly or yearly basis).
Mild ciliary flush.
Corneal epithelial edema.
Small to mid size, non-pigmented keratic precipitates in central and inferior cornea.
Trace flare and cells.
Hypochromia of iris (Reported in upto 40% of patients; this may cause confusion with Fuch’s Heterochromic Iridocyclitis [FHI]).
IRIS FLUORESCEIN ANGIOGRAPHY:
Early segmental iris ischemia with late congestion and leakage has been described.
Normal, open angles with occasional debris and characteristic absence of synechiae.
IOP elevation may precede or follow the anterior chamber reaction.
IOP is out of proportion to the inflammatory process. Usually ranges from 40-60 mmHg. It coincides with the appearance and duration of the inflammatory process.
IOP and facility of outflow return to normal between the attacks. Severe cases with optic nerve and visual field (VF) changes have been reported.
Glaucoma is attributable to inflammatory changes in the trabecular meshwork. Histology of the trabecular meshwork during the attack revealed numerous mononuclear cells in the tissue.
Other theories of mechanism include increased aqueous production due to elevated levels of prostaglandins in the aqueous. There is also an association with chronic open angle glaucoma.
Anterior chamber tap for viral PCR and analysis of specific antibody production (for CMV and herpes simplex).
VF testing / RNFL analysis for glaucomatous damge.
Ancillary tests to exclude other causes of unilateral uveitis and secondary glaucoma.
Atypical cases of Fuchs Hetrochromic Iridocyclitis
Non specific hypertensive Iridocyclitis
Herpetic anterior uveitis
Acute angle closure glaucoma
CMV-induced anterior uveitis
Aim of treatment is controlling the inflammation and raised IOP.
Topical corticosteroids are usually effective for the uveitic component.
In confirmed CMV infection, specific treatment can be initiated and given for 2-3 months.
IOP can be controlled with aqueous suppressants. Apraclonidine was found to be particularly effective. The efficacy of PG-analogues has not been well established.
Prophylactic therapy in between the attacks is not recommended.
Glaucoma filtering surgery may be required in medically resistant cases.
Recurrences decrease with age.
Visual prognosis is usually good.
Chronically high IOP with glaucomatous optic nerve degeneration has been reported in 25% cases in a study.
Patients with 10 years or more of PSS have a 2.8 times higher risk of developing glaucomatous optic nerve and VF damage, when compared to patients with less than 10 years of the disease.
PSS has also been linked to Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION) during acute elevation of IOP in patients with small cups.