Document Detail


Freezing increment in keratophakia.
MedLine Citation:
PMID:  3915238     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In homoplastic keratomileusis, keratophakia, and epikeratophakia, the corneal tissue that provides the final refractive lenticule undergoes a conformational change when frozen. Because corneal tissue is composed primarily of water, an assumed value of 9.08% (approximate volumic percentage expansion of water when frozen) is frequently used for the increase in thickness, or freezing increment, rather than measuring it directly. We evaluated 32 cases of clinical keratophakia and found the increase in thickness to average 37 +/- 21%. In this series of 32 cases, the percentage of patients with a greater than 4 D residual refractive error was 16%. If an assumed freezing increment of 9.08% had been used, the percentage would have been 28%, with two-thirds of these 28% manifesting a marked undercorrection. Because of a lack of studies documenting the behavior of corneal tissue following cryoprotection and freezing, it is suggested that measurements be taken during homoplastic surgery to minimize the potential for significant inaccuracy in obtaining the desired optic result.
Authors:
C A Swinger; H J Wisnicki
Related Documents :
10361148 - Stabilization of polymer-based gene delivery systems.
20105458 - Stabilization of bacteriophage during freeze drying.
16289668 - Innovative procedure for the determination of gross-alpha/gross-beta activities in drin...
18563418 - Is the strategy for cold hardiness in insects determined by their water balance? a stud...
19049198 - Excess enthalpy and luminescence studies of sno2 nanoparticles.
12153458 - Regulation of fluoride ion release from na2sif6 contained in resin based on hydrophobic...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Cornea     Volume:  4     ISSN:  0277-3740     ISO Abbreviation:  Cornea     Publication Date:    1985-1986
Date Detail:
Created Date:  1986-07-30     Completed Date:  1986-07-30     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8216186     Medline TA:  Cornea     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  225-8     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Corneal Transplantation*
Freezing*
Humans
Refraction, Ocular
Refractive Surgical Procedures*
Grant Support
ID/Acronym/Agency:
03346//PHS HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Thromboxane, prostacyclin, and the hemodynamic effects of graded bacteremic shock.
Next Document:  Clinicopathologic studies of keratoplasty eyes obtained surgically.