Intraocular Lens Measurement Information
Prior to all cataract surgery, a patient’s eye needs to be measured in order to determine which strength/power of the intraocular lens is required to be implanted. Everyone’s eyes are different, so the strength of your new lens must be carefully calculated to optically match your eye. Both eyes are measured at this time to ensure accuracy. Please note, you have options on the method by which you would like to have your eyes measured: Ultrasound or Laser Biometry plus Corneal Topography. The Laser Biometry and Corneal Topography are highly recommended if you would like the most accurate method of measurement available.
Ultrasound A Scan
This is done using ultrasound wavelengths. Drops are used to freeze your eyes and a technician will place a probe on your cornea to send soundwaves to measure your eye. This test is covered by OHIP; however, it is not as accurate as laser biometry. Even when selecting the standard intraocular lens implant (covered by OHIP), we still recommend having laser biometry measurements for better accuracy.
Laser Biometry
Nidek AL-Scan & Zeiss IOL Master 700
This is a laser eye measurement. It is quick and easy with no instruments touching your eye. It is done by the patient focusing on a blinking light. This test generates the most accurate measurements for selecting the correct power of intraocular lens for your eye. It is highly recommended by our surgeons and is required if choosing a non-OHIP implant. Both eyes must be measured at the same time for accurate results.
Corneal Topography
This test is done in the same manner as the laser biometry. It provides detailed corneal mapping and assists our surgeon with selecting which intraocular lens implant is best for you. It detects information on astigmatisms which would be missed with conventional testing, significantly impacting the outcome of your surgery. This test is also highly recommended by our surgeons and is required if selecting a non-OHIP lens implant. Both eyes must be measured at the same time for accurate results.
*EYE MEASUREMENTS AND INTRAOCULAR LENS ARE BILLED SEPARATELY*
All eye measurements are billed by this office. All upgraded intraocular lenses are to be paid for at The Ottawa Hospital or a private surgical centre prior to your surgery.
Types of Intraocular Lenses
The characteristics of an intraocular lens implant can be divided up into two major categories: the power of the lens and the specific lens type. The power of the lens is measured in diopters, similar to a glasses prescription. The particular power of lens that your eye will need depends on a number of factors such as the shape and length of your eye. The more accurate the measurements of your eye, the more precise the power of the lens selected will be. There are a number of lens options that are available to you. The types of lenses can be divided into five different types: aspheric or spherical, astigmatism or non-astigmatism correcting, medium, extended, and full range lens. The lens that you select with your surgeon will be based on your visual goals, lifestyle, and personal preferences.
Intraocular Lens Implants covered by OHIP
Known as medically necessary implants
Spheric Monofocal Intraocular Lens (Standard Lens)
This lens corrects vision at a single focus, typically distance. When used with ultrasound biometry measurements, there is NO cost to the patient. Glasses will likely be needed after surgery. This lens does not correct for astigmatism.
Intraocular Lens Implants NOT covered by OHIP
Known as non-medically necessary implants, these lenses require laser biometry and corneal topography to maximize their benefits.
Aspheric Monofocal & Monofocal Toric Intraocular Lens
This lens corrects vision at a single focus – typically distance. Vision at near and intermediate distances will require spectacle correction. Night vision is enhanced compared to the standard lens. The toric version of this lens is used to reduce and correct astigmatism.
Medium Range of Vision Intraocular Lens
The lens is designed to provide clear vision for enhanced distance and dashboard vision. Spectacle correction will be required for computer work and reading. Night vision is enhanced compared to the standard lens. The toric version of this lens is also available for individuals with astigmatism.
Extended Range of Vision Intraocular Lens
This lens is designed to provide clear vision for distance and intermediate. The toric version of this lens is also available for individuals with astigmatism. Night vision is enhanced compared to the standard lens. Spectacle correction will be required for computer work and reading.
Full Range of Vision Intraocular Lens
This lens is designed to provide clear vision for distance, intermediate, and near. This reduces the need for spectacles for most activities. The toric version of this lens is also available for individuals with astigmatism. Some patients may experience significant glare with this lens. Spectacle correction will be required for small print.
*This information will be discussed during your pre-operative consultation*
With all hospital based procedures, there is no post-operative refractive guarantee. Ultimately, glasses may be needed or an investment into corneal refractive surgery.
You must be logged in to post a comment.