Which of the following will cause Bull’s eye retinopathy
**Core Concept**
Bull's eye retinopathy is a characteristic fundoscopic finding associated with chloroquine and hydroxychloroquine toxicity. It is a result of the deposition of the drug in the retinal pigment epithelium, leading to photoreceptor degeneration.
**Why the Correct Answer is Right**
The correct answer is related to the mechanism of chloroquine toxicity. Chloroquine is a weak base that accumulates in the acidic environment of the retinal pigment epithelium, causing damage to the photoreceptors. This leads to the characteristic bull's eye appearance on fundoscopy, with a central zone of atrophy surrounded by a ring of preserved retina. The retinal pigment epithelium is responsible for the phagocytosis of photoreceptor outer segments, and chloroquine toxicity disrupts this process.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because chloroquine toxicity is not primarily associated with this condition. Other drugs like tamoxifen, amiodarone, and phenothiazines can cause retinal toxicity, but not bull's eye retinopathy specifically.
* **Option B:** This option is incorrect because chloroquine toxicity is not primarily associated with this condition. Other conditions like age-related macular degeneration, diabetic retinopathy, and retinal vein occlusions can cause atrophy of the retina, but not bull's eye retinopathy specifically.
* **Option C:** This option is incorrect because chloroquine toxicity is not primarily associated with this condition. Other conditions like central serous chorioretinopathy and retinal detachment can cause fluid accumulation in the retina, but not bull's eye retinopathy specifically.
**Clinical Pearl / High-Yield Fact**
Chloroquine and hydroxychloroquine toxicity can be prevented by regular monitoring of serum drug levels and visual acuity, as well as regular fundoscopic examinations. Patients on long-term therapy should have their eyes examined every 6-12 months.
**Correct Answer:** C. Chloroquine