BY OZANA MORARU, MD

As anyone who performs cataract and corneal refractive surgeries knows, it is crucial today to have a plethora of procedures and technologies available to patients. This is because there is not one single procedure that fits the needs of every patient. The benefit to offering a variety of corrective procedures, from refractive cataract surgery, to refractive lens exchange, to LASIK, to corneal transplantation, is that you can appeal to a larger patient
base. The drawback, however, can be that your practice requires a lot of different instrumentation in order to carry out the variety of procedures you offer.
One reason our center decided to purchase the Femto LDV Z8 (Ziemer) is because it is a versatile platform capable of performing both corneal and cataract surgeries. Due to the Ziemer femtosecond laser’s relatively small size, we are able to house it in our OR the whole day, during all procedures—even the ones we perform without femtosecond assistance. In this regard, not only do we eliminate the loss of time wheeling equipment in and out of the OR, but it is more comfortable for the patient because we avoid the need to change ORs or even for patients to move between surgical beds in the same OR. Moreover, it allows us to perform both standard cataract surgeries and laser cataract surgeries on the same day, in the same OR, and, in terms of scheduling patients for surgery, it doesn’t matter who has phacoemulsification cataract surgery and who has laser cataract surgery. In other words, we can schedule surgeries in any order, according to the patient’s appointment.

WORKFLOW WITH THE FEMTO LDV Z8
For laser cataract surgery, the patient comes into the OR, we drape him or her, and then we initiate the laser part of surgery. Immediately afterward, we wheel the Femto LDV Z8 a few centimeters away and continue with the manual portions of the cataract procedure. We lower the surgical microscope (which hangs from the ceiling) and start with phacoemulsification; the phaco machine is already close to the surgeon, and the patient is already draped. For corneal transplant surgeries, our workflow is very similar in that all aspects of the procedure can be done in the same OR. First, we prepare the donor cornea with the Femto LDV Z8, and then we perform the transplantation on the recipient cornea with the Z8.

For refractive surgery, most specifically LASIK, we do still need to move the patient to another OR after the Femto LDV Z8 is used to cut the flap, as our excimer laser is housed in another OR. In this scenario, we have one surgeon perform the corneal flap with the Z8 in our main OR and another surgeon immediately afterward perform the LASIK procedure in a secondary OR. This is our typical LASIK work flow because the excimer laser is quite large and cannot fit in our main OR, where we perform cataract and other anterior segment surgeries, and where we have our Z8. In our new clinic, which is about to be finished next year, we will then be
able to update our workflow and house all of our machines in the same OR: one Femto LDV Z8, one excimer laser, and two phaco machines. Thus, all of the cataract and corneal procedures that we perform will be done in the same OR, with a better workflow for all the procedures and for all
patients. Right now, we use the Femto LDV Z8 for the following procedures: cataract surgery, penetrating keratoplasty (mushroom and top-hat designs), deep anterior lamellar keratoplasty (DALK), corneal flaps in LASIK procedures, and tunnel creation for implantation of intrastromal corneal ring segments for keratoconus and corneal ectasia.

MAJOR BENEFITS
Having the possibility to use only one laser machine for all types of procedures has two major benefits: First, the initial investment can be allotted for several patients and surgeries, thus being easier to cover in time and more justifiable, and, second, the laser’s small footprint allows us to be more organized in the OR, in comparison with having several different
lasers for different surgeries. I don’t have clinical experience with every femtosecond laser on the market, but, between the experience I have had
with a couple of other platforms and as far as I have seen during presentations and read in articles, the Femto LDV Z8 seems to be the most versatile femtosecond laser available today worldwide. I previously used the LenSx femtosecond laser (Alcon) for 5 years, but because it can be used for cataract surgery only, such an expensive machine was not feasible in our practice, and we could not justify the investment.
Moreover, it is a big machine and it requires permanent air conditioning, a continuous low temperature, and a certain humidity, all of which made our surgical costs even higher.

Figure 1. The Femto LDV Z8 used during nucleus fragmentation (left and right).

On the other hand, the Z8 has a smaller footprint, it is easy to handle, it is mobile, and there are no environmental necessities.
Above all, it allows better cutting precision and safety during surgery. Therefore, it can be used as often and for as many procedures as possible. We have found that it is easy to dock; there are few patient complaints; it produces perfect corneal incisions and capsulotomies; and we have experienced no vacuum loss, no miosis, nor conjunctival hemorrhages. In terms of corneal surgery, we noticed precision in cutting the clear corneal tissue, both in LASIK cases and in corneal transplant procedures.

CASES IN POINT
White cataracts. Nuclear fragmentation is very well performed with the Femto LDV Z8, even in hard nuclei and white cataracts (although the fragmentation pattern is not always visible from the beginning). For this reason, we almost exclusively perform laser cataract surgery in white cataracts, as it brings a lot of advantages. First, most of these cataracts are
intumescent, with a flat anterior chamber and liquefied cortex. With the subsequently narrow angle, an accidental puncture of the iris or anterior
capsule is more likely with conventional phacoemulsification cataract surgery requiring limbal or clear corneal incisions; this complication is avoided using the femtosecond laser, where OCT technology warns of this possibility and helps the surgeon set proper incision placement.

Figure 2. Mushroom keratoplasty with the Femto LDV Z8
(top, center, and bottom).

Second, the prominent dome of the anterior capsule and the liquefied pressurized cortex in the white intumescent cataract often predispose capsular run-out

(ie, Argentinian flag syndrome) in conventional phacoemulsification with manual capsulotomy. On the contrary, by performing the capsulotomy with the Femto LDV Z8, we can avoid the high possibility of an Argentinian flag syndrome, and we also can safely create the capsulotomy in the desired size and position.
Third, the Femto LDV Z8 brilliantly cuts the nucleus of a white cataract. This can easily be seen when attempting to split the nucleus into pieces: The nucleus pieces exhibit a straight and vertical cut and are very easy to separate during phacoemulsification, which is a sign of an efficient laser precut. Posterior polar cataracts (PPC). When fragmentation is already done by the laser (Figure 1), it avoids the necessity to chop or sculpt the nucleus manually by rotating and splitting it. The surgeon is no longer required to separate the fragments with lateral movements; thus, we avoid the dangerous rotational and lateral forces needed for manual nucleus fragmentation and separation—forces that would put the weakened central zone of the posterior capsule in PPC eyes at risk for major complications.
In these cases, I recommend use of a femtosecond laser pattern with several radial cuts in the nucleus (16, for example).
This results in several smaller fragments that can easily be emulsified and aspirated, without any dangerous force exerted on the posterior capsule. Moreover, because the polar posterior opacities can be seen on OCT, the surgeon can precisely set the depth of the radial nucleus cuts, very close to the posterior capsule, making fragmentation even more complete and efficient.

Lamellar keratoplasty. I consider femtosecond technology very useful in corneal transplant surgeries. In DALK, the Femto LDV Z8 brings more precision in performing the circular cut at the correct depth and in tunnel creation in the big-bubble technique. However, it is equally useful in penetrating keratoplasties. For example, in very advanced keratoconus,
central leucomas, and scars, or in an eye with hydrops, the Femto LDV Z8 allows one to make a large graft to better cover the ectasia and to reduce postoperative astigmatism.

How can we obtain all these requirements? By performing a mushroom keratoplasty with the Femto LDV Z8, which can be safely tailored to the patient’s ectatic cornea (Figure 2) and by the use of integrated intraoperative OCT.

CONCLUSION
The Femto LDV Z8 is a versatile, compact, and precise platform capable of performing both cataract and corneal refractive surgeries. We have found it to be a welcomed addition in our OR as well as useful in not just routine cases but also complex cases as well.
OZANA MORARU, MD
Medical Director, Oculus Private Eye Clinic, Bucharest, Romania
ozana@eye.ro
Financial disclosure: None

BY JODHBIR S.MEHTA, BS c (HONS), MBBS, PhD, FRCO phth , FRCS(Ed), FAMS

Laser cataract surgery has been a viable alternative to conventional cataract surgery for more than a decade now. Inflammation management remains important independent of the surgery type: Not only does it influence corneal edema and central macular thickness, but today’s patients have high expectations for their visual recovery and for reduced pain postoperatively, so that they may return to their everyday activities as soon as possible after cataract surgery. With a handful of femtosecond laser
platforms and one nanosecond platform available today to assist in a multitude of steps in cataract surgery, it is important for surgeons and their practices to consider the benefits of each platform and to contemplate how incorporating one of them could help to produce superior surgical outcomes for their patients.

I have conducted a number of studies proving the benefits of a low-energy laser (Femto LDV Z8, Ziemer) in corneal surgery 1 and in cataract surgery. 2 With new clinical data on the Femto LDV Z8 emerging, more benefits of this low-energy laser in cataract surgery have been coming to light in the recent years and months. For instance, it has previously been shown that, in a case-controlled study, 1-day postoperative corrected distance visual acuity was significantly better after laser cataract surgery with the Femto LDV Z8 than it was after conventional phacoemulsification. 3 The indication here,
then, is that a low-energy laser platform like the Femto LDV could offer advantages in early visual rehabilitation. It has also been hypothesized that a low-energy laser could potentially decrease the extent of prostaglandin surge compared to higher-energy lasers (Figure 1) and, in return, reduce oxidative stress (for more information on prostaglandins, oxidative stress, and other inflammation indicators, see the Table).
I recently conducted a trial to compare the oxidative stress, prostaglandin E2 (PGE2), and cytokine levels after conventional and laser-assisted phacoemulsification with the Femto LDV Z8. 4 A cohort of patients were also given a topical NSAID preoperatively in the eye that received femtosec-
ond treatment. In short, what we found was that, compared with conventional cataract surgery with phacoemulsification, the Femto LDV Z8 induced a significantly higher PGE2 level and no significant difference in malondialdehyde (MDA) and aqueous flare levels.

However, capsulotomy cre­ation with the Femto LDV Z8 causes the lowest level of PGE2 release compared with high-energy systems. Further, we found that the addition of a topical NSAID preoperatively reduced PGE2 surge and, finally, that the amount of oxidative stress induced during phacoemulsification—both conventional and laser—strongly correlated with effective phacoemulsification time (EPT) and was independent of the surgery type.

RESULTS
Aqueous PGE2 and MDA levels. We found that the PGE2 level in the laser group was significantly higher (175.6 ±125.3 pg/mL) than it was in the conventional group (68.8 ±47.6 pg/mL) and that, in the laser group, PGE2 levels were significantly reduced among the eyes that received topical NSAID preoperatively (63.4 ±35.9 pg/mL). Again, this is much lower than compared with higher-energy laser systems. There was an increase in PGE2 levels in all groups immediately postoperatively (Figure 2), indicating that the preoperative NSAID only suppressed the rise in PGE2 after laser treatments at the beginning of surgery, but it had no effect at the end of the surgical procedure. Regarding MDA levels, the use of a topical NSAID did not suppress the increase of MDA caused by the laser pretreatment.

Cytokines, chemokines, and growth factor. The concentrations of IL-1RA were significantly higher in the laser group than in the conventional phacoemulsification group. Yet, when the preoperative NSAID was delivered in the laser group, there was a significantly lower concentration
of a number of inflammatory mediators. This is beneficial, as inhibiting cytokines, chemokines, and growth factor has the potential to limit the amount of pseudophakic cystoid macular edema. Capsulotomy creation with the Femto LDV Z8 causes the lowest level of PGE2 release compared with high-energy systems. 5-8 Authors have reported PGE2 levels ranging from 182.1 to 1911.4 pg/mL with high-energy laser platforms. 5,6,9,10 This is much higher than our reported level of 175.6 ±125.3 pg/mL (Figure 1).

CONCLUSION
PGE2 levels increase after both laser cataract surgery and conventional phacoemulsification, but significantly higher PGE2 levels are typically seen with laser cataract surgery.
Compared to the levels of PGE2 previously reported with high-energy laser platforms, the low-energy laser induces less release of the PGE2. When a topical NSAID was incorporated, the release of PGE2 in the low-energy laser was further reduced, to the levels seen in the conventional
phacoemulsification group. The oxidative stress induced during phacoemulsification strongly correlated with EPT and not the type of the surgery. EPT after femtosecond laser pretreatment of the lens is significantly shorter than with conventional cataract surgery, 11 which could potentially lead to reduced oxidative stress.

Also noteworthy is that the laser group had higher concentrations of IL-1RA than the conventional phacoemulsification group. Seeing that IL-1RA has been shown to suppress the proliferation of lens epithelial cells, this may be another positive attribute of laser cataract surgery in the battle against posterior capsular opacification.

1. Riau AK, et al. Comparative study of nJ- and muJ-energy level femtosecond lasers: Evaluation of flap adhesion strength,
   stromal bed quality, and tissue responses. Invest Ophthalmol Vis Sci. 2014;55(5):3186-3194.
2. Williams GP, et al. The effects of a low-energy, high frequency liquid optic interface femtosecond laser system on lens
   capsulotomy. Sci Rep. 2016;6:24352.
3. Pajic B, Cvejic Z, Pajic-Eggspuehler B. Cataract surgery performed by high frequency LDV Z8 femtosecond laser: Safety,
   efficacy, and its physical properties. Sensors (Basel). 2017;pil:E1429.
4. Liu Y-C, Setiawan M, Ang M, et al. Changes in aqueous oxidative stress, prostaglandins, and cytokines: Comparisons of
   low-energy femtosecond laser–assisted cataract surgery versus conventional phacoemulsification. J Cataract Refract Surg.
   2019;45:196-203.
5. Schultz T, Joachim SC, Kuehn M, Dick HB. Changes in prostaglandin levels in patients undergoing femtosecond laser-assisted
   cataract surgery. J Refract Surg. 2013;29:742-747.
6. Jun JH, Yoo YS, Lim SA, Joo CK. Effects of topical ketorolac tromethamine 0.45% on intraoperative miosis and prostaglandin
   E2 release during femtosecond laser–assisted cataract surgery. J Cataract Refract Surg 2017; 43:492-497.
7. Wang L, Zhang Z, Koch DD, Jia Y, Cao W, Zhang S. Anterior chamber interleukin 1b, interleukin 6 and prostaglandin E2 in
   patients undergoing femtosecond laser-assisted cataract surgery. Br J Ophthalmol 2016;100:579-582.
8. Schultz T, Joachim SC, Szuler M, Stellbogen M, Dick HB. NSAID pretreatment inhibits prostaglandin release in femtosecond
   laser-assisted cataract surgery. J Refract Surg 2015;31:791-794.
9. Kiss HJ, Takacs AI, Kranitz K, Sandor GL, Toth G, Gilanyi B, Nagy ZZ. One-day use of preoperative topical nonsteroidal anti-
   inflammatory drug prevents intraoperative prostaglandin level elevation during femtosecond laser-assisted cataract surgery.
   Curr Eye Res. 2016;41:1064-1067.
10. Nishi O, Nishi K, Ohmoto Y. Effect of interleukin 1 receptor antagonist on the blood-aqueous barrier after intraocular lens
    implantation. Br J Ophthalmol. 1994;78:917-920.
11. Dick, H. B. and T. Schultz A review of laser-assisted versus traditional phacoemulsification cataract surgery. Ophthalmol Ther.
    2017;6(1):7-18.
    JODHBIR S. MEHTA, BS c (Hons), MBBS, P h D, FRCO phth , FRCS(E d ), FAM
    Head, Corneal and External Eye Disease Department; Senior Consultant,
    Refractive Surgery Department, Singapore National Eye Centre
    Head, Tissue Engineering and Stem Cells Group, Singapore Eye Research Institute
    jodmehta@gmail.com
    Financial disclosure: Travel support (Ziemer)

Early signs of corneal asymmetries are often visible on the posterior surface first – and that’s why the reliable measurement of both anterior and posterior surfaces is vitally impor tant. GALILEI, a diagnostic device from Ziemer, is able to make all the measurements required for cataract and refractive surgery planning in a single session, making it a truly complete solution for ophthalmic surgeons.

Placido topography, Dual-Scheimpflug tomography, and optical biometry, with all measurements aligned to first Purkinje reflex, are combined within the GALILEI device to assist surgeons in reliably measuring the anterior and posterior surfaces, as well as the eye’s axial length. The system’s two Scheimpflug cameras provide precise pachymetry and elevation data, which aid in the early detection of asymmetry and bulging.

Figure 1. The Ziemer GALILEI device.

Renowned cornea and refractive surgeon Shady Awwad, Associate Professor of Clinical Ophthalmology and Director of the Refractive Surgery Center at the American University of Beirut, uses GALILEI’s Dual-Scheimpflug to screen candidates for laser vision correction. For the last few months he has been using GALILEI’s latest report, to be added shortly: the Corneal Thickness Progression Report. The report, which consists of three x/y graphs, four maps, and a set of indices, compares the patient’s measured data with data from the normal population, and shows the change in corneal thickness towards the periphery relative to the thinnest point. Awwad says, “I believe the Corneal Thickness Progression Report is one of the most sensitive tools to help detect early ectasia. I start the analysis by looking at the captured image, to make sure the measurement is unobstructed and centered, and to assess the position of the measurement center vis-à-vis the center of the cornea.” Awwad then evaluates the “Quadmap” (the anterior and posterior instantaneous curvature, posterior Best Fit Sphere, and pachymetry maps, see Figure 2) before checking the Corneal Thickness Progression Report. Awwad says the report is invaluable when planning his surgeries: “The Corneal Thickness Progression Report is key in identifying very early ectatic corneas (keratoconus suspects), and I have found it to be very sensitive and capable of producing specific data. It often shows values positive for early ectasia when other traditional parameters show normal to borderline levels. I believe it provides an extra safety net in making the decision whether or not to proceed with laser vision correction.” (see Figure 3) In addition to the x/y graphs, the Report includes a Corneal Thickness Progression map, which visualizes the data in an easy-to-read map. It is unique, as it provides surgeons with the precise location of suspicious regions within the cornea. Awwad says, “The Corneal Thickness Progression map displays the rate of change in corneal pachymetry with respect to the thinnest point at any given point in the cornea. Whereas the x/y graphs average corneal thickness change at a given distance from the thinnest point and over all meridians. The problem with the latter approach is that early abnormal pachymetric changes, typically focal, will be diluted by the system, averaging them with other areas in the cornea. Instead, the Corneal Thickness Progression map can help the clinician depict an early focal pachymetric change, typically infero-temporal or inferior, that is faster than in the rest of the corneal areas, and potentially faster than the expected normal range. This has been shown to be one of the earliest manifestations of ectasia.”

In summary, the additional information provided by the GALILEI helps clinicians with diagnosis and decision making – thus offering solid support in refractive surgery planning. Shady Awwad draws a strong conclusion: “The Corneal Thickness Progression Report is a boon for ophthalmologists involved in laser vision correction. Used in combination with other parameters, it allows us to make confident surgical decisions.”

Figure 2. “Quadmap” tomography of the right eye of a patient with left eye
keratoconus. The patient’s right eye shows no obvious signs of the disease.

Figure 3. Corneal Thickness Progression Report of the same patient’s
right eye. The rate of pachymetry change is highest at the
inferotemporal quadrant, as opposed to the other sectors, specifically
the superonasal quadrant, signaling early ectatic disease in the
seemingly normal right eye.

The GALILEI G4 is CE marked and FDA cleared. The GALILEI G6 is CE marked and pending FDA clearance. For some countries, availability may be restricted due to regulatory requirements. Please contact Ziemer for details.