Spherical Aberrations Resulting from Abnormal Q-Value
Q-Value
Q = –2 in advanced KC or after correction of +5 hyperopia
Q = –1 in moderate KC or after correction of +2 hyperopia
Q = –0.52, no spherical aberration is found.
Q = –0.26 to –0.35 in most normal corneas with the least tolerated spherical aberration.
Q = 0, the cornea is spheric with spherical aberrations.
Q = +1 after 8 RK cuts or after correcting –5 myopia.
Q = +2 after making 16 RK cuts or correcting –12 myopia
