Programm                 "Degeneration und Regeneration– Grundlagen, Diagnostik und Therapie"


Hotelbuchung
   Hotel Registration
Grußwort
   Welcome address
Beteiligte Gesellschaften
   Societies involved
DOG Information
   DOG Information
Eröffnung des Kongresses
   Opening Ceremony
Preise
   Awards
Ablauf der Tagung 2003
   General overview of congress
Lageplan der Räumlichkeiten
   Map of Congress Center
Wissenschaftliche Themen
   Scientific topics
Symposien
   Symposia
Wissenschaftliches Programm
   Scientific program
Posterpräsentationen
   Poster Presentation
Kurse
   Courses
Begleitende Veranstaltungen
   Accompanying program
Arbeitssitzungen
   Working sessions
Rahmenprogramm
   Social program
Allgemeine Informationen
   General Information
Autorenindex
   Index of Authors
Industrieaussteller
   Commercial exhibitors
Sponsoren
   Sponsors
Impressum



DOG Homepage


Abstract
Abstract

IOL Calculation after Corneo-Refractive Surgery

Haigis W.1, Langenbucher A.2, Seitz B.2
1Dept. Ophthalmology, Wuerzburg University; 2Dept. of Ophthalmology, University of Erlangen-Nuremberg

Purpose: IOL calculation after corneo-refractive surgery is a challenge becoming more and more important in the future. When current analytical IOL formulas are applied, difficulties arise especially due to the failure of classical keratometry. Instead, alternative methods were proposed (topography, contact lens method, refractive history method, regression procedures) the results of which, however, are partially not correctly interpreted. A systematic overview of the difficulties of current power formulas and possible solutions for eyes after corneo-refractive surgery does not exist and is attempted in this study.
Method: Currently used IOL formulas (Haigis, HoffferQ, Holladay, SRK/T, SRK II) were analyzed mathematically especially regarding variables which are influenced or altered by corneo-refractive surgery.
Results: Naturally, corneal power is the variable which is most affected. Not only is this parameter defined differently in different IOL formulas, but secondary variables derived from it are additionally used in some algorithms to serve as predictors for IOL position. For this purpose, clearly, only values prior to refractive surgery may be used. Further differences lie in the measurement values for corneal power expected by different formulas which can be equivalent or vertex powers.

Zurück | Back