Effect of Refractive Astigmatism on All-Distance Visual Acuity in Eyes With a Trifocal Intraocular Lens

Comparing clinical outcomes of trifocal intraocular lens in patients with and without prior history of laser in situ keratomileusis for myopia

BACKGROUND

To compare clinical outcomes of trifocal intraocular lens in patients with and without prior history of laser in situ keratomileusis (LASIK).

METHODS

A retrospective study included patients who underwent bilateral cataract surgery and PanOptix trifocal intraocular lens (IOLs) implantation. Patients were grouped: Group A for patients with history of LASIK and Group B for patients without history of LASIK. Postoperative outcome measures comprised distance, intermediate, and near visual acuity, manifest refraction, defocus curve, contrast sensitivity, visual quality, patient satisfaction, and the rate of spectacle independence.

RESULTS

A total of 288 eyes (144 patients) were included: 132 eyes in Group A and 156 eyes in Group B. At 6 months post-surgery, patients of both groups achieved a continuous satisfying visual acuity from 33 cm to distance. 73% of eyes in Group A and 75% of eyes in Group B were within ± 0.50 D of emmetropia (P > 0.05). The percentages of eyes within ± 1.00 D of emmetropia were 98% for Group A and 96% for Group B (P > 0.05). The total scores of satisfaction were 52.58 ± 3.46 for Group A and 53.23 ± 3.46 for Group B (P > 0.05). Most of patients (98% for Group A, 99% for Group B) were able to be spectacle independence for daily living. 53% of patients in Group A and 51% in Group B experiencd mild to moderate negative visual symptoms, which made it a little or moderate difficult to drive at night.

CONCLUSIONS

Cataract patients with and without history of LASIK could safely undergo implantation of the PanOptix IOLs, which results in precise refractive outcomes and satisfactory visual acuity. Although contrast sensitivity decreased and some negative visual symptoms were observed, patients' satisfaction was generally high due to the high rate of spectacles independence. There were no statistically significant differences between the study groups.

Tolerance to induced astigmatism of patients with trifocal or extended depth of focus intraocular lens implantation

Background

Residual astigmatism is common after cataract surgery involving implantation of an intraocular lens, yet the tolerance of presbyopia-correcting intraocular lens to astigmatism of different magnitudes and axes is poorly understood. Here we compared visual acuity and quality in the presence of induced astigmatism after implantation of a trifocal or extended-depth-of-focus (EDOF) intraocular lens, the two widely used presbyopia-correcting intraocular lenses.

Methods

At least 3 months after implantation of a TFNT00 or ZXR00 intraocular lens, patients were analyzed by slit-lamp examination, non-contact tonometry, subjective refraction, iTrace aberrometry, and corneal topography. After correction of residual astigmatism, astigmatism of different magnitudes on different axes was induced using cylindrical lenses, and overall visual acuity was measured, while objective visual quality was measured using the Optical Quality Analysis System II. Subjects were also asked about subjective visual quality using the Visual Function-14 questionnaire.

Results

Comparison of 18 individuals who received a trifocal lens and 19 who received an EDOF lens showed that objective visual quality was better in the EDOF group regardless of the magnitude or axis of the induced astigmatism. In both groups, astigmatism of at least -1.00 DC influenced distant vision more severely when the axis was 45° than 0° or 90°, meanwhile astigmatism of at least -1.50 DC influenced near and intermediate vision more severely when the axis was 45° than 0° or 90°.

Conclusion

Trifocal or EDOF intraocular lenses are less tolerant of oblique astigmatism than astigmatism with or against the rule. EDOF lenses may provide better objective visual quality than trifocal lenses in the presence of astigmatism, regardless of its magnitude or axis.

Comparison of Postoperative Axial Rotation of the Toric Intraocular Lens in Cataract Surgery Combined with Vitrectomy versus Cataract Surgery Alone

INTRODUCTION

This study compared the postoperative axial rotation of the toric intraocular lens (T-IOL) after cataract surgery combined with vitrectomy versus cataract surgery alone.

METHODS

This retrospective, non-randomized, observational study enrolled patients who underwent cataract surgery combined with vitrectomy in one eye and cataract surgery alone in the contralateral eye. AcrySof Toric IOLs (Alcon Laboratories) were implanted in both eyes of the same patient. The axial rotation of the T-IOL was analyzed 3 months postoperatively using photographs obtained during and after surgery. In the combined group, T-IOL axial alignment was performed before vitrectomy. Preoperative corneal astigmatism and postoperative residual astigmatism were also compared in both groups.

RESULTS

This study examined 36 eyes of 18 patients (74.7 ± 6.8 years). The axial rotation was 2.94 ± 1.70° in the cataract group versus 3.06 ± 2.34° in the combined group 3 months postoperatively, and the difference lacked significance (p = 0.98). In the combined group, the mean axial rotation during surgery was 2.17 ± 1.80°. Axial rotation within 5° was observed in 17 of 18 eyes (94.4%) in the cataract group and 16 of 18 eyes (88.9%) in the combined group, with no significant difference (p = 0.54). The comparison of postoperative residual astigmatism with preoperative corneal astigmatism revealed a significant improvement from 1.49 ± 0.40 D to 0.39 ± 0.47 D in the cataract group (p < 0.0001) and from 1.61 ± 0.40 D to 0.42 ± 0.43 D in the combined group (p < 0.0001).

CONCLUSIONS

The postoperative axial rotation of the T-IOL in eyes that underwent cataract surgery combined with vitrectomy was stable and comparable to that of eyes that underwent cataract surgery alone.

Hydrophobic Trifocal Toric Intraocular Lens Outcomes in Japanese Eyes After Cataract Surgery

Purpose

To analyze the refractive and visual outcomes following cataract surgery and implantation of a new hydrophobic trifocal toric intraocular lens (IOL) in Japanese eyes with different degrees of corneal astigmatism.

Methods

A total of 66 eyes from 39 patients implanted with a FineVision HP Toric IOL (Beaver-Visitec International Inc) were analyzed retrospectively. The main outcome measures considered were refraction, monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), and distance-corrected intermediate visual acuity (DCIVA) at 80 and 66 cm, uncorrected near visual acuity (UNVA) and distance-corrected near visual acuity (DCNVA) at 40 cm. Eyes were evaluated at three months post-surgery.

Results

Sixty-five eyes (98.48%) were within ±0.50D of spherical equivalent, and all were within ±1.00D (mean: 0.00±0.21D). Moreover, 63 eyes (95.45%) had ≤0.50D of residual astigmatism, and all had ≤1.00D (mean: -0.08±0.23D). Similarly, 58 (87.88%) and 60 eyes (90.91%) had ≥20/20 UDVA and CDVA, respectively, with 65 (98.48%) and 66 eyes (100%) achieving ≥20/25 UDVA and CDVA, respectively. In addition, 28 (42.42%) and 23 eyes (34.85%) had ≥20/25 DCIVA at 80 and 66 cm, respectively, with 49 (74.24%) and 52 eyes (78.79%) achieving ≥20/32 DCIVA at 80 and 66 cm, respectively. Finally, 39 (59.09%) and 40 eyes (60.61%) had ≥20/20 UNVA and DCNVA, respectively, with 58 (87.88%) and 59 eyes (89.39%) achieving ≥20/25 UNVA and DCNVA, respectively.

Conclusion

Our study shows that implantation of the new hydrophobic FineVision HP Toric IOL results in accurate refractive outcomes, with good visual acuity at different distances, in Japanese eyes.

Clinical Performance of an Omnidirectional Aberration-Free Trifocal Toric Intraocular Lens

Purpose

To assess the refractive and visual outcomes at different distances following cataract surgery with implantation of an omnidirectional aberration-free diffractive trifocal toric intraocular lens (IOL).

Methods

A total of 24 patients who underwent bilateral implantation with the TrivaT-aAY IOL were analyzed at 3-4 months post-surgery. Refractive error, monocular and binocular uncorrected and corrected-distance visual acuity (UDVA, CDVA), uncorrected and corrected-distance intermediate visual acuity (UIVA, CDIVA) at 60 cm, uncorrected and corrected-distance near visual acuity (UNVA, CDNVA) at 40 cm, monocular and binocular defocus curve and rotational stability were measured. Patients also completed the Catquest-9SF questionnaire at the last postoperative visit.

Results

The postoperative mean values of binocular logMAR CDVA, CDIVA and CDNVA were -0.06±0.06, 0.05±0.07 and 0.07±0.08, respectively. One hundred percent of patients showed a cumulative binocular CDVA ≥20/25, and 95.83% of patients showed a cumulative binocular CDIVA and CDNVA ≥20/32. The mean postoperative spherical equivalent was 0.07±0.26D and 100% and 97.92% eyes were within ±1.00D and ±0.50D, respectively. The mean postoperative refractive cylinder was -0.22±0.29D and 100% and 89.58% eyes showed a value ≤1.00D and ≤0.50D, respectively. The defocus curves showed a wide range of useful vision, with visual acuity values >0.2 logMAR. Mean absolute IOL rotation was 2.19±2.17 degrees and all eyes had a rotation <10 degrees. For the questionnaire, 95.83% of patients reported being quite satisfied to very satisfied with their vision and about 79.17% did not report any difficulty with their vision in their everyday life. Between 83.33% and 95.83% of patients reported no difficulty performing different tasks. No intra- and postoperative complications were reported during the follow-up.

Conclusion

Our study shows that the TrivaT-aAY IOL provides good visual acuities at all distances and refractive outcomes with excellent rotational stability and with high satisfaction among our patients after its implantation.

A New Methodology for Evaluating the Potential Impact of Residual Refractive Astigmatism in Pseudophakic Patients

Purpose

To validate a new methodology to evaluate the impact of astigmatism in pseudophakia using an astigmatic defocus curve.

Setting

Hospital Oftalmológico de Brasilia, Brazil.

Design

Non-randomized cohort study.

Methods

For every point of the defocus curve, from -2.00 to +3.00 with 0.50D intervals, visual acuity was assessed with optically induced astigmatism (0.50D, 1.00D and 1.50D at 90 and 180 degrees) in pseudophakic patients implanted with a refractive-enhanced intraocular lens.

Results

Twelve patients were analyzed. A statistically significant difference was found between the 90° (ATR) and 180°(WTR) axis with 1.50D astigmatism, providing better visual acuity in ATR astigmatism (p < 0.05).

Conclusion

This new methodology is reproducible, useful and may predict residual astigmatism tolerance in pseudophakic patients, which may help with surgery planning and IOL decision-making.

Effect of Long-Acting Diquafosol Sodium on Astigmatism Measurement Repeatability in Preoperative Cataract Cases with Dry Eyes: A Multicenter Prospective Study

INTRODUCTION

Dry eye can compromise corneal astigmatism measurement repeatability during preoperative cataract surgery examination. No previous studies have analyzed the effectiveness of long-acting 3% diquafosol sodium (LA-DQS) on astigmatism measurement repeatability. This research assessed the effect of LA-DQS on astigmatism measurement repeatability in preoperative patients with cataract and short tear break-up time (TBUT) type dry eyes in both eyes of the same patient. Correlations between repeatability and TBUT, corneal high-order aberrations (HOAs), and corneal astigmatism magnitude were also analyzed.

METHODS

In total, 122 eyes (61 patients) with short TBUT-type dry eye were enrolled. Preoperatively, only one eye of all patients was treated with LA-DQS for 4 weeks. TBUT and corneal HOAs were checked using CASIA 2 before and 4 weeks post-treatment. The cylindrical power and meridian of astigmatism were measured at 3- and 4-week post-treatment using IOLMaster 700. Power vectors J0 and J45 were used for astigmatism calculations. Repeatability of astigmatism measurements was assessed as the within-subject standard deviation (Sw). The relative effects of TBUT and HOAs on J0 Sw and J45 Sw were also analyzed. Comparative changes in these variables were evaluated between treated and non-treated eyes, with additional analysis of their correlations.

RESULTS

Treated eyes exhibited significant improvements in TBUT, HOAs, and post-treatment measurements of J0 Sw and J45 Sw at 3 and 4 weeks. In non-treated eyes, J0 Sw and J45 Sw showed significant correlation with TBUT and corneal HOAs. HOAs showed stronger relative associations with J0 Sw and J45 Sw than TBUT. In non-treated eyes, no significant correlation was found between cylindrical power and astigmatism measurement repeatability.

CONCLUSIONS

In short TBUT-type dry eye, preoperative treatment with LA-DQS significantly improved astigmatism measurement repeatability. This may improve the precision of intraocular lens (IOL) power calculations regardless of the magnitude of corneal astigmatism, especially when toric IOLs are used.

Femtosecond laser-assisted astigmatic keratotomy versus toric IOL implantation for correcting astigmatism in cataract patients: a systematic review and meta-analysis with trial sequential analysis

AIMS

To compare the refractive and visual outcomes of femtosecond laser-assisted astigmatic keratotomy (FSAK) and toric intraocular lens (IOL) implantation for correcting astigmatism in cataract patients.

METHODS

Studies were retrieved from the Ovid-Medline, EMBASE, Cochrane Central Register of Controlled Trials and Scopus which compared FSAK and toric IOL for astigmatism correction in cataract patients. Outcome measures included postoperative refractive cylinder, correction index, uncorrected distance visual acuity (UDVA), the proportion of patients achieving a residual refractive cylinder of 1.00 dioptre or less, target-induced astigmatism (TIA) and surgically induced astigmatism (SIA). The trial sequential analysis (TSA) was used to collect firm evidence supporting our conclusion.

RESULTS

9 studies encompassing 590 participants were analysed. The meta-analysis revealed that toric IOLs could result in less postoperative refractive cylinder and provide better UDVA compared with FSAK. The TSA disclosed strong evidence of lower postoperative refractive cylinder in the toric IOL group compared with that of the FSAK group. FSAK showed a smaller correction index and lower mean TIA and SIA compared with toric IOLs.

CONCLUSIONS

For cataract patients, both FSAK and toric IOLs are effective methods for correcting astigmatism. However, toric IOLs offer less postoperative astigmatism and result in better postoperative UDVA compared with FSAK. In vector analysis of astigmatism, toric IOLs can also produce higher TIA and SIA. Additionally, neither method is associated with severe untreatable complications. Therefore, the conclusion is that toric IOLs are the preferred choice for astigmatism correction in cataract patients and FSAK serves as a viable alternative when toric IOLs are contraindicated.

Visual and Refractive Outcomes of a New Hydrophobic Trifocal Toric Intraocular Lens

Purpose

To evaluate the visual outcomes and efficacy of astigmatism correction using a new hydrophobic trifocal toric intraocular lens (IOL).

Methods

This study involved 62 eyes implanted with the FineVision HP Toric IOL. The visual and refractive outcomes were assessed preoperatively and 6 weeks after the surgery. Specifically, monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA) at 80 and 60 cm and uncorrected near visual acuity at (UNVA) at 40 cm were evaluated. The rotational stability of the lens was also assessed.

Results

Sixty-one eyes (98.39%) were within ±1.00D and 55 eyes (88.71%) were within ±0.50 D of spherical equivalent, with a mean value of 0.09±0.39 D. 51 (82.26%) and 61 (98.39%) eyes had a UDVA of ≥20/20 and ≥20/25, respectively, and for CDVA these values were as follows: 59 (95.16%) and 62 eyes (100%), respectively. The mean UDVA and CDVA were 0.01±0.06 and -0.01±0.04logMAR, respectively. Greater than or equal to unaided 20/20 vision was achieved at 40 cm in 42 (67.74%), UIVA at 60 cm in 42 (67.74%) and 50 eyes (80.65%) at 80 cm. Those achieving ≥20/25 were 56 (90.32%, 40 cm), 59 (95.16%, 60 cm), and 62 eyes (100%, 80 cm). Postoperative mean values were 0.04±0.07, 0.03±0.07, and 0.00±0.07logMAR for UCNVA, UIVA at 60 cm, and UIVA at 80 cm, respectively. The mean rotation of the IOL was 5.8 degrees.

Conclusion

This hydrophobic trifocal toric IOL provides good refractive outcomes with excellent visual acuity across multiple distances, providing a full range of focus.

Influence of corneal astigmatism on near and far vision in eyes with bifocal intraocular lenses

Here, we present a full wave propagation model that quantitatively assesses the effect of astigmatism on visual functions in eyes with diffractive bifocal IOLs. The proposed model with bifocal IOLs evaluated the image quality of each focus at varying degrees of corneal astigmatism with the metrics of modulation transfer function and light-in-the-bucket. The results show that corneal astigmatism alters the distance-near image quality balance. Positive (negative) astigmatism has more detrimental effects on far (near) vision. Additionally, bifocal IOLs are more vulnerable to corneal astigmatism, highlighting the need to consider multifocal toric IOLs with astigmatism greater than 1.0 D. The numerical results closely agreed with previous relevant clinical findings, suggesting the clinical usability of the presented method in predicting the postoperative visual function of patients.

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.

Comparative Analysis of Tolerance to Experimentally Induced Astigmatism with Three Types of Multifocal Intraocular Lenses

Purpose

The effect of residual astigmatism and its axis on distance and near visual acuities (VAs) with multifocal intraocular lenses (IOLs) has not been studied extensively. This study compared the tolerance to experimentally induced residual astigmatism among bifocal, trifocal, and extended depth-of-focus (EDOF) IOLs.

Patients and Methods

This retrospective, comparative study included 70 eyes of 70 patients implanted with bifocal, trifocal, or EDOF IOLs. Distance and near VAs were assessed with experimentally induced astigmatism by placing positive cylindrical lenses in increments of 0.50 diopters to 2.00 diopters at 90° and 180° axes over the best distance correction.

Results

Both distance and near VAs worsened with increasing magnitudes of experimentally induced astigmatism except in the EDOF group, in which the near VA remained within a clinically acceptable limit, ie, within one line from the best corrected VA under all ranges of experimentally induced astigmatism. Furthermore, the EDOF group showed the highest astigmatic threshold for losing VA lines following experimental astigmatic induction at both distance and near. The distance VA was generally better at with-the-rule (WTR) than against-the-rule (ATR) astigmatism for all three IOL groups. On the other hand, the near VA was generally better at WTR than ATR astigmatism in the bifocal group, comparable between WTR and ATR astigmatism in the trifocal group, and generally better at ATR than WTR astigmatism in the EDOF group.

Conclusion

The EDOF IOL demonstrated the highest tolerance to experimentally induced astigmatism at both distance and near. VA was generally less affected by WTR astigmatism than ATR astigmatism, especially at distance. We proposed the residual astigmatism thresholds for clinically acceptable VA reduction in all three IOL groups.

Clinical outcomes of trifocal toric intraocular lenses

The purpose of this report is to summarize the visual and refractive outcomes of patients with trifocal toric intraocular lens (IOL) implants. A peer-reviewed literature search in different databases was carried out to identify clinical publications reporting outcomes of patients with this type of implant. The analysis considered information on the sample of eyes, type and power of the trifocal toric IOLs, biometric preoperative data, postoperative refraction, rotational stability, visual acuity at different distances and other analyses undertaken, such as contrast sensitivity or quality of vision questionnaires. 20 clinical studies, encompassing a total of 1404 eyes implanted with three commercially available trifocal toric IOLs, were included in this review. The analysis assessed the outcomes reported for the AT LISA tri toric 939MP IOL, involving 3 articles and 313 eyes; the FineVision toric POD FT IOL, with 7 articles studying 370 eyes, and the AcrySof IQ PanOptix toric IOL, involving 11 articles and 721 eyes. Our assessment of the outcomes of the various studies indicates that the efficacy of the refractive correction (both sphere and cylinder) and visual acuity at different distances was similar between the IOL models. The same was found for the patients' quality of vision and satisfaction levels, in addition to photic phenomena reported. The outcomes summarized in this report lead us to conclude that the use of trifocal toric IOLs allows complete visual restoration over a wide range of distances.

Comparison of astigmatism correction and visual outcomes in mix-and-match implantations of trifocal intraocular lenses with femtosecond laser-assisted arcuate keratotomy and contralateral bifocal Toric intraocular lenses

Introduction

Astigmatism reduces the postoperative visual performance after non-toric intraocular lenses (IOLs) implantation, and limits the use of refractive IOLs in cataract surgery. The purpose of this study was to compare the efficacy in astigmatism correction and the postoperative visual outcomes between the implantation of a trifocal IOL with femtosecond laser-assisted arcuate keratotomy (FSAK) in one eye and a bifocal toric IOL (TIOL) in the other, in patients with cataract and moderate astigmatism.

Methods

This prospective observational paired-eye study enrolled patients with cataract and corneal astigmatism (CA) between 0.75 and 2.25 D in both eyes. The patients underwent a mix-and-match treatment comprising trifocal IOL implantation with FSAK and bifocal TIOL implantation. We compared the visual acuity (VA) at all distances, defocus curve, postoperative refractive astigmatism (RfA), CA, high-order aberrations, modulation transfer function (MTF) curve, and Strehl ratio between the two eye groups.

Results

In total, 41 patients (82 eyes) were enrolled and completed a 6-month follow-up. The 1- and 3-month uncorrected distance VA and 3-month uncorrected near VA were greater in eyes with bifocal TIOLs than with trifocal IOLs and FSAK (p = 0.036, 0.010, and 0.030, respectively), whereas the latter had greater uncorrected intermediate VA at every visit and greater VA in the intermediate range of defocus curve (at -1.50 and - 2.00 D) than the eyes with bifocal TIOLs. The postoperative RA of the eyes with trifocal IOL and FSAK was significantly higher than that of the bifocal TIOL-implanted eyes at the 3- and 6-month follow-ups.

Discussion

Both FSAK and TIOL implantation effectively reduce pre-existing moderate astigmatism in patients with cataract. The eyes with bifocal TIOLs had more stable long-term astigmatism correction, whereas those with trifocal IOLs and FSAK had better intermediate VA. Therefore, a mix-and-match implantation of trifocal IOL with FSAK and contralateral bifocal TIOL could achieve effective astigmatism correction and provide an overall optimal VA.

Effect of postoperative residual astigmatism on visual outcomes after trifocal intraocular lens implantation

Purpose

The aim of this study was to evaluate the effect of residual astigmatism on postoperative visual outcomes after trifocal intraocular lens implantation.

Methods

In this prospective observational study, we divided 156 eyes into two groups according to postoperative astigmatism measured by subjective optometry and followed them up for 3 months. Visual acuity, modulation transfer function (MTF) curves, Strehl ratio (SR), Visual Function Index-14 scores, and photic phenomena were compared.

Results

Linear regression analysis revealed a weak correlation between residual astigmatism and uncorrected distance visual acuity (UDVA) (r = 0.190, P = 0.016) at 3 months and a significant between-group difference at 1- and 3-month postoperative UDVA (P = 0.038, P = 0.018, respectively). MTF curve values and SR (MTF-10 total, MTF-10 cornea, MTF-30 total, MTF-30 cornea, SR Total, and SR cornea) were significantly worse (P < 0.001), and the Visual Function Index-14 scores were lower in the 0.5 < astigmatism ≤ 1.25 D group (P < 0.05) than in the astigmatism ≤ 0.5 D group. No significant differences were found in the frequency, severity, and bothersomeness of photic phenomena (P > 0.05).

Conclusion

Postoperative residual astigmatism affects the UDVA of the trifocal intraocular lens-implanted eyes. Although we found no significant differences in uncorrected intermediate and near visual acuity, both objective and subjective visual quality were affected, suggesting the need for surgical planning when the anticipated postoperative astigmatism is >0.5 D.

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.

Visual and Refractive Efficacy of Panoptix Toric Intraocular Lens in a Clinical Setting

Purpose

Trifocal Intraocular Lenses (IOLs) were developed to provide patients with effective near, intermediate and distance vision, thus minimizing spectacle dependency. Residual astigmatism has previously been shown to impact unaided visual acuity across all distances; therefore, to optimise the expected outcomes, consideration of preoperative corneal astigmatism is essential. The purpose of this study was to provide a real-world, multi-site review of visual and refractive outcomes in eyes undergoing implantation with the Panoptix Trifocal toric IOL platform.

Patients and Methods

This study represents a two-fold approach. Patients who had previously undergone routine cataract removal and IOL insertion with the Panoptix Toric IOL were retrospectively analysed for routine efficacy and safety endpoints ("Retrospective Cohort"). Data was retrieved from the preoperative, surgical and postoperative visits (range 2-6 weeks). A further subset of patients undergoing lens removal and bilateral Panoptix Toric IOL insertion were identified at surgery ("Qualitative Cohort"). These patients underwent additional testing inclusive of quality of vision questionnaire and bilateral defocus curve.

Results

A total of 466 eyes of 254 patients were included in the retrospective cohort. Between 91% and 98% of eyes, respectively, were within 0.50D and 1.00D of target. Mean absolute difference from Spherical Equivalent (SE) target was 0.22 ± 0.24Ds. Following surgery, 94% of eyes demonstrated a refractive astigmatism of 0.50D or less. Further, 61% eyes achieved uncorrected distance visual acuity (UDVA) of 20/20 or better, increasing to 94% achieving 20/32 or better. Seventy percent of eyes unilaterally achieved N5 unaided and 66.0% achieved N8 or better at intermediate. In the qualitative cohort, no patient described any symptom as significant or requested explant.

Conclusion

In a real-world setting, the PanOptix toric trifocal IOL continues to demonstrate refractive accuracy and good visual performance at all focal distances. This IOL also exhibited good quality of vision, with minimally bothersome visual disturbances or photic phenomena.

Evaluation of Refractive Accuracy of ORA and the Factors Impacting Residual Astigmatism in Patients Implanted with Trifocal IOLs During Cataract Surgery: A Retrospective Observational Study

Purpose

Patients and Methods

Results

Conclusion

Refraction Shift After Nd:YAG Posterior Capsulotomy in Pseudophakic Eyes: A Systematic Review and Meta-analysis

PURPOSE

To explore ocular refraction shift after Neodymium: yttrium aluminum garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases until November 10, 2021. Studies on the evaluation of changes in spherical equivalent (SE), cylindrical error (CE), or anterior chamber depth (ACD) after Nd:YAG laser capsulotomy were included in the meta-analysis. The review was registered in the international platform of registered systematic review and meta-analysis protocols (INPLASY202120059).

RESULTS

A total of 805 eyes from 18 studies were included in the final analysis. The pooled mean differences in SE from baseline to postoperative follow-up points were not significant (1 hour: 0.04 diopters [D], 95% CI: -0.13 to 0.21, P = .644; 1 week: 0.04 D, 95% CI: -0.12 to 0.20, P = .640; 1 month: 0.05 D, 95% CI: -0.06 to 0.16, P = .349). There was no significant difference between baseline CE and any subsequent visit (1 week: 0.14 D, 95% CI: -0.06 to 0.33, P = .172; 1 month: 0.17 D, 95% CI: -0.04 to 0.38, P = .108). No statistical difference in ACD from baseline was observed either (1 hour: 0.01 mm, 95% CI: -0.07 to 0.09, P = .846; 1 week: -0.12 mm, 95% CI: -0.24 to 0.01, P = .079; 1 month: -0.06, 95% CI: -0.14 to 0.01, P = .110).

CONCLUSIONS

Neither ocular refraction nor ACD changed within 1 month after laser capsulotomy, suggesting laser capsulotomy did not affect ocular refraction in short-term observation. [J Refract Surg. 2022;38(7):465-473.].

Visual Performance of a Novel Optical Design of a New Multifocal Intraocular Lens

PURPOSE

To evaluate the optical performance and quality of vision of a novel optical design of a new trifocal intraocular lens (IOL) using a proprietary modified algorithm.

METHODS

In this prospective, non-randomized, single-armed, single-center, open-label study, a total of 20 patients (40 eyes) who were candidates for multifocal lens implantation were recruited for implantation with the multifocal Intensity SL IOL (Hanita Lenses). Evaluation performed at 1 and 7 to 10 days and 1 and 3 months after implantation included corrected and uncorrected distance visual acuities at far, intermediate (80 cm), and near (40 cm). Monocular and binocular visual acuities, defocus curves, and contrast sensitivity were measured and questionnaires for grading subjective visual quality, satisfaction, and visual function were provided.

RESULTS

Three months postoperatively, monocular uncorrected visual acuity for distance, intermediate, and near averaged 0.03 ± 0.11, 0.09 ± 0.09, and -0.22 ± 0.09 logMAR, respectively (Snellen 20/21.4, 20/24.6, and 20/12). Corrected monocular visual acuity for distance, intermediate, and near averaged -0.07 ± 0.06, 0.03 ± 0.09, and -0.25 ± 0.07 logMAR (20/17, 20/21.4, and 20/11.2), respectively. Binocular corrected visual acuity for distance, intermediate, and near was -0.1 ± 0.06, -0.02 ± 0.09, and -0.28 ± 0.04 logMAR (20/15.8, 20/19, and 20/10.5), respectively. Contrast sensitivity was similar to the normal population in photopic and mesopic conditions. Defocus curves showed that this IOL provided visual acuity of 20/28.9 or better between a defocus of +1.00 and -3.50 diopters. The Visual Function Index-14 questionnaire showed that patients reported high satisfaction. Patients specifically noted good quality of vision at near and intermediate distances.

CONCLUSIONS

The Intensity SL IOL can provide good quality distance, intermediate, and particularly strong near vision after cataract surgery and independence from spectacles with good patient satisfaction. [J Refract Surg. 2022;38(3):150-157.].

Defocus curves: Focusing on factors influencing assessment

ABSTRACT

Defocus curve assessment is used to emulate defocus over a range of distances and is a valuable tool that is used to differentiate the performance of presbyopia-correcting intraocular lenses. However, defocus curves are limited by a lack of standardization, and multiple factors can impact their generation and interpretation. This review discusses key factors that influence the assessment of defocus curves, including pupil size, level of contrast, sphere versus cylinder defocus, viewing distance, monocular versus binocular assessment, use of Snellen versus logarithm of the minimum angle of resolution charts, and diopter range and step size. There are also different methods to analyze defocus curves, including the direct comparison method, range-of-focus analysis, and area under the curve analysis, which can impact result interpretation. A good understanding of these factors and standardization of the methodology are important to ensure optimal cross-study comparisons.

Cases of replacing diffractive bifocal intraocular lens with extended depth of focus intraocular lens due to waxy vision

Purpose

To investigate the postoperative course of patients who explanted a diffractive bifocal intraocular lens (IOL) due to waxy vision and implanted with an extended depth of focus IOL.

Methods

This study evaluated 29 eyes of 25 patients who underwent diffractive bifocal IOL explantation followed by TECNIS Symfony^® implantation because of dissatisfaction due to waxy vision at the Takabatake West Eye Clinic between January 2018 and November 2019. The indication criteria for this surgery were patients with uncorrected distance visual acuity of 0.05 logMAR or better, without eye diseases that may affect visual function, and no dissatisfactions about photic phenomena. We investigated patient demographics, uncorrected and corrected visual acuity, manifest refraction, contrast sensitivity, subjective symptoms, time to IOL explantation, explanted IOL type, and spectacle independence.

Results

The time to the IOL exchange after the initial IOL implantation was 55.3 ± 50.4 days (range: 14–196 days). The logMAR corrected distance visual acuity before and after IOL exchange were −0.13 ± 0.06 and −0.14 ± 0.06, respectively (p = 0.273). After IOL exchange surgery, the area under log contrast sensitivity function increased significantly from 1.07 ± 0.12 to 1.21 ± 0.12 (p < 0.001), and the waxy vision symptoms improved. The spectacle independence rate at the last visit was 88.0%.

Conclusion

For patients who complain of waxy vision despite good visual acuity after diffractive bifocal IOL implantation, exchange to extended depth of focus IOL was considered one of the useful surgical options.

Impact of residual astigmatism and defocus in eyes with trifocal intraocular lenses

PURPOSE

To assess the impact on visual function of different residual astigmatic situations combined with 0.50D negative defocus at different distances in patients with trifocal intraocular lenses (IOLs).

SETTING

Clínica Rementería, Madrid, Spain.

DESIGN

Prospective case series.

METHODS

The study included patients with the AcrySof® IQ PanOptixTM IOL. Visual acuity (VA) was measured at far distance (0.00 diopters [D] of vergence), at -1.5D, -2.5D and -3.0D of vergence. Residual astigmatism was induced by adding 0.50 and 1.00D cylindrical lenses placed at 90° (against the rule - ATR), 45° (oblique) and 180° (with the rule - WTR). All measurements were made with distance correction (emmetropia as the reference situation) and with a simulated residual myopia of 0.50D.

RESULTS

The study included 61 eyes of 61 patients. Residual astigmatism of 0.50D and 1.0D was induced in 28 and 33 eyes, respectively. For both groups distance and intermediate VA was better for the reference situation (P<0.001 for all cases). With 1.0D of cylinder (without and with induced defocus), the proportion of patients who lost ≥2 lines was higher for the ATR astigmatism. For near vision, differences were smaller for all simulated situations.

CONCLUSION

Residual astigmatism of up to 0.50D, regardless of its orientation, seems to be tolerated at all distances. For astigmatisms of 1.0D, distance and intermediate VA decreased significantly, and ATR orientations showed worse results in a higher proportion of patients. The combination of astigmatism with residual myopia significantly decreased distance VA while this negative shift had less impact on near VA.

Effects of Rebamipide on Differences in Power and Axis of Corneal Astigmatism Between Two Intra-patient Keratometric Measurements in Dry Eyes

Introduction

This study investigated the effect of rebamipide on discrepancies in the power and axis of astigmatism between two intra-patient keratometric measurements in patients with dry eyes.

Methods

Fifty-eight dry eyes (with a short tear breakup time [TBUT] of less than 5 s) were analyzed. Patients with dry eye were treated with 2% rebamipide ophthalmic suspension (group R) or Mytear^® artificial tear ophthalmic solution (group M) for 4 weeks. TBUT and corneal higher-order aberrations (HOAs) were evaluated at baseline and 4 weeks after treatment. Astigmatism power and axis were measured twice during both evaluations, at 5-min intervals. Baseline and post-treatment measurements were compared. Changes in TBUT and HOAs, and intra-patient discrepancies in astigmatism power and axis measurements were evaluated.

Results

HOAs showed significant positive correlations with intra-patient differences in astigmatism power and axis (P < 0.001). At the 4-week post-treatment follow-up, TBUT increased, and HOAs and astigmatism power and axis discrepancies decreased in a significant number of patients in group R (P < 0.001). In group M, only differences in astigmatism power decreased in a significant number of cases (P = 0.005). The degree of change in the intra-patient difference in astigmatism power between the two post-treatment keratometric measurements was significantly greater in group R than in group M (P < 0.001). In group R, baseline HOAs exhibited a significant positive correlation with changes in HOAs and intra-patient differences in astigmatism power (both P < 0.001). In group M, baseline HOAs were only significantly correlated with changes in intra-patient differences in astigmatism power (P = 0.030).

Conclusion

In dry eyes with short TBUTs, rebamipide significantly improved the corneal surface condition and significantly reduced intra-patient discrepancies in astigmatism power and axis measurements. Rebamipide may improve the accuracy of intraocular lens (IOL) power calculations in dry eyes, particularly when toric IOLs are implanted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00368-9.

This study investigated the effect of rebamipide on discrepancies in power and axis of astigmatism between two intra-patient keratometric measurements in patients with dry eyes. Short tear break-up time and corneal high-order aberrations were evaluated at baseline and 4 weeks after treatment. Astigmatism power and axis were measured twice at both evaluations. Baseline and post-treatment measurements were compared, and changes in short tear break-up time and high-order aberrations, as well as intra-patient discrepancies in astigmatism power and axis measurements, were evaluated. High-order aberrations at baseline showed significant positive correlations with intra-patient differences in astigmatism power and axis. Rebamipide significantly improved the corneal surface condition and significantly reduced intra-patient discrepancies in astigmatism power and axis measurements. Rebamipide may improve the accuracy of intraocular lens power calculations in dry eyes, particularly when toric intraocular lenses are implanted.