Cloudy Eye (Corneal Edema) in Horses

Key Takeaways

Cloudy eye, also called corneal edema, describes an opacification of the eye which makes the outer surface of the eyeball appear gray, white, or blueish instead of clear.

• Eye cloudiness in horses is a common symptom of various eye disorders or diseases, including infection, injury, inflammation, glaucoma, or tumors

• Corneal edema is often seen with other symptoms such as squinting, eye discharge, and visible signs of discomfort

• The color or size of the cloudy area may vary, but this does not necessarily reflect severity of the underlying condition

• Diagnosis involves a thorough eye examination and fluorescein staining

• Further diagnostics involving cultures and biopsies may be required

• Treatment varies based on diagnosis and may include anti-inflammatories, antibiotics, antimicrobials, topical steroids or removal of the affected eye

• In some cases, monitoring for further progression is all that is required

A Closer Look: What is Cloudy Eye in Horses?

When any cloudiness is observed in the eye of a horse, prompt veterinary care is important, especially if accompanied by signs of pain. Quick diagnosis and initiation of treatment is paramount to ensure there is no further damage to the eye.

Both the area of cloudiness in the eye, and color of the cloudiness itself may vary based on the condition. 

For example, an ulcer may present with a small cloudy area, whereas glaucoma may cause cloudiness of the entire eye.

While cloudiness is often white or gray in color, a blue hue may also be observed.

Possible Causes

Cloudiness is observed in a wide variety of conditions involving the eye, including:

• Ulcers

• Lacerations

• Abscesses

• Punctures

• Glaucoma

• Fibrosis (scarring)

• Keratitis (inflammation of the cornea)

• Fungal, bacterial, or parasitic infections of the eye

• Tumors

• Equine Recurrent Uveitis

• Corneal Mineralization

• Cataracts

Risk Factors

Cloudy eyes are secondary to almost all eye conditions seen in horses, and is therefore a common symptom. It is important to note that the amount of cloudiness observed does not necessarily reflect on the severity of the underlying condition.

Testing and Diagnosis

Diagnosing the cause of cloudy eyes begins with a patient history and thorough ophthalmic examination including fluorescein staining. 

Most eye conditions can be diagnosed with careful examination of the eye, however further testing may include:

• Eye pressure testing

• Fungal or bacterial culture

• Biopsy

Treatment depends on diagnosis of the condition, and may include:

• Anti-inflammatories

• Immune-mediated medication

• Antibiotics or antimicrobials

• Steroid eye drops

• Enucleation (removal of the eye)

• Debridement

• Other eye-sparing surgeries of the eye

With conditions such as scarring, cataracts and mild keratopathies (conditions affecting the cornea), treatment may not be necessary and instead, monitoring for further changes is warranted.

Similar symptoms

There are no other symptoms that can be mistaken for cloudiness, however it is important to visualize the cloudiness in good light to ensure it is not just a light artifact.

Associated Symptoms

Cloudy eyes are often observed with squinting, excessive tearing (epiphora), restlessness, or agitated head movements.