Femtosecond laser-assisted cataract surgery (LCS) versus phacoemulsification cataract surgery (PCS): a single centre prospective comparative cohort study of surgical outcomes and safety from 4080 cases

Session Details

Session Title: Femtocataract I

Session Date/Time: Sunday 14/09/2014 | 08:00-10:00

Paper Time: 08:00

Venue: Boulevard A

First Author: : B.Vote AUSTRALIA

Co Author(s): :    S. Ewe   R. Abell   E. Darian-Smith   J. Kan   P. Allen  

Abstract Details

Purpose:

To investigate the intraoperative complications, surgical outcomes and safety of femtosecond laser-assisted cataract surgery (LCS) using Catalys (Optimedica, CA) compared to conventional manual phacoemulsification cataract surgery (PCS).

Setting:

Ambulatory Day Surgery Operating Theatre

Methods:

All consecutive eyes undergoing LCS or PCS by a total of 5 surgeons from a single centre between May 2012 and November 2013 were prospectively evaluated. Patients who had no contraindications to LCS were offered Femtosecond laser pretreatment to their cataract surgery at an out-of-pocket cost of $750 AUD. LCS contraindications included age <22 years, extensive corneal scarring, corneal ring inlays, past glaucoma filtration surgery or incisional refractive surgery (e.g. radial keratotomy). Based on this clinic-socioeconomic cohort selection PCS cases underwent manual corneal incisions and capsulorhexis followed by standard phacoemulsification and insertion of intraocular lens, whilst LCS cases underwent Catalys femtosecond laser pretreatment with anterior capsulotomy, lens fragmentation, +/- corneal incisions, followed by standard phacoemulsification and insertion of intraocular lens. Scheimflug imaging within the Pentacam was used to objectively assess cataract grade using the Pentacam Nucleus Staging [PNS]. After the laser procedure, the number of vacuum attempts, docking attempts, issues with vacuum or docking, treatment time, vacuum time, and OCT adjustments required were recorded. Intraoperative complications were recorded on the operation report including corneal haze intraoperatively, post-laser induced miosis, anterior capsulotomy tag, anterior capsule tear, posterior capsule tear, posterior capsule rupture, and lens dislocation.

Results:

Four-thousand and eighty consecutive eyes underwent LCS (n=1852) and PCS (n=2228) by five surgeons at a single centre. Patient demographics and baseline characteristics were similar between both groups. In particular, there was no significant difference between groups in terms of ocular co-morbidities, pupil size intraoperatively, cataract grade and age. Mean cataract grade was 2.81 ± 0.65 PNS in the LCS group compared with 2.80 ± 0.71 PNS in the PCS group. With regards the laser pretreatment, all aspects of the procedure improved with experience - significant improvement in vacuum attempts, docking attempts, image surface recognition adjustments, treatment time, and vacuum time during the laser procedure. Anterior capsule tears occurred in 1.84% in LCS treated eyes compared with 0.22% in PCS treated eyes (p<0.0001). There was no difference between incidence of anterior capsule tears in the first and second half of LCS cases. Anterior capsulotomy tags occurred in 1.62% of LCS cases. There was no significant difference in posterior capsule tears between LCS and PCS (0.43% vs. 0.18%, NS). Incidence of significant intraoperative corneal haze affecting surgical field view and intraoperative miosis was higher in the LCS group (p<0.001). Effective phacoemulsification time was significantly lower in the LCS group (p<0.0001).

Conclusions:

This large prospective single-centre study evaluates the safety and learning curve of Catalys femtosecond laser-assisted cataract surgery with a contemporaneous comparative cohort of standard phacoemulsification cataract surgery cases. We found a significantly higher rate of anterior capsule tears in the LCS group, which was not related to the learning curve. Evidence-based guidelines for phacoemulsification cataract surgery suggest a capsule complication frequency of less than 2% should be achievable. Our anterior capsular tear rate is below this figure in the LCS group (1.84%), but does not compare favorably with our concurrent PCS benchmark of 0.22% (of 2,228 cases). Published peer-reviewed research studies have yet to compare LCS complication rates with concurrent phacoemulsification capsule complication rates, unlike our study, which has prospective comparative cohorts. Within both surgery groups, none of the complicated cases were noted peri-operatively to have risk factors such as weak zonules, shallow anterior chamber, small pupil, high vitreous pressure, or poor visibility during surgery. We also found no difference between cataract grade and age between the two groups, and the complicated cases were no more likely to be older or have denser cataracts than those without complications. There was however no significant difference in complications such as posterior capsule tear and dropped nucleus, which might be considered more clinically relevant for refractive outcomes and patient satisfaction. Significant intraoperative complications that are likely to affect refractive outcome and patient satisfaction were low in both groups. Femtosecond laser-assisted cataract surgery appears to be as safe as conventional phacoemulsification cataract surgery, however anterior capsule tears and tags remain a concern. Capsule complications of LCS in our study were not related to the surgeon learning curve, but rather to other effects that may be patient or operative (laser) related.

Financial Interest:

NONE