IOL calculation

Online calculation of intraocular lenses has been offered by the ultrasound laboratory of the University Eye Clinic Würzburg as a novel and special service since July 19, 1996. Calculations may be performed for two user-defined intraocular lenses on the basis of different algorithms. At present, the SRK II formula , the HOFFER Q formula as well as our own algorithm (IOL calculation according to HAIGIS) are implemented. It is planned to add further lens calculation algorithms in the future.

IOL calculation according to HAIGIS may be carried out in several ways:

- In default mode the calculation is based on the A- or ACD constants entered for the individual IOLs;

- For an individual calculation surgeon-specific constants are used, which are derived from an analysis of the respective surgeon's postoperative results. As a prerequisite, reports of postoperative data must be sent back. Thus, individual results may continuously be improved by adapting the respective constants with every new data set reported back.

- If, additionally, data for the fellow eye is entered, aniseikonia can be calculated (acc. to GERNET) to assess differences in images sizes of both eyes.

Standard calculation

Extended calculation

More detailed IOL calculations, offering more options than implemented here, can be carried out with specially designed software packages:
- HOFFER Q (+ Holladay and SRK/T) formula: software Hoffer Programs, EyeLab KHofferMD@AOL.com
- HOLLADAY (2) formula: software IOL Consultant (Holladay Consulting, Inc.)

Comments and critics welcome. Please email to: wh@ocucalc.de

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Last Revision: June 22, 2015 WH

-	In default mode the calculation is based on the A- or ACD constants entered for the individual IOLs;
-	For an individual calculation surgeon-specific constants are used, which are derived from an analysis of the respective surgeon's postoperative results. As a prerequisite, reports of postoperative data must be sent back. Thus, individual results may continuously be improved by adapting the respective constants with every new data set reported back.
-	If, additionally, data for the fellow eye is entered, aniseikonia can be calculated (acc. to GERNET) to assess differences in images sizes of both eyes.