Spherical aberration, visual performance and pseudoaccommodation of eyes implanted with different aspheric intraocular lens

Clinical Outcomes of a Monofocal, Optimized, Aspheric, Hydrophobic Acrylic Intraocular Lens Implant

Purpose

To evaluate the refractive and visual outcomes of eyes implanted with monofocal, optimized, aspheric, hydrophobic acrylic intraocular lenses (IOL) following cataract surgery.

Methods

The study assessed 55 eyes implanted with CT LUCIA® 621P IOLs (Carl Zeiss Meditec AG, Jena, Germany) at 3-months postsurgery. The main outcome measures were refractive error, monocular corrected distance visual acuity (CDVA), monocular uncorrected distance visual acuity (UDVA), photopic and mesopic contrast sensitivity, and wavefront aberrations. Patients were asked to complete the Catquest-9SF questionnaire.

Results

At 3 months, the cumulative Snellen visual acuity was 20/20 in 94.55% of eyes and 20/25 or better in 100%. The difference between the UDVA and CDVA was either the same (70.91%) or better (29.09%) in all eyes. The mean Snellen decimal UDVA and DCVA were 1.07 ± 0.15 and 1.13 ± 0.11, respectively. The safety and efficacy indexes were 1.48 and 1.40, respectively. 47.27% of eyes showed a spherical equivalent ±0.13 D, with 92.73% of the eyes were within ±0.50 D and all eyes were within ±1.00 D. The mean spherical equivalent was -0.03 ± 0.30 D and the mean refractive cylinder -0.36 ± 0.34 D. The log photopic and mesopic contrast sensitivity functions were good and similar for all spatial frequencies. All patients reported being either fairly satisfied (score 3) or very satisfied (score 4) with their vision (mean = 3.64 ± 0.49). No intra- and postoperative complications were reported during the 3 months of follow-up.

Conclusion

The current study demonstrates that excellent visual and refractive outcomes, as well as patient satisfaction, can be achieved after cataract surgery with optimized, aspheric CT LUCIA 621P monofocal IOLs.

Spherical Aberration of Astigmatic Corneas in a Cataract Population

PURPOSE

To study the distribution of spherical aberration (SA) in astigmatic corneas in a cataract population and the relationship between magnitude of corneal astigmatism and fourth-order corneal SA.

METHODS

Data routinely collected using a Scheimpflug camera (Pentacam; Oculus Optikgeräte GmbH) were retrospectively analyzed. Patients with a minimum age of 60 years were included. Total corneal SA (from anterior and posterior corneal surface) was obtained for a 6-mm cor-neal area aligned with the pupil center. Exclusion criteria were insufficient measurement quality, total deviation index (Belin/Ambrósio Deviation) greater than 1.60, and corneal thickness at the thinnest point of less than 490 μm. One eye per patient was chosen randomly. Eyes were divided into low (≤ 1.00 diopters [D]), moderate (> 1.00 to ≤ 2.00 D), and high (> 2.00 D) astigmatism groups according to the Scheimpflug measurements.

RESULTS

A total of 528 eyes were included in this analysis. Low astigmatism was found in 129 patients, moderate astigmatism in 265 patients, and high astigmatism in 134 patients. Mean astigmatism was 0.68 ± 0.24, 1.45 ± 0.28, and 2.91 ± 0.95 D in the low, moderate, and high astigmatism groups, respectively. Mean corneal SA in patients with moderate and high astigmatism was higher than in the low astigmatism group. The difference reached the significance level for the comparison of low and high astigmatism groups (P = .023). The fourth-order SA increased gradually with the magnitude of astigmatism with a slope of 0.015.

CONCLUSIONS

SA was significantly larger in the cataract population with high corneal astigmatism. The increase of positive sign SA with the magnitude of astigmatism suggests that patients with moderate to high astigmatism may benefit more from intraocular lenses with negative sign SA correction. [J Refract Surg. 2023;39(8):532-538.].

Refractive and Visual Outcomes of a Monofocal Non-Constant Aberration Aspheric Intraocular Lens

Purpose

To evaluate the refractive and visual outcomes following cataract surgery and implantation of a new monofocal non-constant aberration aspheric intraocular lens (IOL).

Methods

Ninety eyes of 86 patients who underwent implantation the CT LUCIA 621P IOL (Carl Zeiss Meditec AG) were retrospectively analyzed in this study. Main outcome measures were refractive error and monocular corrected distance visual acuity (CDVA) and monocular uncorrected distance visual acuity (UDVA) values. Patients were evaluated at 1-month post-surgery and intra- and post-operative complications were recorded.

Results

Eighty percent of the eyes showed a CDVA of 20/25 or better before surgery. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.64±0.22 and 0.89±0.13, respectively. All eyes showed the same or better difference between UDVA and CDVA. In relation to the postoperative spherical equivalent, the highest percentage of eyes, 31.11%, was for the range between −0.50 and −0.14D followed by 22.22% for the ±0.13D range. Ninety percent of the eyes were within ±1.00 D and 73.33% of eyes within ±0.50 D. The mean postoperative spherical equivalent was −0.18±0.55D. 37.78% and 76.67% of the eyes showed a value ≤0.50 D and ≤1.00D, respectively, being the mean postoperative refractive cylinder −0.81±0.50D. No adverse events were reported in whole sample intra and postoperatively.

Conclusion

The present study shows that cataract surgery with an monofocal non-constant aberration aspheric IOL implantation resulted in good visual performance and refractive outcomes. This lens may be considered as a valid choice for patients in a standard-routine cataract surgery practice.

Optical Performance of a Monofocal Intraocular Lens Designed to Extend Depth of Focus

PURPOSE

To test the performance of a new monofocal intraocular lens, intended to extend depth of focus (Tecnis Eyhance, ICB00; Johnson & Johnson Vision, Inc) (ICB-IOL), in comparison to a standard monofocal IOL (Tecnis 1-piece, ZCB00; Johnson & Johnson Vision, Inc) (ZCB-IOL) of the same platform and material.

METHODS

Assessment of the optical performance of the two IOLs was made in vitro using an optical test bench with a model eye. The spherical aberration, modulation transfer function (MTF), and area under the MTF (MTFa) were obtained for pupil sizes ranging from 2 to 5 mm. Through-focus MTFa curves between -3.00 and +1.00 diopters (D) were obtained with three pupil sizes (2, 3, and 4.5 mm). Halo formation was also assessed for both lenses.

RESULTS

The ICB-IOL had slightly worse optical quality at its best focus (ie, lower MTF scores at distance vision) and more negative spherical aberration than the ZCB-IOL for pupils ranging from 2 to 3 mm. The maximum of the through-focus MTFa curve of the ICB-IOL with a 2-mm pupil shifted to a myopic defocus of -0.50 D. For larger pupils (≥ 3.5 mm), there were no differences in spherical aberration, MTF scores, and halo energy between the two lenses.

CONCLUSIONS

The new ICB-IOL is a modified monofocal lens with 0.50 D of additional power in its central 2-mm zone and more negative spherical aberration values, which induce a myopic shift of the maximum of optical quality and could improve intermediate vision. For pupils larger than 3.5 mm, there were no differences between IOLs. The new ICB-IOL design would produce photic phenomena comparable to a standard IOL. [J Refract Surg. 2020;36(9):625-632.].

Management of Cataract in Patients with Age-Related Macular Degeneration

Cataract and age-related macular degeneration (AMD) are two of the most common eye diseases of aging. This review addresses the pre-operative, intra-operative, and post-operative considerations in managing cataract in patients with age-related macular degeneration. Surgery for visually significant cataracts in patients with AMD can substantially improve the quality of life and reduce the risk of falls. Pre-operative optical coherence tomography is now recommended where possible to identify pre-existing macula disease. Careful counselling of patients is required before cataract surgery, especially with respect to the expected visual outcome, intraocular lens choice and potential risks of surgery. Real-world data has suggested 6 months of intravitreal anti-VEGF therapy for neovascular AMD before cataract surgery is compatible with optimum long-term visual outcomes. Patients receiving intravitreal therapy for neovascular AMD should be advised of the slightly higher risk of intraoperative complications and the surgeon should be prepared to manage these during the operation. During cataract surgery, unnecessary light exposure should be avoided to reduce phototoxicity. Careful planning of intravitreal therapy for neovascular AMD just before cataract surgery allows the eye greater recovery time in the post-operative period before further planned intravitreal therapy.

Comparison of the Visual Performance after Implantation of Three Aberration-correcting Aspherical Intraocular Lens

PURPOSE

To compare the visual performance after implantation of three aberration-correcting aspherical intraocular lens (IOL).

MATERIALS AND METHODS

Seventy-seven eyes of 77 cataract patients were divided into three groups: 26 eyes implanted with a non-constant aberration IOL (LUCIA 601P IOL, Zeiss Company, Germany); 26 eyes implanted with a spherical aberration -0.18μm IOL (CT ASPHINA 509M, Zeiss Company, Germany) and 27 eyes implanted with a spherical aberration -0.27μm IOL (AMO Tecnis ZCB00, Johnson & Johnson Surgical Vision, USA). Three months after operation, the distance visual acuity, wavefront aberrometry, contrast sensitivity, intraocular stray light, IOL decentration, and tilt were evaluated.

RESULTS

Three months postoperatively, no statistically significant differences were found in uncorrected distance visual acuity and corrected distance visual acuity (p≥.83). The RMS for total ocular coma was statistically significantly lower in the Lucia group (p=.03) and spherical aberration was statistically significantly lower in the Tecnis group (p<.01). No statistically significant differences were observed among the three lenses in higher order aberration (p=.85) and in contrast sensitivity under both photopic and mesopic lighting conditions (p≥.05). The intraocular stray light was statistically significantly better in the Lucia group (p=.04). No statistically significant differences were observed with respect to IOL decentration (p=.75) and tilt (p=.89).

CONCLUSIONS

Cataract surgery with non-constant aberration IOL resulted in lower coma and better intraocular stray light than with the spherical aberration -0.18μm and -0.27μm IOLs despite equivalent postoperative levels of visual acuity and contrast sensitivity.

Pupil Function in Pseudophakia: Proximal Miosis Behavior and Optical Influence

The pseudophakic eye lacks the ability to produce a refractive change in response to object proximity. Thus, individual anatomical features such as the pupil size play an important role in achieving functional vision levels. In this work, the range of pupil sizes at varying object distance was measured in pseudophakic participants. Furthermore, the impact of the measured values on eye optical quality was investigated using a computer simulation model. A binocular eye-tracker was used to measure the participants’ pupil sizes at six object distances, ranging from 0.33 m (i.e., vergence of 3.00 D) to 3.00 m (i.e., vergence of 0.33 D), while observing a Maltese cross with a constant angular size of 1 ∘ . In total, 58 pseudophakic participants were enrolled in this study (age mean ± standard deviation: 70.5 ± 11.3 years). The effects of object distance and age on pupil size variation were investigated using linear mixed effects regression models. Age was found to have a small contribution to individual variability. The mean infinite distance pupil size (intercept) was 4.45 ( 95 % CI: 2.74, 6.17) mm and the mean proximal miosis (slope) was − 0.23 ( 95 % CI: −0.53, 0.08) mm/D. The visual acuity (VA) estimation for a distant object ranged from − 0.1 logMAR (smallest pupil) to 0.04 logMAR (largest pupil) and the near VA ( 0.33 m) when mean proximal miosis was considered ranged from 0.28 logMAR (smallest pupil) to 0.42 logMAR (largest pupil). When mean distance pupil was considered, proximal miosis individual variability produced a variation of 0.04 logMAR for the near object and negligible variation for the distant object. These results support the importance of distance pupil size measurement for the prediction of visual performance in pseudophakia, while suggesting that proximal miosis has a negligible impact in VA variability.

Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses

PURPOSE

To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses.

METHODS

120 eyes of 60 patients underwent phacoemulsification. In patients' eyes, an aberration-free IOL (Aspira-aA; Human Optics) or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics) was randomly implanted. After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed.

RESULTS

Contrast sensitivity was significantly higher in eyes with Aspira lens under mesopic conditions with 12 cycles per degree (CPD) and under photopic conditions with 18 CPD (p = 0.02). Wavefront measurements showed a higher total spherical aberration with a minimal pupil size of 4 mm in the Aspira group (0.05 ± 0.03) than in the Tecnis group (0.03 ± 0.02) (p = 0.001). Strehl ratio was higher in eyes with Tecnis (0.28 ± 0.17) with a minimal pupil size larger than 5 mm than that with Aspira (0.16 ± 0.14) (p = 0.04). In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm.

CONCLUSIONS

Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. In contrast, this could not be shown in eyes with pupils under 4 mm or larger. This trial is registered with Clinicaltrials.gov NCT03224728.

Optimizing cataract surgery in patients with age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of visual impairment. The development of cataract in AMD patients poses challenges in assessing timing of surgery, predicting potential benefit to the patient of surgery, and predicting short- and long-term effects of surgery on progression of their AMD. Although traditional cataract surgery remains the mainstay of treatment, recently several devices have been developed to address the specific needs of AMD patients with cataract. We look at the associations between cataract and AMD and outline the treatment approaches to cataract surgery in AMD, looking at the potential benefits and risks of both traditional approaches and newer devices. We provide clinicians treating patients with AMD and cataract with a framework for choosing the appropriate management.

Visual outcome and optical quality after bilateral implantation of aspheric diffractive multifocal, aspheric monofocal and spherical monofocal intraocular lenses: a prospective comparison

AIM

To evaluate the visual function after bilateral implantation of aspheric diffractive multifocal Tecnis ZMA00, aspheric monofocal ZA9003 versus spherical monofocal Akreos Adapt intraocular lenses (IOLs).

METHODS

Tecnis ZMA00, Tecnis ZA9003 or Akreos Adapt IOLs were bilaterally implanted in 180 eyes from 90 patients. The following parameters were assessed 3 months postoperatively: monocular and binocular uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) for distance, intermediate and near, spherical aberration (SA), contrast and glare sensitivity, near point refractive power, uncorrected and best-corrected near stereoscopic acuity (NSA). Patient satisfaction was assessed by a questionnaire.

RESULTS

Three months postoperatively, the monocular and binocular UCVA and DCVA at near of Tecnis ZMA00 were significantly better than other two groups. The mean SA for 5.0mm optical zone in Tecnis ZMA00 and Tecnis ZA9003 was significantly lower than that in Akreos Adapt. Mean contrast sensitivity and glare sensitivity were better for Tecnis ZA9003 group than for other two groups. Patients with Tecnis ZMA00 had higher monocular and binocular near point refractive power and uncorrected NSA than monofocal groups. The patients in Tecnis ZMA00 had higher mean values for halo compared with other two groups.

CONCLUSION

Tecnis ZMA00 provided better near VA and uncorrected NSA and higher near point refractive power than monofocal IOLs and patients were spectacle independent. The IOLs with Tecnis aspheric design improved contrast and glare sensitivity. Patients with Tecnis ZMA00 reported more disturbances on visual phenomena of halo.

The impact on vision of aspheric to spherical monofocal intraocular lenses in cataract surgery: a systematic review with meta-analysis

PURPOSE

To provide a summary of the impact on vision of an aspheric intraocular lens (IOL) compared with a spherical IOL in cataract surgery.

DESIGN

Systematic review with meta-analysis.

PARTICIPANTS

Patients from published randomized controlled trials (RCTs) of cataract surgery with aspheric compared with spherical monofocal IOL implantation.

METHODS

We systematically searched the peer-reviewed literature in MEDLINE, EMBASE, Web of Science, BIOSIS, and the Cochrane Library according to the Cochrane Collaboration method to identify relevant RCTs. The inclusion criteria were RCTs on cataract surgery comparing the use of aspheric versus spherical IOL implantation that assessed visual acuity, contrast sensitivity, or quality of vision. The effects were calculated as mean differences or standardized mean differences (Hedges' g) and pooled using random-effect models.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), contrast sensitivity, and subjective perception of the quality of vision.

RESULTS

Forty-three studies provided data and were included, comprising 2076 eyes implanted with aspheric IOLs and 2034 eyes implanted with spherical IOLs. The BCVA showed a significant difference for aspheric IOLs (-0.01 logarithm of the minimum angle of resolution; 95% confidence interval [CI], -0.02 to -0.00). For contrast sensitivity, a significant advantage for aspheric IOLs was found under photopic and mesopic light conditions (photopic: Hedges' g 0.42, 95% CI 0.24-0.61 (3 cycles per degree [cpd]) to 0.53, 95% CI 0.33-0.73 (12 cpd); mesopic: Hedges' g 0.49, 95% CI 0.23-0.75 (1.5 cpd) to 0.76, 95% CI 0.52-1.00 (18 cpd)). Questionnaires targeting the subjective perception of quality of vision yielded less conclusive results.

CONCLUSIONS

Overall, a patient may achieve better contrast sensitivity with an aspheric IOL than with a spherical IOL, especially under dim light. There was no clinically relevant difference in BCVA between aspheric and spherical IOL implantation. The findings on the subjective perception of visual quality were heterogeneous with no clear result favoring either option.

Visual and optical performance of eyes with different corneal spherical aberration implanted with aspheric intraocular lens

AIM

To compare the visual and optical performance of eyes with different corneal spherical aberration (SA) implanted with spherical aberration-free intraocular lens (IOLs).

METHODS

Thirty-six patients with different corneal SA had phacoemulsification with implantation of spherical aberration-free IOLs. Patients were divided into 3 groups according to the value of preoperative corneal SA. Eyes with corneal SA <0.10µm were assigned to group A, those with 0.10 ≤corneal SA <0.20µm to Group B, and those with 0.20≤ corneal SA <0.35µm to Group C. Best-corrected visual acuity (BCVA), contrast sensitivity, corneal SA, total ocular aberrations, and depth of focus were recorded 3 months postoperatively. Distance-corrected near and intermediate visual acuity was studied to measure depth of focus.

RESULTS

BCVA and contrast sensitivity were similar between groups. There were no significant differences in distance-corrected near or intermediate visual acuity. Corneal SA was similar before and 3 months after surgery in the 3 groups. With a 5.0mm pupil diameter, root mean square values for total ocular higher-order aberrations (HOAs) were lower in groups A and B than in group C. Total ocular SA was lower in group A than in groups B and C. SA was also lower in group B than in group C. Coma and trefoil were similar between the groups.

CONCLUSION

Implantation of spherical aberration-free IOLs in eyes with different corneal SA results in similar visual performance at BCVA, contrast sensitivity and depth of focus.

A new method of cornea modulation with excimer laser for simultaneous correction of presbyopia and ametropia

PURPOSE

To investigate the outcomes of simultaneous correction of presbyopia and ametropia by a bi-aspheric cornea modulation technique, based on the creation of a central area hyperpositive for near vision and leaving the pericentral cornea for far vision in hyperopic, emmetropic, and myopic presbyopic patients.

SETTING

Sixty eyes of 30 patients were treated with the PresbyMAX technique by one surgeon (D.U.) at the Eye Hospital Bellevue, Kiel, Germany.

METHODS

Twenty eyes with hyperopic presbyopia, 20 eyes with emmetropic presbyopia, and 20 eyes with myopic presbyopia underwent Femto-Lasik, and were assessed up to 6 months postoperatively. All eyes underwent cornea treatment using the PresbyMAX® software, delivering a bi-aspheric multifocal ablation profile developed by SCHWIND eye-tech-solutions (Kleinostheim, Germany). All flaps were created by Ziemer LDV Femtolaser (Port, Switzerland).

RESULTS

The mean binocular distance of uncorrected visual acuity (DUCVA) improved in the hyperopic group from 0.28 ± 0.29 logMAR to -0.04 ± 0.07 logMAR, in the emmetropic group from -0.05 ± 0.07 logMAR to 0.02 ± 0.11 logMAR, and in the myopic group from 0.78 ± 0.27 logMAR to 0.09 ± 0.08 logMAR. The mean binocular near uncorrected visual acuity (NUCVA) increased in the hyperopic group from 0.86 ± 0.62 logRAD to 0.24 ± 0.23 logRAD, and in the emmetropic group from 0.48 ± 0.14 logRAD to 0.18 ± 0.11 logRAD. The myopic presbyopes showed a decrease of the mean binocular NUCVA from 0.04 ± 0.19 logRAD to 0.12 ± 0.18 logRAD. The mean postoperative spherical equivalent for distance refraction was -0.13 ± 0.61 D for the hyperopic presbyopia, -0.43 ± 0.35 D for the emmetropic presbyopia, and -0.68 ± 0.42 D for the myopic presbyopia group, whereas the software took aim at -0.50 D in all groups.

CONCLUSIONS

In presbyopic patients without symptomatic cataracts, but refractive errors, PresbyMAX® will decrease the presbyopic symptoms and correct far distance refraction in the same treatment, offering spectacle-free vision in daily life in most of the treated patients. Further investigation is necessary to evaluate the overall benefit of this procedure.

Real and pseudoaccommodation in accommodative lenses

In the attempt to manage presbyopia, different intraocular lens designs have been proposed such as monofocal IOLs with monovision or multifocal IOLs. Even though the lenses mentioned offer satisfactory visual results, contemporary ophthalmology has not completely answered the presbyopic dilemma by simulating the accommodative properties of the crystalline lens itself. Accommodative IOLs were designed to fill this gap and provide satisfactory vision for all distances by restoring some degree of "pseudoaccommodation." Pseudo accommodative capability can be linked to monofocal IOL's as well but the results are not satisfactory enough to fully support unaided near vision. Pseudoaccommodation is a complex phenomenon that can be attributed to several static (i.e., pupil size, against-the-rule cylindrical refractive error, multifocality of the cornea) and dynamic (i.e., anterior movement of the implant itself) factors. Objective measurement of the accommodative capability offered by the accommodative IOLs is extremely difficult to obtain, and different methods such as autorefractometers, retinoscopy, and ultrasound imaging during accommodative effort, ray tracing, or pharmacological stimulation have been developed but the results are sometimes inconsistent. Despite the difficulties in measuring accommodation, accommodative IOLs represent the future in the attempt to successfully "cure" presbyopia.

Wavefront analysis, contrast sensitivity, and depth of focus after cataract surgery with aspherical intraocular lens implantation

PURPOSE

To determine whether implantation of an aspherical intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery without critical reduction of depth of focus.

DESIGN

Double-blinded, randomized, prospective study.

METHODS

In an intraindividual study of 25 patients with bilateral cataract, an aspherical IOL (Akreos Advanced Optic [AO]; Bausch & Lomb, Inc., Rochester, New York, USA) was implanted in one eye and a spherical IOL (Akreos Fit; Bausch & Lomb, Inc) in the fellow eye. Higher-order aberrations with a 5- and 6-mm pupil were measured with a dynamic retinoscopy aberrometer at 1 and 3 months after surgery. Uncorrected and best-corrected visual acuity and contrast sensitivity under mesopic and photopic conditions also were measured. Distance-corrected near and intermediate visual acuity were studied as a measurement of depth of focus.

RESULTS

There was no statistically significant difference between eyes in uncorrected and best-corrected visual acuity at 1 and 3 months after surgery. There was a statistically significant between-group difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. The Akreos AO group obtained statistically significant lower values of higher-order aberrations and spherical aberration with 5- and 6-mm pupils compared with the Akreos Fit group (P < .05). There was no significant difference in distance-corrected near and intermediate visual acuity between both groups.

CONCLUSIONS

Aspherical aberration-free Akreos AO IOL induced significantly less higher-order aberrations and spherical aberration than the Akreos Fit. Contrast sensitivity was better under mesopic conditions with the Akreos AO with similar results of depth of focus.