Femto-Phaco for Posterior Polar Cataracts?

Due to weakened and sometimes defective posterior capsules, removing posterior polar cataracts carries the heightened risk of posterior capsule rupture (PCR). Adjustments to phacoemulsification (phaco) techniques can reduce this stress. Two experts debated the merits of using standard phaco or a femtosecond laser to pre-segment the nucleus at a recent conference.

Advantages of standard phaco

Arguing for standard phaco, Soon-Phaik Chee MD outlined techniques for preserving fragile capsules when removing posterior polar cataracts of various densities. “I truly believe standard phaco is safe and effective, and you’ll see why,” she said.

Noting PCR risk with posterior polar cataracts increases when patients are younger than 40 years, have grade 4 or denser cataracts, or have a polar opacity 4.0 mm or larger, Dr Chee said anterior segment optical coherence tomography helps assess for this risk.^1–3 She recommended the following strategies for avoiding PCR: 

• Isolate a layer of cortex encompassing the polar opacity to be removed after nucleus phacoemulsification. Use hydrodelineation or hydrodelamination rather than hydrodissection. Viscodissection can be used to dissect the cortex and epinucleus.
• Use slow-motion phaco with reduced parameters, avoiding nucleus rotation and decentration. Successful techniques can include bimanual phaco, sideways sculpting, chop-and-tumble, manual nuclear delamination without fluid, and cross-and lamellar-chopping techniques.
• Strip the cortex towards the polar opacity, lifting it last.
• Avoid polishing the posterior capsule.
• Maintain anterior chamber space and avoid over-pressurising the eye.

Furthermore, she emphasised a gentle approach as well as the importance of good technique. “If you don’t have good technique, you are going to break the capsule anyway.”

To determine whether manual or femto-assisted surgery had better outcomes, Dr Chee reviewed results from her clinic. Over five years, 187 posterior polar cataracts were removed: 136 by femto-phaco, mostly performed by Dr Chee or a fellow, and 51 manually, mostly by residents. There was a mixture of densities in both groups. Outcomes were similar among the 12 intraoperative PCRs, with 9 occurring in femto cases and 3 in manual cases—resulting in a PCR rate of 6.7% for femto, 5.9% for manual, and 6.4% overall.

“Looking at these data, my residents did quite well. Standard phaco is truly safe and effective—as long as we do the right technique,” Dr Chee concluded.

Benefits of femto-phaco

Dagny Zhu MD argued that femtosecond laser-assisted phaco is safer than standard phaco for posterior polar cataracts. Although the literature shows PCR rates have dropped from as high as 26–36% in the 1990s to around 7–8% in recent years due to improved manual techniques, she noted using femtodelineation before nuclear removal can further reduce PCR rates—one groundbreaking study by Dr Abhay Vasavada and colleagues demonstrated rates as low as 4.4%.⁴

Echoing Dr Chee, Dr Zhu emphasised the need to reduce stress on the capsular bag to avoid PCR. One key is avoiding sudden, rapid build-up of hydraulic pressure inside the capsular bag.

“Even if there is a tear, you still want to minimise the pressure because you don’t want to expand the tear.”

Femtodelineation helps by cutting three concentric cylinders in the nucleus, which pre-softens it to make removal more predictable and with less manipulation and creates shock-absorbing zones that cushion the posterior capsule, Dr Zhu explained. A variation on the technique adds vertical chops, further pre-softening the nucleus.

Removal starts at the dense nuclear centre and moves precisely along pre-cut lines outward and downward, layer by layer, Dr Zhu said. This protects the weak posterior capsule and exposes the posterior polar component so it can be carefully removed last, starting from the epi-nucleus periphery and moving inward. The technique also leaves a perfectly centred capsulotomy in case a sulcus IOL is needed. “The full procedure is like a beautiful dance, [one] facilitated by the femtosecond laser.”

To further reduce pressure build-up in the capsule, Dr Zhu also recommended changing femto settings from standard procedures. She lowers the pulse power and increases spot separation, reducing bubbling-associated pressure rises. She also leaves a 500-micron safety zone from the posterior capsule and keeps the capsular-zonular diaphragm from bulging forward with viscoelastic.

Dr Zhu concluded that femtodelineation is safer than standard phaco for removing posterior polar cataracts. “Yes, you can get away with a manual technique, but we have data showing the PCR rate is lower with the femtodelineation.”

The debate took place during the 2025 ASCRS annual meeting in Los Angeles.

Soon-Phaik Chee MD is an ophthalmologist in private practice, visiting consultant to the Singapore National Eye Centre, and adjunct professor at Duke NUS Medical School in Singapore. chee.soon.phaik@snec.com.sg

Dagny Zhu MD is medical director and partner at NVISION Eye Centers, Rowland Heights, California, US. Dagny.Zhu@nvisioncenters.com

1. Hayashi K, Hayashi H, Nakao F, et al. J Cataract Refract Surg, 2003 Jan; 29(1): 45–49.

2. Kymionis GD, Diakonis VF, Liakopoulos DA, et al. Clin Ophthalmol, 2014; 8: 215–217.

3. Titiyal JS, Kaur M, Shaikh F, et al. J Cataract Refract Surg, 2020 Sept; 46(9): 1266–1272.

4. Vasavada AR, Vasavada V, Vasavada S, et al. J Cataract Refract Surg, 2015 Apr; 41(4): 702–707.