Method, ophthalmic measuring system and computer-readable storage medium for selecting an intraocular lens

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the determining of the at least one selection parameter comprises performing a regression analysis configured to establish a relationship between one or more input variables and one or more output variables;
• wherein the input variables of the regression analysis comprise:
• an axial length (ALpre) of the eye which is measured before the natural lens has been at least partially removed from the capsular bag;
• the axial position parameter, which is an axial distance (AD) along the optical axis of the eye between the axial position of the portion of the anterior surface of the at least partially empty capsular bag and an axial position of a central portion of a cornea of the eye, and
• a local mean surface refractive power of the cornea (Kpre), which is defined as
• K
• pre
• =
• 0.332
• 2
• ·
• (
• 1
• r
• 1
• +
• 1
• r
• 2
• )
• ,
• with r1 and r2 being principal radii of curvature of the cornea, wherein the local mean surface refractive power is measured at the apex of the cornea and before the natural lens (2) has been at least partially removed from the capsular bag.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the determining of the at least one selection parameter comprises performing a regression analysis for determining constants of an equation wherein the equation has not more than three input variables which are used in the regression analysis and one or more output variables which are used in the regression analysis;
• wherein the three input variables are:
• a first input variable which is determined depending on the axial position parameter;
• a second input variable which is an axial length of the eye;
• and
• a third input variable which is a refractive power of the cornea wherein the one or more output variables comprise an optical power of the intraocular lens;
• wherein the regression analysis is performed for determining the constants c0, c1, c2, and c3 in the following equation:
• PIOL=c0+c1·ALpre+c2·Kpre+c3·AD,
• wherein PIOL is the optical power of the intraocular lens;
• ALpre is the axial length of the eye;
• AD is the axial position parameter and Kpre is the refractive power of the cornea.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the determining of the at least one selection parameter comprises performing a regression analysis for determining constants of an equation wherein the equation has not more than three input variables which are used in the regression analysis and one or more output variables which are used in the regression analysis;
• wherein the three input variables are:
• a first input variable which is determined depending on the axial position parameter;
• a second input variable which is an axial length of the eye;
• and
• a third input variable which is a refractive power of the cornea
• wherein the refractive power of the cornea is a local mean surface refractive power of the cornea,
• wherein the local mean surface refractive power (Kpre) of the cornea is defined as
• K
• pre
• =
• 0.332
• 2
• ·
• (
• 1
• r
• 1
• +
• 1
• r
• 2
• )
• ,
• with r1 and r2 being principal radii of curvature of the cornea.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the at least one selection parameter is further determined depending on a local mean surface refractive power of the cornea (Kpre), which is defined as
• K
• pre
• =
• 0.332
• 2
• ·
• (
• 1
• r
• 1
• +
• 1
• r
• 2
• )
• ,
• with r1 and r2 being principal radii of curvature of the cornea.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye, the method comprising:

• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the determining of the at least one selection parameter comprises performing a regression analysis for determining constants of an equation wherein the equation has not more than three input variables which are used in the regression analysis and one or more output variables which are used in the regression analysis;
• wherein the three input variables are:
• a first input variable which is determined depending on the axial position parameter;
• and
• a second input variable which is an axial length of the eye;
• and
• a third input variable, which is a central cornea thickness
• wherein the regression analysis is performed for determining the constants a0, a1, and a2 in the following equation:
• ACDpostOP=a0+a1·(AD+CCT)+a2·ALpre,
• wherein:
• AD denotes the axial position parameter;
• CCT denotes the central cornea thickness;
• ALpre denotes the axial length of the eye;
• and
• ACDpostOP denotes the predicted postoperative anterior chamber depth.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter;
• wherein the determining of the at least one selection parameter comprises performing a regression analysis for determining constants of an equation wherein the equation has not more than three input variables which are used in the regression analysis and one or more output variables which are used in the regression analysis;
• wherein the three input variables are:
• a first input variable which is determined depending on the axial position parameter;
• and
• a second input variable which is an axial length of the eye;
• and
• a third input variable, which is a central cornea thickness
• wherein the one or more output variables comprise an effective lens position.

A method of determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye;

• the method comprising:
• acquiring, by an optical coherence tomography (OCT) system, OCT data indicative of an axial position of at least an outer portion of an anterior surface of an at least partially empty capsular bag of the eye, relative to an optical axis of the eye, wherein the OCT data are acquired after a natural lens of the eye has been at least partially removed from the capsular bag;
• reading the OCT data by a data processing system;
• determining a connecting line between two portions of an edge of an opening in the anterior surface, depending on the OCT data;
• determining an axial position parameter, which is representative of the axial position of the outer portion of the anterior surface, depending on the OCT data;
• and
• determining the at least one selection parameter for selecting the intraocular lens depending on the determined axial position parameter.