01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Blood interferes with the normally transparent optical pathway through the vitreous. A relatively small amount can produce conspicuous moving opacities, while dense haemorrhage may reduce vision enough to prevent reading or navigating safely. The appearance of the symptom does not identify its source. Bleeding may arise from a vessel torn during posterior vitreous separation, fragile neovascular vessels, trauma or another posterior-segment lesion. Ask about new flashes and field loss as well as the severity of haze, because a retinal tear can be hidden by the very blood it has caused.
A history of diabetes makes proliferative disease plausible but should not close the differential. Establish whether the eye has known neovascularisation, previous panretinal photocoagulation, injections or retinal surgery, and obtain the last retinal-team plan where available. Review anticoagulants and antiplatelets, their indication and recent changes. These medicines may affect the bleeding context, but labelling the event anticoagulant-related does not exclude an underlying tear or vessel abnormality. Medication changes should follow a coordinated clinical assessment rather than an instruction to stop treatment independently.
The central management decision is whether the retina can be evaluated and whether a lesion needs prompt treatment. Some haemorrhages can clear under observation after an adequate specialist assessment, while others need early vitrectomy to reveal and treat the source or to address detachment. The choice depends on suspected aetiology, ultrasound findings, recurrent bleeding, visual needs and the reliability of follow-up. A period of observation should have a clear examination plan and explicit triggers for intervention; it is not simply waiting until the patient can see again.
Key points
- Vitreous haemorrhage describes blood within the vitreous cavity and is a finding requiring a cause.
- Proliferative diabetic retinopathy, retinal tears, trauma and other retinal vascular disease are important possibilities.
- Patients may describe black dots, cobwebs, smoke, red haze or sudden painless reduction in vision.
- Examine the retina when possible and use specialist B-scan assessment when blood prevents an adequate fundal view.
- A negative ultrasound must be interpreted with its technical limitations, the clinical risk and the plan for repeat assessment.
- NICE's three-month non-clearing diabetic haemorrhage recommendation must not be applied as a waiting rule for new unexplained bleeding or a threatened macula.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Fragile abnormal vessels
Proliferative retinal disease can produce neovascular vessels that bleed into the vitreous. Diabetes is an important setting, while other ischaemic retinal processes may also cause neovascularisation.
Mechanical vessel injury
Posterior vitreous separation, a retinal tear or trauma can disrupt a vessel and release blood. The bleeding may hide the structural lesion that requires urgent treatment.
Other posterior pathology
Retinal vascular abnormalities, a mass or other posterior-segment disease can contribute to haemorrhage. An unexplained or recurrent episode warrants reconsideration rather than indefinite attribution to a nonspecific bleed.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Loss of optical transparency
Blood cells and associated material scatter and block light traversing the vitreous. The patient may notice mobile shadows, diffuse haze or a substantial reduction in visual acuity.
- 2Obscured retinal anatomy
Dense blood limits the examiner's view as well as the patient's sight. Imaging and repeated assessment may be needed to establish whether a tear, detachment or proliferative lesion is present.
- 3Persistence and rebleeding
Blood can clear gradually, but ongoing vascular fragility or traction may cause further episodes. Recurrence and uncertain retinal anatomy influence the balance between observation and surgery.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
A shower of dark spots, smoke-like obscuration or marked painless blur can indicate vitreous blood. Ask whether the symptom developed with flashes or a fixed missing area.
Blood can make retinal details difficult or impossible to inspect. The inability to see the retina is a diagnostic limitation that increases the need for specialist assessment.
Known diabetic neovascularisation or other ischaemic retinal disease suggests fragile abnormal vessels as a source. Existing retinal records help establish whether the current event fits the previous anatomy.
A curtain, trauma, new pain, an afferent pupil abnormality or rapidly deteriorating function suggests additional structural or pressure-related disease. These findings should shape the referral urgency and examination precautions.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Visual acuity and ocular historyFirst step - Why
- Measure functional loss and identify clues to the bleeding source.
- Interpretation and limitations
- Record each eye's acuity, prior retinal treatment, trauma, diabetes and antithrombotic use. A previously normal screening result does not exclude a new retinal tear.
- 02
Dilated retinal and anterior-segment examination - Why
- Look for blood, pigment, retinal lesions and pressure-related complications.
- Interpretation and limitations
- Document the extent of visible retina and any area obscured. Assess intraocular pressure only when the globe is intact and the examiner is appropriately trained.
- 03
Specialist ophthalmic B-scan ultrasound - Why
- Assess retinal attachment and posterior structures behind an opaque vitreous.
- Interpretation and limitations
- A scan can identify important structural pathology, but small breaks may be missed and performance depends on technique. Interpret a negative result within an active retinal follow-up plan rather than as definitive exclusion.
- 04
Cause-directed imaging and medical testing - Why
- Investigate retinal vascular activity and relevant systemic contributors.
- Interpretation and limitations
- As visibility permits, the specialist may use retinal imaging or angiography. Blood count or coagulation testing is selected from the history, with INR relevant to warfarin rather than a universal test for every anticoagulant.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Uncomplicated vitreous floaters
Condensed vitreous can create stable mobile opacities without haemorrhage. A sudden dense shower, marked haze or visual decline needs assessment for blood and its cause.
Retinal detachment
A fixed shadow or missing field may accompany or follow haemorrhage from a retinal break. The two conditions can coexist and require examination of retinal attachment.
Inflammatory vitreous opacity
Cells and inflammatory debris can also cloud the vitreous and reduce vision. Slit-lamp and posterior assessment help distinguish inflammation from blood and identify any infectious component.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01Acute presentationFind the source behind the haemorrhageFirst stepA new episode of visual haze or loss is suspected to represent vitreous blood.+
- 1Arrange emergency ophthalmic assessment and communicate accompanying flashes, field change, trauma and the degree of visual loss.
- 2Support examination of retinal attachment with suitable imaging when blood obscures the view, avoiding pressure if an open globe is possible.
- 3Make clear that diabetes or anticoagulant use is contextual information and does not itself identify the source or make urgent assessment unnecessary.
02Diabetic haemorrhage under retinal careBalance observation against active treatmentSpecialist assessment attributes the bleed to proliferative diabetic retinopathy and establishes the retinal anatomy.+
- 1Treat and monitor the active proliferative disease, considering a temporary anti-VEGF approach when haemorrhage prevents indicated panretinal photocoagulation.
- 2NICE advises considering vitrectomy when diabetic proliferative haemorrhage has not cleared within three months, and performing it within three months of offering it.
- 3Do not use that timing to delay intervention for a retinal detachment involving or threatening the macula, an uncertain dangerous source or another indication for earlier surgery.
03Persistent or uncertain bleedingReassess the need for vitreoretinal surgeryThe haemorrhage recurs, does not clear as expected or continues to hide a concerning retinal lesion.+
- 1Review the original diagnosis, serial examination and ultrasound findings, visual function and the patient's ability to attend monitoring.
- 2Discuss vitrectomy as a way to remove opaque vitreous and treat identified breaks, traction or proliferative pathology, with risks and alternatives made explicit.
- 3After surgery, provide a specific drop and review plan, and explain posturing and gas precautions whenever a tamponade has been used.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Missed retinal injury
A hidden tear or detachment can progress while attention focuses on whether blood is clearing. Specialist follow-up must address the source and retinal integrity.
Ongoing functional impairment
Persistent haemorrhage can restrict mobility, reading and work even when the underlying retina has useful potential. Functional burden is part of the discussion about intervention.
Pressure or treatment complications
Blood-related processes and subsequent retinal surgery can be accompanied by pressure disturbance, recurrent haemorrhage or other ocular complications. New pain or deterioration requires prompt reassessment.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- During observation, document whether blood is clearing and whether increasing retinal visibility has revealed a previously hidden lesion.
- Repeat specialist examination or imaging according to risk; subjective improvement in haze does not prove that an associated break is safely treated.
- Give immediate-return advice for new flashes, a curtain, worsening acuity, substantial pain or nausea, with an accessible out-of-hours destination.
- Coordinate diabetic and blood-pressure care and any antithrombotic review with the relevant clinicians while maintaining the retinal treatment plan.
- Consider functional consequences while vision is poor, including falls, reading medicines, work, caring duties and safe transport to repeated eye appointments.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Ultrasound has an operating context
Studies of non-diabetic vitreous haemorrhage show that retinal-break detection by B-scan varies. The lesson is to integrate imaging with specialist judgement and follow-up, not to impose one sensitivity estimate on every operator and device.
Clearing blood may reveal disease
Improved visual access can uncover a tear, proliferative vessels or another lesion. A patient who notices clearer vision may still need the planned examination to identify and treat the source.
Diabetic timing is indication-specific
The NICE non-clearing haemorrhage threshold applies to an assessed proliferative diabetic presentation. It should not be transferred to acute unexplained haemorrhage or used to override a separate macula-threatening detachment recommendation.
Stopping anticoagulation is not diagnosis
Antithrombotic interruption carries its own clinical consequences and cannot substitute for identifying the retinal lesion. Share medication decisions with the prescriber and retinal team, taking bleeding severity and indication into account.
11Common pitfallsFrequent interpretation and management errors.
- 01
Attributing sudden vitreous blood entirely to diabetes without assessing for a tear or detachment.
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Writing retina normal when haemorrhage prevented the peripheral retina from being seen.
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Treating one negative B-scan as a guarantee that observation needs no further examination.
- 04
Applying a three-month observation period to all causes of vitreous haemorrhage rather than to the specific NICE diabetic context.