Intraoperative SD-OCT parameters may be new key for IOL power calculation
Click Here to Manage Email Alerts
Key takeaways:
- Intraoperative SD-OCT may provide accurate prediction of postoperative anatomical lens position.
- Lens meridian position is the most significant predictor for postoperative anatomical lens position.
By measuring lens meridian position intraoperatively, spectral-domain OCT may provide accurate prediction of postoperative anatomical lens position, according to a study.
In 97 eyes of 62 patients who underwent cataract surgery at the Storm Eye Institute, Medical University of South Carolina, between October 2018 and March 2020, the spectral-domain OCT (SD-OCT) of the Catalys femtosecond laser platform (Johnson & Johnson Vision) was used intraoperatively to measure lens anatomy parameters, including lens meridian position (LMP), lens thickness, volume and diameter, central corneal thickness and anterior chamber depth. Anatomical lens position (ALP), defined as the distance from the anterior surface of the IOL and the anterior surface of the cornea, was measured postoperatively by swept-source OCT optical biometry. A formula based on preoperative biometric data and postoperative refraction was used to back calculate theoretical effective lens position (ELP).
Image: Adobe Stock
LMP was the most significant predictor for postoperative ALP. Back-calculated ELP (5.25 ± 0.57 mm) could not be considered interchangeable with postoperative ALP (4.85 ± 0.37 mm).
“It is conceivable that emerging IOL formulas based on ALP by measuring intraoperative LMP may provide improved refractive outcomes compared to current formulas based on ELP,” the authors wrote. “Given that LMP is a metric measured by intraoperative OCT, it may be of value to develop devices that can measure LMP preoperatively, so it can be added as a metric to IOL formulas.”
In the correlation of LMP and ALP, variabilities were found according to the type of IOL used. As the authors noted, differences in optical design, geometry, mechanical properties and refractive index may play a role and should be subject to further analysis in future studies.
IOL power calculation remains a challenge, even with today’s advanced formulas, the authors said. SD-OCT LMP could be used as a metric to estimate postoperative IOL position, and further studies are needed to analyze the impact of this parameter on postoperative refractive outcomes.
Collapse
Read more about
Click Here to Manage Email Alerts