What are the symptoms and treatment for bubbles in clear fluid in the sclera?

Bubbles in Clear Fluid in the Sclera

The appearance of "bubbles" or clear fluid-filled spaces in or around the sclera most commonly represents filtering blebs (post-glaucoma surgery), conjunctival cysts, chemosis (conjunctival edema), or in rare cases, fluid in the sub-Tenon space from posterior scleritis or uveal effusion syndrome. Immediate ophthalmologic evaluation with slit-lamp examination, B-scan ultrasonography, and assessment for underlying inflammatory or structural disease is essential to determine the specific etiology and guide treatment.

Clinical Presentation and Key Diagnostic Features

The clinical context determines the likely diagnosis:

Post-Surgical Filtering Blebs

• Appearance: Elevated, fluid-filled conjunctival elevation overlying the sclera, typically in the superior quadrant following trabeculectomy or glaucoma drainage device surgery 1
• Symptoms: Usually asymptomatic unless infected (bleb-related endophthalmitis) or leaking, which presents with hypotony 1
• Management: Observation if functioning well; topical antibiotics if erosion present; surgical revision if leaking or infected 1

Conjunctival Chemosis or Cysts

• Appearance: Clear fluid accumulation causing conjunctival swelling that may appear bubble-like
• Associated findings: May occur with allergic conjunctivitis, inflammation, or venous congestion
• Evaluation: Slit-lamp examination to differentiate from deeper pathology 1

Posterior Scleritis with Sub-Tenon Fluid

• Key diagnostic feature: Fluid in the sub-Tenon space around the optic disc creating a "T-sign" on B-scan ultrasonography 1
• Clinical presentation: Middle-aged women with deep ocular pain, hyperemia of conjunctiva and large scleral vessels, painful eye movements, choroidal folds, serous retinal detachment, and optic disc edema 1
• Imaging findings: No leakage on fluorescein angiography (FA) or indocyanine green angiography (ICGA) 1
• Treatment: Corticosteroids and other systemic immunosuppressive medication 1, 2

Uveal Effusion Syndrome

• Presentation: Abnormal collection of fluid expanding the suprachoroidal space, may have associated shifting subretinal fluid 3
• Patient profile: Most typically middle-aged men with relapsing-remitting course, often hypermetropic 3
• Pathophysiology: Reduced macromolecular diffusion through thickened sclera interfering with normal transscleral albumin egress, or swollen sclera compressing transscleral vessels 3
• Diagnosis of exclusion: Rule out inflammatory and hydrostatic causes first 3
• Treatment: Full-thickness sclerectomies to provide exit for choroidal fluid (anatomic improvement in ~83% after single procedure, ~96% after one or two procedures); systemic steroids are not effective 3

Diagnostic Workup Algorithm

Step 1: Detailed History

• Timing of onset (acute vs. gradual) 1
• Prior ocular surgery, particularly glaucoma procedures 1
• Pain characteristics (deep pain suggests posterior scleritis) 1
• Systemic autoimmune disease history 2, 4

Step 2: Comprehensive Examination

• Visual acuity measurement 1
• Intraocular pressure (elevated with bleb leak, reduced with hypotony or uveal effusion) 1, 3
• Slit-lamp biomicroscopy to localize fluid (conjunctival vs. episcleral vs. deeper) 1
• Dilated fundus examination for choroidal folds, serous detachment, optic disc edema 1
• Gonioscopy if glaucoma-related 1

Step 3: Ancillary Testing

• B-scan ultrasonography: Essential to identify T-sign (posterior scleritis), choroidal detachment (uveal effusion), or assess when media opaque 1, 3
• Optical coherence tomography (OCT): Evaluate for subretinal fluid, choroidal thickness, macular involvement 1
• Fluorescein and indocyanine green angiography: Posterior scleritis shows no leakage; helps differentiate from other causes of serous detachment 1

Treatment Based on Etiology

For Posterior Scleritis

Initiate systemic corticosteroids as first-line therapy 1, 2:

• Oral prednisone 1 mg/kg/day with gradual taper
• Add steroid-sparing immunosuppressive agents (methotrexate, azathioprine, mycophenolate) for chronic or recurrent cases 2
• Consider biologic agents (anti-TNF alpha, anti-CD20) for refractory disease 2

For Uveal Effusion Syndrome

Surgical intervention is the definitive treatment 3:

• Full-thickness sclerectomies in affected quadrants to decompress vortex veins
• Avoid systemic steroids (ineffective for this condition) 3
• Visual acuity improves by ≥2 lines in 56% of eyes, remains stable in 35%, worsens in 9% 3

For Post-Surgical Blebs

Management depends on bleb integrity 1:

• Leaking bleb with hypotony: Pressure patching initially; if persistent, surgical wound revision with conjunctival/pericardial graft coverage 1
• Bleb erosion: Topical antibiotics until surgical closure can be performed; thoroughly release traction, debride epithelialization, re-cover with pericardium or grafted conjunctiva 1
• Functional bleb: Observation with routine monitoring 1

Critical Pitfalls to Avoid

• Do not assume all scleral "bubbles" are benign conjunctival cysts—failure to diagnose posterior scleritis or necrotizing scleritis can lead to rapid scleral destruction and vision loss 5, 4
• Do not delay B-scan ultrasonography when the clinical picture is unclear or media is hazy 1, 3
• Do not treat uveal effusion syndrome with systemic steroids—this is ineffective and delays appropriate surgical management 3
• Do not overlook systemic autoimmune disease—scleritis frequently associates with rheumatoid arthritis and other connective tissue disorders requiring systemic workup 2, 4
• In post-surgical cases, do not underestimate small amounts of wound leakage—these rarely resolve spontaneously and require intervention 1