A 62-year-old man with primary open-angle glaucoma has a vertical cup-to-disc ratio of 0.8 in the right eye and 0.5 in the left eye. This inter-eye asymmetry of 0.3 is considered significant because it suggests glaucomatous damage. What is the minimum inter-eye cup-to-disc asymmetry that is generally considered clinically significant for glaucoma suspicion?
- A 0.1
- B 0.2 ✓
- C 0.3
- D 0.4
Correct answer: B. 0.2
Explanation
A cup-to-disc ratio asymmetry of 0.2 or greater between the two eyes is considered clinically significant and warrants further evaluation for glaucoma. Asymmetry of 0.1 can be physiological. The threshold of 0.2 is consistently cited in standard ophthalmology texts and forms a key screening criterion in POAG suspects.
Reference: The Glaucoma Book: A Practical, Evidence-Based Approach to Patient Care, 2010 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.