Definition

Leukocoria, also known as white pupil or cat's eye, is an abnormal white reflex from the pupil. This condition is often the first sign of various serious eye disorders. Leukocoria is commonly associated with congenital cataracts, Coats' disease, retinoblastoma, retinopathy of prematurity, toxocariasis infection, and other eye disorders. It is particularly concerning in children and requires immediate detection and treatment.

Causes

Leukocoria is caused by an abnormal pupil reflex due to blockage of blood vessels around the retina, which is reflected through the pupil. Several diseases can cause leukocoria, including eye infections such as uveitis, endophthalmitis, and toxocariasis infection, lens opacities like cataracts, persistent hyperplastic primary vitreous (PHPV), retinal disorders such as retinoblastoma, retinal detachment, and retinopathy of prematurity, high myopia, coloboma, Coats' disease, and other internal eye disorders.

Risk Factor

Risk factors for leukocoria include hereditary genetic factors, a family history of diseases related to leukocoria, and a history of premature birth, which can indicate retinopathy of prematurity. Birth trauma, which can cause bleeding in the eyeball, can also be one of the risk factors of leukocoria.

Symptoms

Leukocoria is characterized by a whitish pupillary reflex. The pupil may appear normal in room light but lacks a red reflex on ophthalmoscope examination. The initial sign of leukocoria is often recognized by family members as cat's eyes or through light flashes in photographs.

Diagnosis

Diagnosis of leukocoria involves a comprehensive evaluation, including in-depth interviews regarding symptoms, past medical history, birth history, and family history. Subsequently, eye physical examination includes checking pupillary reflexes, slit lamp examination, ophthalmoscopy, ultrasonography, and other relevant tests.

Pupillary reflex examination is conducted in a dark room using an ophthalmoscope. When light is projected into the eye, a normal red reflex should appear from both eyes symmetrically. The reflex is considered abnormal if it is reduced, white, has dark spots, or shows asymmetry (Bruckner's reflex).

If the results of the eye reflex examination are not certain, eye drops for pupils can be given first before examination. The color of pupillary reflexes can also be a characteristic of a disease such as retinoblastoma characterized by vaginal discharge reflexes, in congenital cataracts are characterized by bluish ash reflexes, in Coats disease and retinal exfoliation characterized by yellow reflexes.

Ultrasonography is recommended for all patients with leukocoria to detect intraocular calcification (90%), particularly in retinoblastoma. Retinoblastoma is seen as a solid mass in the retina with the ability to reflect it high due to calcification.

Optical Coherence Tomography (OCT) is a non-invasive test to assess fluid, swelling, or fibrosis at the back of the eye. CT scans are generally avoided in children due to radiation exposure but useful if intraocular calcification is uncertain. MRI is the preferred diagnostic tool for detecting intracranial spread of retinoblastoma and other secondary tumors.

Blood tests can be used to detect TORCH infections (Toxoplasma gondii, Rubella, CMV, Herpes simplex virus). Genetic tests aid in diagnosing retinoblastoma, Coats' disease, and other genetic conditions.

Management

Leukocoria is a sign of underlying eye disease, so its management depends on the disease causing the symptoms. For retinoblastoma, treatment options include:

• Enucleation: This surgical procedure involves the removal of the entire eyeball, sometimes including the conjunctiva, particularly for blind and painful eyes. Part of the optic nerve is also excised to prevent intracranial spread.
• Chemoreduction: This therapy aims to reduce the size of the tumor.
• Thermotherapy: Heat from infrared rays is used to induce tumor cell death, with temperatures ranging from 40°C to 60°C.
• Cryotherapy: This treatment freezes and destroys the tumor cell layer.
• Laser Photocoagulation: This therapy uses heat energy from laser rays to produce scars that limit the tumor's blood supply. It is particularly useful for large tumors that have undergone chemoreduction.
• Radiotherapy: This important modality is used for tumors that have shrunk due to chemoreduction or reappeared after chemotherapy.

Other than retinoblastoma leukocoria can also be caused by other conditions. In Coats' disease, it is managed with laser or cryotherapy to remove retinal fluid. For leukocoria caused by cataracts, surgical procedures can be a treatment option. Surgery performed between ages 2 to 6 months can yield good results.

In toxocariasis infection, corticosteroids are the main treatment to control inflammation, often accompanied by anti-worm therapy. In retinopathy of prematurity, the condition is managed with observation, retinal laser, cryotherapy, and retinal surgery. Immature retinal blood vessels are observed and repeatedly evaluated.

Complications

Complications of leukocoria vary with the underlying diagnosis. For retinoblastoma, the possible complications include tumor invasion into the sclera and choroid, metastasis, and death. For uveitis or eye infections in children, complications include amblyopia (lazy eye), cataracts, glaucoma, and cystoid macular edema. Complications of cataracts and cataract surgery include amblyopia, anisometropia, capsular opacification, secondary glaucoma, uveitis, postoperative endophthalmitis, and retinal detachment. Complications that often occur from thermotherapy include iris atrophy, paraxial lens opacities, and retinal detachment.

Prevention

Increasing knowledge and awareness of leukocoria is crucial for early diagnosis and treatment. Children with a family history of retinoblastoma, premature birth, and a history of TORCH infections need close monitoring and periodic evaluations to detect abnormalities early.

When to See a Doctor?

Seek immediate medical attention if your child exhibits white spots on the black part of the eyes, inability to see properly, white light in the eyes when photographed, resembling cat eyes, and difficulty with daily activities (e.g., watching TV too close, frequent falls, or bumping into objects). Early consultation with an ophthalmologist is essential for prompt diagnosis and management.

Looking for more information about other diseases? Click here!