Leukocoria

A white pupillary reflex (white pupil) observed when light shines through the pupil in place of the normal red reflex. It is a sign, not a diagnosis, and every case needs urgent evaluation because retinoblastoma is potentially lethal.

• Causes in children:
  • Retinoblastoma (the most important malignant cause of a white pupil), usually before age 5.
  • Congenital and developmental cataract.
  • Persistent fetal vasculature (persistent hyperplastic primary vitreous).
  • Retinopathy of prematurity in preterm infants with retinal detachment.
  • Coats disease (exudative telangiectasia, usually boys aged 6 to 8 years, unilateral).
  • Ocular toxocariasis (granuloma, history of exposure to puppies or soil).
  • Retinal detachment, familial exudative vitreoretinopathy, Norrie disease, incontinentia pigmenti, retinal dysplasia.
  • Coloboma of the retina or optic disc, myelinated nerve fibres, vitreous haemorrhage, endophthalmitis, uveitis (pars planitis), and intraocular tumours (astrocytic hamartoma, medulloepithelioma).
• Adults rarely present with leukocoria; mature cataract or organised vitreous haemorrhage can cause it.

• White or yellow reflex seen in flash photographs (absence of red eye effect in one eye), by parents or the paediatrician; strabismus (second most common sign of retinoblastoma), poor vision or fixation, red painful eye, hyphaema, pseudohypopyon, glaucoma, orbital cellulitis like presentation.
• Cataract: lens opacity with a visible white lens; microphthalmos, nystagmus; bilateral cataract has metabolic and genetic causes.
• Persistent fetal vasculature: microphthalmos, shallow chamber, retrolental white mass and stalk, elongated ciliary processes.
• Coats disease: yellow subretinal exudate, telangiectatic vessels with "light bulb" aneurysms.
• Retinoblastoma: creamy white mass, calcification, vitreous seeding, enlarged feeder vessels, familial history, hereditary form often bilateral and multifocal.
• Toxocara: peripheral granuloma or posterior pole mass with a vitreous band, mild uveitis, eosinophilia in some.
• Retinopathy of prematurity: preterm birth, ridge, fibrovascular proliferation, traction detachment.

• Red reflex test and Bruckner test; examination under anaesthesia if not cooperative with full dilation (cyclopentolate 1 percent plus phenylephrine 2.5 percent), indirect ophthalmoscopy with scleral depression, slit lamp, intraocular pressure and axial length.
• B-scan ultrasound (calcification suggests retinoblastoma; cataract, persistent vasculature, retinal detachment, mass lesions identified); A-scan for axial length.
• MRI brain and orbits with contrast and fat suppression for retinoblastoma (assess optic nerve invasion, pineal tumour in trilateral disease); avoid CT in children because of radiation and increased secondary tumour risk in germline cases.
• Fluorescein angiography in Coats disease and familial exudative vitreoretinopathy; wide field imaging (RetCam).
• Do not biopsy or needle an intraocular mass when retinoblastoma is possible (risk of tumour spread).
• Blood tests: full count, genetic testing (RB1 mutation in blood), Toxocara serology (ELISA, titre), TORCH screen, galactose and metabolic screen in bilateral cataract, urinalysis, family examination (parents' fundus for regressed retinoma).

• Retinoblastoma: refer within 24 to 48 hours to a specialised centre; treatment depends on stage: intravenous chemoreduction (vincristine 0.05 mg/kg, etoposide 5 mg/kg and carboplatin 18.6 mg/kg or 560 mg/m2, for 6 cycles every 3 to 4 weeks), intra arterial melphalan (0.4 to 0.5 mg/kg), intravitreal melphalan (20 to 30 micrograms) for seeds, focal therapy (laser thermotherapy, cryotherapy, plaque brachytherapy), enucleation for advanced disease (with a long optic nerve section, at least 10 mm), adjuvant chemotherapy for high risk histology, and genetic counselling; screen siblings and offspring by examination under anaesthesia from birth.
• Congenital cataract: surgery (lens aspiration with posterior capsulorhexis and anterior vitrectomy) within 6 weeks for unilateral visual axis opacities and within 8 weeks for bilateral; aphakic contact lens or primary intraocular lens, amblyopia treatment.
• Persistent fetal vasculature: lensectomy and vitrectomy early to preserve vision in anterior or mixed types, amblyopia therapy; posterior forms carry a guarded prognosis.
• Coats disease: laser photocoagulation or cryotherapy to leaking vessels, intravitreal anti-VEGF (bevacizumab 0.625 mg or ranibizumab 0.1 mg), steroid injections, vitrectomy for detachment.
• Ocular toxocariasis: oral prednisolone 1 mg/kg daily with taper over 4 to 6 weeks, periocular triamcinolone, albendazole 400 mg twice daily (children 15 mg/kg/day) for 5 to 14 days; vitrectomy for traction.
• Retinopathy of prematurity: laser photocoagulation or intravitreal anti-VEGF for treatment requiring disease; vitrectomy for detachment.
• Reassure parents about prognosis and need for regular follow up; amblyopia and glasses as needed.