Hyphema in Cats: Symptoms and Treatment

What Is Hyphema in Cats?

Hyphema in cats is when blood collects in the front of the eye. The eye is a complex organ with multiple connected and highly detailed parts that work together to let a cat see.  

Inside and surrounding the eye are many blood vessels that bring oxygen and nutrients to the eye.  

When these vessels, specifically the retinal and/or uveal blood vessels, are damaged, blood spills into the anterior chamber, leading to hyphema. 

Hyphema may not always be a medical emergency, but it should always be treated as such because it is often caused by things like trauma, cancer, or clotting dysfunction and it can result in loss of vision.  

Symptoms of Hyphema in Cats

The most obvious symptom of hyphema in cats is a red eye.  

The degree of redness can vary, and it may show as a clot, settling of blood (redness) in the bottom half of the eye, or a general red/bloody eye.  

Additionally, along with hyphema, you may notice:  

• Miosis (constricted, small pupil) 

• Bluish haze to the cornea (edema) 

• Inflamed conjunctiva (swollen membrane on eye and inner eyelids) 

• Squinting or pawing at the eyes 

• Swelling of the eye globe (buphthalmos) 

• Blindness 

• Hypopyon (inflammatory cells in the eye), often appears as a white opacity in the eye 

• Signs of bleeding elsewhere in the body (i.e., melena, vomiting blood, bruising, or pin-point hemorrhages called petechiae) 

Causes of Hyphema in Cats

Anything that causes damage to the blood vessels within the eyes can lead to hyphema.  

The most common cause is trauma such as blunt force trauma, or a penetrating eye injury likely suffered from an animal attack.  

Other causes include: 

• Uveitis 

• Vasculitis such as that caused by tick-borne disease, toxoplasmosis, or FIP 

• Hypertension (high blood pressure), either primary or secondary (attributed to kidney disease) 

• Tumors 

• Clotting issues or coagulopathy, like those caused by rodenticide toxicity 

• Glaucoma 

• Immune-mediated disease 

• Endocrine disease, such as diabetes or hyperthyroidism  

• Secondary to lens luxation or retinal detachment 

• Post-spay complications (typically mild and temporary) 

How Veterinarians Diagnose Hyphema in Cats

It’s easy to diagnose hyphema with a routine physical examination, but figuring out the underlying cause is, unfortunately, not as straightforward.  

A thorough ophthalmic (eye) examination is needed, with particular attention on eye reflexes; vision assessment; and evaluation of eye pressures (tonometry), corneal ulceration (fluorescein eye stain), and tear production (Schirmer tear test).  

More diagnostics your veterinarian will most likely want to do include: 

• Blood work and urinalysis noting irregularities with kidney and liver values 

• Thyroid profile 

• Blood pressure measurement 

• Tick titers or PCR testing for infectious disease 

• FeLV, FIV, and heartworm testing 

• Clotting profile (PT/PTT) in cases of suspected poisoning or clotting deficiencies 

• Ocular ultrasound to check on the state of the retina, presence of tumor, or lens luxation 

Upon scheduling your veterinary appointment, please bring all prior medical histories including recent travel history, current and past parasite control, and any medications your cat is currently taking.  

Treatment of Hyphema in Cats

Treatment for hyphema is twofold: therapy to treat the underlying cause (such as surgery, chemotherapy, antibiotics, or blood transfusion) and therapy directed at the eye itself to lower pain and inflammation (swelling).  

In complicated cases, referral to an ophthalmologist may be needed. 

Anti-inflammatory eye drops, such as flurbiprofen or diclofenac, or steroids like prednisolone acetate are helpful to control the secondary swelling as well as prevent the bleed from getting worse.  

Additionally, atropine eye drops help dilate the eye to reduce pain. For some cats, an injection into the eye with TPA (tissue plasminogen activator) can be done to help break up the clot. 

Pain medications and systemic steroids or NSAIDs, like Onsior, may also be given.  

Cats who develop glaucoma or other conditions as a complication of hyphema require lifelong medication.  

In severe cases, enucleation (removal) of the eye may be needed.  

Recovery and Management of Hyphema in Cats

The overall outlook for cats with hyphema varies and is often related to the underlying disease. But the outlook is generally good if you get early and aggressive treatment for it, especially to save the cat’s vision. 

Full recovery may take several weeks if uncomplicated.  

Recurrent or chronic hyphema carries a worse outlook as secondary glaucoma and phthisis bulbi (shrinkage of the globe) or cataract formation and posterior synechiae (the iris sticking to the lens) may happen.  

Prevention of Hyphema in Cats

Unfortunately, not all causes of hyphema can be prevented. There are, however, a few recommendations that can decrease your cat’s likelihood of getting the condition: 

• Routine physical examinations, including blood work screening for infectious disease and endocrine disease 

• Routine deworming and heartworm prevention 

• Keeping your cat indoors away from wildlife and potential trauma like motor vehicle accidents and animal attacks