Hyphaema
Pathophysiology, Grading, Complications & Management
Examination question · ~1200 words
What is hyphaema? Discuss its pathophysiology, classification, complications, and stepwise management — including special considerations for sickle cell disease and paediatric cases.
Try to outline your answer mentally before expanding sections below.
Hyphaema is the presence of blood in the anterior chamber (AC) of the eye, resulting most commonly from blunt or penetrating ocular trauma causing rupture of iris root or ciliary body vasculature. It represents a true ocular emergency due to its potential for serious complications including raised intraocular pressure (IOP), corneal blood staining, optic atrophy, and permanent visual loss. The hallmark of management is early recognition, appropriate grading, prevention of secondary haemorrhage (rebleed), and careful IOP control — with particular vigilance in sickle cell disease where much lower IOP thresholds pose optic nerve risk.
Hyphaema is defined as the presence of blood in the anterior chamber of the eye, lying between the cornea and iris. It most commonly results from blunt or penetrating ocular trauma causing rupture of the iris root or ciliary body vasculature. It is a vision-threatening ocular emergency with significant risk of both acute IOP elevation and long-term visual sequelae.
Traumatic (Most Common)
- Blunt trauma — most common; contrecoup effect ruptures iris root or ciliary body (CB) vessels
- Penetrating trauma — direct vascular injury
- Post-surgical — cataract surgery, trabeculectomy, keratoplasty, post-LASIK flap trauma
Spontaneous (Non-Traumatic)
| Category | Examples |
|---|---|
| Neovascularisation | NVG, PDR, rubeosis iridis, sickle cell retinopathy |
| Haematological | Sickle cell disease/trait, haemophilia, thrombocytopenia, anticoagulant use |
| Iris/Ciliary tumours | Iris melanoma, juvenile xanthogranuloma (JXG), leukaemia |
| Vascular anomalies | Iris haemangioma, microhyphaema in Fuchs uveitis |
| Iatrogenic | Ahmed/Baerveldt tube erosion, IOL-iris chafe syndrome |
Hyphaema is graded on the basis of blood height as a percentage of anterior chamber depth on slit-lamp examination, using the standard classification system:
| Grade | Description | Risk of Complications |
|---|---|---|
| Grade I | Blood fills < 1/3 of AC | Low |
| Grade II | Blood fills 1/3 – 1/2 of AC | Moderate |
| Grade III | Blood fills > 1/2 of AC, not total | High |
| Grade IV / 8-Ball | Total AC filled with blood (often dark/clotted) | Very High |
| Microhyphaema | RBCs in AC visible on slit-lamp only; no visible layer | Minimal |
8-Ball Hyphaema: Total anterior chamber filled with dark, deoxygenated blood. The characteristic dark (not bright red) appearance results from haemoglobin deoxygenation in the hypoxic, static AC environment. High risk of corneal staining and IOP spike; surgical evacuation often required.
Primary Bleed
Blunt trauma generates rapid antero-posterior compression followed by equatorial expansion of the globe. This contrecoup effect shears the fragile vessels at the iris root and anterior ciliary body, producing immediate haemorrhage into the AC.
Secondary Haemorrhage (Rebleed) — 2nd to 5th Day
Premature clot retraction and lysis via fibrinolysis exposes torn vessel ends, leading to secondary bleeding. Peak incidence occurs 2–5 days post-injury. The rebleed is typically more severe than the primary bleed and is responsible for the majority of vision-threatening complications.
- Peak fibrinolytic activity: AC fibrinolytic enzyme activity peaks at 48–72 hours — the critical window for rebleed
- Risk factors for rebleed: Grade III–IV hyphaema, sickle cell trait/disease, aspirin/NSAID use, coagulopathy, vigorous physical activity, young age
| Complication | Mechanism | Key Management Points |
|---|---|---|
| IOP Elevation (Acute) | Trabecular meshwork blockade by RBCs and debris | Occurs in ~30%; treat medically first; monitor daily |
| IOP Elevation (Chronic) | Ghost cell glaucoma; haemolytic glaucoma; angle recession | Gonioscopy essential at 4–6 weeks post-trauma to assess angle damage |
| Corneal Blood Staining | Haemoglobin breakdown products enter corneal stroma; risk factors: IOP >25 mmHg + Grade III/IV hyphaema + compromised corneal endothelium | Commences centrally and inferiorly; clears centripetally (peripheral clears first; central staining persists longest); colour progression: yellow → green → grey → white (months to years); may be permanent |
| Optic Atrophy | Prolonged IOP elevation compresses optic nerve; critical threshold differs by systemic disease | Normal: IOP >30 mmHg for >48–72 h; Sickle cell: IOP >24 mmHg for >24 h |
| Synechiae | Organisation of clot; posterior synechiae and PAS formation | More common with delayed clot clearance; may limit mydriasis |
| Amblyopia | Deprivation in children < 8 years due to corneal opacity/blood | Urgent visual rehabilitation and vigorous optical correction essential post-clearance |
Sickle cell disease (HbSS) and even sickle trait (HbAS) significantly alter hyphaema management due to sickling in the hypoxic, acidotic, hyperosmolar anterior chamber environment. The AC becomes a high-risk zone for red cell polymerisation and vaso-occlusion.
| Parameter | Normal Patient | Sickle Cell Patient |
|---|---|---|
| IOP threshold for optic nerve risk | >30 mmHg for >48–72 h | >24 mmHg for >24 h |
| Systemic CAI (acetazolamide) | Acceptable | AVOID (causes metabolic acidosis, promoting sickling) |
| Topical CAI (dorzolamide) | Acceptable | AVOID (systemic absorption risk) |
| Epinephrine/adrenaline | Can use | AVOID (vasoconstriction promotes sickling and ischaemia) |
| Aspirin / NSAIDs | Avoid (rebleed risk) | Strictly avoid |
| Surgical intervention threshold | IOP >35 for >7 days; Grade IV; corneal staining | Lower threshold; IOP >24 for >24 h warrants urgent surgical evacuation |
Mandatory
- Detailed history: mechanism of injury, timing of event, current medications (aspirin, warfarin, NSAIDs, anticoagulants)
- Visual acuity (Snellen): baseline essential for medicolegal documentation and prognostication
- IOP measurement: tonometry (Goldmann applanation or Tono-Pen in acute setting); note: IOP may be falsely low if ciliary body trauma causes shutdown, despite TM blockade
- Slit-lamp examination: grade hyphaema (height as % of AC), clot status (liquid vs organised), AC reaction, corneal clarity, iris/CB integrity
- Dilated fundus examination: if media clarity permits; assess optic disc and retina
- B-scan ultrasonography: mandatory when fundal view obscured; rule out vitreous haemorrhage, retinal detachment, intraocular foreign body (IOFB), posterior globe rupture
Selective / For Systemic Evaluation
- Haemoglobin electrophoresis: all African-American patients and high-risk populations; rule out sickle cell disease/trait
- CBC, PT, aPTT: if spontaneous hyphaema or suspected coagulopathy
- CT orbit/face: if penetrating injury, suspected IOFB, or orbital fracture
- Gonioscopy: DEFERRED until 4–6 weeks post-injury — acute gonioscopy risks corneal pressure → clot dislodgement → rebleed
- Ultrasound biomicroscopy (UBM): assess angle recession, cyclodialysis cleft, ciliary body tears (delayed assessment)
- OCT: macular status once hyphaema clears for final visual prognosis assessment
Goal of conservative management: prevent rebleed, control IOP, ensure clot absorption, and prevent corneal staining.
| Measure | Drug/Intervention | Rationale |
|---|---|---|
| Activity restriction | Bed rest with head elevated 30–45° | Gravity settles clot inferiorly; reduces rebleed risk; minimise Valsalva and physical exertion |
| Eye protection | Rigid Fox shield (not patch) | Protects from further trauma; preserves corneal access if examination needed |
| Cycloplegia | Atropine 1% TDS–QID or Cyclopentolate 1% TDS | Reduces iris movement; stabilises blood-aqueous barrier; provides analgesia; prevents synechiae. Note: pilocarpine is contraindicated — increases iris/CB congestion and movement, worsening bleeding |
| Topical steroids | Prednisolone acetate 1% QID | Reduces AC inflammation; decreases PAS formation |
| Antifibrinolytics | Aminocaproic acid (ACA) 50 mg/kg PO every 4 hours for 5 days (max 30 g/day); or Tranexamic acid (TXA) as alternative | Inhibits fibrinolysis; stabilises clot; reduces rebleed rate from ~30% to ~3–5%. ACA side effects: nausea, systemic hypotension. TXA: fewer systemic effects, emerging preferred agent |
| IOP control | Beta-blockers (timolol), alpha-agonists (brimonidine), topical prostaglandins (latanoprost); systemic: mannitol (safe in SCD) — avoid acetazolamide in SCD | Target IOP < 25 mmHg in normal patients; < 24 mmHg in sickle cell disease |
| Analgesic | Paracetamol (acetaminophen) | AVOID aspirin/NSAIDs — platelet dysfunction increases rebleed risk |
Absolute Indications for Surgical Evacuation
- IOP > 35 mmHg unresponsive to maximal medical therapy for > 7 days
- IOP > 60 mmHg for > 48 hours (risk of optic atrophy)
- Grade IV (8-ball) hyphaema with progressive corneal staining
- Corneal blood staining in children (deprivation amblyopia risk; lower threshold)
- Sickle cell disease/trait: IOP > 24 mmHg for > 24 hours despite maximal safe medical therapy
Surgical Options
| Procedure | Indication | Notes |
|---|---|---|
| AC washout (paracentesis/irrigation-aspiration) | Liquid or semi-liquid clot; moderate hyphaema | Simplest approach; side-port incision with gentle aspiration; risk of rebleed if clot adherent |
| Manual clot expression | Organised clot (after 5–7 days) | Side-port incision + gentle hydrodissection; lower rebleed risk if clot well-organised |
| Trabeculectomy / tube surgery | Concurrent angle recession glaucoma or chronic IOP elevation | Addresses both acute hyphaema evacuation and long-term angle dysfunction |
| Tissue plasminogen activator (t-PA) intracameral injection | Organised, adherent clot not amenable to mechanical evacuation | Intracameral 10–25 µg in 0.1 mL; risks rebleed; reserve for cases where mechanical evacuation fails |
- Non-accidental injury (NAI) / child abuse: bilateral hyphaema or hyphaema without clear mechanism warrants safeguarding concern and investigation
- Amblyopia risk: if media opacity persists > 1 week in child < 8 years, urgent surgical evacuation and vigorous optical rehabilitation (glasses/patches) are mandatory
- Lower surgical threshold: consider surgical evacuation at lower IOP levels and smaller hyphaema grades than in adults
- Juvenile xanthogranuloma (JXG): spontaneous hyphaema in infants/young children; look for characteristic skin nodules; self-limited course typical
- Sickle cell screening: mandatory in all at-risk children; use haemoglobin electrophoresis
- Post-clearance optical rehabilitation: vigorous spectacle/contact lens correction + patching as needed to prevent amblyopia
Trap 1 — FALSE
“Pilocarpine is the cycloplegic of choice in hyphaema because it reduces pupil movement.”
Atropine (or cyclopentolate) is the cycloplegic of choice. Pilocarpine is contraindicated because it increases ciliary body congestion, iris movement, and vascular turbulence — worsening bleeding. Atropine provides cycloplegia and reduces iris/CB movement, stabilising the blood-aqueous barrier.
Trap 2 — FALSE
“Aspirin is an appropriate analgesic choice in hyphaema because it provides pain relief without affecting IOP.”
Aspirin is strictly contraindicated. Aspirin inhibits platelet function and dramatically increases the risk of secondary haemorrhage. Paracetamol (acetaminophen) is the analgesic of choice in hyphaema.
Trap 3 — FALSE
“Systemic carbonic anhydrase inhibitors (e.g. acetazolamide) are safe and effective IOP-lowering agents in sickle cell hyphaema.”
Systemic CAIs are contraindicated in sickle cell disease/trait. They cause metabolic acidosis, lowering AC pH and promoting sickling. Even topical CAIs (dorzolamide) may have systemic absorption — should be avoided. Use osmotic agents (mannitol) or other safe agents (beta-blockers, alpha-agonists, prostaglandins) instead.
Trap 4 — FALSE
“Normal IOP in a patient with Grade IV hyphaema indicates low risk of angle-closure glaucoma.”
IOP can be falsely low in hyphaema. Large clot blockade of the trabecular meshwork is offset by ciliary body trauma causing hypotony/shutdown. Do NOT assume normal IOP means absence of glaucoma risk. Continue close IOP monitoring and assess for secondary glaucoma mechanisms (ghost cells, angle recession).
Trap 5 — FALSE
“Gonioscopy should be performed in the acute phase of hyphaema to assess for angle damage.”
Gonioscopy is contraindicated acutely. Any corneal pressure risks dislodging the clot and provoking secondary haemorrhage. Defer gonioscopy to 4–6 weeks post-injury when clot is stabilised, allowing safe assessment of angle recession and long-term glaucoma risk.
Trap 6 — FALSE
“8-ball hyphaema appears as bright red blood filling the entire anterior chamber.”
8-ball hyphaema appears dark (not bright red). The blood trapped without circulation becomes deoxygenated, producing dark haemoglobin — the characteristic dark, deoxygenated appearance giving the name '8-ball.' The darkness reflects hypoxia, not fresh bleeding.
Trap 7 — FALSE
“Tissue plasminogen activator (t-PA) is a safe first-line treatment for organised hyphaema clots.”
t-PA (intracameral 10–25 µg) lyses organised clots but carries significant risk of rebleeding. It is reserved for organised, adherent clots where mechanical evacuation is not feasible or has failed — not a first-line approach.
Q: What is the difference between microhyphaema and Grade I hyphaema?
A: Microhyphaema: RBCs are suspended in the AC and visible on slit-lamp examination, but no visible blood layer forms. Grade I hyphaema: visible blood layer occupies < 1/3 of the AC height on slit-lamp. Microhyphaema carries minimal complication risk; Grade I carries low-moderate risk.
Q: Why is the 2nd–5th day window critical in hyphaema management?
A: Peak fibrinolytic activity in the AC occurs at 48–72 hours. Premature clot dissolution via fibrinolysis exposes torn vessel ends, causing secondary haemorrhage (rebleed) — often larger and more severe than the primary bleed. This rebleed window is the most critical period for vision-threatening complications.
Q: What is ghost cell glaucoma and how does it differ from acute IOP elevation in hyphaema?
A: Ghost cell glaucoma: degenerated RBCs from vitreous haemorrhage enter the AC through a disrupted posterior capsule or zonular defect. These rigid, khaki-coloured cells (vs malleable fresh RBCs) mechanically block the trabecular meshwork, causing refractory open-angle glaucoma confirmed on gonioscopy. Acute IOP elevation in hyphaema results from fresh RBCs and debris acutely blocking the TM.
Q: How does angle recession cause glaucoma?
A: Blunt trauma tears the ciliary body between the circular and longitudinal muscle fibres, producing a deep, irregular angle on gonioscopy. Long-term trabecular meshwork dysfunction (from structural distortion and possible direct TM damage) leads to open-angle glaucoma, often presenting years after the initial injury. Risk is proportional to the extent of recession: > 180° = significant lifetime glaucoma risk (up to 50%).
Q: What is the mechanism and dose of aminocaproic acid (ACA) in hyphaema?
A: ACA is an antifibrinolytic that competitively inhibits plasminogen activators, preventing premature fibrinolysis of the primary clot and reducing secondary haemorrhage (rebleed) from ~30% to ~3–5%. Dose: 50 mg/kg PO every 4 hours for 5 days (maximum 30 g/day). Common side effects: nausea, hypotension. Systemic thrombosis (DVT/PE) is a rare but serious complication requiring cautious use.
Q: Why does sickle cell disease/trait dramatically lower the IOP threshold for optic nerve damage in hyphaema?
A: Sickled cells in the trabecular meshwork are inherently more rigid and hypoxic. Elevated IOP further compromises laminar perfusion pressure in the optic nerve head. The combination of sickling-induced vaso-occlusion and ischaemia at the optic disc — compounded by raised IOP — causes optic nerve damage at much lower pressure thresholds (>24 mmHg for >24 h) than in non-SCD patients (>30 mmHg for >48–72 h). The AC's hypoxic, acidotic environment is ideal for sickling.
A 35-year-old man with known sickle cell trait (HbAS) presents with Grade III traumatic hyphaema following blunt ocular trauma. On Day 3 post-injury, his IOP measures 26 mmHg despite timolol 0.5% and brimonidine 0.2% TID. His visual acuity is 6/60, and clot organisation is progressing. Outline your specific management strategy and identify critical pitfalls to avoid in this case.
Clinical Context & Risk Stratification
In sickle cell trait (HbAS), the anterior chamber is hypoxic, acidotic, and hyperosmolar — an ideal environment for red cell sickling and vaso-occlusion. Although HbAS is 'trait' (not full disease HbSS), it creates clinically significant risk in the hyphaemic eye. Grade III hyphaema on Day 3 places this patient squarely in the peak rebleed window (Days 2–5). IOP of 26 mmHg exceeds the critical 24 mmHg threshold for optic nerve risk in sickle cell, mandating urgent escalation beyond topical therapy.
Specific Management Steps
1. Admit for intensive monitoring: Daily IOP measurement, visual acuity assessment, clot status evaluation (risk of rebleed). 2. Escalate IOP control — add systemic osmotic agent: Mannitol 1–2 g/kg IV (osmotic agent safe in SCD — does not cause metabolic acidosis like CAI). Consider oral hyperosmotic agents if IV not feasible. 3. Continue/optimise topical agents: Maintain timolol and brimonidine; consider adding latanoprost (prostaglandin analogue — safe in SCD). 4. Continue antifibrinolytic therapy: Maintain aminocaproic acid (ACA) 50 mg/kg PO every 4 hours × 5 days total, OR switch to tranexamic acid (TXA) — fewer systemic side effects and equally effective. No contraindication unless active DVT/PE. 5. Maintain strict systemic hydration: Prevent sickling of RBCs in systemic and local circulation; aim for adequate fluid intake. 6. Consider supplemental oxygen: Reduces systemic and local hypoxaemia, reducing sickling. 7. Avoid precipitants of sickling: No fever, avoid dehydration, prevent cold exposure.
Surgical Indications for This Patient
If IOP remains > 24 mmHg despite maximal safe medical therapy for > 24 hours — proceed urgently to surgical evacuation (lower threshold than non-SCD). Options: (a) AC irrigation-aspiration via paracentesis: side-port incision, gentle aspiration of liquid/semi-liquid clot using balanced salt solution irrigation; (b) Anterior vitrectomy with lensectomy if posterior extension; (c) Trabeculectomy if concurrent angle recession glaucoma develops and long-term IOP control anticipated. Choose based on clot status and angle anatomy assessed by gonioscopy (deferred to 4–6 weeks if not urgent).
Critical Pitfalls to Avoid
(a) Acetazolamide: Induces metabolic acidosis — lowers AC pH, promoting sickling in the hypoxic AC. Absolutely contraindicated. (b) Dorzolamide or topical CAI: Even topical agents have systemic absorption; avoid. (c) Aspirin/NSAIDs: Platelet inhibition worsens rebleed risk. Use only paracetamol for analgesia. (d) Epinephrine/adrenaline: Causes vasoconstriction, worsening ischaemia in SCD. Avoid. (e) Delayed gonioscopy acutely: Corneal pressure risks clot dislodgement and rebleed. Defer to 4–6 weeks when clot stabilised. (f) Pilocarpine: Increases iris/CB movement and vascular congestion — worsens bleeding. Use atropine for cycloplegia. (g) Missing rebleed window: Close monitoring Days 2–5; fibrinolytic peak at 48–72 hours. (h) Assuming normal IOP is safe: IOP can be deceptively low despite TM blockade; continue vigilance.
Prognosis & Long-Term Follow-Up
Immediate prognosis: Depends on speed of clot absorption and prevention of corneal blood staining. In sickle cell, aggressive IOP control is essential given the low optic nerve tolerance threshold. Long-term risks: (1) Angle recession glaucoma: Perform gonioscopy at 6 weeks to assess extent of ciliary body tear (recession > 180° = high lifetime glaucoma risk); (2) Chronic IOP elevation: Annual IOP monitoring for life, especially if significant recession documented; (3) Corneal scarring/staining: Risk if IOP elevation prolonged; (4) Amblyopia (if paediatric case): urgent optical rehabilitation. Final visual outcome: Dependent on resolution of hyphaema without corneal staining, absence of optic nerve damage, and success of refractive correction post-clearance.
References
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- Gharaibeh A, Savage HI, Scherer RW, Goldberg MF, Lindsley K. Medical interventions for traumatic hyphaema. Cochrane Database Syst Rev. 2019;1:CD005431.
- American Academy of Ophthalmology. Basic and Clinical Science Course: Section 8 — External Disease and Cornea. AAO; 2022–2023.
- StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Hyphaema. https://www.ncbi.nlm.nih.gov/books/NBK507802/
- MillennialEYE. Corneal Blood Staining. 2017. https://millennialeye.com/articles/2017-mar-apr/corneal-blood-staining/