Squinting (Blepharospasm) in Cats

Key Takeaways

Blepharospasm is a term that describes repeated, spasmodic movement of the eyelids, commonly referred to as squinting. 

• Blepharospasm is a broad symptom that is seen as a feature of different underlying diseases in cats, including injury, infection, inflammation, and developmental abnormalities

• Cats with blepharospasm present with significant, recurrent closure of one or both eyes

• While all cats blink or squint occasionally, particularly in bright light, true blepharospasm is an obvious, persistent abnormality

• In many cases cats keep the eyelids of the affected eye completely shut

• Investigation involves physical and ophthalmic examination

• Treatment depends on the underlying disease process but often includes topical eye drops or medications such as anti inflammatories, pain relief, steroids, antibiotics, and eye lubricants

• Prognosis varies; most cases resolve with treatment, but some underlying conditions result in severe disease and loss of the eye

A Closer Look: What is Squinting in Cats?

Blepharospasm is a common presentation in cats that normally indicates pain in or around the eye. Severe blepharospasm makes examination of the eye difficult and sometimes conceals severe underlying injury.

Triggers of blepharospasm are rarely life-threatening but are usually painful and require prompt veterinary attention to avoid further damage to the eye and potential blindness.

Possible Causes

Blepharospasm has a variety of underlying diseases processes, including:

Infections, including

• Bacterial conjunctivitis

• Chlamydia

• Calicivirus

Inflammation, such as

• Uveitis

• Allergic conjunctivitis

• Insect bite hypersensitivity

Injuries, such as a foreign body or damage from a cat fight.

Immune-mediated triggers, including self-trauma due to allergies and itchiness.

Developmental conditions, such as

• Entropion

• Ectopic cilia

• Eyelid colobomas

• Cherry eye

Risk Factors

The severity of blepharospasm varies significantly depending on the severity of the underlying trigger.

Mild disease such as allergic conjunctivitis results in mild symptoms, and sometimes resolves without intervention. Injuries, such as a penetrating foreign body to the eye, results in severe pain and persistent blepharospasm.

Blepharospasm may affect one or both eyes. Injuries normally affect one eye, whereas blepharospasm of both eyes often indicates infections such as calicivirus.

Testing and Diagnosis

Investigation of blepharospasm involves:

• Physical examination

• Ophthalmic examination, often under sedation for a full examination, and includes fluorescein staining, measurement of intraocular pressure, and measurement of tear production

• Bloodwork

• Testing  for specific bacteria or viruses

Treatment options vary depending on the underlying disease. Medications may be topical or systemic. Common options include:

• Antibiotics • Steroids • Pain relief

• Anti-inflammatories • Lubricants

In addition, treatment may include wound management and surgery. In severe cases, surgical removal of the eye may be necessary.

Similar symptoms

Symptoms that are sometimes mistaken for blepharospasm include:

• Cherry eye (elevated third eyelid)

• Enophthalmos - retraction of the eyeball

Associated Symptoms

Other symptoms common seen alongside blepharospasm include:

• Itchiness of the eye

• Redness of the eyes or eyelids

• Epiphora - excessive discharge from the eyes

• Swollen eyelids