Incorrectly Focused Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) Laser Beam Leads to Massive Destructive Effects in Small-Aperture (Pinhole) Intraocular Lenses.

INTRODUCTION: Pinhole intraocular lenses (IOLs) were developed to improve reading by compensating for loss of accommodative function. The IC-8® Apthera™ is a small-aperture presbyopia-correcting IOL that combines the proven principle of small-aperture optics with an aspheric monofocal lens to deliver a continuous range of vision for patients with cataracts from distance to near vision. Posterior capsule opacification is the most common sequela after cataract surgery. It is effectively treated by laser capsulotomy. However, if the laser beam is incorrectly focused, the IOL can be permanently damaged (pits/shots). METHODS: In this experimental study, yttrium-aluminum-garnet (YAG) pits were purposefully created. Defects were analyzed and compared between the periphery of the ring in the clear area of the hydrophobic acrylic lens and at the carbon black (CB)-polyvinylidene fluoride (PVDF) filtering component (FilterRing™) of the pinhole lens. All defects were made using identical settings/energy levels (2.6 mJ). The damage induced to the IC-8® Apthera™ IOL was examined by low-magnification images, light microscopy, scanning electron microscopy, and micro-computed tomography (micro-CT). RESULTS: YAG defects in the carbon black filter ring were much more severe than those in the clear zone due to the high absorption of the carbon black. Massive defects and destruction of the lens with tearing out of fragments and particles were observed. The missing volume calculated from the micro-CT reconstruction was 0.266 mm3, which is 1.6% of the entire IOL volume, or more than 1000 times the volume damaged in the largest shot in the periphery. CONCLUSION: Based on the results, we highly recommend using the lowest possible energy levels, posterior offset setting, and circular pattern for maximum safety when performing laser capsulotomy with pinhole implants. Care should be taken to avoid creating irreversible iatrogenic defects that may affect overall quality. The safest area for performing capsulotomy seems to be the periphery of the ring segment. Video available for this article.

Calculated Drug Concentrations in Currently Available Intravitreal Therapies: Determination of Dilution Factor and Deviation From Recommended Doses.

In ophthalmology, intravitreal therapies are currently not personalized/customized and are not adjusted to the individual vitreous volume. With reference to the recently published calculation formula for a more accurate estimation of the vitreous body, we determined the dose of intravitreal medication for different vitreous volumes and compared them with the average volume. Using the axial length of the eye, the formula for the vitreous volume exact (VIVEX) can provide a more accurate indication of the vitreous volume in individual cases than an assumed standard volume of 4 mL. The concentration of active substances in small eyes may be twice as high as that in normal-sized emmetropic eyes. In contrast, large eyes may show less than half of the recommended drug concentration. The calculated concentrations of the investigated intravitreal drugs in small and large eyeballs showed impressive differences with large deviations from the recommended doses. Further systematic studies should follow to find out whether this has any impact on the effectiveness or side effects of the injected drugs.

Image Contrast and Spectral Transmission of Presbyopia-Correcting Intraocular Lenses: Evaluating the Impact of Nd:YAG Laser Associated Defects.

PURPOSE: Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered gold standard in the treatment of posterior capsule opacification (PCO). In this laboratory study, we measured spectral transmission to evaluate the image contrast and analyze the impact of Nd:YAG associated defects in presbyopia-correcting intraocular lenses (IOLs). METHODS: Two hydrophobic, acrylic IOLs as classic multifocal lenses with diffractive ring segments and different amount of near addition (A, B), one hydrophilic, trifocal IOL (C), one sector-shaped, plate haptic IOL (D) and one hydrophobic, enhanced depth of focus (EDOF) IOL (E) were studied. Measurements included surface topography characterization, United States Air Force resolution test chart (USAF) analysis, spectral transmittance measurements and through focus contrast measurement. Measurements were done with unaltered samples, damages (n = 7) were intentionally created in the central 3.5 mm zone using a photodisruption laser (2.0 mJ) and measurements were repeated. RESULTS: Significant differences were shown between unmodified samples and samples with YAG pits. The YAG-pits decreased the image contrast and spectral transmission and changed results of USAF test images. The imaging contrast decreased to 66%, 64%, 60%, 52% and 59% with the YAG shots in samples (A-E). The light transmission decreased to 88%, 87%, 92%, 79% and 91% (A-E) on average between 400 nm to 800 nm. In all IOLs a reduction of the relative intensity of transmitted light was observed. CONCLUSION: The image performance of all tested presbyopia-correcting IOLs is significantly influenced and disturbed by YAG-pits. The intensity of transmitted light is reduced in the wavelength between 450-800 nm. USAF test targets show worse results compared to unmodified samples and contrast is significantly deteriorated. No ranking/rating among tested IOLs should be made as many other factors play a role in real world scenario. High care should be taken when performing Nd:YAG capsulotomy on premium IOLs to avoid any damages.

Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser treatment in ophthalmology: a review of the most common procedures Capsulotomy and Iridotomy.

Nowadays, lasers are used in various medical fields. Ophthalmology was the first medical specialty to utilize lasers in patient treatment and still remains the leading medical field that uses laser energy for both therapeutic and diagnostic purposes. The neodymium: yttrium-aluminum-garnet (Nd: YAG) laser is one of the most common lasers used in ophthalmology. It is a solid-state laser with a wavelength of 1064 nm that works on the principle of photodisruption. Since its introduction in ophthalmology over 40 years ago, it has found various applications, mainly for procedures where cutting or disruption of ocular tissue is required. Compared to surgical alternatives, the use of Nd: YAG lasers on ocular tissue is minimally invasive. In this review, we focus on the two most common ophthalmic applications of Nd: YAG laser - laser peripheral iridotomy and posterior capsulotomy. The history of the techniques, current trends, potential complications, and the prognosis for future use is discussed.

Optical Bench Evaluation of the Latest Refractive Enhanced Depth of Focus Intraocular Lens.

Purpose: Any new intraocular lens (IOL) on the market claims to outperform competitors. We aimed to estimate the modulation transfer function (MTF) for different defocus of a novel refractive enhanced depth of focus (EDoF) IOL and the simulated visual acuity over this range of vision. Further, we analyzed the wavefront pattern produced by this IOL to reveal the function of the IOL's optics. Methods: For the novel TECNIS® PureSee® (ZEN00V) IOL, through frequency and through focus MTF were recorded on the optical bench (ISO-2 Cornea 0.28 µm, 546 nm). MTFa and the simulated visual acuity were calculated for different defocus. Apertures of 3 mm and 4.5 mm were applied. Higher order aberrations of the IOLs' optics were recorded and analyzed. Results: PureSee® IOL demonstrated a considerable depth of focus of about 1.7 D at the spectacle plane and a continuous simulated visual acuity over this range of defocus. For the 4.5 mm aperture, near focus depth was reduced, yet far distance MTF was even better. Higher order aberrations revealed increased primary and secondary spherical aberrations. Conclusion: Optical bench results suggest that the new ZEN00V matches the clinical criteria of an EDoF IOL by an increased range of vision and is far distance dominant for an enlarged pupil. This behaviour seems to be due to subtle power changes in the central optics that produce a complex modification of wavefront.

A Novel 3D High Resolution Imaging Method Using Correlative X-Ray and Electron Microscopy to Study Neodymium-Doped Yttrium Aluminum Garnet Laser-Induced Defects in Intraocular Lenses.

INTRODUCTION: Cataract extraction is the most frequently performed ophthalmological procedure worldwide. Posterior capsule opacification remains the most common consequence after cataract surgery and can lead to deterioration of the visual performance with cloudy, blurred vision and halo, glare effects. Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy is the gold standard treatment and a very effective, safe and fast procedure in removing the cloudy posterior capsule. Damaging the intraocular lens (IOL) during the treatment may occur due to wrong focus of the laser beam. These YAG-pits may lead to a permanent impairment of the visual quality. METHODS: In an experimental study, we intentionally induced YAG pits in hydrophilic and hydrophobic acrylic IOLs using a photodisruption laser with 2.6 mJ. This experimental study established a novel 3D imaging method using correlative X-ray and scanning electron microscopy (SEM) to characterize these damages. By integrating the information obtained from both X-ray microscopy and SEM, a comprehensive picture of the materials structure and performance could be established. RESULTS: It could be revealed that although the exact same energies were used to all samples, the observed defects in the tested lenses showed severe differences in shape and depth. While YAG pits in hydrophilic samples range from 100 to 180 µm depth with a round shape tip, very sharp tipped defects up to 250 µm in depth were found in hydrophobic samples. In all samples, particles/fragments of the IOL material were found on the surface that were blasted out as a result of the laser shelling. CONCLUSION: Defects in hydrophilic and hydrophobic acrylic materials differ. Material particles can detach from the IOL and were found on the surface of the samples. The results of the laboratory study illustrate the importance of a precise and careful approach to Nd:YAG capsulotomy in order to avoid permanent damage to the IOL. The use of an appropriate contact glass and posterior offset setting to increase safety should be carried out routinely.

VIVEX: A Formula for Calculating Individual Vitreous Volume: A New Approach Towards Tailored Patient Dosing Regime in Intravitreal Therapy.

INTRODUCTION: Personalized medicine and patient-tailored drug dosing have been substantiated through thousands of clinical studies, demonstrating their safety and efficacy. The principle: "as much as necessary, as little as possible" is widely spread. Quantities and doses are therefore adjusted individually. This is not the case for intravitreal injections in the context of retinal diseases. Intravitreal injections are not adjusted in relation to the vitreous volume. The vitreous body is described as "approx. 4 cm3" in the literature. METHODS: In this retrospective observational study, we included 72 eyes of patients who had undergone magnetic resonance imaging (MRI) of the orbit and biometry measurements of the anterior chamber depth (ACD) and axial length. After segmentation of the volume data, the vitreous volume was extracted by voxel integration, and a simple prediction model was derived to determine the vitreous volume from the axial length (AL) measurement with AL3·π/6·(0.76 + 0.012·(AL-24). This is the volume of a sphere AL3·π/6 and a correction term 0.76 + 0.012·(AL-24) to account for the portion of the vitreous in the entire globe and the proportional increase of the vitreous portion for long (myopic) eyes. RESULTS: Emmetropic eyes with an axial length of 22.50-23.50 mm had a vitreous volume of around 4.5-5.5 cm3. Myopic eyes with an axial length of 30.00 mm had a calculated vitreous volume of 9.0-10.0 cm3. Hypermetropic eyes with an axial length of 20.00 mm showed a vitreous volume of 3.0-4.0 cm3. CONCLUSIONS: By implementing the new calculation formula on the IOLCON website, it will be easy to get the exact individual vitreous volume. The data could be used by retinal surgeons prior to surgery. The knowledge of anatomical dimensions and exact individual vitreous volume seems to be important for gas and silicone oil fillings. With the newly derived knowledge, multicentric studies can evaluate the impact of the dose in intravitreal therapies. Patient-tailored dosing could prevent side effects and improve effectiveness.

Video analysis of optic-haptic-interaction during hydrophobic acrylic intraocular lens implantation using preloaded injectors.

OBJECTIVE: To compare the optic-haptic interaction of different hydrophobic acrylic IOLs after using six preloaded injectors. METHODS: We reviewed the video-recordings of procedures on a total of 388 eyes that underwent phacoemulsification and intraocular lens (IOL) implantation. For six preloaded injectors: multiSert (Hoya Surgical Optics) [System 1], TECNIS Simplicity (Johnson & Johnson Vision) [System 2], TECNIS iTec (Johnson & Johnson Vision) [System 3], AutonoMe (Alcon, Laboratories) [System 4], Bluesert (Carl Zeiss Meditec) [System 5], and Prosert (OphthalmoPro GmbH) [System 6], we noted in each case the time of IOL delivery and made a descriptive observation of IOL insertion and optic-haptic-interaction. RESULTS: We defined standard haptic behavior where the haptics emerged "folded" from the injector and quickly recovered their pre-implantation appearance. The incidence where the leading haptic emerged in a deformed way for System 1 was 20%, System 2: 19%, System 3: 14%, System 4: 56%, System 5: 24% and System 6: 5%. For trailing haptic deformed behavior, the incidence was 36%, 6%, 4%, 8%, 18% and 2%, respectively for Systems 1 to 6. Optic-haptic adhesion occurred in 2% of cases for System 1, 44% for System 2, 52% for System 3, 48% for System 4, and 11% for System 6 (P < 0.05). Adhesion was not found with System 5. CONCLUSIONS: We observed different deformed behavior for leading and trailing haptics in the six preloaded systems, some systems had as much as 52% optic-haptic adhesion.

Clinical Performance of New Enhanced Monofocal Intraocular Lenses: Comparison of Hydrophobic C-loop and Hydrophilic Plate-Haptic Platform.

INTRODUCTION: Enhanced monofocal intraocular lenses (IOLs) represent a new type of lens, which should lead to a very good distance vision similar to monofocal IOLs and an improved intermediate vision without increasing the risk for photic phenomena. METHODS: The aim of this clinical observation/registry study was to directly compare two different IOL platforms (hydrophilic acrylic L-333 (group A) vs hydrophobic acrylic AN6Q (group B)) with the same enhanced monofocal optic principle but different material and haptic design in clinical routine. A total of 102 cataract cases (51:51) were included in the study. Groups A and B were similar regarding demographics, age (71.6 ± 9 years for L-333 and 73.6 ± 8 years for AN6Q) and their calculated IOL power (20.9 ± 2.0 D for L-333 and 21.5 ± 3.4 D for AN6Q). Spherical equivalent (SE), (un)corrected distance, intermediate visual acuity, the surgeons' experience and patient feedback were assessed postoperatively. RESULTS: SE improved significantly in the AN6Q group, while the L-333 group showed a slightly smaller standard deviation postoperatively. In group A the uncorrected distance visual acuity (UDVA) improved from pre-op (0.43 ± 0.16 logMAR) to 1 month post-op (0.06 ± 0.04 logMAR) significantly and in group B from pre-op (0.54 ± 0.19 logMAR) to (0.05 ± 0.06 logMAR) postoperatively. Both groups showed excellent outcomes for distance without negative side effects. On testing uncorrected intermediate vision (80 cm) with Radner charts, 80% reached line 5 (0.0 logRAD) with fewer than one mistake and 10% reached line 4 (- 0.1 logRAD) in group A; 74% reached line 5 with fewer than one mistake and 4% reached line 4 in group B. CONCLUSION: Both IOL models (groups A and B) provided satisfying results regarding implantation behaviour, refractive error, visual acuity and overall patient satisfaction. The haptic design might influence the outcome of refractive error. Long-term follow-up data should be considered in multicentre studies to further characterize both platforms and to optimize IOL power calculation (constants, surgeon factor). It was shown that the enhanced monofocal optic can provide good visual acuity for far distance and improve intermediate distance. This type of new monofocal optic design, which however must be strictly separated from typical refractive/diffractive multifocal, presbyopia-correcting lenses, could be a good option in standard cataract care.

Nano-Indentation to Determine Mechanical Properties of Intraocular Lenses: Evaluating Penetration Depth, Material Stiffness, and Elastic Moduli.

INTRODUCTION: Intraocular lenses (IOL) should remain in the eye for life after implantation into the capsular bag during cataract surgery. The material must meet various requirements. It is crucial that the material has the best biocompatibility, and it should be flexible and soft for best possible implantation process but also sufficiently stable and stiff for good centering in the eye and posterior capsule opacification prevention. METHODS: In this laboratory experiment, we used nano-indentation for the mechanical assessment of three hydrophobic acrylic (A, B, C), three hydrophilic acrylic (D, E, F), and one silicone (G) intraocular lens. We wanted to determine whether some react more sensitively to touching/handling than others. The indentation elastic modulus and the creep were obtained from the force displacement curve. For measuring penetration depth and testing of possible damage to the intraocular lenses, the samples were measured at room temperature. A 200-µm-diameter ruby spherical tipped indenter was used for all the tests. Indentations were made to three different maximum loads, namely 5 mN (milli Newton), 15 mN, and 30 mN and repeated three times. RESULTS: The lowest penetration depth (12 µm) was observed with IOL B. However, IOL A, D, and F showed similar low penetration depths (20, 18, and 23 µm, respectively). Lenses C and E showed slightly higher penetration depths of 36 and 39 µm, respectively. The silicone lens (G) showed the greatest penetration depth of 54.6 µm at a maximum load of 5 mN. With higher maximal loads (15 and 30 mN) the penetration depth increased significantly. Lens C, however, showed the same results at both 15 and 30 mN with no increase of penetration depth. This seems to fit well with the material and manufacturing process of the lens (lathe-cut). During the holding time of 30 s at constant force all six acrylic lenses showed a significant increase of the creep (CIT 21-43%). Lens G showed the smallest creep with 14%. The mean indentation modulus (EIT) values ranged from 1 to 37 MPa. IOL B had the largest EIT of 37 MPa, which could be caused by the low water content. CONCLUSION: It was found that results correlate very well with the water content of the material in the first place. The manufacturing process (molded versus lathe-cut) seems to play another important role. Since all included acrylic lenses are very similar, it was not surprising that the measured differences are marginal. Even though hydrophobic materials with lower water content showed higher relative stiffness, penetration and defects can also occur with these. The surgeon and scrub nurse should always be aware that macroscopic changes are difficult to detect but that defects could theoretically lead to clinical effects. The principle of not touching the center of the IOL optic at any time should be taken seriously.

Enhanced Depth of Focus Intraocular Lenses: Through Focus Evaluation of Wavefront-Shaping versus Diffractive Optics.

Introduction: A new class of nondiffractive, wavefront-shaping Enhanced-Depth-of-Focus (EDoF) IOLs has been introduced very recently to cope with photic phenomena known from diffractive EDoF IOLs. We investigated the through focus modulation transfer function (MTF) of two wavefront-shaping EDoF IOLs compared to an established diffractive EDoF IOL on the optical bench. Such comparison on the optical bench had not been performed before and is of high clinical importance for the cataract surgeon. Material and Methods: Tecnis Symfony (diffractive) and the wavefront-shaping Acrysof IQ Vivity and LuxSmart Crystal IOLs (22 D each) were assessed by the OptiSpheric IOL PRO 2 imaging test bench with an ISO-2 cornea and a wavelength of 546 nm. Apertures of 3 mm and 4.5 mm were applied. Results: For all three IOLs, two peaks showed up in the through focus MTF curves representing the primary and secondary focus. For Symfony, these peaks were most distinct. Power difference between far and intermediate focus was 1.25 D (Symfony), 1.75 D (Vivity), and 1.5 D (LuxSmart) with an aperture of 3 mm. With an aperture of 4.5 mm, only for LuxSmart, power difference diminished slightly to about 1 D, and only the MTF in the intermediate focus decreased for all lenses. Conclusion: For all three IOLs, we could confirm a considerable depth of focus that was most extended for Vivity. Both new wavefront-shaping IOLs had lower values of peak MTF but a markedly more continuous through focus behavior compared to the diffractive EDoF IOL.

Clear corneal incision, an important step in modern cataract surgery: a review.

A clear corneal incision (CCI) is the most commonly used entrance site in modern phacoemulsification cataract surgery. Despite some initial concerns about increased endophthalmitis rates through a self-sealing CCI, recent literature suggests that the risk of infection with proper wound construction and all other necessary precautions is minimal. The technique of creating a clear corneal incision has, with recent developments in corneal imaging, undergone critical appraisal leading to a better understanding of incision architecture. Many surgeons operate through smaller incisions, and they have a wide choice of surgical instruments to create their corneal incisions. The aim of this review is to discuss the history and the current status of clear corneal incision creation, the design and materials of surgical blades, and the current trends in manufacturing and sustainability. Although disposable instruments have some advantages and are very popular, recycling, if possible, and avoiding unnecessary plastic waste are important considerations. In any case, the step of CCI is a small one for the surgeon, but a big one for the eye. That is why it has to be done with the utmost precision and in-depth knowledge is important.

Depth of focus of four novel extended range of vision intraocular lenses.

PURPOSE: To assess the depth of focus of four latest non-diffractive extended range of vision IOLs on the optical bench. Such comparison had not been done before. METHODS: We assessed and compared the through focus modulation transfer function (MTF) of the following novel IOLs with a nominal power of 22 D: Acrysof Vivity, LuxSmart Crystal, RayOne EMV and Tecnis Eyhance. An ISO-2 model eye was applied with apertures of 3 and 4.5 mm with monochromatic light of 546 nm. Measurements were done on OptiSpheric IOL PRO 2 optical bench. RESULTS: For the aperture of 3 mm, Eyhance and RayOne EMV showed the most pronounced peak in MTF with only little enlarged depth of power. Vivity and LuxSmart showed two peaks of about 1.7 D respectively 1.3 D depth of focus, yet reduced MTF and with maxima differently located. For 4.5 mm, MTF values for Eyhance and particularly for RayOne EMV dropped. For Vivity and LuxSmart, only the peak for the secondary focus decreased. CONCLUSION: Vivity and LuxSmart showed a larger depth of focus for our measuring conditions than Eyhance and RayOne EMV. Correspondingly, the peak MTF was best for Eyhance and RayOne ERV with small aperture. With the larger aperture, RayOne EMV considerably lost performance.

Implantable vision-enhancing devices and postoperative rehabilitation in advanced age-related macular degeneration.

Age-related macular degeneration (AMD) results in progressive vision loss that significantly impacts patients' quality of life and ability to perform routine daily activities. Although pharmaceutical treatments for AMD are available and in clinical development, patients with late-stage AMD are relatively underserved. Specialized rehabilitation programs and external low-vision aids are available to support visual performance for those with advanced AMD; but intraocular vision-improving devices, including implantable miniature telescope (IMT) and intraocular lens (IOL) implants, offer advantages regarding head motion, vestibular ocular reflex development, and depth perception. IMT and IOL technologies are rapidly evolving, and many patients who could benefit from them remain unidentified. This review of recent literature summarizes available information on implantable devices for improving vision in patients with advanced AMD. Furthermore, it discusses recent attempts of developing the quality of life tests including activities of daily life and objective assessments. This may offer the ophthalmologist but also the patient a better possibility to detect changes or improvements before and after surgery. It is evident that surgery with new implants/devices is no longer the challenge, but rather the more complex management of patients before and after surgery as well as the correct selection of cases.

Effect of decentration and tilt on four novel extended range of vision intraocular lenses regarding far distance.

PURPOSE: To analyze the effect of decentration and tilt on four novel non diffractive extended range of vision intraocular lenses (IOLs). METHODS: Acrysof Vivity, LuxSmart Crystal, RayOne EMV and Tecnis Eyhance were compared on the optical bench (power of 22 D each). Modulation transfer functions were obtained and Strehl ratio was calculated in an ISO-2 model. Apertures of 3 mm and 4.5 mm were applied. For qualitative assessment, United States Airforce (USAF) chart images were evaluated. Additional to centered IOLs, tilt of 5 degrees and decentration of 1 mm were applied. RESULTS: RayOne EMV was very robust against misalignment but had considerable deterioration of modulation transfer function (MTF) for large aperture with USAF images seriously blurred. Tilt and decentration decreased the performance of Eyhance significantly but had minor impact on the performance of Vivity and LuxSmart. For 4.5 mm aperture, MTF and Strehl ratio decreased markedly for all IOLs compared to 3 mm aperture size. The best MTF and Strehl ratio was obtained for Eyhance IOL well centered for both sizes of aperture. CONCLUSION: Tilt and decentration had a major impact on the performance of Eyhance only, which performed best of all IOLs tested when well centered. With large aperture, performance of all IOLs significantly decreased. Manufacturer's different approaches for these novel IOLs to increase depth of focus by increasing spherical aberration lead to a different performance in respect to contrast function and sensitivity to misalignment. Our results apply to the distance vision. Near vision performance will be evaluated in a separate investigation.

Evaluating Optical Quality of a New Hydrophilic Enhanced Monofocal Intraocular Lens and Comparison to the Monofocal Counterpart: An Optical Bench Analysis.

INTRODUCTION: The aim of the study was to analyze the optical properties of a new hydrophilic enhanced monofocal intraocular lens (IOL) using optical bench analysis and compare it with its monofocal counterpart. METHODS: This laboratory study investigates the enhanced monofocal intraocular lens (L-333) and the monofocal counterpart (L-313) IOL by Teleon Surgical, Spankeren, Netherlands on the optical bench, using OptiSpheric IOL PRO2 (Trioptics, Germany) in order to assess the optical quality according to ISO 11979 with ISO-2 Cornea. IOLs (power 22.0 D) were evaluated regarding through frequency modulation transfer function (MTF), Strehl ratio (SR), and through focus MTF at 50 lp/mm using a 3.0-mm and a 4.5-mm aperture. Tilt and decentration were applied. In addition, wavefront measurements were obtained using WaveMaster® IOL 2 device (Trioptics, Germany) and analyzed. RESULTS: Centered: The MTF (mean) at 50 lp/mm (L-333/L-313) with 3.0 mm aperture was 0.606/0.724 and with 4.5 mm aperture 0.330/0.409. The SR (mean) with 3.0 mm aperture was 0.586/0.809 and with 4.5 mm aperture 0.330/0.348. Decentered by 1 mm: The MTF (mean) at 50 lp/mm (L-333/L-313) with 3.0 mm aperture was 0.485/0.705 and with 4.5 mm aperture 0.255/0.374. The SR (mean) with 3.0 mm aperture was 0.457/0.739 and with 4.5 mm aperture 0.185/0.268. Tilted by 5 degrees: The MTF (mean) at 50 lp/mm (L-333/L-313) with 3.0 mm aperture was 0.577/0.657 and with 4.5 mm aperture 0.345/0.336. The SR (mean) with 3.0 mm aperture was 0.583/0.702 and with 4.5 mm aperture 0.269/0.237. In through focus MTF and aperture of 3.0 mm, the L-333 showed a peak of 0.41 with some enlarged depth of power of about 2 D. For the aperture of 4.5 mm, the MTF values of L-313 and L-333 were slightly reduced; L-333 showed an MTF peak of 0.23 and some reduced depth of power of about 1.5 D. Wavefront measurements showed no major aberrations for the L-313, while a combination of moderate increase in Z 4-0 and Z 6-0 with opposite sign was revealed for the L-333. CONCLUSION: The enhanced monofocal Lentis Quantum (L-333) produces some enlarged depth of focus by combining spherical aberration of different order and opposite sign. The Lentis Quantum performs very well in comparison to the aspherical monofocal counterpart owing to its optical design. Results with large apertures were sufficient too, suggesting that  the lens is a good option in eyes with a wide pupil and thus in refractive surgeries of young patients.

Enhanced Depth-of-focus Intraocular Lenses: Latest Wavefront-shaped Optics versus Diffractive Optics.

SIGNIFICANCE: The modulation transfer functions (MTFs) of two novel enhanced depth-of-focus (EDoF) intraocular lenses (IOLs) were compared with an established diffractive EDoF IOL. Such assessment, which was not described before in the literature, is of high clinical impact in lens surgery. PURPOSE: A new kind of nondiffractive, wavefront-shaped EDoF IOLs has been introduced very recently to cope with halos and glare known from diffractive optics. We aimed to assess the performance of two of these novel EDoF IOLs compared with an established diffractive EDoF IOL. METHODS: TECNIS Symfony, AcrySof IQ Vivity, and LuxSmart Crystal IOLs (22 D each) were assessed by the OptiSpheric IOL PRO 2 imaging test bench with an ISO-2 cornea and a wavelength of 546 nm. Measurements were carried out by TRIOPTICS GmbH. Through-frequency MTF, Strehl ratio, and U.S. Air Force targets were evaluated. A decentration of 1 mm and a tilt of 5° as well as different apertures of 3 and 4.5 mm were applied additionally. RESULTS: TECNIS Symfony performed superiorly to Vivity and LuxSmart for our settings. The diffractive optics of Symfony showed a considerable decrease in MTF and Strehl ratio when decentered. Overall, decentration had more impact on MTF and Strehl ratio than tilt. Larger aperture led to a decreased MTF and Strehl ratio for all IOLs tested. U.S. Air Force targets had better contrast for Symfony and for small aperture. CONCLUSION: The novel wavefront-shaped EDoF IOLs failed to outperform the established diffractive achromatic optics of Symfony EDoF IOL with respect to MTF and qualitative contrast function. These results apply only to the distance viewing condition. Near vision performance will be evaluated in a future study.

Impact of Decentration and Tilt on Spherical, Aberration Correcting, and Specific Aspherical Intraocular Lenses: An Optical Bench Analysis.

INTRODUCTION: The human eye is not optically symmetrical, and very few intraocular lens (IOLs) are perfectly centered in the eye. That is why contrast sensitivity can degrade in some conditions, especially in low light. In an optical bench analysis, we compare spherical (A), aberration correcting (B), and specific aspherical lenses (C) in terms of impact of decentration and tilt on the modulation transfer function as well as the simulated overall quality with USAF test targets. MATERIAL AND METHODS: The OptiSpheric IOL PRO2 was used to measure the optical performance of IOLs (A, B, C). In order to assess the optical quality of the IOLs, the optical quality parameters for the aperture size of 3.0 mm and 4.5 mm at the IOL plane were assessed. Through Frequency Modulation Transfer Function (MTF) and Strehl Ratio (SR) values, as well as the "US Airforce 1951 resolution test chart images" as qualitative simulation, were analyzed. All measurements (ISO) were repeated and done for centered, decentered (1 mm), and tilted (5°) IOLs. RESULTS: Centered: The MTF (mean) at 50 lp/mm (IOL A, B, C) with 3.0-mm aperture was 0.794/0.716/0.797 (ISO-1 cornea) and 0.673/0.752/0.723 (ISO-2 cornea) and with 4.5-mm aperture 0.728/0.365/0.751 (ISO 1) and 0.276/0.767/0.505 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.763/0.829/0.898 and with 4.5-mm aperture 0.228/0.386/0.432. Decentered by 1 mm: The MTF (mean) at 50 lp/mm with 3.0-mm aperture was 0.779/0.459/0.726 (ISO 1) and 0.695/0.381/0.662 (ISO 2). The MTF (mean) at 50 lp/mm with 4.5-mm aperture was 0.732/0.348/0.653 (ISO 1) and 0.355/0.069/0.346 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.829/0.543/0.397 and with 4.5-mm aperture was 0.259/0.145/0.192. Tilted by 5°: The MTF (mean) at 50 lp/mm with 3.0-mm aperture was 0.731/0.705/0.751 (ISO 1) and 0.623/0.727/0.732 (ISO 2). The MTF (mean) at 50 lp/mm with 4.5-mm aperture was 0.579/0.406/0.701 (ISO 1) and 0.277/0.512/0.429 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.539/0.478/0.514 and with 4.5-mm aperture was 0.262/0.136/0.201. CONCLUSION: Aberration correcting IOLs perform best when perfectly centered. The optical performance of aberration correcting IOLs can be markedly downgraded by misalignment. The examined ZO optic performed well in decentration and tilt. The ZO concept seems to be a good alternative to aspheric lenses, as it achieves to combine benefits of spherical and aspheric intraocular lenses. There is no perfect IOL, but fitting and choosing the right one for the individual case seems to be crucial to take advantage of benefits and minimize disadvantages. This is why knowledge of optical properties is also mandatory for the surgeon.