Loa Loa Worm in Eye: Symptoms and Treatment

If you are feeling the distinct, highly distressing sensation of a worm moving across your eye, it is likely because an adult Loa loa worm is migrating beneath the surface ^[1]. This phenomenon, often called the “African eye worm,” happens when the adult parasite (transmitted by deer fly bites in West and Central Africa) travels through the subconjunctival space—the tissue just under the clear membrane that covers the white part of your eye ^[2].

What To Do Right Now
If you currently see or feel the worm, follow these immediate steps:

• Do not touch or rub your eye, and never attempt to remove it yourself. Digging at the eye with tweezers or your fingers can cause severe injury or vision damage.
• Take a close-up photo or video of your eye. The worm moves quickly. If it disappears before you see a doctor, having visual proof is incredibly helpful for an accurate diagnosis ^[1].
• Go to an ophthalmologist (eye specialist) or the emergency room. They have the tools to safely and immediately remove the worm while it is visible.

What Else You Might Experience

The physical movement of the Loa loa worm is alarming, but the symptoms are generally temporary. You may experience:

• A severe foreign body sensation (the feeling that something is stuck in your eye) ^[3]
• Acute eye pain, redness, and irritation ^[2]
• Occasional floaters or temporary visual blurring ^[3]
• The visible appearance of a wriggling, thread-like worm crossing the white of the eye ^[1]

Note: You might also notice sudden, itchy, non-painful swellings on your arms or legs. These are called “Calabar swellings” and are a very common, normal symptom of a Loa loa infection.

Will This Cause Permanent Eye Damage?

While it is extremely unsettling to see and feel a worm in your eye, the Loa loa worm usually does not cause permanent eye damage or blindness ^[4].

It is important to distinguish Loa loa (loiasis) from another type of filariasis known as Onchocerca volvulus (which causes “river blindness”). River blindness causes progressive, chronic damage to the cornea and retina through a severe inflammatory response ^[5]. In contrast, the ocular symptoms of Loa loa are primarily caused by the mechanical movement of the adult worm ^[6].

What happens if the worm moves away before the doctor sees it?
Do not panic. If the worm leaves your eye, it is simply migrating back into the soft tissues under your skin. It cannot burrow deeper into the interior of your eyeball, nor does it travel into your brain. Once the worm moves out of the eye, the eye typically recovers fully without lasting vision loss ^[1].

(Note: While very high levels of microscopic young worms in the blood can occasionally cause changes to the retina, severe eye damage from Loa loa is not the norm ^[5][7].)

How Is It Treated?

Treating Loa loa requires a two-step approach: addressing the adult worm in the eye and clearing the remaining infection from your body.

1. Immediate Relief: Surgical Removal
If the worm is visible, the standard and most effective intervention is surgical extraction ^[1]. An ophthalmologist will numb your eye with local anesthetic drops and carefully make a small incision to pull the adult worm out ^[2]. This outpatient procedure provides immediate relief from the pain ^[1]. Doctors may also prescribe corticosteroid eye drops afterward to calm any lingering inflammation ^[1].

2. Treating the Underlying Infection: Medication
Removing the worm from your eye does not cure the infection, as there are likely microscopic young worms (microfilariae) in your blood.

Crucial Warning: Before starting any medication to kill Loa loa, your doctor must perform a blood test to measure your microfilarial load (the amount of young worms currently in your bloodstream) ^[8].

• Rapid die-off risk: If your worm count is high, taking rapid-acting parasite medications like diethylcarbamazine (DEC) can cause the worms to die off too quickly. This can trigger a severe, potentially life-threatening complication called encephalopathy (brain inflammation) ^[9][10].
• Safe reduction: If your blood test shows a very high worm count, your medical team may first use a medication called albendazole, which reduces the worm count much more slowly and safely ^[11][12]. They may also perform a procedure called apheresis (filtering the blood to physically remove the worms) before using stronger medications ^[13].

Always ensure your healthcare provider is experienced in treating tropical diseases and has checked your blood levels before prescribing medication for loiasis.