A psychiatric patient on regular treatment had his routine check-up. His fundus shows the below finding. The most probable drug implicated is ( Pigmented retinal epithelium)
**Core Concept**
The question is testing the association between the use of certain psychiatric medications and their side effects on the retina, specifically the pigmented retinal epithelium. This is a classic example of a pharmacological interaction between a drug and its effects on ocular structures.
**Why the Correct Answer is Right**
The pigmented retinal epithelium is a layer of cells in the retina responsible for phagocytosing shed photoreceptor outer segments. Certain medications, particularly those with anticholinergic properties, can cause a condition known as retinal pigment epithelial changes or retinal pigment epithelium changes. This can lead to the accumulation of lipofuscin, a pigment that can cause the retinal epithelium to appear pigmented on examination. In psychiatric patients, medications like chlorpromazine, perphenazine, and others with antipsychotic properties can cause these changes.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a medication that is known to cause retinal pigment epithelium changes. While some medications may have similar side effects, they are not as commonly associated with this specific change.
**Option B:** This option is incorrect because it does not mention a medication that is known to cause retinal pigment epithelium changes. This option may be a distractor to test the student's knowledge of other medications that can cause ocular side effects.
**Option C:** This option is incorrect because it does not specify a medication that is known to cause retinal pigment epithelium changes. This option may be a distractor to test the student's knowledge of other medications that can cause ocular side effects.
**Clinical Pearl / High-Yield Fact**
It is essential for clinicians to be aware of the ocular side effects of psychiatric medications, including retinal pigment epithelium changes, and to monitor patients regularly for these changes. This can help prevent long-term vision loss and other complications.
**Correct Answer:** C. Chlorpromazine