Click on a link below
the item to your computer.
The SIA Calculator is no longer offered as a download, but instead is now operating on our website.
Haigis Formula Optimization — Haigis-300.xls (Microsoft Excel)
This Excel spreadsheet can be used to submit data for optimizing the a0,
a1 and a2 constants for the Haigis formula. The corneal power should be entered
in diopters and not mm.
Because this exercise requires Dr. Hill a significant time to
complete, requests for this service must come DIRECTLY FROM THE
SURGEON whose data this represents
and NOT from support staff. Requests from support staff WILL
BE RETURNED UNANSWERED.
Address your subject line to read: "Haigis optimization." Along with
the completed Haigis-300.xls spreadsheet, the text of the e-mail should include
the manufacturer and model of the IOL, such as Alcon SN60WF, the biometry
method employed, such as Lenstar or IOLMaster and the name of the requesting
surgeon. If less than 200 valid cases are submitted, only the a0 Haigis constant
will be optimized with the Haigis a1 and the a2 constants remaining at default
values. It is best to submit approximately 225 cases so that more than 200
cases will remain after the exclusion of any outliers.
entering data into your Excel spreadsheets, please download
(below) and follow them exactly.
This download is a set of detailed instructions on how to complete and submit the Excel spreadsheet that will be used to derive your set of surgeon and IOL specific a0, a1 and a2 Haigis constants for optical biometry.
Refractive Vergence Formula — R-verg-Hill.xls (Microsoft
A Microsoft Excel spreadsheet containing the refractive vergence formula
as outlined in:
Holladay JT: Standardizing constants for ultrasonic biometry,
keratometry, and intraocular lens power calculations. J Cataract Refract
The more sophisticated "Holladay R Formula" is
recommended and is part of the
IOL Consultant software package.
Correcting for Vertex Distance — Vertex.xls (Microsoft
Be sure to maintain the correct sign (+ or -) when entering the refractive
data, or the results will not be accurate.
IOLMaster Checklist — IOLMaster_checklist.pdf (Adobe Acrobat
The above .pdf file contains the checklist that our staff uses when measuring
the axial length, central corneal power, ACD, and horizontal corneal diameter
using the IOLMaster. The .pdf file contains three identical checklists. We
suggest separating each copy and having them laminated individually to allow
various staff members easy access to their own copy.