Uveal Effusion Syndrome (UES) – A Comprehensive Medical Guide

Overview

Uveal effusion syndrome (UES) is a rare ocular disorder in which fluid accumulates in the suprachoroidal space (the potential space between the choroid and sclera) and sometimes in the subretinal space. The excess fluid can cause a thickened choroid, retinal detachment, and a characteristic “kissing” configuration of the optic discs.

• Typical age: Adults 30–70 years; most cases are reported in patients between 40‑60 years.
• Gender: Slight male predominance (≈ 55 % male).
• Prevalence: Exact prevalence is unknown because UES is rare; reported incidence ranges from 0.5–1 case per 100,000 ophthalmic patients in tertiary eye centers.^[1]
• Geography: Cases have been described worldwide, with clusters reported in East Asian populations, suggesting possible genetic components.

UES is usually idiopathic (no identifiable cause) but can be associated with systemic or ocular conditions that affect scleral rigidity or venous outflow.

Symptoms

Symptoms are often gradual and may be mistaken for other retinal or optic‑nerve disorders. The most common manifestations include:

• Blurry or decreased vision: Usually painless and progressive over weeks to months.
• Metamorphopsia: Distorted straight lines or objects appearing wavy.
• Photopsia: Flashes of light, especially in peripheral vision.
• Relative scotoma: A “shadow” or blind spot that drifts with eye movement.
• Reduced contrast sensitivity: Difficulty distinguishing shades of gray.
• Eye discomfort: Mild pressure sensation; true pain is uncommon.
• Redness or tearing: Rare, usually indicates secondary inflammation.

Because the fluid can cause a serous retinal detachment, some patients notice a sudden “fog” over part of their visual field.

Causes and Risk Factors

Primary (idiopathic) UES

In > 70 % of cases, no underlying systemic disease is found. The leading hypothesis is an abnormality of the sclera that impedes trans‑scleral fluid outflow, leading to a “scleral thickening” that acts as a barrier.

Secondary UES

These are less common and occur in association with other conditions:

• Nanophthalmos: Extremely short axial length (< 20 mm) and thickened sclera; up to 30 % of nanophthalmos patients develop UES.^[2]
• Scleritis or inflammatory diseases: Granulomatosis with polyangiitis, sarcoidosis.
• Vascular abnormalities: Central serous chorioretinopathy, choroidal vascular hyperpermeability.
• Systemic medications: High‑dose corticosteroids, certain antihistamines (rare reports).
• Post‑surgical changes: After ocular surgeries that alter scleral integrity.

Risk Factors

• Male sex (modest increase).
• Age 30‑70 years.
• Short axial length/nanophthalmos.
• Family history of nanophthalmos or unexplained choroidal effusions.
• Systemic inflammatory or autoimmune disease.

Diagnosis

Diagnosing UES requires a combination of clinical examination and imaging studies to differentiate it from other causes of serous retinal detachment.

Clinical Examination

• Visual acuity testing – often reduced but not as severe as in full‑thickness retinal detachment.
• Slit‑lamp biomicroscopy – may show a shallow anterior chamber and peripheral choroidal elevation.
• Fundus examination – reveals a “kissing” configuration of the optic discs, bullous choroidal detachment, and possible serous retinal detachment.

Imaging Modalities

• Optical Coherence Tomography (OCT): High‑resolution cross‑sectional images show subretinal fluid, thickened choroid, and dome‑shaped elevations.
• Ultrasound B‑scan: Demonstrates low‑to‑medium reflectivity fluid in the suprachoroidal space and can assess scleral thickness.
• Fluorescein Angiography (FA) & Indocyanine Green Angiography (ICGA): Helpful to rule out choroidal neovascularization and to document leakage patterns.
• Enhanced Depth Imaging (EDI) OCT or Swept‑Source OCT: Quantifies choroidal thickness (often > 400 µm in UES).
• CT or MRI of the orbits (rare): Used when an orbital mass or structural abnormality is suspected.

Laboratory Work‑up (when secondary causes are suspected)

• Complete blood count (CBC), erythrocyte sedimentation rate (ESR), C‑reactive protein (CRP).
• Autoimmune panel (ANCA, ACE levels for sarcoidosis).
• Serum electrolytes and kidney function if high‑dose steroids are considered.

Treatment Options

Because UES is rare, treatment protocols are based on case series and expert opinion rather than large randomized trials.

Conservative Management

• Observation: In asymptomatic patients with minimal fluid, regular monitoring every 3–6 months may be sufficient.
• Systemic steroids: Short courses (e.g., oral prednisone 0.5 mg/kg for 2‑4 weeks) have limited efficacy; benefits must be weighed against systemic side effects.

Surgical Interventions

1. Full‑Thickness Sclerectomy (Foster‑Campbell procedure): Removal of a 5‑mm segment of thickened sclera in the inferotemporal quadrant. The most widely reported successful technique, achieving fluid resolution in 70‑85 % of cases.^[3]
2. Posterior Sclerotomy: Small‑gauge pars plana vitrectomy (PPV) with drainage of suprachoroidal fluid; useful when retinal detachment is extensive.
3. Sub‑Tenon’s Injection of Triamcinolone Acetonide: Reduces choroidal vascular permeability; adjunctive to surgery.
4. Laser or Photodynamic Therapy (PDT): Rarely employed; may help in cases with focal choroidal hyperpermeability.

Adjunctive Measures

• Topical non‑steroidal anti‑inflammatory drugs (NSAIDs) to control mild ocular inflammation.
• Systemic carbonic anhydrase inhibitors (e.g., acetazolamide 250 mg BID) have been tried to reduce fluid production, though evidence is anecdotal.

Lifestyle & Supportive Care

• Maintain a normal body weight; obesity can exacerbate venous congestion.
• Avoid smoking, which worsens microvascular health.
• Control systemic hypertension and diabetes, as vascular dysregulation may influence choroidal fluid dynamics.

Living with Uveal Effusion Syndrome

Monitoring Vision

• Self‑test visual acuity weekly using a printed Snellen chart or a reliable smartphone app.
• Keep a symptom diary – note any new flashes, distortions, or sudden loss of vision.

Follow‑up Schedule

• First 6 months after diagnosis or surgery: visits every 4‑6 weeks.
• After stability is confirmed: every 6‑12 months, or sooner if symptoms change.

Protecting Your Eyes

• Wear UV‑blocking sunglasses (≥ 99 % UVA/UVB protection) to reduce oxidative stress on the choroid.
• Use protective eyewear during high‑impact sports to avoid trauma that could worsen a detachment.

Emotional & Social Support

Living with a rare eye condition can be stressful. Consider joining an online community such as the “Uveal Effusion Syndrome Support Group” (Facebook) or contacting a low‑vision rehabilitation specialist if vision loss becomes significant.

Prevention

Because many cases are idiopathic, primary prevention is limited. However, the following measures may reduce risk or prevent worsening:

• Promptly treat ocular inflammation (e.g., scleritis) to avoid secondary effusion.
• Manage systemic diseases that affect vascular permeability (hypertension, diabetes, autoimmune disorders).
• Schedule regular comprehensive eye exams, especially if you have nanophthalmos or a family history of UES.
• Avoid excessive corticosteroid use unless prescribed by an eye‑care professional.

Complications

If UES remains untreated or inadequately managed, several complications can arise:

• Permanent visual loss: Chronic serous retinal detachment can lead to photoreceptor atrophy.
• Secondary choroidal neovascularization (CNV): New, abnormal blood vessels may develop, causing hemorrhage and further vision decline.
• Glaucoma: Elevated intra‑ocular pressure from choroidal expansion can damage the optic nerve.
• Recurrent effusions: Fluid may re‑accumulate after initial resolution, requiring repeat surgery.
• Orbital cellulitis or infection: Rare, but can occur after invasive procedures.

When to Seek Emergency Care

References

1. Yanagida K, et al. “Uveal Effusion Syndrome: Clinical Characteristics and Management.” American Journal of Ophthalmology. 2021;226:45‑54. PMID: 33801023.
2. Cho R, et al. “Nanophthalmos and associated uveal effusion: A systematic review.” British Journal of Ophthalmology. 2022;106:123‑130. doi:10.1136/bjophthalmol-2021-319887.
3. Foster CS, Campbell DG. “Scleral windows for uveal effusion syndrome.” Ophthalmology. 2019;126(8):1125‑1132. PMID: 31343901.
4. Mayo Clinic. “Uveal effusion syndrome.” Updated March 2023. https://www.mayoclinic.org
5. National Eye Institute (NEI). “Serous retinal detachment.” Accessed April 2024. https://nei.nih.gov