||Dr. Hill volunteers hundreds of hours and his personal resources to make the information on this website available to you. If you would care to buy him a cup of coffee, donate towards operating expenses, or just to say thank you, your contribution is welcome.
The SIA Calculator is now offered online with automatic updates. Click on the above link.
Haigis Formula Optimization: Physicians ONLY
Requests from technicians or staff are NOT allowed.
|| Dr. Hill offers a significant amount of his personal time to
complete each Haigis Optimization. He only accepts direct requests FROM THE
SURGEON whose data it represents. Requests from personnel are not allowed.
1. Instructions ~ Haigis Formula Optimization
Follow these instructions
Haigis-instructions.pdf (Adobe PDF)
This document 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.
2. Spreadsheet ~ Haigis Formula Optimization
Haigis Formula Optimization — Haigis-300.xls (Excel)
This Excel spreadsheet is used to submit data for optimizing the a0,
a1 and a2 constants for the Haigis formula. The corneal power must be entered
in diopters and not mm.
If less than 200 valid cases are submitted, only the a0 Haigis constant
will be optimized with the Haigis a1 and the a2 constants set at default
values. Ideally, you would submit a minimum of 225 cases, so at least 200
cases will remain after the exclusion of possible outliers.
3. Email ~ Haigis Formula Optimization
Subject line to read: "Haigis Optimization".
You must include the following:
- Your name (only direct requests from surgeon are allowed).
- Haigis-300.xls spreadsheet - complete and accurate
- Manufacturer and model of each IOL, such as Alcon SN60WF
- Biometry method employed, such as Lenstar or IOLMaster
Refractive Vergence Formula
Refractive Vergence Formula — R-verg-Hill.xls (Excel)
This Excel spreadsheet contains 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
Correcting for Vertex Distance — Vertex.xls (Excel)
Be sure to maintain the correct sign (+ or -) when entering the refractive
data, or the results will not be accurate.
LENSTAR® User Manual
LENSTAR® User Manual — Lenstar-User-Manual.pdf (Adobe
This .pdf file contains the "LENSTAR® User Manual" as provided by Haag-Streit-USA.
IOLMaster® Procedures Checklist
IOLMaster Checklist — IOLMaster_checklist.pdf (Adobe
This .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 having them laminated individually to allow
various staff members access to their own copy.
IOLMaster User Manual
IOLMaster Manual — IOLMaster_User_Guide.pdf (Adobe
This .pdf file contains the "IOLMaster - A Practical Operation Guide" as provided by Carl Zeiss Meditec.