Leukocoria: A Differential
Last updated: October 2026
Leukocoria — a white pupillary reflex instead of the normal red reflex — is a sign, not a diagnosis, but it's the sign no ophthalmologist can afford to be casual about, since retinoblastoma sits at the top of every differential list until excluded.
Why the urgency
Retinoblastoma is diagnosed in roughly 47% of children referred with leukocoria to tertiary centres, and leukocoria is the presenting sign in the majority (32-73%) of retinoblastoma cases — but it's a sign shared by many other conditions, several of which are also vision- or life-threatening in their own right.
The core differential
| Cause | Distinguishing clue |
|---|---|
| Retinoblastoma | Calcification on ultrasound (seen in ~90% of cases) — highly specific; elevated mass on fundus exam; may have associated strabismus |
| Congenital cataract | Opacity visible in the lens itself on slit lamp exam, anterior to the retina — no mass behind it |
| Persistent fetal vasculature (PFV/PHPV) | Usually unilateral, microphthalmic eye, retrolental fibrovascular stalk visible, often with an elongated ciliary process ("dragging") |
| Coats disease | Telangiectatic retinal vessels with subretinal lipid exudation, typically unilateral, boys affected more often, no calcification on ultrasound (a key point distinguishing it from retinoblastoma) |
| Retinopathy of prematurity (stage 4-5) | History of prematurity is the key clue — see our ROP page |
| Retinal detachment (other causes) | Thorough fundus exam for a mass lesion or seeds to differentiate from retinoblastoma-associated detachment |
| Toxocariasis / other posterior inflammation | History of pica or geophagia, exposure to puppies; inflammatory signs, granuloma |
| Uveal coloboma | Sharply demarcated, glistening white, bowl-shaped excavation — no elevated mass, distinguishing it from tumour |
| Familial exudative vitreoretinopathy (FEVR) | Peripheral avascular retina, often bilateral, family history — genetically distinct from ROP but can look similar |
| Simple asymmetric refractive error / strabismus | Can produce an asymmetric red reflex (Bruckner test) without true leukocoria — always worth ruling out as a benign mimic before extensive workup |
Practical workup sequence
- Ocular ultrasound (B-scan) in every case — inexpensive, non-invasive, and highly specific for detecting the calcifications characteristic of retinoblastoma
- Dilated fundus exam under anaesthesia if needed, given the exam demands in an infant
- MRI (avoid CT where possible, to limit radiation exposure in a child with a possible heritable cancer predisposition) to assess for optic nerve or intracranial extension if retinoblastoma is confirmed or strongly suspected — see our Retinoblastoma Genetics page for what happens next if confirmed
- Biopsy is not performed for suspected retinoblastoma — the risk of extraocular tumour seeding makes this contraindicated; diagnosis relies entirely on clinical exam and imaging
A practical real-world detection tip
A substantial proportion of retinoblastoma cases (up to 80% in one study) are first noticed by parents in recreational flash photographs, where the tumour produces a white reflex instead of the normal "red-eye" — worth mentioning to families as something to watch for, since this often prompts presentation earlier than a routine well-child exam might catch it.
2026 update: how retinoblastoma is treated now
| Approach | What to know |
|---|---|
| Grouping | International Intraocular Retinoblastoma Classification (IIRC, groups A–E) guides treatment: see gradings page |
| Intravenous chemoreduction | Vincristine, etoposide and carboplatin with focal laser or cryotherapy; standard for bilateral disease |
| Intra-arterial chemotherapy | Melphalan delivered through the ophthalmic artery; high globe salvage for group C–D eyes and many group E eyes |
| Intravitreal and intracameral chemotherapy | Melphalan or topotecan for vitreous and aqueous seeds |
| Enucleation | Still curative for advanced unilateral disease; examine the optic nerve and choroid for high-risk features |
| Survival | Over 95% in high-income countries but far lower in many low-income countries, mostly from late presentation |
Sources for this update: Abramson DH, et al. Ophthalmic artery chemosurgery for retinoblastoma. Ophthalmology. 2016;123:1505-1512 | Global Retinoblastoma Study Group. Global retinoblastoma presentation and analysis by national income level. JAMA Oncol. 2020;6:685-695.
Revise with flip cards
Key references: A Stepwise Approach to Leukocoria, AAO EyeNet. | Educational Case: Retinoblastoma. 2025. | Moran CORE: Leukocoria in Children.
📘 Want the exam-ready deep dive? This topic, and much more is covered in Ophthalmology Explorer (A High-Yield Clinical Reference for Ophthalmology Residents, Fellows & Board Exams) — available on Kindle. See all my books.
Want to know more about treatment? Read about Paediatric Eye Checkup at Sadbhaav or book a consultation with Dr. Dhaval Patel.