Pupil diameter and the principal ray Aaron M. Fay, Stephen L. Trokel, M.D., Joseph A. Myers, C.R.A. ' ,;
ABSTRACT
< P~eement of the surgical zone is critical in refractive procedures
',,:thatalter a 'portion of the corneal curve. An improperly centered ':()ptical zone may produce glare, decrease best corrected visual acu>itY,and decrease contrast sensitivity. For proper placement, the new : slIri'ac::e.s1wuJdbe centered around the line of sight, which is the ..;~in~ipalrayfrom tbeobject of regard that passes through the image patient's ,pupil as projected on the cornea. This point is not :;B~$$atiIyat · thegeomettic center of the cornea and is found by J9.c.a:tin.g , .th~center of the pupil while the patient is maintaining " iiXationcoaxialIy with the surgeon. However, the pupil does not :;(Iilat~ concentrically and its geometric center moves as the pupil ; (l,iam~ter changes. We have found a shift up to 0.7 mm in the geo
ABSTRACT
< P~eement of the surgical zone is critical in refractive procedures
',,:thatalter a 'portion of the corneal curve. An improperly centered ':()ptical zone may produce glare, decrease best corrected visual acu>itY,and decrease contrast sensitivity. For proper placement, the new : slIri'ac::e.s1wuJdbe centered around the line of sight, which is the ..;~in~ipalrayfrom tbeobject of regard that passes through the image patient's ,pupil as projected on the cornea. This point is not :;B~$$atiIyat · thegeomettic center of the cornea and is found by J9.c.a:tin.g , .th~center of the pupil while the patient is maintaining " iiXationcoaxialIy with the surgeon. However, the pupil does not :;(Iilat~ concentrically and its geometric center moves as the pupil ; (l,iam~ter changes. We have found a shift up to 0.7 mm in the geo
