Bull’s-Eye Maculopathy is a description, not a diagnosis. The concentric ring of parafoveal atrophy around a spared fovea is instantly recognisable, and the reflex is to blame hydroxychloroquine.
But a target-shaped macula has many causes, and several are inherited diseases that no drug review will explain.
For clinicians, recognizing that Bull’s-Eye Maculopathy is a pattern with a broad differential matters because the work-up and the counselling differ completely between a drug toxicity and a cone dystrophy.
The task is not to name the ring, but to find out what made it.
What Is Bull’s-Eye Maculopathy?
Bull’s-Eye Maculopathy is a ring of parafoveal retinal pigment epithelial depigmentation and atrophy that surrounds a relatively spared central fovea, giving a target appearance.
The key points are:
- It is a morphological sign, not a single disease
- The fovea is characteristically spared, at least early
- It reflects loss of the parafoveal photoreceptors and RPE
- Its causes span toxic, hereditary, and degenerative disease
Seeing the ring should trigger a differential, not a diagnosis.
Causes and Differential Diagnosis
The differential is the heart of the topic.
- Hydroxychloroquine and chloroquine toxicity — the classic drug cause, dose- and duration-related
- Cone and cone-rod dystrophy — photophobia, poor colour vision, abnormal cone responses on ERG
- Stargardt disease — flecks and a dark choroid on angiography
- Age-related macular degeneration and central areolar choroidal dystrophy
- Benign concentric annular macular dystrophy
- Systemic and neurodegenerative disease — Bardet–Biedl syndrome and Batten disease
- Other drugs — clofazimine and, rarely, others
Age, drug history, symptoms, and family history are what separate these causes long before any test is ordered.
Fundus Explorer Pro
Photograph the retinal findings described here with the phone already in your pocket — 22 D optics and built-in illumination in one handheld unit.
From Choroida — the team behind this siteWhy the Hydroxychloroquine Reflex Misleads
Attributing every bull’s-eye to hydroxychloroquine causes errors in both directions.
- A young patient with photophobia and poor colour vision is far more likely to have a cone dystrophy than drug toxicity
- Labelling an inherited dystrophy as “drug toxicity” delays genetic diagnosis and counselling
- Conversely, dismissing true early hydroxychloroquine damage misses a chance to stop the drug
The drug history must fit the dose, duration, and imaging before hydroxychloroquine is accepted as the cause.
Diagnostic Evaluation
Multimodal imaging and electrophysiology sort the causes out.
Imaging
- Fundus autofluorescence shows a parafoveal ring of altered autofluorescence
- OCT demonstrates parafoveal loss of the ellipsoid zone and outer retina, with foveal sparing
Functional and Genetic Testing
- Electroretinography distinguishes a generalised cone or cone-rod dystrophy from a localised toxicity
- Genetic testing confirms an inherited dystrophy and guides counselling
- A careful drug and dosing history remains essential throughout
Imaging shows the ring; electrophysiology and genetics reveal why it is there.
Management
Management depends entirely on the underlying cause.
- Drug toxicity — stop or review the offending agent in discussion with the prescriber
- Inherited dystrophies — genetic counselling, low-vision support, and monitoring
- Age-related and degenerative causes — managed on their own pathways
- All patients benefit from documentation and structured follow-up
The correct treatment starts with the correct cause, which is why the differential comes first.
Prognosis
Outcome tracks the underlying disease.
- Early drug toxicity may stabilise once the drug is stopped, though damage can progress
- Inherited dystrophies are typically progressive
- Foveal involvement, whatever the cause, marks a worse visual prognosis
In practice, the value of the bull’s-eye sign is that it forces a search for a specific, sometimes treatable, cause.
Document what you see
Two smartphone imaging tools built for everyday clinic use — one for the slit lamp, one for the fundus.
From Choroida — the team behind this siteReferences
- Marmor MF, Kellner U, Lai TYY, Melles RB, Mieler WF. “Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision).” Ophthalmology. 2016;123(6):1386–1394.
- Kurz-Levin MM, Halfyard AS, Bunce C, et al. “Clinical Variations in Assessment of Bull’s-Eye Maculopathy.” Archives of Ophthalmology. 2002;120(5):567–575.
- Michaelides M, Hardcastle AJ, Hunt DM, Moore AT. “Progressive Cone and Cone-Rod Dystrophies: Phenotypes and Underlying Molecular Genetic Basis.” Survey of Ophthalmology. 2006;51(3):232–258.
- American Academy of Ophthalmology. “Bull’s Eye Maculopathy.” EyeWiki.
Test yourself
A few questions straight from this article.
-
What defines the fundus appearance of bull's-eye maculopathy?
It is a ring of parafoveal retinal pigment epithelial depigmentation and atrophy surrounding a relatively spared fovea, giving the target appearance. -
Bull's-eye maculopathy is best understood as which of the following?
It is a description rather than a diagnosis. Seeing the ring should trigger a differential spanning toxic, hereditary and degenerative disease, not a single conclusion. -
Which classic drug cause of bull's-eye maculopathy is dose- and duration-related?
Hydroxychloroquine and chloroquine toxicity is the classic drug cause, and it is dose- and duration-related, so the drug history must fit before it is accepted as the cause. -
A young patient with photophobia and poor colour vision and a bull's-eye macula most likely has what?
A young patient with photophobia and poor colour vision is far more likely to have a cone dystrophy than drug toxicity, and mislabelling it delays genetic diagnosis and counselling. -
Which cause of bull's-eye maculopathy shows flecks and a dark choroid on angiography?
Stargardt disease is distinguished within the bull's-eye differential by retinal flecks and a dark choroid on angiography. -
What does fundus autofluorescence typically show in bull's-eye maculopathy?
Fundus autofluorescence shows a parafoveal ring of altered autofluorescence, mapping the ring of RPE damage that produces the target appearance. -
What is the characteristic OCT finding in bull's-eye maculopathy?
OCT demonstrates parafoveal loss of the ellipsoid zone and outer retina, with the fovea itself relatively spared. -
Which test distinguishes a generalised cone or cone-rod dystrophy from localised toxicity?
Electroretinography separates a generalised cone or cone-rod dystrophy from a localised toxicity, while genetic testing confirms an inherited dystrophy and guides counselling. -
Besides hydroxychloroquine and chloroquine, which drug is named as a cause of bull's-eye maculopathy?
Clofazimine is listed among the other drug causes of the bull's-eye pattern, alongside the classic antimalarials. -
Which feature marks a worse visual prognosis in bull's-eye maculopathy, whatever the cause?
Foveal involvement marks a worse visual prognosis regardless of cause. Early drug toxicity may stabilise once the drug is stopped, whereas inherited dystrophies are typically progressive.
