Femto vs traditional: Comparative study
When introducing a new technology into current medical practices, it is always most important to know that the procedure is
safe and predictable. We have already performed the femto-assisted procedure on 100 eyes in our clinic we have experienced
no laser related complications. This demonstrates to us that the LensAR is safe even though we have only started to use it
in our practice. For the traditional phacoemulsification we used the OS3 phaco system (Oertli, Berneck, Switzerland). All
patients where operated under topical anaesthesia and the Mydriasert pellet (Théa Pharma, Berlin, Germany) was used for pupil
The femto procedure was performed by one surgeon in all cases, while the second part was performed by two surgeons. Two surgeons
also operated the control group. We chose to implant the Z-FLEX IOL (FirstQ, Mannheim, Germany) in the capsular bag of our
In our study we focused on endothelial cell loss and comparison of total phaco time between the two groups. We found there
was a decrease of both parameters in the RELACS group. In the FDA trial the reduction of ultrasound energy was 38% and 100%
depending on the grade of cataract. The total phaco time in our patients was 1.56 seconds in the LensAR group and 4.88 seconds
in the phaco group for similar ranges of cataract grades (2.4 RELACS vs 2.1 phaco). Endothelial cell loss was 4.0% compared
to 7.0% in the traditional phaco group. We believe that these parameters will decrease even more when surgeons are more adapted
to the new technology.
The rhexis could be performed in all cases, completely by the laser and without any additional manual manipulation required
in any case. Fragmentation of the nucleus was successfully performed in all cases in the LensAR group. In both groups no rupture
of the posterior capsule or capsular tear occurred during the procedure.
Regarding IOL centration and tilt, the early postoperative data are not feasible for consideration of whether there is an
advantage in the RELACS group over the traditional phaco. In particular, we believe that a longer follow up, of at least 6
to 12 months, would be required to find out if any fibrosis or anterior capsule phimosis occurs.
Regarding the refractive outcome after four weeks there was no significant difference between the two groups. Patient satisfaction
after the procedures was the same for both groups, but in the RELACS group, conjunctival haemorrhage caused subjective critical
arguments relating to the docking procedure. The problem with hyposphagma incidence in the femto group may get better once
the surgeon has overcome the learning curve of using a new instrument and hence reducing the amount of time required for docking.
When we started to perform the RELACS technique in October 2012 the docking time was about 4 minutes whereas now the whole
procedure takes on average 2.5 to 3 minutes. We believe that this reduction will lead to less conjunctival problems in the
future. Regarding the haemorrhages, it is important to consider whether our patients are taking anticoagulation medication,
such as warfarin therapy, before performing surgery.
Postoperative eye pressure was the same in both groups.
In the RELACS group it was noted that the formerly used phaco has to be adapted. The fragmented nucleus has to be cracked
or chopped before the emulsification. A divide and conquer technique is, therefore, not needed anymore. The vacuum pressure
was also required at maximum to get the best possible occlusion and reduction of total phaco time related to the fragmentation
of the nucleus. If the vacuum was not consequently used and the phaco technique adapted, the total phaco time was even higher
in some cases in the RELACS group during the early learning curve period. In nearly all of our cataract patients, we used
the same pattern. The only exception was in white cataract patients when we used only two plane cuts (Figure 5).
Figure 5: Lens after fragmentation with two plan cuts. One pie already emulsificated, source Dr Holland.
All patients tolerated the femto procedure well, which may be attributed to the relatively low vacuum pressure of the suction
ring. We have to keep in mind, however, that the femto patients are probably positively motivated also because they knew that
the most modern technique in cataract surgery was used in their eye.
When we started with the RELACS procedure we assumed that there would be limitations when performing surgery on higher grades
of cataracts. Now we believe that, especially in these cases, the RELACS treatment offers a great advantage. Most problems
with the capsulorhexis appear in harder cataracts and higher endothelial cell loss and postoperative corneal decompensations
as well. In one case of a grade 4 cataract, the total phaco time for RELACS procedure was 9 seconds while in the second eye
operated with standard phacoemulsification it was 28 seconds. However, longer follow up would be required to prove if this
reduction in time would be more beneficial than simply for the first preoperative time. The limitations of the RELACS procedure
are, for the moment, pupil size below 4 mm and an opacification of the cornea.
Figure 6: IOL after LensAR RELACS, final of operation.
In our ongoing study the LensAR system has been safe and efficient in performing the rhexis and lens fragmentation. This leads
to a reduced total phaco time and decreased loss of endothelium cells after 4 weeks. The RELACS procedure is comparably well
tolerated to the standard cataract procedure even if it needs more time and is more technically demanding.
An overall conclusion for the comparison of the two procedures and the potential benefit in the RELACS patients needs a longer
follow up of up to 12 months. Besides this, in our opinion, the perfection and predictability of the rhexis and the reduction
of phaco time alone justify the use of the LensAR system.
Dr D. Holland is ophthalmologist and surgeon in the Augenklinik Bellevue, Kiel, Germany. He may be reached by E-mail: firstname.lastname@example.org
Prof. Dr D. Uthoff is ophthalmologist and medical director of the Augenklinik Bellevue, Kiel, Germany. He may be reached by E-mail: email@example.com
Neither author has any financial disclosures relating to the subject matter of this article.