Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1992-8-27
pubmed:abstractText
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.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0003-9950
pubmed:author
pubmed:issnType
Print
pubmed:volume
110
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
994-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Multifocal corneal topographic changes with excimer laser photorefractive keratectomy.
pubmed:affiliation
Doheny Eye Institute, Los Angeles, CA 90033.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't