TL;DR: Blood inside the eye (hyphema) is a high-priority emergency that requires immediate veterinary attention to prevent permanent blindness. It is often a sign of serious underlying conditions like trauma, high blood pressure, or clotting disorders.
What does it mean if my pet has blood inside the eye chamber?
Blood inside the front chamber of the eye is medically referred to as hyphema. This condition occurs when blood vessels within the eye—typically from the iris or ciliary body—rupture and leak fluid into the space between the clear cornea and the lens. It may appear as a small pool of red at the bottom of the eye, a cloudy red haze, or in severe cases, the entire eye may look dark red or black.
Is blood in my pet's eye a veterinary emergency?
- The urgency level for blood in the eye is high, as it is a clinical sign of serious underlying issues like blunt force trauma, high blood pressure, or tumors.
- If not treated immediately, the blood can block the eye's drainage system.
- This blockage leads to secondary glaucoma, a painful spike in eye pressure that can cause permanent blindness within hours.
How does taking a photo of my dog's eye help with emergency triage?
- A photo allows a triage technician to assess the volume of blood in the eye chamber.
- It helps the veterinary team check for signs of external trauma or puncture wounds.
- Technicians can observe the pupil's shape to better understand the extent of the injury.
- This visual information helps the clinic prepare for your arrival and determines how quickly your dog needs to be moved to the front of the line.
Clinical Context (Merck Veterinary Manual)
Hyphema, or hemorrhage in the anterior chamber of the eye, can manifest as small, focal blood clots, diffuse hemorrhage occluding deeper examination, or multiple layers of hemorrhage with older blood appearing purple/black and recent blood appearing bright red. Causes include uveitis, trauma, intraocular neoplasia, retinal detachments and tears, systemic hypertension, coagulation factor abnormalities, platelet disorders, hyperviscosity, congenital ocular anomalies, anterior segment neovascularization, and glaucoma. Acute hyphema generally has a good prognosis if the underlying cause is identified and treated, whereas recurrent or chronic hyphema carries a poor to guarded prognosis due to the risk of secondary glaucoma or phthisis bulbi. Intracameral tissue-plasminogen activator (TPA) can dissolve fibrin less than 10-14 days old and release entrapped red blood cells, but does not prevent future fibrin formation; topical and systemic corticosteroids may be beneficial.
Chapter: Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 497)