Identifying Candidates for Multifocal Lenses
Many factors must be taken into account when you assess a patient’s candidacy for multifocal IOLs. From ocular pathology and biometric candidacy to lifestyle needs, vision goals and personality, knowing what to look for is the key to success.
Explore the tabs below to learn more about how to identify ideal candidates for multifocal IOL implantation.
Multifocal IOL Patient Selection Based on Pre-op Measurements
Accurate preoperative biometry assessment is essential to properly determining whether a patient is a candidate for multifocal IOLs. Keep reading to learn about how refraction, keratometry, corneal assessment and lens power calculation can influence AcrySof® IQ ReSTOR® IOL patient selection.
An axial length measurement that is erroneous by 1 mm will cause a postoperative refractive error of about 3.0 D,1 so A-scan procedures are extremely important. Remember to:
- Consider A-Scan method carefully:
- - Optical coherence is highly accurate but may not measure through dense cataract.
- - Immersion can be variable based on administrator but is more accurate than contact/applanation.
- - Contact/applanation can cause corneal compression causing artificially shortened axial length
measurement that may result in a myopic surprise.
- Recheck if the difference in axial length between the two eyes is > 0.2 mm.
Performing keratometry and assessing the corneal status
When performing keratometry and corneal assessment, remember to:
- Discontinue contact lens wear prior to keratometry (2–4 weeks for soft lenses, longer for hard contacts).
- - Contacts should not be worn again until readings are obtained and confirmed.
- Use one dedicated keratometer, such as the LENSTAR LS 900,*,† IOLMaster† or a manual keratometer of your choice, for all pre- and post-op measurements.
- Check keratometry measurements using topography to confirm irregular readings.
- - If readings are consistently irregular, do not proceed with multifocal IOL implantation.
- Recheck keratometry if readings are < 40.0 D or > 47.0 D (< 40.0 D may indicate previous refractive surgery), or if astigmatism measured correlates poorly with refraction.
- Ensure corneal examination is normal with no significant guttata or epithelial dystrophy.
IOL calculation tips
Target emmetropia for optimal visual performance and refractive outcomes.
Use a new-generation IOL calculation formula, such as the Holladay 2 or SRK/T, and recheck if there is > 2.0 D difference in lens implant powers between eyes.
Personalize your lens constants to compensate for the differences in instrumentation, measurement technique, surgical techniques and calculation methods.
*LENSTAR® is a registered trademark of Haag-Streit.
†Trademarks are the property of their respective owners.