Evaluation of Toric Intraocular Lenses in Patients With Low Degrees of Astigmatism

Clinical Results of a Trifocal Toric Intraocular Lens Using the Holladay Total Surgically Induced Astigmatism Formula for Correcting Low Corneal Astigmatism in Japanese Patients

Purpose

To evaluate the effectiveness and safety of the AcrySof IQ PanOptix toric intraocular lens (IOL) with cylinder power of 1.0 D (TFNT20) in a Japanese population with low corneal astigmatism and compare with historical control data for nontoric IOLs.

Setting

Tokyo Dental College Suidobashi Hospital, Tokyo, Japan.

Design

Prospective, single-center study.

Methods

Patients ≥20 years old received TFNT20 IOL in at least 1 eye based on Alcon Toric calculator (Holladay Total surgically induced astigmatism). Effectiveness endpoints included the percentage of eyes with refractive cylinder ≤0.25 D at 30-60 days after surgery, which was compared with a historical control threshold rate of 29.2% for nontoric IOLs and refractive cylinder ≤0.50 D. Monocular uncorrected distance visual acuity (UDVA; 5 m), uncorrected intermediate visual acuity (UIVA; 60 cm), uncorrected near visual acuity (UNVA; 40 cm), and adverse events were evaluated.

Results

Of 41 eyes implanted with TFNT20 IOLs, 37 eyes (90%) achieved refractive cylinder ≤0.25 D at 30-60 days after surgery, demonstrating the superiority of TFNT20 compared with historical data (P<0.0001). Refractive cylinder of ≤0.50 D was achieved by 41 eyes (100%). At 30-60 days, mean ± SD monocular CDVA was -0.15 ± 0.07 logMAR, UDVA was -0.09 ± 0.09 logMAR, UIVA was -0.00 ± 0.07 logMAR, and UNVA was 0.03 ± 0.07 logMAR. Six eyes (15%) had elevated postoperative intraocular pressure, which returned to normal and was not device-related.

Conclusion

TFNT20 IOLs successfully reduced postoperative refractive cylinder and provided good distance, intermediate, and near uncorrected VAs in Japanese patients with low corneal astigmatism.

Managing low corneal astigmatism in patients with presbyopia correcting intraocular lenses: a narrative review

Cataract surgery has become a refractive procedure in which emmetropia is the goal, with the implantation of extended depth-of-focus or multifocal intraocular lenses (IOLs) being the commonly selected option to restore vision beyond the far distance. The selection criteria for implanting these lenses can differ from those for monofocal IOLs and even between technologies, as eye characteristics can affect postoperative visual performance. Corneal astigmatism is an eye characteristic that can affect visual performance differently, depending on the implanted IOL. The magnitude of corneal astigmatism, the tolerance of the IOL to this astigmatism, economic aspects, comorbidities, and the efficacy of astigmatism treatment are factors that can make surgeons' doubt as to what astigmatism treatment should be applied to each patient. This review aims to summarize the current evidence related to low astigmatism tolerance in presbyopia-correcting lenses, the efficacy achieved through corneal incisions, and their comparison with the implantation of toric IOLs.

Time-efficiency assessment of guided toric IOL cataract surgery: a pilot study

PURPOSE

To compare the time spent on toric intraocular lens (IOL) implantation during cataract surgery using a manual-marking versus a digital image-guided system (the Verion) for toric IOL alignment.

SETTINGS

All procedures were performed at the Instituto Oftalmológico Quirónsalud ophthalmology clinic (A Coruña, Spain).

DESIGN

We designed an experimental and longitudinal (1-month follow-up) study.

METHODS

A total of 98 eyes of 65 participants (68.2 ± 12.2 years) were divided into two groups: 49 eyes operated with toric IOL alignment using a manual-marking technique (manual group) and another 49 eyes operated using image-guided marking (Verion group). The primary variable for comparison between both groups was cataract surgery time. Other outcomes such as toric IOL misalignment, spherical equivalent (SE), astigmatism, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were also measured.

RESULTS

The total cataract surgery time was 2:09 minutes shorter (p  < 0.001) with the Verion system (12:12 ± 2:20) compared to the surgical procedure performed using manual marking (15:27 ± 3:04). One month after surgery, there were no statistical differences in terms of toric IOL misalignment between the Verion (3.38° ± 2.95°) and the manual group (4.66° ± 3.95°). No statistical differences were observed between groups for refractive and visual outcomes either (p ≥ 0.05).

CONCLUSIONS

The cataract surgery time was reduced when the procedure was assisted using the Verion system to align the IOL compared to manual marking, maintaining the same efficacy in terms of toric IOL misalignment, residual refraction, and visual acuity.

Femtosecond laser-assisted arcuate keratotomy at the time of cataract surgery for the management of preexisting astigmatism

PURPOSE

To evaluate the outcomes of femtosecond laser-assisted arcuate keratotomy combined with cataract surgery in eyes with low-to-moderate corneal astigmatism.

SETTING

Eyes of York Private Practice Ophthalmology Clinic, York, Pennsylvania, USA.

DESIGN

Retrospective case series.

METHODS

This retrospective analysis included case records of patients with preexisting corneal astigmatism ranging from 0.5 to 2.0 diopter (D). Study parameters included corneal astigmatism, refractive astigmatism, and uncorrected (UDVA) and corrected (CDVA) distance visual acuities. The results, which were analyzed at 3 months postoperatively, included frequency distribution histograms, vector analysis, and single-angle polar plots.

RESULTS

The study comprised case records of 189 eyes of 143 patients (56 men and 87 women). The postoperative refractive astigmatism was reduced significantly compared with preoperative corneal astigmatism to 0.14 D ± 0.23 (SD) from 0.92 ± 0.34 D (P < .001). One hundred eighty-one eyes (95.8%) demonstrated postoperative refractive astigmatism of 0.5 D or less. The mean surgically induced change along the preoperative steep axis was -0.59 ± 0.56 D, and the change along the orthogonal axis was 0.01 ± 0.35 D. Postoperatively, 171 eyes (90.5%) had astigmatism angle of error of 15 degrees or less. The postoperative mean UDVA and CDVA were 0.09 ± 0.16 logarithm of the minimum angle of resolution (logMAR) and 0.02 ± 0.05 logMAR, respectively. One hundred seventy eyes (90%) had a postoperative UDVA of 20/30 or better. The results demonstrated stability at 12 months postoperatively. No intraoperative or postoperative arcuate keratotomy-related events were observed.

CONCLUSION

The results suggest that femtosecond laser-assisted arcuate keratotomy represents a safe and effective method for astigmatism correction at the time of cataract surgery with demonstrated stability of correction for at least 1 year postoperatively.

Comparing Visual Acuity, Low Contrast Acuity and Refractive Error After Implantation of a Low Cylinder Power Toric Intraocular Lens or a Non-Toric Intraocular Lens

Purpose

To compare uncorrected and best-corrected visual acuity, low contrast acuity, residual refraction and ocular biometry after low cylinder power toric intraocular lens (IOL) or non-toric IOL implantation.

Patients and Methods

This was a non-interventional comparative study of visual outcomes after uncomplicated cataract or refractive lens exchange surgery with either a low cylinder (Low_Cyl) or non-toric (Non_Toric) IOL of similar design implanted (AcrySof^® T2 IQ Toric IOL and AcrySof^® IQ IOL). Subjects in both groups had to have been eligible for the low cylinder IOL based on biometry. They had to have uncorrected distance visual acuity (UDVA) of 20/32 (0.2 logMAR) or better at the time of their single diagnostic study visit. Clinical evaluation included the manifest refraction, visual acuity (VA), low contrast VA and ocular biometry.

Results

A total of 94 eyes were enrolled, 51 Low_Cyl and 43 Non_Toric. The mean manifest refractive cylinder was statistically significantly lower (~0.25 D) in the Low_Toric group (p < 0.01) and significantly more eyes had 0.25 D or less of refractive cylinder in that group (p = 0.03). The orientation of the preoperative anterior corneal astigmatism was a significant cofactor, with the difference between groups more evident when astigmatism was against the rule. Uncorrected high contrast visual acuity was statistically significantly better in the Low_Toric group (p = 0.02) as was the percentage of eyes with 20/20 visual acuity (p = 0.05). Uncorrected low contrast visual acuity was not statistically significantly different in mesopic or photopic conditions.

Conclusion

The low cylinder power toric IOL provided better uncorrected visual acuity and lower residual refractive cylinder than a similar non-toric IOL after cataract surgery.

Trifocal toric intraocular lenses in eyes with low amount of corneal astigmatism

AIM

To evaluate the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with low degrees of corneal astigmatism.

METHODS

Twenty-six eyes of 22 patients who underwent implantation a trifocal toric IOL (FineVision PODFT, PhysIOL s.a., Liege, Belgium) were enrolled. Phacoemulsification with femtosecond laser, capsular tension ring insertion and intraoperative aberrometry were performed in all cases. All IOLs used showed a cylinder power of 1.00 D. Main outcome measures were refractive error and corrected-distance visual acuity (CDVA) and uncorrected-distance visual acuity (UDVA) values. Eyes were evaluated at 4mo post-surgery.

RESULTS

Totally 50% of eyes showed a spherical equivalent (SE) within ±0.13 D and all of them within ±0.50 D. The mean SE and refractive cylinder were -0.02±0.23 and -0.16±0.22 D, respectively. Vector analysis revealed that 100% of eyes were within ±0.50 D for the SE and cylindrical components (J0 and J45). Refractive changes were not correlated with keratometric changes (P>0.05) showing that the reduction in astigmatism comes from the trifocal toric IOL. Of 81% and 96% of eyes showed UDVA and CDVA of 20/20, respectively. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.97±0.05 and 0.99±0.02 (about 20/20), respectively.

CONCLUSION

Our study suggests that the use of this trifocal toric IOL in patients with low amount of astigmatism provides accurate refractive outcomes and enables them to achieve excellent visual acuity.

A Novel Sequential Docking Technique: Use of Femtosecond Arcuate Keratotomy and Femtosecond Assisted Cataract Surgery Using a Pupil Expansion Ring on a Patient with Intraoperative Floppy Iris Syndrome

Purpose

The purpose of this study was to evaluate the efficacy of a novel double-docking technique, incorporating the use of femtosecond laser arcuate keratotomy (FSAK) in correcting low-degree astigmatism and Malyugin ring, in a patient with intraoperative floppy iris syndrome (IFIS).

Methods

A case report of a 72-year-old man with grade 4 cataract, low-degree astigmatism (<2D), and IFIS (pupil size <4 mm, intraoperatively) is presented. The patient underwent cataract surgery using a femtosecond laser to treat low-degree astigmatism because the patient requested for the use of a multifocal  intraocular lens (IOL). The first docking was performed to complete arcuate keratotomy, produce the mainparacentesis incisions, and create clear corneal incisions. Insertion of the Malyugin ring was performed after the first docking, whereas the second one was executed to complete continuous curvilinear capsulotomy and lens fragmentation. The patient's uncorrected visual acuity (UCVA) was measured pre- and post-operatively. The complications were evaluated post-operatively and 3 months later during the follow-up visit.

Results

The patient's UCVA for distance improved from 0.3 (6/12 Snellen equivalent) to 0 (6/6 Snellen equivalent) logMAR post-operatively. During the follow-up visit, the patient's uncorrected near visual acuity was at J2. His corneal astigmatism changed from -1.0 Diopter @177° pre-operative to -0.12 D @173° post-operative. No other intraoperative or post-operative complications were observed.

Conclusion

The double-docking technique, with the use of FSAK, and Malyugin ring produced successful surgical outcomes for the patient. The benefits of this technique allow surgeons to avoid changing the shape of the patient's cornea from the injection of the viscoelastic device into the anterior chamber, which could lower the femtosecond laser's precision and docking location.

Efficacy of astigmatic correction after femtosecond laser-guided cataract surgery using intraoperative aberrometry in eyes with low-to-moderate levels of corneal astigmatism

PURPOSE

To evaluate the efficacy of astigmatic correction with two types of toric intraocular lenses (IOLs) after femtosecond laser-assisted cataract surgery (FLACS) in eyes with low-to-moderate corneal astigmatism using intraoperative aberrometry for optimizing the position of the toric IOL.

METHODS

Retrospective study includes a total of 99 eyes of 73 patients with anterior keratomeric astigmatism ≤ 3 D and undergoing FLACS (Catalys, Johnson & Johnson Vision) with implantation of a monofocal (Ankoris, PhysIOL) or a multifocal toric IOL with the same platform (Pod FT, PhysIOL). In all cases, intraoperative aberrometry was used (Optiwave refractive analysis, ORA, system, Alcon). Visual and refractive outcomes were evaluated preoperatively and at 4 months after surgery with vector analysis of astigmatic changes.

RESULTS

A total of 89.9%, 93.9% and 97.0% showed a postoperative sphere, cylinder and spherical equivalent within ± 0.50 D, respectively. Mean difference vector (DV) was 0.22 ± 0.27 D, mean magnitude of error (ME) was 0.13 ± 0.29 D, and mean angle of error (AE) was 1.52 ± 11.64°. Poor correlations of preoperative corneal astigmatism with DV (r = - 0.032, p = 0.833), ME (r = - 0.344, p = 0.001) and AE (r = - 0.094, p = 0.377) were found. Likewise, no statistically significant differences were found between monofocal and multifocal toric IOL subgroups in DV (p = 0.580), ME (p = 0.702) and AE (p = 0.499).

CONCLUSIONS

The combination of FLACS and intraoperative aberrometry to optimize the position of a toric IOL allows a very efficacious correction of preexisting low-to-moderate corneal astigmatism.

[Toric lens implantation in cataract surgery: Automatic versus manual horizontal axis marking, analysis of 50 cases]

SUBJECT

The main objective of our study is to evaluate the contribution of automated conjunctival recognition in the alignment of toric implants by comparing the automatic alignment optimized with Callisto™ to the manual marking of the horizontal axis.

MATERIALS AND METHODS

We performed a prospective, descriptive, and monocentric study on patients undergoing cataract surgery with toric implantation (Asphina 709 Zeiss), operated by a surgeon with good experience in toricity, between September 2016 and March 2017. We analyzed the agreement between the manual marking of the 0°-180° axis versus the one automatically generated by the Callisto™, as well as the alignment of the IOL and the refractive results at 1 month.

RESULTS

We included 50 eyes of 26 patients. The corrected mean astigmatism was 1.9 D. The mean difference between the 2 axes was 4.7° [0°-12.3°]. Only 50 % of the preoperative manual markings were consistent with the automatic measurement (<5°). At one month, the average rotation recorded was 4.3° [0°-29°]. The alignment was identical for 70 % (n=35) of the IOL (≤5°). As for residual subjective astigmatism, it was on average 0.58 D. The mean visual acuity without correction was 8/10 and 55 % had 10/10 without correction.

DISCUSSION

The refractive performance depends on the preoperative measurement, the correct alignment of the IOL and its stability in the bag. Our study shows the value of automatic conjunctival recognition in the determination of the axis of peroperative alignment, even in an experienced operator. This precision is essential for a good refractive result, especially since the residual astigmatism in case of misalignment will increase with the power of the implant.

CONCLUSION

Our study shows excellent refractive results, whatever the initial astigmatism, using the automatic alignment. The precision of the toric implantation opens the way to the toric multifocal implantation under the best conditions.

Toric lens implantation in cataract surgery: Automated versus manual horizontal axis marking, analysis of 50 cases

SUBJECT

The main objective of our study was to evaluate the contribution of automated conjunctival registration in the alignment of toric intraocular lenses by comparing automated registration optimized with Callisto^® to manual marking of the horizontal axis.

MATERIALS AND METHODS

We performed a prospective, descriptive, monocentric study on patients undergoing cataract surgery with a toric intraocular lens (Asphina 709 Zeiss), performed by a surgeon with good experience in toric implants, between September 2016 and March 2017. We analyzed the agreement between the manual marking of the 0-180° axis versus the one automatically generated by the Callisto™, as well as the alignment of the IOL and the refractive results at 1 month.

RESULTS

We included 50 eyes of 38 patients. The mean corrected astigmatism was 1,9 D. The mean difference between the 2 axes was 4,7° [0-12.3°]. Only 50 % of the preoperative manual markings were consistent with the automated measurement (<5°). At one month, the mean rotation recorded was 4,3° [0-29°]. The alignment was identical for 70 % (n=35) of the IOLs (≤5°). As for residual subjective astigmatism, the mean was 0.58 D. The mean visual acuity without correction was 8/10 and 55 % saw 10/10 without correction.

DISCUSSION

Refractive performance depends on preoperative measurement, correct alignment of the IOL and its stability in the bag. Our study shows the value of automated conjunctival registration in the determination of the intraoperative axis of alignment, even with an experienced surgeon. This precision is essential for a good refractive result, especially since residual astigmatism in the case of misalignment will increase with the power of the implant.

CONCLUSION

Our study shows excellent refractive results, regardless of the initial astigmatism, using automated alignment. Precision of toric implantation opens the way to toric multifocal implantation under the best conditions.