A 55-year-old man with well-controlled primary open-angle glaucoma on timolol shows progressive visual field loss on serial Humphrey perimetry despite an IOP of 14 mmHg. Which structural finding on OCT of the optic nerve head would best correlate with this progression?
- A Thinning of the retinal nerve fibre layer (RNFL) in the inferotemporal sector ✓
- B Increased central corneal thickness
- C Increased cup-to-disc ratio in the horizontal meridian only
- D Thickening of the macula on OCT
Correct answer: A. Thinning of the retinal nerve fibre layer (RNFL) in the inferotemporal sector
Explanation
In glaucoma, retinal ganglion cell axons are lost preferentially in the superior and inferior arcuate bundles. OCT-measured RNFL thinning, especially in the inferotemporal sector (which corresponds to the superior arcuate field), precedes detectable visual field changes by years and is the most sensitive structural marker of progressive glaucomatous damage. Structural OCT changes typically precede functional perimetric changes in early-to-moderate glaucoma.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.