TY - JOUR
T1 - Multifocal Corneal Topographic Changes with Excimer Laser Photorefractive Keratectomy
AU - Moreira, Hamilton
AU - Garbus, Jenny J.
AU - Fasano, Armand
AU - Lee, Martha
AU - Clapham, Terrance N.
AU - McDonnell, Peter J.
PY - 1992/7
Y1 - 1992/7
N2 - Excimer laser photorefractive keratectomy can flatten the central cornea, thereby eliminating myopic refractive errors; in older patients, however, presbyopia limits satisfaction. Computer-assisted topographic analysis of corneas after refractive surgery indicates that a minority of patients achieve a multifocal lens effect, such that they maintain reasonable acuity over a range of defocus. We have purposefully attempted to create a multifocal refractive effect and have analyzed the subsequent topographies quantitatively to determine if multifocality was achieved. In corneas not operated on and plastic hemispheres, a fairly small range of corneal powers is observed; the range of powers is increased after a monofocal ablation. After multifocal ablations, a greater spread of surface powers is observed, often with a bimodal distribution, indicative of an apparent multifocal effect. These observations suggest that in some patients undergoing photorefractive keratectomy for myopia, it may be possible to reduce symptoms of presbyopia, although a decrease in image contrast or monocular diplopia may complicate this approach.
AB - Excimer laser photorefractive keratectomy can flatten the central cornea, thereby eliminating myopic refractive errors; in older patients, however, presbyopia limits satisfaction. Computer-assisted topographic analysis of corneas after refractive surgery indicates that a minority of patients achieve a multifocal lens effect, such that they maintain reasonable acuity over a range of defocus. We have purposefully attempted to create a multifocal refractive effect and have analyzed the subsequent topographies quantitatively to determine if multifocality was achieved. In corneas not operated on and plastic hemispheres, a fairly small range of corneal powers is observed; the range of powers is increased after a monofocal ablation. After multifocal ablations, a greater spread of surface powers is observed, often with a bimodal distribution, indicative of an apparent multifocal effect. These observations suggest that in some patients undergoing photorefractive keratectomy for myopia, it may be possible to reduce symptoms of presbyopia, although a decrease in image contrast or monocular diplopia may complicate this approach.
UR - http://www.scopus.com/inward/record.url?scp=0026635262&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026635262&partnerID=8YFLogxK
U2 - 10.1001/archopht.1992.01080190100036
DO - 10.1001/archopht.1992.01080190100036
M3 - Article
C2 - 1637286
AN - SCOPUS:0026635262
SN - 0003-9950
VL - 110
SP - 994
EP - 999
JO - Archives of ophthalmology
JF - Archives of ophthalmology
IS - 7
ER -