ESCRS - FP21.12 - Iris Registration Success Using Preoperative Topographical Mapping In 3D Confocal Structured Illumination Flacs

Iris Registration Success Using Preoperative Topographical Mapping In 3D Confocal Structured Illumination Flacs

Published 2026 - 44th Congress of the ESCRS

Reference: FP21.12 | Type: Free paper | DOI: 10.82333/nx4d-3k86

Authors: Dr William Bennett Trattler* 1 , Carloz Buznego 1 , Dr Dee Stephenson 2 , Dr Lee Katzman 3

1Ophthalmology,Center For Excellence In Eye Care,Miami,United States, 2Ophthalmology,Stephenson Eye Associates,Venice,United States, 3Ophthalmology,Nvision Eye Center, La Mesa,United States

Purpose

To evaluate the iris registration success rate on a 3D confocal structured illumination femtosecond laser platform using high-resolution diagnostic imaging and color-LED topographical mapping to transfer astigmatic axis measurements during femtosecond laser-assisted cataract surgery (FLACS).

Setting

Multicenter, multi-surgeon study (USA).

Methods

Retrospective, multicenter, non-interventional study of 9,956 eyes undergoing FLACS after preoperative third-generation color-LED topography (Cassini Technologies B.V.). Diagnostic images were exported and used with a 3D confocal structured illumination femtosecond laser platform (LENSAR, Inc.) to enable iris registration and intraoperative cyclotorsion compensation. Primary outcomes were iris registration success rate, magnitude and direction of cyclotorsion (clockwise or counterclockwise), and documented causes of registration failure.

Results

Among 9,956 FLACS cases, iris registration was successful in 98.25% of eyes (1.75% failure). Mean clockwise and counterclockwise cyclotorsion were 5.9° and 6.0°, respectively; 53% rotated clockwise and 47% counterclockwise. Cyclotorsion exceeded 2.5° in 62.75% of eyes, 5.0° in 40.55%, and 10° in 12.27%. Among registration failures, causes included unknown origin (72.4%), cyclotorsion beyond treatment range (17.8%), and shallow anterior chamber depth (9.2%).

Conclusions

In this large multicenter cohort, LED-based iris registration during FLACS demonstrated a high technical success rate. The high prevalence of clinically meaningful cyclotorsion underscores the importance of image-guided registration to compensate for intraoperative rotational changes and support refractive precision.