In a 38-year-old Filipino-Chinese man presenting with unilateral eye redness, discomfort, mild intra‑ocular pressure elevation with episodic spikes, mild anterior chamber inflammation, and an open anterior chamber angle, how should Posner‑Schlossman syndrome be diagnosed and managed?

Posner-Schlossman Syndrome: Diagnosis and Management

In this 38-year-old Filipino-Chinese man with unilateral eye redness, mild IOP elevation with episodic spikes, and mild anterior chamber inflammation with an open angle, you should diagnose Posner-Schlossman syndrome (PSS) and treat with topical corticosteroids combined with IOP-lowering medications, while testing aqueous humor for viral DNA (particularly CMV, HSV, VZV, and HHV-6) to guide antiviral therapy.

Diagnostic Criteria

PSS presents with a characteristic clinical picture that distinguishes it from primary open-angle glaucoma 1:

Key diagnostic features include:

• Unilateral presentation (96.83% of cases) 2
• Recurrent attacks of mild, non-granulomatous anterior uveitis
• Marked IOP elevation (83% have IOP >30 mmHg during attacks) 2
• Open anterior chamber angle on gonioscopy (97.69% of cases) 2
• Keratic precipitates on corneal endothelium (45% of cases) 2
• Minimal anterior chamber cells (33% of cases) 2
• No posterior synechia or posterior segment inflammation
• Complete resolution of IOP and inflammation between attacks 3

This differs from POAG, which requires progressive optic nerve damage, bilateral (though asymmetric) presentation, and absence of inflammatory causes 1.

Diagnostic Workup

Perform the following assessments:

• Gonioscopy to confirm open angles and exclude angle-closure mechanisms
• Slit-lamp examination for keratic precipitates, anterior chamber cells, and iris abnormalities (depigmentation or atrophy in 5.38% of cases) 2
• Optic nerve evaluation with imaging (OCT of RNFL and macula) to assess for glaucomatous damage
• Visual field testing if glaucomatous optic neuropathy is suspected
• Anterior chamber tap with PCR for viral DNA (CMV, HSV, VZV, HHV-6) 4 - this is particularly important as viral etiology guides treatment

Look specifically for iris abnormalities (depigmentation or atrophy), as these influence surgical outcomes if filtration surgery becomes necessary 3.

Medical Management

Initial treatment algorithm:

1. Topical corticosteroids (e.g., betamethasone) to control inflammation 4

   • Average duration: 1.70 ± 0.76 months 2

2. Topical antiglaucoma medications to lower IOP 2, 4

   • Average duration: 1.66 ± 0.81 months 2
   • 26.92% of patients require continued antiglaucoma medications 2

3. Topical antiviral therapy (ganciclovir) if viral DNA detected 4

   • Particularly effective when HHV-6, CMV, or other herpesviruses identified

Important caveat: Unlike typical uveitis, avoid cycloplegics in PSS management 5.

Prognosis and Risk Stratification

PSS is not a benign condition - contrary to older teaching 6:

• 77% of patients relapse on average every 2.2 years 6
• 40% of patients progress to permanent glaucoma, corneal failure, or chronic inflammation 6

Risk factors for progression requiring surgical intervention include 6, 7:

• Older age at presentation (OR = 1.080 per year) 7
• Higher attack frequency (>2 attacks/year; OR = 6.186) 7
• RNFL defects on imaging (OR = 4.804) 7
• Glaucomatous optic neuropathy at presentation 6
• Immunocompromised status 6

Your 38-year-old patient is at moderate risk given his age (fourth decade is most common presentation) 2.

Surgical Management

If medical management fails (17% of patients require surgery) 7:

Surgical hierarchy based on iris status 3:

1. ExPRESS shunt - preferred first-line surgical option

   • 84.21% complete success rate at 12 months 3
   • Superior outcomes in patients with iris abnormalities compared to trabeculectomy (IOP 15.65 vs 22.52 mmHg) 3

2. Ahmed glaucoma valve (AGV) - for high-risk fibrosis patients

   • 100% success rate at 12 months 3
   • Reserved for patients at high risk of filtration failure

3. Trabeculectomy - lowest success rate

   • 58.97% complete success rate at 12 months 3
   • Highest postoperative IOP (20.84 mmHg) 3
   • Greatest BCVA decline 3

Monitoring Strategy

Follow-up schedule:

• During acute attacks: Weekly until IOP normalizes and inflammation resolves
• Between attacks: Every 3-6 months to monitor for:
  • Development of glaucomatous optic neuropathy
  • Progressive RNFL thinning on OCT
  • Visual field defects
  • Iris atrophy progression

Monitor specifically for:

• Attack frequency (document each episode)
• IOP trends between attacks
• Progressive optic nerve changes
• Need for continued antiglaucoma medications

The majority of PSS patients (76.15%) maintain good vision (better than 20/70) with appropriate management 2, but close monitoring is essential given the 40% progression rate 6.