What should be done for an adult patient, possibly with underlying conditions such as hypertension or diabetes, diagnosed with a retinal blood clot (hemorrhage) that obstructs visibility of the retina?

Management of Retinal Hemorrhage Obscuring Fundus Visualization

When a blood clot (vitreous hemorrhage) obscures visualization of the retina, immediate B-scan ultrasonography must be performed to rule out retinal tears or detachment, followed by close weekly monitoring until the hemorrhage clears enough for complete peripheral retinal examination with scleral depression. 1

Immediate Diagnostic Approach

Ultrasound Evaluation

• B-scan ultrasonography is mandatory when media opacity prevents adequate retinal examination to search for retinal tears, retinal detachment, mass lesions, or other causes of vitreous hemorrhage 1
• The sensitivity of B-scan for detecting retinal tears ranges from 44-100%, so negative findings require close follow-up with repeat ultrasonography within 1-2 weeks if retinal tear is suspected 1
• Even with dense vitreous hemorrhage obscuring the posterior pole, the peripheral retina can frequently be examined using indirect ophthalmoscopy with scleral depression 1

Conservative Measures to Clear Hemorrhage

• Bilateral patching and/or head elevation while sleeping may help clear vitreous hemorrhage 1
• Patients with fundus-obscuring hemorrhage and negative ultrasound should be followed weekly until the hemorrhage resolves sufficiently for thorough indirect ophthalmoscopic examination with scleral depression 1

Critical Differential Diagnosis Considerations

Retinal Vein Occlusion

• If the underlying cause is retinal vein occlusion (more common in patients with hypertension, diabetes, hyperlipidemia), urgent ophthalmologic evaluation within 24-48 hours is required to prevent vision-threatening complications 2
• Examination every 4-6 weeks for the first 6 months is essential to monitor for neovascularization that can cause devastating neovascular glaucoma 2
• Slit-lamp examination and undilated gonioscopy must be performed to detect iris or angle neovascularization 2

Retinal Artery Occlusion

• If retinal artery occlusion is suspected, immediate referral to a stroke center within 4.5-6 hours is necessary due to high risk of cerebral stroke (3-6% within first 1-4 weeks, with 20-24% having concurrent acute brain infarction on MRI) 2, 3
• For patients over 50 years old, immediate ESR and CRP testing is mandatory to rule out Giant Cell Arteritis, which requires emergency high-dose corticosteroids to prevent blindness in the fellow eye 2, 3

Systemic Workup Requirements

Cardiovascular Evaluation

• All patients require urgent cardiovascular evaluation, as up to 70% have clinically significant carotid stenosis, and mortality rate is higher than age-matched controls due to cardiovascular disease 2
• Brain MRI with diffusion-weighted imaging should be performed within 7 days, as 19-25% of patients have silent brain infarctions predicting future stroke risk 2
• Carotid imaging and cardiac evaluation are essential since 95% of retinal artery occlusions result from thromboembolic disease 3

Risk Factor Assessment

• Identify and aggressively manage hypertension, diabetes mellitus, hyperlipidemia, glaucoma, carotid artery disease, sleep apnea, and smoking 2
• Hypertension carries an odds ratio of 3.5 for retinal vein occlusion, hyperlipidemia 2.5, and diabetes 1.5 4

Surgical Intervention Timing

Early Vitrectomy Indications

• Early vitrectomy (within 7 days of presentation) for dense vitreous hemorrhage has low complication rates and may be considered to reduce risk of vision loss from macula-involving retinal detachment 1
• Prompt intervention is indicated if a retinal tear is visualized on ultrasonography and the vitreous hemorrhage precludes direct visualization 1
• When anterior segment neovascularization is present with hyphema or vitreous hemorrhage limiting visualization for panretinal photocoagulation, off-label intravitreal anti-VEGF agents may optimize visualization and minimize treatment-related complications 1

Vision-Threatening Complications Requiring Treatment

Neovascularization Management

• Panretinal photocoagulation is the standard treatment to prevent progression to neovascular glaucoma and vitreous hemorrhage in patients with neovascularization 2
• When ocular neovascularization is present, prompt panretinal photocoagulation is indicated 1
• Intravitreal anti-VEGF injections (ranibizumab) are recommended for macular edema following retinal vein occlusion 2

Critical Pitfalls to Avoid

• Never assume a negative B-scan ultrasonography definitively rules out retinal tears—the sensitivity is variable (44-100%), requiring close follow-up 1
• Do not delay systemic workup while waiting for hemorrhage to clear, as stroke risk is highest in the first few weeks after retinal vascular occlusion 2, 3
• Patients with retinal or vitreous hemorrhage have increased risk of multiple retinal tears, requiring meticulous peripheral examination once visualization improves 1
• Regular ophthalmologic examinations for life are necessary to monitor for fellow eye involvement and systemic risk factors 2