Identify the mean deviation (MD) value from the visual field (VF) report
Use the corresponding APD/MD conversion table or nomogram for the specific VF test
Match the MD value to the nearest APD value on the table
If using a formula or software, input the MD value to calculate the estimated APD
Confirm the result with the full VF pattern and clinical findings
Note that APD is not directly derived from MD in all VF systems and may require test-specific reference data