Intraoperative OCT (iOCT) Guidance for Determining Depth of Lens Grooving and Remaining Lens Thickness From the Posterior Capsule During Phacoemulsification in Cataract Surgery

Abstract

Purpose: To explore the utility of intraoperative optical coherence tomography (iOCT) in the determination of phacoemulsification groove depth and remaining lens thickness from the posterior capsule before lens cracking. Methods: In this retrospective analysis of 22 eyes, a remaining lens thickness (RLT) of less than 1.5 mm was defined as a suitable remainder to be achieved before initiating lens cracking. Phacoemulsification of the primary groove was carried out to a depth judged to be adequate by assessment of red reflex. An iOCT image was obtained; if the RLT was greater than 1.5 mm, further grooving was performed and a second iOCT measurement was obtained. Once the RLT was 1.5 mm or less, the surgeon proceeded with nucleus cracking. Results: The RLT was less than 1.5 mm in 90.9% of eyes (20/22). In 2 eyes (9.1%), the RLT was greater than 1.5 mm (cataract grade 2 and 5), which prompted further sculpting to deepen the groove. The final RLT was 0.99 and 0.90 mm in these 2 eyes, followed by lens cracking. Conclusions: Quantitative iOCT measurement enabled objective intraocular visualization of cataract groove depth prior to splitting the nucleus. Groove depth judgment using the red reflex resulted in an inadequate depth of grooving and a RLT of greater than 1.5 mm in 9% of eyes, even for an experienced surgeon. Greater difficulty was found in one dense cataract. The iOCT measurement may have helped dictate the need for further grooving before initiating lens cracking, thus minimizing the risk of a difficult or failed lens cracking. Objective confirmation of groove depth will be particularly useful for novice surgeons as they gain experience with the red reflex assessment and could be a helpful adjunct to phacoemulsification training. [ Journal of Refractive Surgery Case Reports. 2023;3(3):e28–e32.