A pinhole test is performed on a patient with unaided visual acuity of 6/60. Vision improves to 6/9 through the pinhole. This finding indicates that the cause of visual impairment is most likely:
- A Macular pathology
- B Corneal opacity
- C A refractive error ✓
- D Optic neuritis
Correct answer: C. A refractive error
Explanation
C pinhole occluder improves visual acuity in refractive errors by allowing only central light rays to reach the retina, reducing the blur circle. If vision improves with a pinhole, the cause is optical/refractive rather than pathological. Corneal opacity, macular disease, and optic neuritis typically do not improve with a pinhole because the pathology is in the media or neural pathway.
Reference: AAO BCSC Section 3: Clinical Optics, 2023-2024 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.