Noticias 12/16/2021

Transitional conic toric intraocular lens evaluation after femtosecond laser-assisted cataract surgery using intraoperative aberrometry

Por: Antonio Toro

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Transitional conic toric intraocular lens evaluation after femtosecond laser-assisted cataract surgery using intraoperative aberrometry


Francisco Pastor-Pascual

Rafael Pastor-Pascual

Robert Montés-Micó

Ramón Ruiz-Mesa

Pedro Tañá- Rivero



To assess refractive and visual outcomes following phacoemulsification with femtosecond laser-assisted cataract surgery (FLACS) using intra- operative aberrometry and implantation of a toric intraocular lens (IOL) in eyes with different degrees of astigmatism.


One hundred two eyes of 70 patients who underwent implantation of the transitional toric 565 Precizon IOL (Ophtec BV) were enrolled. FLACS, capsular tension ring insertion, and intraoperative aberrometry were performed. Main outcome measures were refractive error, uncorrected- and corrected distance snellen decimal visual acuity values (UDVA and CDVA, respectively), and IOL rotation. Specif- ically, a vector analysis was carried out with J0 and J45 evaluation. Eyes were evaluated 1-year after surgery.


Overall, 94.12% (96 eyes) and 100% (102 eyes) of the eyes showed a spherical equivalent (SE) within ± 0.50D and ± 1.00D, respectively. The mean SE and refractive cylinder were – 0.06 ± 0.29D and – 0.23 ± 0.37D, respectively.

Vector analysis revealed that 100% of the eyes were within ± 0.50D for the J0 and J45 cylindrical com- ponents. The mean toric axis rotation was 1.10 ± 1.71° (from 0° to 5°), 77% (79 eyes), and 100% (102 eyes) of the eyes showed UDVA and CDVA of 20/25, respectively. The postoperative mean values of monocular UDVA and CDVA were 0.88 ± 0.17 and 0.96 ± 0.07 (about 20/20), respec- tively. No patient required IOL realignment during the postoperative follow-up.


The present study suggests that the use of the Precizon IOL after FLACS, using intraoperative aberrometry in patients with different amounts of astigmatism, provides good visual acuity, accurate refractive outcomes, and excellent rotational stability.


Toric – Astigmatism – Intraocular lens – Phacoemulsification – Cataract


Refractive error correction after cataract surgery needs to be minimized or removed to provide our patients the best quality of vision. Accurate preoperative biometry with precise intraocular lens (IOL) power calculation is mandatory for optimum refractive outcomes. Obvi- ously, this necessarily includes also the correction of corneal astigmatism. It has been found that about one third of eyes have 1.00D or more and would benefit from its correction at the time of the surgery [1, 2]. Uncorrected astigmatism affects the quality of vision drastically [3]. A recent systematic review and meta- analysis concluded that toric IOLs provided better uncorrected distance visual acuity (UDVA), greater spectacle independence, and lower amounts of resid- ual astigmatism than non-toric IOLs [4]. This study considers different toric IOL models, preoperative astigmatism (0.75–3.00D), and follow-ups (3–6 months). The benefit of using toric IOLs has also been reported in eyes with high corneal astigma- tism during cataract [5] and refractive lens exchange [6] surgeries.

To correct astigmatism properly, the toric IOL should be placed accurately at the required axis and must remain stable during the postoperative period. Deviation of the axis position may occur either intraoperatively (malposition due to incorrect target or marking the axis) or after implantation (rotation of the lens). The use of intraoperative aberrometry systems helps minimize the incidence of intraopera- tive alignment errors [7, 8]. Previous literature about different toric IOLs usually reports rotational stability of three to six months [4-6] based on the premise that IOLs do not rotate significantly after anterior and posterior capsules fuse. The majority of IOL rotation occurs within the initial days after the surgery [9]. However, the success of a toric IOL needs to be analyzed, considering that it should allow a stable po- sition in the capsular bag over time. Capsular bag shrinkage due to fibrosis is the most frequent cause of IOL rotation and frequently occurs during the first three months after IOL implantation [10-11]. Capsu- lorhexis size, IOL design, and its material may influence the capsule fusion and, hence, IOL rotational stability [12]; in fact, IOL rotation has been associated with increasing capsular bag diameter [13]. Inappro- priate capsulorhexis size for IOL coverage also may contribute to postoperative rotation. Accurate capsu- lotomy with femtosecond laser-assisted cataract surgery (FLACS) may help to create well-centered circular continuous capsulorhexis, providing adequate IOL coverage essential to ensure IOL stability. Despite some authors finding no clinically significant differences (i.e., visual acuity and residual refraction) in eyes treated with standard phacoemulsification and FLACS with toric IOL implantation, some have reported that total ocular higher-order aberrations were slightly lower [14]. In fact, internal vertical was significantly lower in femtosecond eyes [14, 15]. Other authors concluded that FLACS appears to provide improved refractive outcomes in toric IOLs [16]. We should take into account that visual quality may be improved by lower IOL tilt (related to vertical coma) as previously suggested [15]. Then, we consider that accurate capsulotomy with FLACS and the use of an image-guided system may contribute to the success of toric IOL implantation during the early but also late postoperative period.

The objective of our study was to analyze the visual and refractive outcomes of one toric IOL (Precizon), using FLACS and intraoperative aberrometry in cataract patients with a one-year follow-up. This lens has been previously evaluated in vitro [17] and after cataract surgery [18–22]. The clinical studies carried out showed good short-term results, but as far as we know, ours is the first study that showed a longer analysis of the Precizon IOL past one year and used FLACS with intraoperative aberrometry.



We retrospectively examined 102 eyes of 70 patients at the Oftalvist Clinic, Spain. The study was carried out in accordance with the tenets of the Declaration of Helsinki and approved by the Institutional Review Board. Informed consent was obtained from all patients after the nature, and possible consequences of the study were explained. Inclusion criteria included significant cataracts, preexisting corneal astigmatism between 0.75 and 8 D, age between 50 and 90 years. Exclusion criteria consisted of history of glaucoma, macular degeneration or retinopathy; corneal disease; irregular astigmatism; abnormal iris; pupil deformation; and history of prior ocular inflammation.

Intraocular lens

All eyes were implanted with the PrecizonÒ toric IOL Model 565 (Ophtec BV, Groningen, the Netherlands). This IOL is a biconvex, single-piece, aspheric (spher- ical aberration-free design) toric with a transitional conic toric surface. The IOL has a closed-loop haptic design to reduce rotation and a 360-degree square edge (0 degrees angulation). The lens is composed of 25% hydrophilic acrylic (ultraviolet cut-off wavelength at 360 nm) and has an optic body diameter of 6 mm and an overall diameter of 12.5 mm (refractive index of 1.46). A constant for ultrasound is 118.0 and 118.5 for optical biometry. Spherical powers range from + 10.00 to + 30.00 D (0.5D increments) and cylinder powers from 1.00 to 10.00 D (0.5D increments).

Surgical procedure

Before surgery, a 0°–180° axis was marked with all patients sitting upright at a slit-lamp using a horizontal slit beam. Intraoperatively, the intended implantation axis was marked on the limbus after correctly aligning a Mendez ring to the primary marks to ascertain the intended angle of placement according to the preop- erative plan. All surgical procedures were performed under topical anesthesia by FPP, using the LDV Z8 (Ziemer Ophthalmic Systems AG, Port, Switzerland) femtosecond laser platform through a 2.2-mm tempo- rally located clear corneal incision. With the laser system, a standardized 5 mm diameter, laser-assisted capsulotomy centered on the pupil, as well as a ring lens fragmentation pattern, was performed. After cataract removal and posterior capsule polishing, the capsular bag was filled with sodium hyaluronate 10 mg/ml 1%. The toric and spherical IOL powers were determined using the ORA system with Ver- ifEye + (Alcon, Fort Worth, TX, USA). This system (based on Talbot-Moire interferometry) performs real- time calculation of IOL power as well as of the axis under aphakic condition. It allows axis refinement by providing the direction and the magnitude of ration necessary to achieve a minimum residual astigmatism. A capsular tension ring (CTR) was inserted into the capsular bag. The CTR was implanted to improve the stability of the capsular bag, to improve the centration of the IOL, and to facilitate a possible future exchange of the IOL if necessary. The IOL was implanted using a disposable DualTec IOL injector (Ophtec BV, Groningen, the Netherlands). After complete aspira- tion of the viscosurgical device, intraoperative aber- rometry was used to refine the position of the toric IOL axis refinement with the chosen IOL until the ‘‘no recommended rotating’’ instruction appeared.

Preoperative and postoperative assessment

All patients were evaluated previously and the following examinations were carried out: Snellen decimal monocular UDVA and corrected distance visual acuity (CDVA), refraction, corneal topography (Pentacam, Oculus Optikgera ̈te GmbH, Wetzlar, Ger- many), and optical biometry (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany). In addition, slit- lamp examination, Goldmann tonometry for intraoc- ular pressure (IOP) measurement, and dilated fun- doscopy were performed. IOL power calculation was based on IOLMaster measurements, considering a historical level of surgically induced astigmatism by the incision of 0.25 D. IOL power was calculated using the Hoffer Q formula if the axial length was shorter than 22 mm, or using the SRK/T formula if the axial length was 22 mm or longer. IOL cylinder power and target IOL axis were calculated using the online Precizon Toric Calculator (Ophtec, Toric IOL Calcu- lator, The targeted refraction was emmetropia.

Postoperative examinations were performed at the standard visits post-surgery in our center, and the analysis of the outcomes was carried out one year after surgery. A standard ophthalmologic examination, including refraction (sphere, cylinder and axis), IOP measurement, and slit-lamp biomicroscopy, was per- formed. UDVA and CDVA were measured. Rotation of the IOL was assessed after full mydriasis through analysis of the IOL marks. The postoperative IOL mark at one year was compared with the IOL mark at one day after surgery. Clockwise rotation was consid- ered positive rotation and counter clockwise negative rotation. The difference between postoperative day one and postoperative year one was considered IOL rotation.Manifest refractions in conventional script notation (S [sphere], C [cylinder], a [axis]) were converted to power vector coordinates by the following formula:


where SE is the spherical equivalent and J0 and J45 are the two Jackson crossed-cylinders equivalent to the conventional cylinder.

Statistical analysis

Statistical analysis was carried out using SPSS soft- ware (22.0 version, IBM Corp., Armonk, New York, USA). All the measurements are shown as the mean ± standard deviation (SD). The normality dis- tribution was checked by means of the Shapiro–Wilk test and the equal variance test by means of the Brown–Forsythe test. A t-test was used to assess statistically significant differences in postoperative outcomes. The statistical significance limit was set to a P value of less than 0.05 in all cases.


Our study considered the outcomes of 102 eyes of 79 consecutive patients (39 eyes from males and 63 eyes from females) who underwent FLACS with Precizon toric IOL implantation. Patients’ demographics and preoperative data of our sample are shown in Table 1. Mean patient age was 68.29 ± 8.31 years (ranging from 51 to 89 years). All surgeries were uneventful, and there were no complications in any of the cases during the surgery and follow-up. No patient required IOL repositioning due to misalignment, and no posterior capsule opacification was observed during the postoperative follow-up.

m male,

f female,

CDVA distance corrected visual acuity,

K keratometry,

IOL intraocular lens power

Table 1. Demographic characteristics of participants shown as means, standard deviations (SD) and ranges
Table 1. Demographic characteristics of participants shown as means, standard deviations (SD) and ranges

Standard graphs for reporting refractive and visual acuity outcomes were constructed. Figure 1 shows the distribution of SE refraction after the surgery (accu- racy). The highest percentage of eyes, 65.69% (67 eyes), was for the range ± 0.13D, followed by about 18.63% (19 eyes) for the – 0.50 to + 0.14D range; 94.12% (96 eyes) and 100% of eyes were within ± 0.50D and ± 1.00D, respectively. The mean postop- erative SE was – 0.06 ± 0.29D (ranging from 0.63 to – 1.00D). Figure 2 shows the distribution of the refractive cylinder before and after the surgery. Note from this figure the change of distribution after the surgery to low values of astigmatism. Specifically, its analysis after surgery revealed that all eyes showed a value of B 1.00D, 83.34% (85 eyes) B 0.50D, and 69.61% (71 eyes) B 0.25D (see Figure 2). Mean postoperative refractive cylinder (- 0.23 ± 0.37 D, ranging from 0 to – 1.00 D) was significantly reduced compared to preoperative values (see Table 1, p \ 0.05). The power vector analysis is plotted in Figure 3, showing the attempted versus achieved SE (top) and for both components of astigmatism: J0 (middle) and J45 (bottom). Solid lines represent the best-fit line for each graph (regression equations and values were also included), and dotted lines consider intervals of ± 1.00D for SE and ± 0.50D for J0 and J45. As previously indicated, all eyes showed an SE within ± 1.00D and J0 and J45 within ± 0.50D. The power vectors, SE, J0, and J45 refractive components,

Fig 1. Postoperative spherical equivalent refraction (accuracy) one year after surgery
Fig 1. Postoperative spherical equivalent refraction (accuracy) one year after surgery
Fig 2. Distribution of refractive cylinder (D) before and one year after the surgery

decreased significantly after one year of follow-up (p \ 0.05); the SE component dropped from – 1.64 ± 3.72D preoperatively to – 0.06 ± 0.29D one year after surgery; J0 and J45 decreased from – 0.10 ± 1.11D and 0.09 ± 0.67D preoperatively to – 0.02 ± 0.14D and 0.01 ± 0.11D at one year post- operatively, respectively. To visualize the change in refractive cylinder due to the toric IOL implantation better, Figure 4 shows the astigmatic component of the power vector as represented by the two-dimen- sional vector (J0, J45) for refractive astigmatism before and one year after the surgery. The origin in this graph (0, 0) represents an eye free of astigmatism. Inrelation to the rotational stability of the toric IOL, we found at postoperative one year a mean toric axis rotation of 1.10° ± 1.71°, with a range varying from 0° to 5°.

Figure 5 shows the percentage of eyes with cumu- lative preoperative Snellen CDVA and postoperative Snellen UDVA and CDVA (20/x or better). After surgery, 58% of eyes (n = 59) showed a UDVA of 20/20 and improved to 77% (n = 79) for CDVA postoperatively; 77% (n = 79) and 100% (n = 102) of eyes showed UDVA and CDVA of 20/25 or better after the surgery, respectively. Compared to the preoperative CDVA, the percentages of cumulative UDVA and CDVA increased after the surgery. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.88 ± 0.17 and 0.96 ± 0.07, respectively.


Figure 5 shows the percentage of eyes with cumu- lative preoperative Snellen CDVA and postoperative Snellen UDVA and CDVA (20/x or better). After surgery, 58% of eyes (n = 59) showed a UDVA of 20/20 and improved to 77% (n = 79) for CDVA postoperatively; 77% (n = 79) and 100% (n = 102) of eyes showed UDVA and CDVA of 20/25 or better after the surgery, respectively. Compared to the preoperative CDVA, the percentages of cumulative UDVA and CDVA increased after the surgery. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.88 ± 0.17 and 0.96 ± 0.07, respectively.

As introduced, the use of toric IOLs to correct corneal astigmatism at the time of cataract surgery improved our patients’ quality of vision. These lenses increased the percentage of satisfaction, resulting in spectacle independence [4, 23]. In the present study, we analyzed the outcomes at the one-year follow-up, reported after implanting the Precizon toric IOL in a large population. For comparative purposes, we have included in Table 2 those previous clinical studies published about this lens. Five clinical studies reported data with several samples, follow-ups, ages, and corneal astigmatism to be corrected, among other parameters. Specifically, Table 3 shows the mean values and ranges, when available, for visual acuity and refractive outcomes. Rotational stability of the lens for each study was also included.

Fig. 4 Representation of the astigmatic vector (J0 and J45)
Fig. 4 Representation of the astigmatic vector (J0 and J45) before and one year after the surgery. Scatterplot for J0 and J45 calculated with the preoperative and postoperative cylinder. Note that quite black points (which represent an eye free of astigmatism) overlap at 0:0 after the surgery
Fig 3. Attempted versus achieve spherical equivalent (SE) (top)
Fig. 3 Attempted versus achieved spherical equivalent (SE) (top) and the astigmatic J0 (middle) and J45 (bottom) components of the power vector analysis. Solid lines represent the best-fit line for each graph. (Regression equation and values were included.) Dotted lines represent the range of ± 1.00D for the SE graph and ± 0.50 for J0 and J45 components
Table 2 Studies reporting data for the Precizon intraocular lens (IOL)
Table 2 Studies reporting data for the Precizon intraocular lens (IOL)
Table 3. Visual acuity refractive outcomes of the different studies reporting data for the Precizon intraocular lens
In our study, the postoperative refraction was good; 65.69% of eyes had an SE value of ± 0.13D, and 94.12% and 100% of eyes were within ± 0.50D and ± 1.00D, respectively (Figure 1). All eyes showed a refractive cylinder B 1.00D and 83.34% of eyes showed a refractive cylinder of B 0.50D (Fig- ure 2). The mean postoperative refractive cylinder value was – 0.23 ± 0.37D, which was reduced significantly after the surgery (p \ 0.01). SE percentages of ± 0.50D and ± 1.00D were compara- ble or better than those previously reported (see Table 3). Bandeira et al. [21], for example, found values of 67% and 98%, and Vale et al. [18] found values of 97.5% and 100%, respectively. Bandeira et al. [21] used the Haigis formula and an incision of 2.75 mm (including both emmetropia and mild myopia target groups), and Vale et al. [22] used the SRK/T formula with an incision of 2.4 mm. In our case, we used a smaller incision (2.2 mm) and used both the Hoffer Q and SRK/T formulas. A small incision and the use of a custom formula as a function of the axial length seem to produce better refractive outcomes. This assumption correlates with the lower amount of mean postoperative SE and cylinder reported in our case: – 0.06D and – 0.23D, followed by the outcomes reported by Vale et al. [18]: – 0.02D and 0.24D, and by Bandeira et al. [21] (emmetropia target group): – 0.15D and – 0.66D, respectively. In relation to the percentage of astigmatism B 0.50D and B 1.00D, Vale et al. [18] also showed the best outcomes and Bandeira et al. [21] the worst (including both target groups). Another point that should also be noted is that the preoperative corneal astigmatism was different for each study, ranging from 1.32D [22] to 2.34D [18]. Jung et al. [22] indicated that they expected a smaller residual cylinder because they considered both anterior and posterior corneal astig- matism, whereas other previous studies only consid- ered anterior corneal astigmatism. The postoperative values were similar than other studies [18–21] and the present one. They suggested that this might be because the preoperative corneal astigmatism in their study was much smaller than in the others. Our results agree with this assumption, because our mean preoperative value was larger too (1.92D). Also in against-the-rule astigmatism eyes, an underestimation of corneal astigmatism results from ignoring the negative power effect of the steep meridian of the posterior cornea, which tends to be aligned vertically [24]. In another study, Park et al. [25] concluded that vector summa- tion, using both anterior and posterior corneal surface power from the Pentacam instrument, yields the least astigmatic prediction error, pointing out this tool for calculating toric IOL power cylinder. They specifi- cally carried out this study by using the toric Precizon IOL with the IOLMaster and Pentacam in 41 eyes, with corneal astigmatism ranging from 1 to 5D. However, despite the small differences discussed between studies, we have to take into account that all the outcomes reported were good, and this reflects the good predictability of the lens when implanted. The calculation of the IOL power also considers the use of the IOL manufacturer’s online calculator.
In our study specifically, the good outcomes in refractive astigmatism were also shown in the vector analysis for J0 and J45 (see Figure 3 for each predictability graph) and in the distribution of points plotted in Figure 4 between pre- and post-surgery. Note that the spread of the points before the surgery (white circles) changes to a more concentrated distri- bution (black circles) post-toric IOL implantation, indicating a reduction of both components and there- fore the astigmatism. These outcomes agree with those reported by Thomas et al. [20], using the same vector analysis. Other studies [18, 19, 21, 22] analyzing the surgical- and target-induced astigmatism and angle of error also support the good findings reported. It is expected that good refractive findings should be correlated with good visual acuity outcomes. Figure 5 shows that UDVA and CDVA increased after the surgery, with 77% and 100% of eyes with UDVA and CDVA, respectively, of 20/25 or better. Mean values for UDVA and CDVA were 0.88 ± 0.17 and 0.96 ± 0.07, respectively. Mean values reported in other studies (see Table 3) are quite similar. Specifically, Vale et al. [18] reported that 100% of eyes achieved a UDVA of 20/30 or better, and Ferreira et al. [19] and Jung et al. [22] indicated that 82% and 91% of eyes achieved a UDVA of 20/25 or better, respectively. Bandeira et al. [21], in the emmetropia target group, reported 72% and 95% of eyes with UDVA and CDVA of 20/25 or better, and 84% and 98% when it was 20/32 or better. All these values agree with those found in our sample: 77% and 100%, and 94% and 100%, respectively. Toric rotation can be analyzed both directly, using the slit-lamp, and checking the postoperative residual refraction through vector analysis or wavefront aber- rometry. We analyzed the rotation of the lens by measuring the IOL marks with mydriasis, showing a mean toric axis rotation of 1.10° ± 1.71° (range from 0° to 5°). It has been estimated than 1° of rotation can result in a loss up to 3.3% of the IOL cylindrical power [26]. Considering our mean values of rotation (about 1°) and cylindrical power (about 3D), this gives a mean loss of power of about 0.10D, which is clinically negligible. We should consider that 10° or more of rotation, generally, requires surgical repositioning.   We have introduced that deviation might occur intraoperatively or after the surgery. In the first case, the use of intraoperative aberrometry reduces this possibility, because the postoperative rotation of the lens is the source of the deviation. Immediate rotation of the lens may be caused by an incomplete removal of an ophthalmic viscosurgical device [9], and late rotation may occur due to capsule shrinkage and compression of the IOL haptics (in certain IOL designs and materials). It has been suggested that closed-loop haptics (used in this study) are longer than plate haptics, which should give good initial friction, and the loops have a second insertion on the IOL that might resist later capsular compression and subse- quent rotation [18, 27–29]. Our mean value is very good because it is similar to those values found by previous studies on small samples and short follow- ups (from 1.50° to 3°; see Table 3 for detailed mean values and ranges). It has been indicated that IOL rotation may be greater in eyes with long axial lengths up to about 3° [30]. Our sample includes eyes with axial length up to 30.11 mm, but if this happened, it was not clinically relevant. Note that the accuracy of the measurement using the slit-lamp is 5°. Other methods, using digital photography, for example, increased the accuracy of measurement. In our case, no eye showed a larger value than the step of 5°. Clinical evaluation of the lens shows good rotational stability, but despite this, it has been reported in vitro that this lens is robust to rotation. In an optical bench analysis [17], the Precizon lens showed maximum rotation tolerance compared with other toric IOL models (bitoric, posterior toric surface, or with an anterior toric surface), providing superior image quality despite pupil size changes in the presence of decentration. This comes from its transitional conic toric surface (consistent power from the center to the periphery), and an aberration-free IOL tolerates decentration better than a negatively aspheric IOL [31]. This surface blends into the aspheric surface of all meridians, leading to a broader toric surface that could be more tolerant to rotation, misalignment, tilt, and decentration. In addition to the robustness in image quality that the lens provides with decentration, we have to consider the excellent rotational stability of the lens when implanted. The mean values reported previously, confirmed by our results at one year, indicate that the haptic design also offers good stability of the lens, providing a valuable platform that allows correcting a large amount of astigmatism with high-powered toric IOLs. Factors, such as the size and the asymmetry of the capsulorhexis, may affect the rotational stability of the IOL implanted. We consider that the ideal diameter for the capsulorhexis should be adjusted to the IOL optic diameter to maintain an overlap of the anterior edge of the IOL by the capsulorhexis. (In our series, we considered 5 mm.) It has been shown that FLACS produces a more predictable capsulorhexis, allowing a more stable position of the IOL within the capsular bag [14, 32]. Espaillat et al. [14] were the first to analyze exclusively toric IOL with FLACS in a sample of 63 eyes using standard phacoemulsification and 53 eyes with FLACS. They reported that there were no significant differences in UDVA and CDVA between FLACS and standard phacoemulsification. However, Chee et al. [33] found, in 794 surgeries with FLACS and 420 with standard phacoemulsification, that 12% more patients in the FLACS group had UDVA C 20/ 25, although there was no difference between the groups in terms of the percentage of eyes with UDVA C 20/32. The study by Espaillat et al. [14] indicated that FLACS may be associated with a lower absolute SE, but the differences relative to standard phacoemulsification may not always be clinically significant. These authors also found that the residual refractive astigmatism (B 0.50D) was higher in FLACS at both one month and one year (although significant only at one month). Kanellopoulos and Asimellis [16], in 66 eyes with standard phacoemul- sification and 67 with FLACS, also found a higher percentage of eyes with postoperative cylin- der \ 0.50D after FLACS (82.1%) than after standard phacoemulsification (67.7%). Several authors [14, 15] have reported that lower internal vertical coma was statistically significant in FLACS. Miha ́ltz et al. [15] suggested that visual quality may be improved by lower IOL tilt, related to lower magnitudes of coma in FLACS when compared to the standard surgery. Our results with FLACS were good but also comparable with previous studies indicated in Table 2, which used standard phacoemulsification. Matched groups (pre- operative cylinder, SE, and age); using both tech- niques would be needed to confirm this hypothesis. In any case, we consider that better sizing of the capsulorhexis carried out by FLACS is related to better IOL position and consequently a decrease of internal aberrations.

As we have reported, the use of intraoperative aberrometry minimizes the incidence of intraoperative alignment errors [7, 8], allowing realization of the most adequate IOL power and position and reducing  postoperative astigmatism [34]. Intraoperative aber- rometry enables intraoperative measurement of resid- ual refraction, allowing the surgeon to position the lens accurately, based on live residual refractive cylinder results. Hatch et al. [34] found that patients after cataract surgery with IOL toric implantation using intraoperative aberrometry were 2.4 times more likely to have \ 0.50D of postoperative astigmatism. Woodcock et al. [7], in a sample of 242 eyes, found that intraoperative aberrometry increased the percent- age of eyes with postoperative refractive astigma- tism B 0.50D and reduced the mean postoperative refractive astigmatism at one month. In contrast, Solomon and Salas [35], in a comparative study with 104 eyes, concluded that intraoperative markerless, computer-assisted registration, and biometric guid- ance summarily yielded less remaining refractive cylinder than toric IOL placement guided by intraop- erative aberrometry. In our series, we have found intraoperative aberrometry to be an excellent system to control IOL alignment during the surgery.

The outcomes of our clinical study show that the implantation of the Precizon toric IOL, using intraop- erative aberrometry with FLACS, provided good visual and refractive outcomes. Predictability both for SE and astigmatism and excellent rotational stability support the use of this lens in patients with different degrees of corneal astigmatism

Author contributions – FPP conception of work, data analysis and interpretation, writing of manuscript. RPP data acquisition, data analysis and interpretation. RRM; data analysis and interpretation, writing of manuscript, RRM data analysis and interpretation, PTR data analysis and interpretation. All authors read and approved the final manuscript.

Funding None.


Conflict of interest – The authors declare that there is no conflict of interest.

Consent to publish – Patients signed informed consent.

Human and animal rights – All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent – Informed consent was obtained from all individual participants included in the study.

1. Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, Gonzalez-Méijome JM, Cerviño A (2009) Prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg 35:70–75

2. Hoffmann PC, Hu ̈tz WW (2010) Analysis of biometry and prevalence data for corneal astigmatism in 23,239 eyes.J Cataract Refract Surg 36:1479–1485.

3. Atchison DA, Guo H, Charman WN, Fisher SW (2009) Blur limits for defocus, astigmatism and trefoil.Vis Res 49:2393–2403

4. Kessel L, Andresen J, Tendal B, Erngaard D, Flesner P, Hjortdal J (2016) Toric intraocular lenses in the correction of astigmatism during cataract surgery: a systematic review and meta-analysis. Ophthalmology 123:275–286

5. Visser N, Ruız-Mesa R, Pastor F, Bauer NJ, Nuijts RM, Monte ́ s-Mico ́ R (2011) Cataract surgery with toric intraocular lens implantation in patients with high corneal astigmatism. J Cataract Refract Surg 37:1403–1410

6. Ruiz-Mesa R, Carrasco-Sánchez D, Díaz-Alvarez SB, Ru ́ız- Mateos MA, Ferrer-Blasco T, Monte ́ s-Mico ́ R (2009) Refractive lens exchange with foldable toric intraocular lens. Am J Ophthalmol 147(990–6):996

7. Woodcock MG, Lehmann R, Cionni RJ, Breen M, Scott MC (2016) Intraoperative aberrometry versus standard preop- erative biometry and a toric IOL calculator for bilateral toric IOL implantation with a femtosecond laser: one-month results.J Cataract Refract Surg 42:817–825

8. Cionni RJ, Breen M, Hamilton C, Williams R (2019) Retrospective analysis of an intraoperative aberrometry data- base: a study investigating absolute prediction in eyes implanted with low cylinder power toric intraocular lenses. Clin Ophthalmol 13:1485–1492

9. Miyake T, Kamiya K, Amano R, Iida Y, Tsunehiro S, Shimizu K et al (2014) Long-term clinical outcomes of toric intraocular lens implantation in cataract cases with preexisting astigmatism.>J Cataract Refract Surg 40:1654–1660

10. Ohmi S (1993) Decentration associated with asymmetric capsular shrinkage and intraocular lens size. J Cataract Refract Surg 19:640–643

11. Strenn K, Menapace R, Vass C (1997) Capsular bag shrinkage after implantation of an open-loop silicone lens and a poly (methyl methacrylate) capsule tension ring. J Cataract Refract Surg 23:1543–1547

12. Kim MH, Chung TY, Chung ES (2010) Long-term efficacy and rotational stability of AcrySof toric intraocular lens implantation in cataract surgery.Korean J Ophthalmol 24:207–212

13. Ruhswurm I, Scholz U, Zehetmayer M et al (2000) Astig- matism correction with a foldable toric intraocular lens in cataract patients. J Cataract Refract Surg 26:1022–1027

14. Espaillat A, Pérez O, Potvin R (2016) Clinical outcomes using standard phacoemulsification and femtosecond laser- assisted surgery with toric intraocular lenses. >Clin Oph- thalmol 10:555–563

15. Miháltz K, Knorz MC, Ali´p JL et al (2011) Internal aber- rations and optical quality after femtosecond laser anterior capsulotomy in cataract surgery.J Refract Surg 27:711–716

16. Kanellopoulos AJ, Asimellis G (2016) Standard manual capsulorhexis/ultrasound phacoemulsification compared to femtosecond laser-assisted capsulorhexis and lens frag- mentation in clear cornea small incision cataract surgery.Eye Vis (Lond) 29(3):20

17. Kim MJ, Yoo YS, Joo CK, Yoon G (2015) Evaluation of optical performance of 4 aspheric toric intraocular lenses using an optical bench system: Influence of pupil size, decentration, and rotation.J Cataract Refract Surg 41:2274–2282

18. Vale C, Menezes C, Firmino-Machado J, Rodrigues P, Lume M, Tenedório P, Menéres P, Brochado Mdo C (2016) Astigmatism management in cataract surgery with Precizon(Ò) toric intraocular lens: a prospective study. Clin Ophthalmol 10:151–159.

19. Ferreira TB, Berendschot TT, Ribeiro FJ (2016) Clinical outcomes after cataract surgery with a new transitional toric intraocular lens. J Refract Surg 32:452–459

20. Thomas BC, Khoramnia R, Auffarth GU, Holzer MP (2018) Clinical outcomes after implantation of a toric intraocular lens with a transitional conic toric surface. Br J Ophthalmol 102:313–316

21. Bandeira F, Morral M, Elies D, Eguiza S, Souki S, Manero F, Gu ̈ell JL (2018) Transitional conic toric intraocular lens for the management of corneal astigmatism in cataract surgery. Clin Ophthalmol 12:1071–1079

22. Jung NY, Lim DH, Hwang SS, Hyun J, Chung TY (2018) Comparison of clinical outcomes of toric intraocular lens, Precizon vs Tecnis: a single center randomized controlled trial. BMC Ophthalmol 18:292

23. Visser N, Bauer NJ, Nuijts RM (2013) Toric intraocular lenses: historical overview, patient selection, IOL calculation, surgical techniques, clinical outcomes, and complications. J Cataract Refract Surg 39:624–637

24. Goggin M, Zamora-Alejo K, Esterman A, van Zyl L (2015) Adjustment of anterior corneal astigmatism values to incorporate the likely effect of posterior corneal curvature for toric intraocular lens calculation. J Refract Surg 31:98–102

25. Park DY, Lim DH, Hwang S, Hyun J, Chung TY (2017) Comparison of astigmatism prediction error taken with the Pentacam measurements, Baylor nomogram, and Barrett formula for toric intraocular lens implantation. BMC Ophthalmol 17:156

26. Novis C (2000) Astigmatism and toric intraocular lenses. Curr Opin Ophthalmol 11:47–50

27. Buckhurst JP, Wolffshon JS, Davies LN, Naroo SA (2010) Surgical correction of astigmatism during cataract surgery. Clin Exp Optom 93:409–418

28. Patel CK, Ormonde S, Rosen PH, Bron AJ (1999) Postop- erative intraocular rotation; a randomized comparison of plate and loop haptics implants. Ophthalmology 106:2190–2195

29. Prinz A, Neumayer T, Buehl W et al (2011) Rotational stability and posterior capsule opacification of a plate-loop and an open-loop-haptic intraocular lens. J Cataract Refract Surg 37:251–257

30. Shah GD, Praveen MR, Vasavada AR, Vasavada VA, Rampal G, Shastry LR (2012) Rotational stability of a toric intraocular lens: influence of axial length and alignment in the capsular bag. J Cataract Refract Surg 38:54–59

31. Pérez-Vives C, Ferrer-Blasco T, Madrid-Costa D, García- Lázaro S, Montés-Micó R (2014) Optical quality of aspheric toric intraocular lenses at different degrees of decentering. Graefes Arch Clin Exp Ophthalmol 252:969–975

32. Kranitz K, Miháltz K, Sándor GL et al (2012) Intraocular lens tilt and decentration measured by Scheimpflug camera following manual or femtosecond laser-created continuous circular capsulotomy. Refract Surg 28:259–263

33. Chee SP, Yang Y, Ti SE (2015) Clinical outcomes in the first two years of femtosecond laser-assisted cataract surgery. Am J Ophthalmol 159:714–719

34. Hatch KM, Woodcock EC, Talamo JH (2015) Intraocular lens power selection and positioning with and without intraoperative aberrometry. J Refract Surg 31:237–242

35. Solomon JD, Ladas J (2017) Toric outcomes: computer- assisted registration versus intraoperative aberrometry. J Cataract Refract Surg 43:498–504

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