What should be done if diagnosed with a retinal blood clot (hemorrhage) and the retina is not visible, even with ultrasound, potentially due to underlying conditions such as hypertension, diabetes, or atherosclerosis?

Management of Dense Vitreous Hemorrhage Obscuring Retinal Visualization

When a retinal blood clot (vitreous hemorrhage) completely obscures the retina even on B-scan ultrasonography, close weekly follow-up is mandatory until the hemorrhage clears sufficiently for indirect ophthalmoscopy with scleral depression, with consideration for early vitrectomy (within 7 days) to prevent vision-threatening complications. 1

Immediate Assessment Protocol

Initial Diagnostic Steps

• Perform B-scan ultrasonography immediately when media opacity precludes adequate examination of the peripheral retina, searching specifically for retinal tears, retinal detachment, or mass lesions 1, 2
• Recognize that B-scan sensitivity for detecting retinal tears in fundus-obscuring vitreous hemorrhage varies considerably (44%–100%), meaning a negative ultrasound does not definitively rule out pathology 1, 2
• Attempt peripheral retinal examination using indirect ophthalmoscopy with scleral depression, as the peripheral retina can frequently be examined even when the posterior pole is completely obscured 1

Critical Time-Sensitive Management

If B-scan ultrasonography is negative and all retinal details remain obscured:

• Institute weekly follow-up examinations until either the vitreous hemorrhage resolves or a thorough indirect ophthalmoscopic depressed peripheral exam can be performed 1, 2
• Repeat ultrasonographic examination within 1-2 weeks of the initial evaluation when a retinal tear is suspected 1, 2
• Consider bilateral patching and/or head elevation while sleeping to facilitate vitreous hemorrhage clearance 1

Surgical Intervention Considerations

Early Vitrectomy Indications

Early vitrectomy (within 7 days of presentation) should be strongly considered for dense vitreous hemorrhage, as it has been reported to have a low complication rate and may reduce the risk of vision loss from macula-involving retinal detachment 1

Prompt vitrectomy is specifically indicated when:

• A retinal tear is visualized on ultrasonography and the vitreous hemorrhage precludes adequate view for other interventions 1
• The hemorrhage fails to clear sufficiently for examination despite conservative management 1

Systemic Evaluation Requirements

Urgent Stroke Assessment

Given the underlying conditions mentioned (hypertension, diabetes, atherosclerosis), immediate referral to a stroke center is mandatory if this represents a retinal arterial occlusion rather than simple hemorrhage 1, 3

Key systemic workup includes:

• Brain MRI with diffusion-weighted imaging to identify concurrent stroke (present in up to 24% of retinal vascular events) 3
• Vascular imaging (CTA or MRA) to assess for carotid stenosis (present in up to 70% of central retinal artery occlusion cases) 3
• ESR and CRP in all patients over 50 years to evaluate for giant cell arteritis, regardless of whether classic symptoms are present 3

Cardiovascular Risk Factor Management

• Document all cardiovascular risk factors including hypertension, diabetes, hyperlipidemia, and smoking status 1, 4
• Coordinate with primary care for aggressive management of modifiable risk factors 1

Common Pitfalls to Avoid

Examination Errors

• Do not delay gonioscopy before dilation when neovascularization of the iris is suspected or intraocular pressure is elevated, as neovascularization can occur up to 4 months after acute arterial occlusion 2
• Do not rely solely on B-scan ultrasonography given its variable sensitivity; clinical correlation and repeat imaging are essential 1, 2

Management Errors

• Do not assume a negative B-scan ultrasonography rules out retinal pathology—close follow-up remains mandatory 1, 2
• Do not delay referral to a stroke center while attempting additional ophthalmologic testing if retinal arterial occlusion is suspected 1, 3
• Do not wait beyond 1-2 weeks for repeat ultrasonography if a retinal tear is suspected 1, 2

Timing Considerations

• Recognize that patients with retinal or vitreous hemorrhage have an increased risk of multiple retinal tears 1
• Understand that stroke risk remains highest within the first 7 days after onset of visual symptoms, even if vision improves 3

Alternative Examination Techniques During Follow-up

As the hemorrhage begins to clear:

• Utilize slit-lamp biomicroscopy with a mirrored contact lens or condensing lens as an alternative to indirect ophthalmoscopy 2
• Consider wide-field color photography to detect peripheral retinal pathology, though this does not replace careful ophthalmoscopy 1, 2
• Employ optical coherence tomography to evaluate for macular pathology once media clarity permits 2