In collaboration with Giacomo Savini, of Bologna, Italy, Kenneth J. Hoffer, MD, FACS, of Los Angeles, developed spreadsheet program including all of the IOL power calculation formulas for use with eyes that previously underwent LASIK or PRK. Drs. Hoffer and Savini worked on creating the spreadsheet for 2 years; it became available in July 2007. This tool is downloadable at www.EyeLab.com, under the Hoffer/Savini tab. "Every time you double click on the file, it opens a new spreadsheet," Dr. Hoffer explained in a telephone interview with CRST Europe. "You can save the spreadsheet with the patient's name."
Obtaining an accurate corneal power reading in LASIK and PRK eyes is difficult, and many power calculation methods have been proposed. There are 22 published methods that claim to achieve a correct IOL power calculation after LASIK. The Hoffer/Savini LASIK spreadsheet compiles all 22 formulas in one neatly formatted location, so that the surgeon may easily access any one or all the methods (Figure 1).
Within the Hoffer/Savini spreadsheet, the methods are divided into those that predict the true corneal power and those that adjust (ie, fudge) the IOL power. Each category is subdivided into methods that require historical patient data and methods that do not require historical patient data.
A surgeon enters the patient's collected data (ie, contact lens method, base curve of the lens, power, refraction with and without the contact lens). From this information, the results and predicted K reading are automatically calculated.
"The nice thing about this spreadsheet is that you can put in the IOL power that you wind up using, as well as the postoperative refraction, and you have all of this information on a difficult, problematic case on one sheet," Dr. Hoffer said. "You hit the print button, and you can put it in your chart."
The tool helps surgeons to efficiently enter, calculate, and analyze data. Which formula to use, however, is decided by the surgeon. The key benefits of using the program include: (1) it acts as a guide for collecting and inputting data, (2) it instantaneously calculates the answer for all published methods if adequate data are provided, (3) it is easy to use and print out for the patients' charts, and (4) it organizes all information into one place for later verification.
Drs. Hoffer and Savini are conducting an international study. Surgeons interested in participating may send a copy of his collected and entered data to KHofferMD@aol.com.
