DATA GLAUCOMA;                                                               /*
     INTRAOCULAR PRESSURE BEFORE AND AFTER SURGERY FOR GLAUCOMA
     TRTMNT S indicates surgery alone, SD surgery with drug;
     RB = Right eye Before surgery, LA = Left eye After surgery, etc.
     Missing values indicate eyes not treated.                               */
     INPUT ID TRTMNT $ RB RA LB LA @@; CARDS;
 1 SD 26 27 40 25    2 S  34 17 53  8    3 SD  .  . 28 19    4 SD 25 19  .  .
 5 SD 26 19 22 19    6 SD 30 20 40 17    7 SD 40 14 58 18    8 SD 30 18 40 18
 9 S  22 14 30 16   10 SD 36 22 39 24   11 SD 40 22 40 24   14 SD 24 22 25 18
15 SD 30 20  .  .   17 S  26 13  .  .   18 S  26 22 25 10   20 SD  .  . 30 19
21 SD 28 19 30 21   23 S  21 18 20 17   24 SD 35 35 38 27   25 SD 46 30 32 31
;