Effect of astigmatism on visual acuity after multifocal versus monofocal intraocular lens implantation

Refractive Astigmatism Outcomes of Femtosecond Laser-Assisted Arcuate Keratotomies Combined with Femtosecond Laser-Assisted Cataract Surgery: Two-Year Results

PURPOSE

To evaluate the effectiveness and stability of refractive astigmatism reduction after penetrating femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery.

METHODS

Non-randomized retrospective data analysis of all patients that underwent femtosecond laser-assisted cataract surgery with femtosecond laser-assisted arcuate keratotomy over a 4-year period with a non-toric monofocal intraocular lens (2017-2021) at a tertiary care academic center. Postoperative visual acuity, manifest refraction, and predicted residual refractive error were also recorded at 1 month, 3-6 months, 12-18 months, and 2 years postoperatively. Preoperative keratometric astigmatism was compared to postoperative refractive astigmatism using vector calculations and the ASCRS double-angle plot tool.

RESULTS

This study comprised 266 eyes (179 patients) that met inclusion criteria. The mean preoperative keratometric astigmatism magnitude was 0.99 ± 0.53 D. At 1 month, 3-6 months, 12-18 months, and 2 years postoperatively, the mean refractive cylinder was 0.49 ± 0.45 D, 0.49 ± 0.45 D, 0.55 ± 0.54 D, and 0.52 ± 0.46 D, respectively. Horizontal against-the-rule astigmatism showed a higher tendency toward undercorrection than vertical with-the-rule astigmatism, which had a slightly higher tendency toward overcorrection. With-the-rule astigmatism had smaller difference vectors between target-induced astigmatism and surgically induced astigmatism.

CONCLUSIONS

Femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery was an effective option for correcting low-to-moderate corneal astigmatism for up to 2 years.

Using Total Corneal Astigmatism With Femtosecond Laser Cataract Surgery and Arcuate Keratotomy(ies) to Treat Low Amounts of Astigmatism

PURPOSE

The aim of this study was to evaluate outcomes using total corneal astigmatism (TCA) to calculate arcuate keratotomy(ies) (AK) parameters performed with femtosecond laser-assisted cataract surgery to reduce low corneal astigmatism.

METHODS

Patients who had femtosecond laser-assisted cataract surgery and AK with 0.50 diopter (D) to 1.30 D of TCA were included. Exclusion criteria were intraoperative complications, preexisting corneal surgery, and comorbidities that might adversely affect outcomes. Corneal tomography (Galilei G4, Zeimer Ophthalmic Systems AG) was performed preoperatively and 1 month postoperatively. TCA was input into the Donnenfeld limbal relaxing incisions nomogram to calculate the AK parameters. Preoperative and postoperative tomographic and subjective refractive measurements were compared. The Alpins method for vector analysis evaluated results.

RESULTS

Eighty-two eyes of 82 patients were included. Mean preoperative TCA was significantly reduced from 0.80 ± 0.19 D to 0.51 D ± 0.26 D ( P < 0.001). Preoperative posterior corneal astigmatism, -0.28 ± 0.13 D, was unchanged, postoperative posterior corneal astigmatism, -0.28 ± 0.14 D ( P = 0.653). Target-induced astigmatism arithmetic mean (0.82 ± 0.21 D) was greater than that of the surgically induced astigmatism (0.70 ± 0.40 D), resulting in an arithmetic mean difference vector of 0.51 ± 0.27 D with a summated mean at 0.16 D at 20 degrees. The correction index was 0.87, indicating undercorrection. Angle of error arithmetic mean, -1.27 ± 23.27 degrees, indicated good alignment.

CONCLUSIONS

Inputting TCA for calculation of femtosecond laser AK parameters can reduce low amounts of preoperative corneal astigmatism, thereby improving uncorrected vision.

Clinical outcomes of a toric continuous range of vision presbyopia-correcting intraocular lens

PURPOSE

To evaluate the clinical outcomes of the toric version of a presbyopia-correcting intraocular lens (IOL) based on the combination of a diffractive-based extended depth-of-focus (EDOF) pattern and a diffractive multifocal platform.

SETTING

Miranza COI Bilbao, Bilbao, Spain.

DESIGN

Prospective case series.

METHODS

35 patients (51 to 84 years) with corneal astigmatism ranging from 0.75 to 2.19 diopters (D) undergoing bilateral cataract surgery with implantation of the Synergy Toric II IOL were evaluated during a 3-month follow-up. Visual acuity, refraction, defocus curve, and patient-reported outcomes with the Catquest-9SF questionnaire were analyzed. A vectorial analysis was used to analyze the accuracy of astigmatic correction.

RESULTS

Mean 3-month monocular postoperative uncorrected distance, intermediate (80 cm) and near (40 cm) visual acuities were 0.06 ± 0.11 logMAR, 0.13 ± 0.12 logMAR, and 0.13 ± 0.09 logMAR, respectively. Mean monocular distance-corrected intermediate (80 cm) and near visual acuity (40 cm) were 0.11 ± 0.12 logMAR and 0.10 ± 0.10 logMAR, respectively. Mean binocular defocus curve showed visual acuities of 0.10 logMAR or better for defocus levels from +0.50 to -2.50 D. Residual cylinder was within ±0.50 D in 97.0% of eyes. The surgically induced astigmatism prediction error ranged between -0.49 D and 0.50 D, with a mean value of 0.04 ± 0.16 D. Mean absolute IOL rotation was 3.79 ± 2.94 degrees. Significant improvements were found in all Rasch-calibrated scores obtained with Catquest-9SF ( P < .001).

CONCLUSIONS

The implantation of the toric presbyopia-correcting IOL evaluated provides an efficacious astigmatic correction while providing a fully restoration of the visual function across different distances.

Effect of residual sphere on uncorrected visual acuity and satisfaction in patients with monofocal and multifocal intraocular lenses

PURPOSE

To assess the effect of residual sphere on vision and satisfaction in pseudophakic patients.

SETTING

Private clinics, United Kingdom.

DESIGN

Retrospective case series.

METHODS

A multivariate model evaluated the effect of 1-month residual sphere on outcomes of pseudophakic patients. Odds ratios (ORs) were calculated to assess the relative risk of not achieving ≥20/20 monocular uncorrected distance visual acuity (UDVA), ≥20/50 uncorrected near visual acuity (UNVA), and not being satisfied with vision. ORs were assessed for residual sphere -1.00 to +1.00 diopter (D) in quarter-diopter steps, using 0.00 D as a reference.

RESULTS

The analysis included 38 828 multifocal and 11 571 monofocal intraocular lenses (IOLs). The residual myopic sphere ≤-0.25 D and hyperopic sphere ≥+0.50 D had a clinically meaningful effect on UDVA. Although monofocal IOLs had an improvement in UNVA with every additional 0.25 D of myopia, the change in ORs with increasing myopia was not significant for multifocal IOLs. The mean improvement in UNVA comparing eyes with 0.00 D and -1.00 D sphere was 0.26 logMAR for monofocal and 0.03 logMAR for multifocal IOLs. Low near-addition IOLs had a slightly higher gain in UNVA with increasing myopia, but the gain was not as substantial as with monofocal IOLs. The effect of ametropia on satisfaction was more pronounced for multifocal IOLs. For every 0.25 D of residual myopia, there was >25% increase in dissatisfied patients.

CONCLUSIONS

Although myopia improved UNVA in eyes with monofocal IOL, multifocal IOLs did not benefit from residual myopia. Multifocal IOL patients desiring distance vision should be targeted closest to emmetropia, even if it means targeting slight hyperopia.

Comparative Analysis of the Clinical Outcomes of Two Toric Presbyopia-Correcting Intraocular Lenses

INTRODUCTION

To evaluate and compare the clinical outcomes of two toric presbyopia-correcting intraocular lenses (IOLs).

METHODS

Non-randomized prospective comparative study including 86 eyes of 51 patients (age 43-83 years) that underwent cataract surgery with implantation of one of the following two IOLs: TECNIS Toric Synergy (Johnson & Johnson Vision) (Synergy group) or AT LISA tri toric 939MP (Carl Zeiss Meditec) (ATLISA group). Visual and refractive outcomes were evaluated during a 6-month follow-up.

RESULTS

At 6 months after surgery, all eyes achieved uncorrected distance visual acuity 20/25 or better in both groups, whereas 96.2% and 100% of eyes achieved uncorrected near visual acuity (UNVA) 20/25 or better in the ATLISA and Synergy groups, respectively. All eyes achieved postoperative mesopic UNVA 20/30 or better in both IOL groups; 96.2% and 100% of eyes had a manifest cylinder ≤ 0.50 D at 6 months in ATLISA and Synergy groups, respectively. Mean magnitude of error was 0.04 ± 0.20 and - 0.04 ± 0.09 D in ATLISA and Synergy groups, respectively (p = 0.05). In the defocus curve, significant differences were found between IOL groups for most of distance-corrected visual acuities, except those corresponding to defocus of 0 D (p = 0.268) and - 1 D (p = 0.361).

CONCLUSIONS

The two toric presbyopia-correcting IOLs evaluated provide an efficacious astigmatic correction combined with a successful distance, intermediate and near visual rehabilitation. The visual performance seems to be better for most visual demands with the TECNIS Toric Synergy IOL, especially for distances closer than 40 cm.

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Long-term trifocal toric intraocular lens outcomes in Asian eyes after cataract surgery

PURPOSE

To determine the visual and refractive outcomes of trifocal toric intraocular lens (IOL) implantation in Asian eyes with cataract and astigmatism.

SETTING

Asian Eye Institute, Makati City, Philippines.

DESIGN

Prospective study.

METHODS

187 eyes were implanted with the FineVision POD FT IOL and followed for 2 years. The measurements included subjective refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), distance-corrected intermediate visual acuity (DCIVA), uncorrected near visual acuity (UNVA), distance-corrected near visual acuity (DCNVA), defocus curve, photopic and mesopic contrast sensitivity, and rotational stability.

RESULTS

The mean spherical equivalent and cylinder values were, respectively, -0.07 ± 0.34 diopters (D) and -0.48 ± 0.31 D at the 2-year follow-up. At this same follow-up, 69.4% of patients had monocular CDVA and 79.3% had binocular UDVA ≤0.0 logMAR. For intermediate vision, monocular DCIVA reached 74.1%, while binocular UIVA was 86.2% ≤ 0.1 logMAR. Near vision showed 63% for monocular DCNVA and 70.7% for binocular UNVA ≤0.1 logMAR. The mean values at this follow-up were 0.02 ± 0.08, 0.08 ± 0.10, and 0.10 ± 0.12 logMAR for CDVA, DCIVA, and DCNVA, respectively. At the visual acuity threshold of ≤0.20 logMAR, the binocular defocus curve extended up to -3.75 D. Stable contrast sensitivity values were obtained at the different follow-ups. The mean IOL rotation was ≤2 degrees.

CONCLUSIONS

The FineVision POD FT IOL yielded good visual outcomes at far, near, and intermediate distances with accurate refractive outcomes and good rotational stability in Asian eyes.

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.

Optical and Clinical Outcomes of an Enhanced Monofocal Intraocular Lens for High Hyperopia

PURPOSE

To evaluate the optical and clinical performance of an enhanced monofocal intraocular lens (IOL) (TECNIS Eyhance ICB00; Johnson & Johnson Vision) in patients with high hyperopia and a short axial length.

METHODS

Power mapping, wavefront analysis, and the through-focus modulation transfer function area (TF-MTFa) were measured in vitro for three IOL powers (10.00, 20.00, and 30.00 diopters [D]). The clinical study included 22 patients with an axial length of less than 22.5 mm. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and binocular defocus curve were evaluated 6 months postoperatively.

RESULTS

For the three IOL powers, the power mapping revealed an increase in positive power from the periphery to the center of the lens, providing an extra positive correction of 1.00 D for a 2-mm pupil size. The TF-MTFa curves showed only a peak of maximum MTFa at the distance focus. As the pupil size became smaller, there was a focus extension effect, providing an extended depth of focus of up to -1.50 D for a 2-mm pupil size. No significant dependency of the IOL base power on the power profile, wavefront, or optical quality was found. The clinical outcomes showed that all patients achieved a binocular CDVA of 0.1 logMAR or better. The mean visual acuity was better than 0.1 logMAR between +0.50 and -1.50 D of defocus. At a vergence of -2.00 D, the visual acuity was 0.11 ± 0.13 logMAR.

CONCLUSIONS

The monofocal enhanced IOL provided good distance optical and visual quality and optimal visual acuity up to an intermediate-near vision distance of 50 to 40 cm in patients with high hyperopia and a short axial length. [J Refract Surg. 2022;38(9):572-579.].

Comparison of Total Corneal Astigmatism between IOLMaster and Pentacam

Purpose. To compare the total corneal astigmatism (TCA) measured by IOLMaster 700 and Pentacam and to investigate the consistency of corneal keratometry (CK) measured by IOLMaster and Pentacam. Methods. Cataract patients were retrospectively enrolled in March and April, 2021. Retrospective analysis was performed on those patients with binocular and monocular CK measured by IOLMaster and Pentacam. Results. A total of 102 patients (204 eyes) were included, 64 of whom were female (62.75%). The flat (K1) and steep (K2) CK of anterior corneal surface (ACS) and flat (TK1) and steep (TK2) of total cornea measured with IOLMaster 700 were $44.16\pm 1.60\text{D}$ , $45.09\pm 1.68\text{D}$ , $44.12\pm 1.62\text{D}$ , and $45.14\pm 1.69\text{D}$ , respectively. Those measured with Pentacam were $44.31\pm 1.57\text{D}$ , $45.22\pm 1.65\text{D}$ , $44.15\pm 1.67\text{D}$ , and $45.19\pm 1.82\text{D}$ , respectively. The astigmatism of ACS and TCA were $-0.94\pm 0.63\text{D}$ and $-1.02\pm 0.69\text{D}$ ( $p<0.01$ ) in the IOLMaster group and $-0.90\pm 0.59\text{D}$ and $-1.05\pm 0.81\text{D}$ in the Pentacam group, respectively ( $p<0.01$ ). TCA measurement results of IOLMaster and Pentacam were consistent ( $\text{Pearson}=0.710$ , $p<0.01$ ), and there was no significant difference ( $p=0.591$ ). Conclusions. Total corneal astigmatism measured by IOLMaster was consistent with that measured by Pentacam. The difference between the astigmatism of anterior corneal surface and total cornea was detected in the measurement of IOLMaster and Pentacam, respectively.

Toric intraocular lenses: Evidence‐based use

Uncorrected refractive astigmatism degrades visual acuity. Spherical intraocular lenses (IOLs) leave astigmatic errors resident in the cornea manifest in refractive astigmatism. Toric IOLs, correcting for this corneal astigmatism, contribute to spectacle‐free vision in the pseudophakic eye. This review provides information to assist surgeons in a rational choice of eyes suitable for toric IOL implantation, methods of IOL cylinder power calculation, surgical techniques for toric IOLs and management of complications. With appropriate application of this information, correction of visually detrimental astigmatism can be achieved routinely.

Cataract surgery astigmatism incisional management. Manual relaxing incision versus femtosecond laser-assisted arcuate keratotomy. A systematic review

PURPOSE

This systematic review aims to compare corneal astigmatism correction in cataract surgery through corneal relaxing incision, manually and femtosecond laser assisted.

METHODS

The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We used PubMed, Scopus, and Web of Science (WOS) as databases from January 2010 to March 30, 2021. Patients with keratoconus, corneal ectasia, and a previous history of eye surgery were excluded because our aim was to analyze only healthy eyes.

RESULTS

A total of 1025 eyes were evaluated from 946 patients (mean age was 68.90 ± 5.12) in manual incision group articles, while 1905 eyes of 1483 patients (mean age was 65.05 ± 4.57) were evaluated in femtosecond laser arcuate keratotomy (FLAK) articles. The mean uncorrected distance visual acuity (UDVA) was 0.19 ± 0.12 and 0.15 ± 0.05 logMAR for manual incision and FLAK articles, respectively (p = 0.39). The mean correction index (CI) was similar in both groups: 0.77 ± 0.18 in manual incision and 0.79 ± 0.17 in femtosecond laser assisted incision (p = 0.70). Refractive stability was found after 3 months and no serious complications were reported during the follow-up in any group.

CONCLUSION

Both techniques are safe and moderately effective in corneal astigmatism correction in cataract surgery. FLAK represents a more precise and predictable approach. However, since visual and refractive outcomes appear to be similar in both cases, the cost-benefit analysis is controversial.

Optical and Clinical Outcomes of an Extended Range of Vision Intraocular Lens

PURPOSE

To assess the in vitro optical quality and halo formation of the AcrySof IQ Vivity intraocular lens (IOL) (Alcon Laboratories, Inc) and to evaluate the clinical outcomes in patients who had bilateral implantation of this IOL.

METHODS

The optical quality was evaluated with the PMTF optical bench (Lambda-X). Through-focus modulation transfer function area (MTFa) curves between -5.00 and +2.00 diopters (D) were obtained for 3- and 4.5-mm pupil apertures. The halo was assessed in vitro with a test bench. The clinical study included 30 patients. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and binocular defocus curve were evaluated 6 months postoperatively.

RESULTS

The through-focus MTFa curve for the 4.5-mm pupil size showed only one peak at distance focus (38.4 units). For the 3-mm pupil size, the through-focus MTFa showed a lower peak of MTFa (28.9 units), located at -0.70 D, and an extended depth of focus up to -2.20 D. The halo formed was larger and more intense compared to a standard monofocal IOL. The clinical outcomes at 6 months revealed satisfactory visual acuity outcomes. All patients achieved a binocular CDVA of 0.1 logMAR or better. The mean visual acuity was better than 0.2 logMAR between +1.00 and -2.00 D of defocus. At a vergence of -2.50 D, the visual acuity was 0.31 ± 0.09 logMAR.

CONCLUSIONS

The AcrySof IQ Vivity IOL provided good distance optical and visual quality and an extended range of focus of approximately 2.00 D, obtaining an optimal or functional visual acuity up to 50 to 40 cm. The halo formed was low intensity overall, but higher intensity than a monofocal IOL. [J Refract Surg. 2022;38(3):168-176.].

Type of residual astigmatism and uncorrected visual acuity in pseudophakic eyes

It is difficult to assess the pure impact of the type of residual astigmatism (with-the-rule; WTR, against-the-rule; ATR, and oblique astigmatism) on uncorrected distance visual acuity (UDVA) in pseudophakic eyes due to different age distribution of patients between those subgroups. We conducted the current study to investigate the association between astigmatism type and UDVA in eyes after cataract surgery with consideration for various confounding factors such as age. Data were retrospectively collected from 1535 pseudophakic eyes with corrected distance visual acuity (CDVA) of 20/20 or better, and spherical equivalent between − 0.125 D and 0.0 D. They were classified based on the pattern of residual refractive astigmatism into four groups; minimum astigmatism (< 0.5 D), WTR, ATR, and oblique astigmatism groups. The stepwise multivariate regression analysis showed that the magnitude of residual refractive astigmatism (standardized partial regression coefficient β = 0.559, p < 0.001), CDVA (β = 0.381, p < 0.001), minimum astigmatism group (β = − 0.188, p < 0.001), and WTR astigmatism group (β = − 0.058, p < 0.001) were significantly associated with UDVA (r² = 0.795). Variables excluded from the multivariate regression model include age, preoperative corneal astigmatism, axial length, anterior chamber depth, intraocular lens power, and postoperative spherical equivalent. These results indicate that UDVA is significantly better in eyes with minimum and WTR astigmatism than in those with ATR and oblique astigmatism, after adjustment for confounding parameters. In pseudophakic eyes, oblique and ATR astigmatism exerts a greater impact on UDVA than WTR astigmatism does, even after controlling for age.

Rotational Stability of a New Hydrophobic Acrylic IOL With Modified C-loop Haptics

PURPOSE

To assess rotational stability, axial stability, decentration, and tilt of the Rayner RAO800C single-piece hydrophobic acrylic intraocular lens (IOL) (Rayner Intraocular Lenses Ltd) from end of surgery to 4 to 7 months postoperatively.

METHODS

Surgeries were performed at the Department of Ophthalmology at the Medical University of Vienna. A total of 130 eyes of 68 patients received an aspheric hydrophobic Rayner RAO0800C IOL. IOLs were randomly implanted to the 0 ± 10, 45 ± 10, 90 ± 10, or 135 ± 10 degree axis. Baseline measurement was performed with the patient still supine on the operating table. Axis alignment after 1 hour, 1 week, 1 month, and 4 months was evaluated by retroillumination pictures. Postoperative IOL decentration, tilt, and aqueous depth at 4 months were assessed using an anterior segment swept-source optical coherence tomography.

RESULTS

Absolute median IOL rotation from end of surgery to 4 months was 2.4 degrees (range: 0.0 to 85.0 degrees). Median IOL rotation from end of surgery to 1 hour, 1 hour to 1 week, 1 week to 1 month, and 1 month to 4 months was 1.6 (range: 0.0 to 86.2), 1.1 (range: 0.0 to 28.8), 0.6 (range: 0.0 to 5.2), and 0.7 (range: 0.0 to 2.6) degrees. Respective proportions of IOLs rotating more than 5, 10, and 20 degrees from end of surgery to 4 months were 23.9%, 11.0%, and 6.4%. Horizontal and vertical decentration at 4 months was -0.09 ± 0.14 and 0.09 ± 0.14 mm, respectively. Horizontal and vertical tilt at 4 months was -4.78 ± 1.36 and -1.58 ± 1.10 degrees, respectively. A posterior axial shift of 0.052 ± 0.055 mm was observed from 1 week to 4 months.

CONCLUSIONS

Although median IOL rotation appeared to be low, a significant proportion of IOLs rotated postoperatively. Decentration and tilt values were generally low. A minimal posterior optic shift was observed after 1 week. [J Refract Surg. 2021;37(2):112-118.].

Effect of residual astigmatism on uncorrected visual acuity and patient satisfaction in pseudophakic patients

PURPOSE

To evaluate the effect of residual astigmatism on postoperative visual acuity and satisfaction after intraocular lens (IOL) surgery.

SETTING

Private practice, United Kingdom.

DESIGN

Retrospective case series.

METHODS

Postoperative data of patients who had previously undergone refractive lens exchange or cataract surgery were used in a multivariate regression model to assess the effect of residual astigmatism on 3 months postoperative monocular uncorrected distance visual acuity (UDVA) and patient satisfaction. The analysis was based on residual refraction in the dominant eye of each patient. Odds ratios were calculated to demonstrate the effect of increasing residual astigmatism on UDVA and satisfaction with separate calculations for monofocal and multifocal IOLs.

RESULTS

Three months postoperative outcomes of 17 152 dominant eyes were used in multivariate regression analysis. Compared with eyes with 0.00 diopter (D) residual astigmatism, the odds of not achieving 20/20 vision in eyes with 0.25 to 0.50 D residual astigmatism increased by a factor of 1.7 and 1.9 (P < .0001) in monofocal and multifocal IOLs, respectively. For the residual astigmatism 0.75 to 1.00 D, the odds ratio for not achieving 20/20 vision compared with eyes with no astigmatism was 6.1 for monofocal and 6.5 for multifocal IOLs (P < .0001). The effect of residual astigmatism on satisfaction was more evident at the 0.75 to 1.00 D level, where the odds of not being satisfied with vision increased by a factor of 2.0 and 1.5 in patients with monofocal and multifocal IOLs, respectively (P < .0001). The orientation of astigmatism was not a significant predictor in multivariate analysis.

CONCLUSIONS

Multivariate analysis in a large population of patients demonstrated that low levels of residual astigmatism can degrade visual acuity. Corneal astigmatism of 0.50 D or greater should be included in surgical planning.

Randomized trial comparing visual outcomes of toric intraocular lens implantation using manual and digital marker

Purpose:

The aim of this study was to compare the visual outcome of participants undergoing toric intraocular lens (IOL) implantation after cataract extraction using manual marking versus digital marking for intraoperative guidance.

Methods:

Randomized controlled trial of participants with cataract and corneal astigmatism of 1.00 D-4.50 D. The eyes were grouped into manual marking (Group 1) and digital marking (Group 2). Preoperative Uncorrected distance visual acuity (UDVA), Corrected distance visual acuity (CDVA), and corneal astigmatism were determined. IOL power and axis of alignment were determined using Barrett toric calculator. Eyes were marked by bubble marker and Mendez ring in group 1 and by VERION (Alcon, Fort Worth, Texas) digital overlay in Group 2. Postoperatively, UDVA, CDVA, residual refractive cylinder and IOL misalignment were determined (iTrace system, Tracey technologies) at 1 week, 6 weeks, and 3 months.

Results:

A total of 61 eyes of 50 participants, 31 in Group 1 and 30 in Group 2, were studied. The mean postoperative cylindrical error was 0.50 ± 0.39 D in Group 1 and 0.29 ± 0.34 D in Group 2 (P = 0.03). 67.74% (n = 21) and 93.55% (n = 29) eyes achieved a residual astigmatism of ≤0.50 D and ≤1.00 D, respectively, in Group 1, whereas 83.33% (n = 25) and 100% (n = 30) eyes achieved a residual astigmatism of ≤0.50 D and ≤1.00 D, respectively, in Group 2 at 3 months postoperatively. Toric IOL misalignment was 4.71 ± 3.12° in Group 1 and 4.03 ± 2.99° in Group 2 (P = 0.39).

Conclusion:

Accurate manual marking and digital marking are equally effective guides for toric IOL alignment, intraoperatively.

Clinical Outcomes With a New Continuous Range of Vision Presbyopia-Correcting Intraocular Lens

PURPOSE

To evaluate the clinical outcomes including patient-reported outcome measures in a sample of eyes undergoing bilateral cataract surgery with implantation of a new model of presbyopia-correcting intraocular lens (IOL).

METHODS

This non-randomized prospective case series enrolled 206 eyes of 103 patients undergoing phacoemulsification cataract surgery with bilateral implantation of the TECNIS Synergy IOL (Johnson & Johnson Vision). High and low contrast visual acuity, refractive, defocus curve, and patient-reported visual performance (Catquest-9SF questionnaire) outcomes were evaluated during a 3-month follow-up.

RESULTS

A total of 96.1% (99 of 103) and 91.3% (94 of 103) of patients achieved binocular postoperative uncorrected distance (UDVA) and near visual acuity (UNVA) of 0.00 logMAR (20/20), respectively. Mean postoperative mesopic UNVA for both eyes was 0.14 ± 0.03 logMAR. Likewise, mean binocular UDVA and UNVA were 0.00 ± 0.03 and 0.04 ± 0.02 logMAR. An almost flat mean defocus curve was obtained, with visual acuities between 0.00 and 0.10 logMAR for most defocus levels in both eyes. A reduction of contrast led to a limited but statistically significant change in UNVA in both eyes (P < .001). The Rasch calibrated scoring of item 2 and the Rasch calibrated mean score of the Catquest-9SF questionnaire increased significantly with surgery (P < .001).

CONCLUSIONS

This new presbyopia-correcting IOL provides a continuous range of functional focus, with a limited deterioration under mesopic conditions, which is perceived as a satisfactory outcome by the patient if proper patient selection is performed. [J Refract Surg. 2021;37(4):256-262.].

Refractive and Visual Outcome of Misaligned Toric Intraocular Lens After Operative Realignment

PURPOSE

The study was performed to evaluate the refractive and visual outcome of patients with misaligned toric intraocular lenses (IOLs) after operative realignment, with and without back-calculation of the toric axis after implantation of the IOL.

DESIGN

Institutional, retrospective case-control study.

METHODS

This is a retrospective case series of 39 patients who underwent a second operation to realign a misaligned toric IOL from August 2013 to December 2019 at the Department of Ophthalmology, Goethe University, Frankfurt, Germany. Ideal toric axis was calculated using the back-calculator astigmatismfix.com.

RESULTS

The study consists of 39 treated eyes (20 [51%] right eyes). The toric IOLs showed a postoperative misalignment of 25.69 ± 26.06°. Postrotational, uncorrected distance visual acuity (UDVA) improved from 0.39 ± 0.29 logMAR to 0.27 ± 0.18 logMAR. Refractive outcome showed a reduction of residual sphere and cylinder. The postoperative UDVA when performing alignment to the preoperative calculated axis (51%) was 0.24 ± 0.16 logMAR with a cylinder of 0.90 ± 0.90 diopter (D). In the group with alignment to a back-calculated axis (49%), the UDVA was 0.32 ± 0.20 logMAR with a cylinder of 0.76 ± 0.72 D. High cylinder power IOLs (≥2 D) showed a higher decrease in residual cylinder when back-calculation was performed than low cylinder power IOLs (<2 D) (27% vs 9%). The mean spherical equivalent prediction error of the back-calculator was 0.54 ± 0.55 D.

CONCLUSION

Realignment of misaligned toric IOLs improves visual acuity and reduces residual refractive errors. Especially for high cylinder power IOLs, better refractive outcome can be seen when performing a back-calculation before realignment.

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

PURPOSE

To investigate the effect of refractive astigmatism on all-distance visual acuity (VA) in eyes implanted with a diffractive trifocal or bifocal intraocular lens (IOL).

DESIGN

Cross-sectional study.

METHODS

Fifty eyes with trifocal IOLs (PanOptix; Alcon) and 50 eyes with bifocal IOLs (ReSTOR +3D) were enrolled. After simulating astigmatism by adding cylindrical lenses of 0, 0.5, 0.75, 1.0, and 1.5 diopters (D), the corrected logarithm of minimal angle of resolution (logMAR) VA was measured using an all-distance vision tester.

RESULTS

Mean VAs at most distances significantly worsened in proportion to the added astigmatism (P ≤ .0111) with no significant differences in near VA at 0.3 m in the trifocal group or in intermediate VA at 0.7 m in the bifocal group. Mean intermediate VA at 0.5 m was significantly better in the trifocal group than in the bifocal group when the astigmatism was 0.75 D or less (P ≤ .0472), but VA at distances of ∞ and 5.0 m were significantly worse in the trifocal group when the astigmatism was 0.5 D or more (P ≤ .0457). Useful mean logMAR VA of 0.20 was achieved at all distances when the astigmatism was 0.75 D or less in the trifocal group and 1.0 D or less in the bifocal group.

CONCLUSIONS

All-distance VA, particularly distance VA, worsened more in proportion to astigmatism with a trifocal IOL than with a bifocal IOL. Useful VA was achieved when the astigmatism was 0.75 D or less with a trifocal IOL, suggesting that astigmatism correction is necessary when astigmatism is more than 0.75 D.

Handling regular and irregular astigmatism during cataract surgery

PURPOSE OF REVIEW

There are several different approaches to handling regular and irregular astigmatism during cataract surgery, but still much debate on which solutions are most effective given unique patient circumstances. In this review, we examine recent literature and studies to highlight some of the most effective ways to plan preoperatively, manage regular and irregular astigmatism during cataract surgery, as well as managing postoperative complications.

RECENT FINDINGS

Recent developments in technology have provided increased courses of action for astigmatism management during cataract surgery. Additional options of toric IOLs with presbyopic platforms, light adjustable lenses, intraocular pinhole lenses, online technological tools and platforms, wavefront or topographic laser technology, and phototherapeutic keratectomy are all effective solutions to managing regular and irregular astigmatism. In this review, we will explore optimal approaches for unique situations.

SUMMARY

With increased technology, research, and methods, correcting regular and irregular astigmatism during cataract surgery is achievable in most patients. With in-depth preoperative planning, analysis of patient-specific factors, and a tailored approach, surgeons can obtain excellent uncorrected vision for patients.

FOCUSED (Femtosecond Optimized Continuous Uncorrected Sight with EDOF and Diffractive Multifocal IOLs) - A Review

PURPOSE OF REVIEW

The aim of this article is to review techniques to maximize all-distance uncorrected visual acuity and minimize photic phenomena after the implantation of multifocal and extended-depth of focus (EDOF) intraocular lenses (IOLs). This review examines the role of femtosecond laser-assisted cataract surgery (FLACS) in postoperative minimization of astigmatism and optimization of outcomes with multifocal and EDOF lenses.

RECENT FINDINGS

By incorporating intraoperative and preoperative imaging, femtosecond platforms such as those that utilize iris or conjunctival vessel registration, can enable a precision of corneal incisions and toric IOL markings that enable the lowest possible postoperative levels of astigmatism. Current studies suggest that with increasing IOL complexity, that is, trifocal versus bifocal, image degradation with even low levels of postoperative astigmatism are increased. To this end, current data support the utility of femtosecond laser arcuate incisions to enable the achievement of 0.5 D or less postoperative astigmatism for best outcomes with multifocal lenses.

SUMMARY

The synergistic combination of multifocal/EDOF IOLs with FLACS is an extremely promising route in achieving postoperative spectacle independence for patients. The marriage of the precision of FLACS with the increasing complexity of multifocal/EDOF IOLs will fuel nomogram adjustment and systematic improvements, such as the Wörtz-Gupta formula. Such strategies provide an unprecedented precision to cataract surgery that makes FOCUSED (Femtosecond Optimized Continuous Uncorrected Sight with EDOF and Diffractive Multifocal IOLs) a reality.

Rotation Characteristics of Three Toric Monofocal Intraocular Lenses

Purpose

To evaluate the rotational stability of the three monofocal toric intraocular lenses (IOLs) via data from an online toric IOL back-calculator.

Methods

A retrospective data review of an online toric IOL back-calculator, which allows users to input preoperative toric planning information, postoperative lens orientation, and subjective refraction. Inputted data were used to determine the optimal orientation of the toric IOL to minimize residual refractive astigmatism. Aggregate data from 3/11/2019 to 3/10/2020 were extracted and validated. Only data with ≥0.5D of residual refractive astigmatism were used in the study. Pre-operative intended IOL orientation and post-operative IOL orientation were used to calculate IOL rotation.

Results

After validation, 5397 entries were determined to represent patient eyes, of which 3238 represented the three monofocal IOLs evaluated. The rate of rotation for AcrySof, TECNIS, and enVista Toric IOLs was 72.7%, 83.4%, and 83.0%, respectively, and location only significantly impacted TECNIS IOLs. The magnitude of rotation for rotated IOLs was similar for all models and was significantly more for IOLs initially placed in the oblique axis. All IOL models tended to rotate in a counterclockwise direction (53.2%, 73.0%, 69.7%, respectively; p<0.05), and the tendency was greater for IOLs initially located horizontally.

Conclusion

The AcrySof IQ Toric IOL was more rotationally stable than both the TECNIS and enVista Toric IOLs; there was no significant difference in rotational stability of the latter two.

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.

[Etiopathogenesis of primary open-angle glaucoma]

The article reviews literature covering the etiopathogenesis and risk factors for the development of primary open-angle glaucoma (POAG). Currently, this problem is one of the most complex and controversial in ophthalmology. The review considers the main theories: vascular, mechanical (retentional, hydromechanical), dystrophic (theory of primary scleropathy), metabolic, concept of liquor hypertension, concept of the individual norm of intraocular pressure, as well as POAG risk factors.

Evaluating Refractive and Visual Outcomes After Bilateral Implantation of an Apodized Diffractive Multifocal Toric Intraocular Lens with a Moderate Add in the Dominant Eye and a Higher Add in the Fellow Eye

Purpose

To review refractive, visual acuity, defocus curve and subjective visual quality results after bilateral implantation of an apodized diffractive toric intraocular lens (IOL) with a moderate add in the dominant eye and a higher add in the non-dominant eye.

Setting

One site in Gainesville, GA, USA.

Design

Single arm, non-randomized prospective study.

Methods

This was a single-arm prospective study of visual acuity and subjective visual quality after implantation of a toric low-add apodized diffractive multifocal IOL in the dominant eye and a higher add IOL of the same type in the non-dominant eye three months after surgery. Binocular visual acuity at 4 m, 60 cm and 40 cm was tested. Other tests included refraction, defocus curve measurement and evaluation of the quality of vision. Toric IOL orientation was also measured.

Results

A total of 29 subjects were enrolled. There were no statistically significant differences in the mean keratometry, corneal astigmatism or IOL sphere power implanted in the dominant and non-dominant eyes. Vision was preferred without any correction in more than half of the eyes tested (32/58, 55%). The residual refractive astigmatism was ≤ 0.50 D in 100% of eyes. Seventy-five percent of subjects (22/29) had 0.10 logMAR (20/25 Snellen) binocular uncorrected visual acuity at all tested distances. Glare and haloes were the most common visual disturbances, but most subjects (22/29, 76%) reported that they were not bothered by any visual disturbances. In 97% of eyes (56/58), the measured difference in orientation between 1 month and 3 months was less than 5 degrees, with no change more than 14 degrees.

Conclusion

This blended bifocal IOL modality appears to be well-tolerated by subjects with a good range of vision and minimal bother from visual disturbances.

How much astigmatism to treat in cataract surgery

PURPOSE OF REVIEW

Astigmatism correction in cataract surgery is a common surgical challenge. Although there are numerous approaches to its treatment during cataract surgery, there remains a lack of consensus on what level of postoperative astigmatism to target. We examine the literature to determine the effect of astigmatism on visual function and provide a recommendation on how much to treat in cataract surgery.

RECENT FINDINGS

Distance visual acuity decreases as myopic, hyperopic, or mixed astigmatism increases. Near visual acuity decreases with hyperopic astigmatism but improves with myopic astigmatism. The effect of astigmatism is generally independent of axis; however, against-the-rule (ATR) astigmatism with mild myopia may benefit reading. A progressive ATR shift occurs with age whether or not an individual undergoes cataract surgery. In the presence of higher order aberrations, correction of astigmatism below 0.5 D shows minimal practical benefit. Presbyopia-correcting intraocular lenses (IOLs) are sensitive to astigmatism but achieve distance visual acuities similar to monofocal IOLs and reach their full near and/or intermediate potential when residual astigmatism 0.5 D or less.

SUMMARY

In cataract surgery, we recommend correction to 0.5 D or less of postoperative residual astigmatism to achieve optimum visual function and patient satisfaction following cataract surgery.

Phacoemulsification With 3.0 and 2.0 mm Opposite Clear Corneal Incisions for Correction of Corneal Astigmatism

PURPOSE

To compare the effect of 3.0 and 2.0 mm opposite clear corneal incisions (OCCIs) in phacoemulsification on reduction of preexisting corneal astigmatism, and their impact on corneal aberrations.

METHODS

This study is a prospective randomized controlled study that included 140 patients with age-related cataract and regular corneal astigmatism ≥0.75 diopter (D). Phacoemulsification was performed using on-meridian 3.0 or 2.0 mm corneal incision with or without an OCCI. Cases were divided into 4 groups: 3.0 mm OCCIs, 3.0 mm single clear corneal incision (3.0 mm SCCI), 2.0 mm OCCIs, and 2.0 mm SCCI. Keratometry and topography were performed at 3 months postoperatively. The variations in corneal astigmatism and aberrations were recorded. Surgically induced astigmatism was calculated using vector analysis.

RESULTS

The corneal astigmatism reduction was 0.61 ± 0.38 D in the 3.0 mm OCCIs group, significantly higher than the other groups (P ≤ 0.004); and 0.29 ± 0.29 D in the 2.0 mm OCCIs group. The mean surgically induced astigmatism was 1.07 ± 0.51 D in the 3.0 mm OCCIs group, higher than 0.61 ± 0.35 D in the 2.0 mm OCCIs group (P = 0.001). The root mean square values of corneal trefoil, spherical aberration, and total higher order aberrations increased at 3 months postoperatively, but there were no significant differences between OCCI and SCCI groups.

CONCLUSIONS

On-meridian 3.0 mm OCCIs are effective for correcting mild-to-moderate corneal astigmatism during cataract surgery, exerting no additional impact on corneal aberration compared with SCCI.