Loop macro until empty row

Hello!
I have begun a macro that cuts data from the first cell in even numbered rows(beginning on row four), and pastes it into a new column on the end. I would like to be able to loop this process until two consecutive empty rows.
I am new to this, and would be very thankful for helpful suggestions!

Sub CommentMove()

'
' CommentMove Macro
'
'    Move Comments to Column T one row up
'
   
 Range("T1").Select
    ActiveCell.FormulaR1C1 = "Comments"
    Range("A4").Select
    Selection.Cut
    ActiveCell.Offset(-1, 19).Select
    ActiveSheet.Paste
    ActiveCell.Offset(3, -19).Select
    Selection.Cut
    ActiveCell.Offset(-1, 19).Select
    ActiveSheet.Paste
    ActiveCell.Offset(3, -19).Select
  
End Sub