In automated perimetry using the Humphrey Field Analyzer, which global index MOST specifically reflects the pattern (non-uniform spatial distribution) of visual field loss, with relative insensitivity to diffuse depression?

• A Mean deviation (MD)
• B Visual field index (VFI)
• C Short-term fluctuation (SF)
• D Pattern standard deviation (PSD) ✓

Explanation

Pattern standard deviation (PSD) measures point-to-point variation in sensitivity after correcting for any overall elevation or depression, making it ideal for detecting focal or localised glaucomatous defects independent of diffuse media opacity. Mean deviation reflects overall sensitivity loss regardless of pattern. VFI is a percentage weighted toward the central field used for progression rate calculations. Short-term fluctuation estimates intra-test variability.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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