The most common causes of incomplete capsulotomies after laser-assisted cataract removal include eye tilt and air bubbles or ocular secretions at the interface, according to research published in British Journal of Ophthalmology. The study also uncovers that secondary capsulorhexis after incomplete capsulotomy is the most common risk factor for anterior capsule tears.
For the most part, femtosecond laser-assisted cataract surgery (FLACS) has helped to reduce overall surgical complications by making procedures quicker and making the capsulotomy process more predictable, with consistent size and shape. However, FLACS brings with it some unique complications, such as incomplete capsulotomies. These complications, if left untreated, can result in later issues of intraocular lens (IOL) decentration or tilt, posterior capsule rupture, or nucleus dislocation and vitreous prolapse.
This prospective, consecutive, cohort study looked at 1600 eyes of 1140 patients (mean age 67.28±12.92 years) who underwent FLACS between May 2015 and December 2018 by a single surgeon. All surgical procedures were filmed.
Incomplete capsulotomies were found in 52 (3.25%) eyes and 22 (1.38%) had radial anterior capsule tears. The surgical videos were analyzed by 2 other ophthalmologists. They determined that the most common causes of incomplete capsulotomies were eye tilt (16 eyes, 30.77%), air bubbles or ocular secretions at the interface (14 eyes, 26.92%) and white cataracts (7 eyes, 13.46%). Additionally, 54.55% (12/22) of the anterior capsule tears were due to incomplete capsulotomy and secondary capsulorhexis, the report explains.
The physician analysts also note a significant difference between the first 200 eyes and subsequent groups in terms of the incidence of incomplete capsulotomies, with the latter patients showing significantly better outcomes and fewer complications. This suggests a physician learning curve, according to the investigators. “There was a steep learning curve for laser capsulotomy in the first 100 operated eyes, as evidenced by the higher complication rate, but this stabilized after 200 procedures,” the report says.
“A tilt of only 7.5° is sufficient to cause an incomplete capsulotomy pattern,” the study explains. “[W]e suggest performing redocking once significant tilting is noticed. The extent of eye tilt-induced incomplete capsulotomy is usually large and often located in the superior area. This may be caused by Bell’s phenomenon when stressed patients try to close their eyes.”
Additionally, the researchers offer guidance for managing patients with air bubbles and ocular secretions identifiable on microscopy at the interface. “We suggest routinely applying a drop of 0.3% sodium hyaluronate on the operated eye to wash away ocular secretions and facilitate suction before docking. It is beneficial to squeeze out the air bubbles and ocular secretions before suctioning when the front edge of the water ripple crosses the midline and forms a U shape. Once a closed bubble is formed between the interface and the cornea before suction, the interface should be released for redocking.”
Investigators say the study results may be subject to bias, as it involved only a single surgeon, reducing generalizability among other surgeons.
“Most capsulorhexis tears can be avoided if incomplete capsulotomies are recognised early and treated properly. We hope that our results and experience can help shorten the learning curve for beginners, so that ophthalmologists can master this useful technology more quickly and proficiently,” the researchers report.
Wei Wang, Xinyi Chen, Xin Liu, et al. Lens capsule-related complications in femtosecond laser-assisted cataract surgery: a study based on video analysis. Bri J Ophthalmol. Published online February 1, 2022. doi:10.1136/bjophthalmol-2021-320842