Different Types Of Intraocular Lenses Research Articles

Stereopsis Following Implantation of Presbyopia-Correcting Intraocular Lenses: A Narrative Review.

Recent advancements in cataract surgery have broadened its scope from mere vision restoration to include correction of refractive errors and presbyopia. This evolution has introduced multifocal and extended depth-of-focus (EDOF) intraocular lenses (IOLs), allowing enhanced vision across multiple distances. However, the influence of these advanced IOLs on stereopsis remains controversial. Factors influencing stereopsis after surgery include visual acuity, interocular differences, residual astigmatism, and the type of IOL, etc. Binocular vision integration and neuroadaptation further affect stereopsis, especially in cases of presbyopia-correcting IOLs. It is widely acknowledged that bilateral implantation of presbyopia-correcting IOLs yield superior stereopsis compared to unilateral implantation. However, there remains no consensus on whether binocular implantation of multifocal or monofocal IOLs provides superior stereopsis. Most studies suggest no significant difference in stereopsis between these two types of implants. Among different types of multifocal IOLs, refractive multifocal IOLs may offer better stereopsis than diffractive multifocal IOLs when implanted bilaterally. Emerging EDOF and hybrid multifocal-EDOF IOLs also demonstrate promising postoperative stereopsis. Additionally, a mix-and-match strategy with different types of IOLs implanted in each eye may result in interocular differences in visual acuity at certain distances, potentially affecting stereopsis. Nevertheless, with appropriate selection, most patients can achieve satisfactory postoperative stereopsis. This review synthesizes current literature on the effects of presbyopia-correcting IOLs on postoperative stereopsis recovery following cataract surgery. Studies on stereopsis outcomes with different IOLs have yielded mixed results, urging further investigation for optimized surgical strategies and patient outcomes.

Effects of different types of intraocular lens implantation on patient's visual quality and function after phacoemulsification

Objective: To explore the effects of different types of intraocular lens (IOL) implantation on patient's visual quality and function after phacoemulsification. Methods: The clinical data of patients with monocular cataract who underwent phacoemulsification in the Department of Ophthalmology, People's Hospital Affiliated to Shandong First Medical University between December 2021 and May 2023 were retrospectively analyzed. According to the types of IOL, the patients were divided into monofocal group, bifocal group and depth of focus extension group. Three months later, uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), best corrected intermediate visual acuity (BCIVA), uncorrected near visual acuity (UCNVA) and best corrected near visual acuity (BCNVA) were detected. Contrast sensitivity and total wavefront aberration were measured by visual function analyzer. Satisfaction with visual quality was evaluated by hospital-made satisfaction questionnaire. Results: A total of 92 patients were included, with 31 males and 61 females, and their age was (61.8±5.2) years. There were 43, 28 and 21 cases in monofocal group, bifocal group and depth of focus extension group, respectively. No statistically significant difference was found in clinical baseline data among the three groups. UCIVA, UCDVA, BCIVA and BCDVA in depth of focus extension group were 1.01±0.13, 0.92±0.18, 1.21±0.19 and 1.20±0.23, respectively, which were higher than those in monofocal group (0.62±0.12, 0.74±0.13, 1.02±0.17, 1.07±0.19, respectively) and bifocal group (0.67±0.15, 0.78±0.14, 1.01±0.16, 1.01±0.18, respectively), while absolute value of spherical equivalent [(-0.42±0.07) D] was lower than that in the other two groups [ (-0.49±0.05) D and (-0.45±0.08) D] (both P<0.05). UCNVA and BCNVA in bifocal group were 0.91±0.18 and 1.25±0.18, which were higher than those in depth of focus extension group (0.63±0.24 and 1.19±0.17) (both P<0.05). There were no significant differences in contrast sensitivity among the three groups under day vision or between monofocal group and bifocal group under night vision (all P>0.05), but the contrast sensitivity was higher in depth of focus extension group under night vision (3.0, 6.0, 12.0 c/d) than other two groups (all P<0.05). The score of ocular discomfort was the highest in bifocal group, followed by depth of focus extension group and monofocal group (both P<0.05). The score of visual interference in bifocal group was lower than that in monofocal group and depth of focus extension group (both P<0.05). The scores of subjective feeling in bifocal group and depth of focus extension group were higher than that in monofocal group (both P<0.05). The reading score was the highest in bifocal group, followed by depth of focus extension group and monofocal group (both P<0.05). There was no significant difference in total low-order aberration among the three groups (P=0.472). The total aberration and higher-order aberration [(0.74±0.35) μm and (0.41±0.12) μm] were the highest in monofocal group, followed by bifocal group [(0.61±0.21) μm and (0.22±0.09) μm] and depth of focus extension group [(0.46±0.13) μm and (0.06±0.09) μm] (all P<0.05). Conclusions: IOL implantation with depth of focus extension can enhance visual range, night vision and contrast sensitivity, and thus effectively improve postoperative visual quality and function in cataract patients. The bifocal IOL can better improve the patient's UCNVA and BCNVA, resulting in high satisfaction with visual quality.

Comparative study of the glistening between four intraocular lens models assessed by OCT and deep learning.

To evaluate the glistening in 4 different models of intraocular lenses (IOLs) using optical coherence tomography (OCT) and deep learning (DL). Centro Internacional de Oftalmología Avanzada (Madrid, Spain). Cross-sectional study. 325 eyes were assessed for the presence and severity of glistening in 4 IOL models: ReSTOR+3 SN6AD1 (n = 41), SN60WF (n = 110), PanOptix TFNT (n = 128) and Vivity DFT015 (n = 46). The presence of glistening was analyzed using OCT, identifying the presence of hyperreflective foci (HRF) in the central area of the IOL. A manual and an original DL-based quantification algorithm designed for this purpose was applied. Glistening was detected in 22 (53.7%) ReSTOR SN6AD1, 44 (40%) SN60WF, 49 (38.3%) PanOptix TFNT, and 4 (8.7%) Vivity DFT015 IOLs, when any grade was considered. In the comparison of the different types of IOLs, global glistening measured as total HRF was 17.3 ± 25.9 for the ReSTOR+3; 9.3 ± 15.7 for the SN60WF; 6.9 ± 10.5 for the PanOptix; and 1.2 ± 2.6 for the Vivity ( P < .05). There was excellent agreement between manual and DL-based quantification (≥0.829). It is possible to quantify, classify and compare the glistening severity in different IOL models using OCT images in a simple and objective manner with a DL algorithm. In the comparative study, the Vivity presented the lowest severity of glistening.

Evaluation of visual performance and eye movements in patients with blue light-filtering intraocular lenses versus ultraviolet light-filtering intraocular lenses.

Eye movement plays an important role in visual perception and provides essential visual information for everyday tasks. Our previous study indicated that the visual performance and eye movement pattern were impaired in age-related cataract patients and could be improved after cataract surgery, but the impact of different intraocular lens (IOL) types was obscure. Previous studies found that blue light might affect the eye movement pattern and cognitive function. In this study, we explored the visual performance and eye movement pattern in post-cataract surgery patients implanted with blue light-filtering IOLs or ultraviolet (UV) light-filtering IOLs to further understand the impact of different types of IOLs on and daily visual performance and eye movement pattern and to help ophthalmologists and patients make the personalized option of IOL types in future. Patients after both-eye cataract surgeries were included in this study. Eye movement behaviors were automatically recorded by an eye tracker while performing three performance-based everyday tasks (non-social object search, face recognition, and reading). Visual performance and eye movement parameters were compared between participants with blue light-filtering IOLs and UV light-filtering IOLs. The correlation between visual performance and eye movement parameters was explored to determine which eye movement parameters had a significant influence on visual performance outcomes. A total of 30 patients (16 with blue light-filtering IOLs and 14 with UV light-filtering IOLs) were included. In this study, we found that the eye movement pattern was slightly different with these two IOLs: during non-social object visual search task, time to first fixation and fixation counts before first fixation were notably increased in yellow-tinted blue light-filtering IOL patients. During reading task, a higher total fixation count was also found in blue light-filtering IOL patients. However, the visual performance of these two IOLs was close, except for a quicker search of the target object with clear UV light-filtering IOLs. Both blue light-filtering and UV light-filtering IOLs were able to successfully restore visual function and yield satisfactory outcomes after cataract surgery. Although subtle, yellow-tinted IOLs did have a slight but significant impact on visual performance and the eye movement pattern of elderly patients when handling everyday tasks.

Comparison of the Incidence of Nd:YAG Laser Capsulotomy Based on the Type of Intraocular Lens.

Background and Objectives: Posterior capsular opacification (PCO) is the most common long-term complication of successful cataract surgery and can cause visual impairment. We aimed to investigate the effects of intraocular lens (IOL) characteristics on PCO by comparing the incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy for different types of intraocular lenses. Materials and Methods: A retrospective analysis was performed on 2866 eyes that underwent cataract surgery between January 2010 and December 2017, with at least 5 years of follow-up. The IOLs used for surgery were the hydrophobic lenses SN60WF (Alcon, Fort Worth, TX, USA), ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA), and MX60 (Bausch & Lomb, Rochester, NY, USA), and the hydrophilic lens MI60 (Bausch & Lomb, Rochester, NY, USA). We analyzed the incidence of Nd:YAG laser capsulotomy according to the type of IOL used. Results: The incidence of Nd:YAG laser capsulotomy was significantly higher with MI60 lenses (31.70%, 175/552 eyes) compared to SN60WF (7.90%, 113/1431 eyes), ZCB00 (10.06%, 64/636 eyes), and MX60 (10.57%, 13/123 eyes; p < 0.001) lenses. The incidence of Nd:YAG laser capsulotomy was significantly lower with the hydrophobic IOLs (8.68%, 190/2190 eyes) than with the hydrophilic IOL (31.70%, 175/552 eyes; p < 0.001). Over time, the rate of increase in the cumulative number of Nd:YAG laser capsulotomy cases was the highest with MI60. The cumulative rate of Nd:YAG laser capsulotomy during the first 3 years was 4.90% with SN60WF (70/1431 eyes), 6.76% with ZCB00 (43/636 eyes), 8.94% with MX60 (11/123 eyes), and 26.10% with MI60 (144/552 eyes) lenses. Conclusions: The incidence of PCO is influenced by the material of the IOLs. The hydrophilic IOL was associated with a higher rate of Nd:YAG laser capsulotomy than the hydrophobic IOLs, with a shorter time to Nd:YAG laser capsulotomy.

Approach to the design of different types of intraocular lenses based on an improved sinusoidal profile.

An approach is presented to design different types of Intraocular lenses (IOLs) with a uniform optimization algorithm. An improved sinusoidal phase function is proposed to realize adjustable energy allocations in different diffractive orders according to the design aims. By setting specific optimization goals, different types of IOLs can be designed using the same optimization algorithm. With this method, bifocal, trifocal, extended-depth-of-focus (EDoF), and mono-EDoF IOLs are successfully designed and their optical performance under monochromatic and polychromatic light is evaluated and compared with their commercial counterparts. The result shows that most of the designed IOLs, even though they don't have any multi-zones or combination of diffractive profiles, have superior or comparable performance to their commercial counterparts in terms of optical performance under monochromatic light. The result demonstrates the validity and reliability of the approach proposed in this paper. With this method, the development time of different types of IOLs could be reduced considerably.

Latest Development in Extended Depth-of-Focus Intraocular Lenses: An Update.

In recent years, there has been an overwhelming influx of different types of intraocular lenses (IOLs) as treatment for presbyopia. The extended depth-of-focus (EDOF) technology creates a single elongated focal point to enhance depth of focus, in contrast to the multiple foci of multifocal (MF) lenses. In this way, the EDOF lenses aim to reduce photic phenomena, glare, and halos, which have been reported in MF IOLs. A potential disadvantage of this is a blur due to decreased retinal image quality when the amount of the aberrations is increased excessively. Multifocality and EDOF characteristics are not exclusive of each other. Frequently, EDOF IOLs are combined with MF optical designs, a bifocal IOL may exhibit EDOF characteristics, likewise an aspheric monofocal IOL or a diffractive or refractive trifocal IOL. Thus, EDOF lenses are commonly subjected to confusion. A wide range of different types of EDOF lenses are available on the market to surgeons. In this practical update, we aim to clarify what is a true EDOF lens, classify the different types of the EDOF lenses based on their optical principle and review their recently reported outcomes. Comprehensive patient examination and selection, combined with knowledge of the most updated options and adequate patient counseling, can avoid dissatisfaction and yield the desired outcomes.

The role and clinical significance of intraoperative optical coherence tomography for cataract surgery

AbstractPurpose: to evaluate the clinical significance of intraoperative spectral domain optical coherence tomography (iOCT) in cataract surgery with implantation of different types of intraocular lenses (IOL).Methods: In this retrospective observational study, the iOCT image data of 151 cataract cases with different types of implanted IOLs were analysed. For intraoperative imaging a Rescan® 700 was used and the following image criteria were traced: standard surgical steps, IOL optic position, IOL haptic position. Patient eyes were divided into: group 1: n = 101 eyes with lens‐in‐bag (LIB); group 2: n = 15 eyes with bag‐in‐the‐lens IOL (BIL); group 3: 5 eyes with iris‐claw IOL (ICL); group 4: 15 eyes with intrascleral fixated 3‐piece IOL (3‐IOL); group 5: 15 eyes with intrascleral fixated Carlevale IOL (C‐IOL). The data were post‐processed and evaluated statistically.Results: iOCT enabled an additional control of subsequent surgical steps in all studied cases: LIB: the completeness of hydrodissection and hydrodelineation, condition of hydrated paracentesis (in 11% of cases ‐ an incomplete adaptation of paracentesis); BIL: separation of anterior hyaloid and correct implantation of capsular edges into the IOL; ICL: thickness of the iris fold between IOL claws; 3‐IOL/C‐IOL: the position of optic with regard to the iris and position of the haptic in the intrascleral space.Conclusions: The application of iOCT assisted cataract surgery with different IOLs generates useful live data that potentially reduce the risks of intra‐ and postoperative complications (posterior capsule rupture, hypotony, etc.). It can confirm the correct positioning of alternative IOL types intraoperatively, which is crucial to facilitate an optimal IOL performance. The use of iOCT shall be considered during learning process in cataract surgery.

Visual Outcomes and Optical Quality of Accommodative, Multifocal, Extended Depth-of-Focus, and Monofocal Intraocular Lenses in Presbyopia-Correcting Cataract Surgery

A bayesian network meta-analysis (NMA) can help compare the various types of multifocal and monofocal intraocular lenses (IOLs) used in clinical practice. To compare outcomes of presbyopia-correcting IOLs frequently recommended in clinical practice through a bayesian NMA based on a systematic review. Medline (PubMed) and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched on May 15, 2021, from inception. Based on the research question, randomized clinical trials assessing multifocal IOLs in patients who underwent bilateral cataract extraction were searched. Nonrandomized studies, studies in patients with unilateral or contralateral cataract extractions, duplicated studies, conference abstracts, and nonpeer-reviewed articles were excluded. Descriptive statistics and outcomes were extracted. The NMA was conducted to compare different types of IOLs. The mean differences for continuous variables, odds ratios for binary variables, 95% credible intervals (CrIs), and ranks of interventions were estimated. The outcomes examined included binocular visual acuities by distance and optical quality, including glare, halos, and spectacle independence. This NMA included 27 studies comprising 2605 patients. For uncorrected near visual acuity, trifocal IOLs (mean difference, -0.32 [95% CrI, -0.46 to -0.19]) and old bifocal diffractive IOLs (mean difference, -0.33 [95% CrI, -0.50 to -0.14]) afforded better visual acuity than monofocal IOLs. Regarding uncorrected intermediate visual acuity, extended depth-of-focus IOLs provided better visual acuity than monofocal IOLs. However, there were no differences between extended depth-of-focus and trifocal diffractive IOLs in pairwise comparisons. For uncorrected distant visual acuity, all multifocal IOLs were comparable with monofocal IOLs. There were no statistical differences between multifocal and monofocal IOLs regarding contrast sensitivity, glare, or halos. For patients considering a multifocal IOL due to presbyopia, bilateral implantation of a trifocal IOL might be an optimal option for patients without compromising distant visual acuity.

Commentary: Decision-making in the management of surgical aphakia.

According to the 2015–2019 survey by the National Programme for Control of Blindness and Visual Impairment, uncorrected aphakia accounts for 1.7% of blindness and vision impairment in adults aged >50 years in India.[1] Anisometropia, aniseikonia, prismatic distortion of images (jack-in-the-box phenomenon) and the weight of high hyperopic spectacles demands rehabilitation in surgical aphakia with an intraocular lens (IOL) implantation. IOLs provide a better field of vision and less image disparity, and are more acceptable cosmetically. The standard of care of in-the-bag implantation of an IOL, may not be feasible in circumstances where there is a lack of posterior capsular support. Such instances are not uncommon in a regular cataract surgeon’s practice. Further recourse depends on the presence or absence of sulcus support. While, in the presence of an adequate sulcus support, a foldable 3-piece or a rigid polymethyl methacrylate (PMMA) IOL is preferred, in its absence, the choice of IOL fixation depends on the surgeon’s expertise. We congratulate the authors for summarizing the desired options for aphakia management by the anterior and posterior segment surgeons, in their study “Preferred practice patterns in Aphakia management in adults in India - A Survey”.[2] Although this study elaborates on the preferred site of IOL fixation being the iris and scleral-fixated IOLs by anterior and posterior segment surgeons, respectively, the results cannot be extrapolated to a larger population, considering the minimal response rate (4.8%). The primary indication for secondary IOL, age of the patient at surgery, associated ocular and systemic conditions, level of training of surgeons, and the availability of different types of IOLs should also be considered when such a survey is being conducted. Optical correction is a critical component of visual rehabilitation in aphakia. There are pros and cons to each of the modalities of IOL fixation. Owing to the higher risk of hyphema, secondary glaucoma and corneal endothelium decompensation, either scleral-fixated or iris-fixated IOLs are being preferred over the use of angle-fixated anterior chamber IOLs nowadays.[3] The decision to use iris-fixated or scleral-fixated IOLs depends on the expertise of the surgeon.[45] The visual outcome in both types of IOL fixation are comparable at variable follow-up periods, although long-term prospective studies are required to confirm the same.[5678] Each of these methods have inherent complications associated with them. Iris-fixated IOLs, either anteriorly or posteriorly, are associated with iris erosion, pigment dispersion, corectopia, hyphema, IOL subluxation, cystoid macular edema, chronic uveitis and secondary glaucoma.[58] In addition to the aforementioned complications, scleral-fixated IOLs, either sutured or suture-less, are associated with vitreous hemorrhage, haptic exposure, retinal detachment, scleral thinning and IOL tilting and/or dislocation.[59] As opposed to the in-the-bag IOL and angle-fixated anterior chamber IOL (ACIOL), the procedure for iris-fixated and scleral-fixated IOLs is technically challenging, has a steep learning curve and needs expertise. The long-term stability of the these IOLs as well as complications are yet to be studied prospectively. Nevertheless, these results cannot be extrapolated to the pediatric aphakic population. Age, size of the eyeball, corneal diameter, primary indication of aphakia, eye growth, systemic associations, and high prediction errors are factors to be considered while planning IOL implantation in children. Primary IOL implantation is usually discouraged in children with small eyes (short axial length/microcornea) and those with associated anterior and posterior segment pathologies. When children reach the appropriate age, and their eyes are of the adequate size with open angles on gonioscopy and have no contraindications, a secondary three-piece IOL or a PMMA IOL in-the-sulcus/in-the-bag can be planned.[10] When sulcus examination becomes difficult clinically, ultrasound biomicroscopy of the anterior segment can be done. This provides the surgeon with information on the status of ciliary sulcus and its surrounding tissue preoperatively.[10] The vigilance on the postoperative course in children should be high as they are at a risk of excessive postoperative inflammation and rise in intraocular pressure. In specific cases such as ectopia lentis caused by Marfan syndrome, it is preferrable to leave the children aphakic and rehabilitate them with contact lenses or spectacles. Thus, for a customized approach to manage a case of aphakia, weighing the risks and benefits of the procedure is encouraged. Various factors to be considered are age, indications, contraindications, site of IOL fixation, IOL POWER calculation formula, IOL material/designs and expertise in the procedure. The historic Latin phrase, Primum non nocere, meaning, “First, do no harm,” should be respected, and selected cases should be left aphakic and rehabilitated with contact lenses or spectacles, rather than implant an IOL and cause irreversible damage due to glaucoma, corneal decompensation and retinal detachment.

Assessment of spectral properties of positive dysphotopsia or glare caused by LED sources for different types of intraocular lenses.

Light emitting diodes (LEDs) have become a major source of lighting conditions. The increased prevalence of LED light sources introduces new concerns for the spectral effects of positive dysphotopsia (PD) or glare type photic phenomena for pseudo-phakic patients with intraocular lenses (IOLs). A significant amount of work has been published in the area of spectral discomfort and sensitivity of LEDs as well as automotive lighting. The wavelength dependence or spectral properties of PD due to LEDs for IOLs has not been reported. This study, to our knowledge, is the first one to assess the glare characteristics of four commercially available IOL models with different material types and design features using an optical bench and non-sequential ray trace simulations with LEDs of different wavelengths. A novel approach of representing the reflected and transmitted IOL glare utilizing Fresnel coefficients is found to be in close agreement with the measurements.

Comparison of tolerance to decentration and tilt in the early postoperative period between the continuous range and bifocal intraocular lens implantation in myopic eyes

Objective: To compare decentration and tilt tolerances between continuous range intraocular lens (IOL) and bifocal IOL in myopia during the early stages post intraocular implantation. Method: A retrospective cohort study was conducted using follow-up data of 145 patients (145 eyes) who underwent phacoemulsification combined with IOL implantation in the Eye & ENT Hospital of Fudan University from January 2018 to December 2020. According to whether the axial length was less than 24.5 mm, patients were divided into non-myopic and myopic groups. According to IOL type, patients were divided into extend depth of focus (EDOF) ZXR00 IOL group (myopic 38 eyes, non-myopic 41 eyes) and bifocal ZMB00 IOL group (myopic 23 eyes, non-myopic 43 eyes). The distance and near visual acuity (log of the minimum angle of resolution visual acuity), IOL tilt and decentration, intraocular high-order aberration (HOA), coma, trefoil, spherical aberrations, modulation transfer function (MTF), as well as VF-14 index and the incidence of dysphotopsia were compared between the 2 groups at 3 months after surgery. Statistics were performed using Student's t-test, χ2 test, Pearson correlation analysis and multiple linear regression analysis. Results: In either the myopic or non-myopic group, no significant differences were found in age, gender, eye laterality, axial length and IOL degree between eyes with the two different types of IOLs (all P>0.05). At 3 months after surgery, there was no significant difference in uncorrected and best-corrected distance visual acuity between the ZXR00 IOL group and the ZXR00 IOL group, while uncorrected near visual acuity was better in the ZMB00 IOL group than the ZXR00 IOL group (t=10.41, P<0.01). The total postoperative IOL decentration in the ZXR00 IOL group and ZMB00 IOL group in myopic eyes were (0.32±0.17) and (0.38±0.16) mm, respectively, which were greater than those in non-myopic eyes [(0.22±0.12), (0.28±0.12) mm; t=3.16, 2.57; both P<0.05]. However, there were no significant differences in IOL tilt between myopic and non-myopic eyes in the 2 groups (both P>0.05). There were no significant differences in postoperative IOL tilt and decentration between the 2 groups regardless of myopia or non-myopia (all P>0.05). In myopic eyes, HOA, coma aberration and spherical aberration in the ZXR00 IOL group were significantly lower than those in the ZMB00 IOL group, while the total ocular MTF (38.15±10.12) was significantly higher than that in the ZMB00 IOL group (30.46±10.53) (all P<0.05). Pearson correlation analysis and multiple linear regression analysis showed a positive correlation between postoperative HOA and both IOL tilt and decentration in the ZMB00 IOL group (r=0.627, 0.726; β=0.446, 0.587; all P<0.01). However, no such relationship was found in the ZXR00 IOL group (all P>0.05). In myopic eyes, when the IOL tilt aberration and decentration were greater than the median, the HOAs in the ZXR00 IOL group [(0.33±0.14), (0.27±0.11) μm] were lower than those in the ZMB00 IOL group [(0.88±0.56), (0.96±0.45) μm], while the total ocular MTF (42.87±10.97, 40.22±9.30) were higher than those in the ZMB00 IOL group (25.02±8.99, 29.87±10.19) (all P<0.05). In myopic eyes, the proportion of patients with visual interference symptoms in the ZXR00 IOL group [42.11% (16/38)] was significantly lower than that in the ZMB00 IOL group [78.26%(18/23), χ²=7.59, P<0.05]. Conclusion: During the early stages after IOL implantation in myopic eyes, EDOF IOL is more tolerant to decentration and tilt than bifocal IOL.

Effect of the spectral power distribution on visual performance of subjects implanted with intraocular lenses with or without a blue light-filter under night-driving conditions

In old subjects, the effect on visual performance of the interaction between the spectral power distribution of street lamps and the different types of intraocular lenses (IOLs) is unknown. Contrast threshold (CT) and reaction time (RT) were analysed in off-axis vision at mesopic illumination conditions provided by high-pressure sodium and metal-halide lamps, using a Maxwellian view optical system. Four groups of subjects participated: 10 young subjects, 20 elderly subjects with cataracts and the same subjects after cataract surgery were divided into two groups, 10 subjects implanted with a blue light-filtering and 10 subjects with a non-blue light-filtering IOL (NBIOL). Age-related cataract impairs detection and reaction capabilities; tasks that are nevertheless improved after surgery. The type of lamp does not affect both tasks in the case of the blue light-filtering IOL group, but it does in the NBIOL group. When comparing the two lenses, no detrimental effect of the blue light filter is observed in both tasks. In conclusion, at representative night-driving conditions, the spectral power distribution of the street lamp does not have a clinically relevant effect on visual tasks such as CT and visual RT in pseudophakic subjects, regardless of the type of IOL implanted.

Research Progress Concerning a Novel Intraocular Lens for the Prevention of Posterior Capsular Opacification.

Posterior capsular opacification (PCO) is the most common complication resulting from cataract surgery and limits the long-term postoperative visual outcome. Using Nd:YAG laser-assisted posterior capsulotomy for the clinical treatment of symptomatic PCO increases the risks of complications, such as glaucoma, retinal diseases, uveitis, and intraocular lens (IOL) pitting. Therefore, finding how to prevent PCO development is the subject of active investigations. As a replacement organ, the IOL is implanted into the lens capsule after cataract surgery, but it is also associated with the occurrence of PCO. Using IOL as a medium for PCO prophylaxis is a more facile and efficient method that has demonstrated various clinical application prospects. Thus, scientists have conducted a lot of research on new intraocular lens fabrication methods, such as optimizing IOL materials and design, and IOL surface modification (including plasma/ultraviolet/ozone treatment, chemical grafting, drug loading, coating modification, and layer-by-layer self-assembly methods). This paper summarizes the research progress for different types of intraocular lenses prepared by different surface modifications, including anti-biofouling IOLs, enhanced-adhesion IOLs, micro-patterned IOLs, photothermal IOLs, photodynamic IOLs, and drug-loading IOLs. These modified intraocular lenses inhibit PCO development by reducing the residual intraoperative lens epithelial cells or by regulating the cellular behavior of lens epithelial cells. In the future, more works are needed to improve the biosecurity and therapeutic efficacy of these modified IOLs.

In vitro optical performance of multifocal and extended depth-of-focus intraocular lenses in spherical aberration conditions.

To evaluate and compare the optical performances of 4 different types of intraocular lenses (IOLs) in various spherical aberration (SA) conditions. POSTECH, Pohang, South Korea. In vitro laboratory study. A custom optical bench system with adaptive optics was used. A monofocal IOL, a bifocal IOL, a trifocal IOL, and an extended depth-of-focus (EDoF) IOL from Zeiss were evaluated by measuring through-focus modulation transfer function (MTF) as a function of vergence. MTF changes with SA from -0.1 to +0.1 with 0.05 μm step size were analyzed and compared. In aberration-free conditions, the 4 IOLs showed different MTF curves consistent with their designs. In SA conditions, all the IOLs showed MTF value decreases and the decrease rates at the far focus varied from 28% to 38% per 0.1 μm SAs. The trifocal IOL had low MTF values at the intermediate focus in the noise level with ±0.1 μm SAs. All tested IOLs showed MTF decreases with SA in different levels. The trifocal and EDoF IOLs were the most and least sensitive to SA among the evaluated IOLs. The study results might be useful in the selection of IOLs for cataract patients with SA.

Live surgery outcomes in cataract surgery.

To evaluate and compare the outcomes of live surgery (LS) and no-live surgery (NLS) on cataract surgery with implantation of different types of intraocular lenses (IOLs). Retrospective, contralateral eye, case series of patients that underwent cataract surgery in live or non-live view during two consecutive editions of national meetings. Both eyes of the same patients were implanted with the same IOL, one in LS and the other in NLS. 108 eyes of 54 patients, aged between 50 and 82 (72 ± 8.2) and implanted with different types of IOLs, were reviewed. Both eyes in each patient were well matched at baseline in terms of intraocular biometric characteristics, corneal curvature and endothelial cell density (ECD) (p > 0.05). There are no statistically significant differences between the biometric and topographic parameters, aberrometric data and the loss of ECD in the post-operative outcomes (p > 0.05). However, comparing the different types of IOLs, there is a significant loss of ECD in eyes implanted with a toric IOL during LS (p = 0.0014 and p = 0.04, in 2017 and 2018 edition respectively). In this series of live cataract surgery, eyes operated in LS or NLS have comparable outcomes, underlying the importance and the benefits of live view in terms of medical education and the low-risk of complications. Nevertheless, we have found a significant increase in ECD loss in patients implanted with toric IOLs during LS.

Relationship Between Postoperative Intraocular Lens Shift and Postoperative Refraction Change in Cataract Surgery Using Three Different Types of Intraocular Lenses.

IntroductionUnderstanding the relationship between postoperative intraocular lens (IOL) shift and refractive change is crucial for the accuracy of predicted postoperative refraction (PPR). We assessed the relationships between different IOL fixation methods, haptic designs, and several metrics.MethodsSingle-center, open-label study which included 69 eyes. We preoperatively measured the anterior chamber depth (ACD), lens thickness (LT), axial length (AL), and PPR. AcrySof IQ (n = 27) and FineVision (n = 24) were fixed in the bag, and FEMTIS (n = 18) was fixed in capsulorhexis. At 1 day, 1 week, and 1 month postoperatively, we checked the IOL position and refraction and compared the IOL shift, refraction change, and the margin of error of the predicted PPR (PR-PPR difference). We also analyzed the correlation between postoperative and preoperative variables.ResultsFEMTIS showed the highest stability in terms of IOL shift and refraction. The in-the-bag-fixated IOLs showed a significant forward shift between 1 day and 1 week postoperatively. There were significant differences in the PR-PPR difference between the IOLs. ACD and AL showed significant positive correlations, and LT showed a significant negative correlation with IOL shift and change in PR between 1 day and 1 week, but not between 1 week and 1 month postoperatively.ConclusionThe relationship between postoperative IOL shift and refraction change varied according to IOLs with different haptic types. Capsulorhexis fixation may be more stable than in-the-bag fixation. Furthermore, preoperative ACD, LT, and AL may be useful factors to predict IOL shift, change in PR, and to a lesser extent the degree of the margin of error in clinical practice. Our findings may improve the accuracy of PPR and refractive outcomes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40123-021-00390-x.

Does Every Calculation Formula Fit for All Types of Intraocular Lenses? Optimization of Constants for Tecnis ZA9003 and ZCB00 Is Necessary.

Background and Objectives: To evaluate the performance of intraocular lenses (IOLs) using power calculation formulas on different types of IOL. Materials and Methods: 120 eyes and four IOL types (BioLine Yellow Accurate Aspheric IOL (i-Medical), TECNIS ZCB00, TECNIS ZA9003 (Johnson & Johnson) (3-piece IOL) and Softec HD (Lenstec)) were analyzed. The performance of Haigis, Barret Universal II and SKR-II formulas were compared between IOL types. The mean prediction error (ME) and mean absolute prediction error (MAE) were analyzed. Results: The overall percentage of eyes predicted within ±0.25 diopters (D) was 40.8% for Barret; 39.2% Haigis and 31.7% for SRK-II. Barret and Haigis had a significantly lower MAE than SRK-II (p < 0.05). The results differed among IOL types. The largest portion of eyes predicted within ±0.25 D was with the Barret formula in ZCB00 (33.3%) and ZA9003 (43.3%). Haigis was the most accurate in Softec HD (50%) and SRK-II in Biolline Yellow IOL (50%). ZCB00 showed a clinically significant hypermetropic ME compared to other IOLs. Conclusions: In general, Barret formulas had the best performance as a universal formula. However, the formula should be chosen according to the type of IOL in order to obtain the best results. Constant optimizations are necessary for the Tecnis IOL ZCB00 and ZA9003, as all of the analyzed formulas achieved a clinically significant poor performance in this type of IOL. ZCB00 also showed a hypermetropic shift in ME in all the formulas.

Visual function and mobility after multifocal versus monofocal intraocular lens implantation

ABSTRACT Clinical relevance: Mobility and fall risk may be important considerations in choosing between intraocular lenses. Background: Fall risk in older adults increases when wearing multifocal spectacles, but little is known about mobility among individuals with different types of intraocular lenses. This study compared visual function, fall risk and balance control following bilateral implantation of monofocal or multifocal intraocular lenses. Methods: This was a non-randomised, cross-sectional study involving adults with bilateral intraocular lenses. Participants completed questionnaires concerning physical functioning, fall history and balance-related confidence. Binocular visual acuity, contrast sensitivity (Pelli-Robson chart and computerized testing), depth perception and glare sensitivity were assessed. Physical performance measures included the Sensory Organization Test, preferred gait speed, Dynamic Gait Index and wayfinding in a virtual environment. Results: Fifteen participants (mean ± standard deviation, 67.1 ± 6.8 years) had monofocal intraocular lenses and 14 participants (68.1 ± 6.1 years) had multifocal intraocular lenses. Contrast sensitivity in the monofocal group was significantly better than that in the multifocal group (p = 0.02) at intermediate and high spatial frequencies. Contrast sensitivity of the monofocal group also was less affected by glare than the contrast sensitivity of the multifocal group, at an intermediate spatial frequency (p = 0.02). However, the multifocal group had significantly better Dynamic Gait Index scores (p = 0.04), even after controlling for perceived physical function. Conclusions: The participants with monofocal intraocular lenses generally had better contrast sensitivity than did those with multifocal intraocular lenses. However, the scores on a mobility test that is associated with fall risk were worse for those with monofocal lenses.

Straylight in Different Types of Intraocular Lenses.

PurposeTo show the importance of measuring the angular distribution of straylight as an in vitro test for intraocular lenses (IOLs).MethodsThe optical integration method was implemented to measure the point spread function, up to 5.1°, of IOLs immersed in a wet cell. The straylight parameter was calculated as the product of the point spread function by the squared angle. The effect of the scattered light is shown in extended images of a target surrounded by headlamps as glare sources. Three different IOLs were tested: (1) AcrySof IQ SN60WF, monofocal, (2) AcrySof IQ PanOptix, trifocal, and (3) Tecnis Symfony ZRX00, bifocal with extended depth of focus. Measurements were compared to previously reported clinical studies where the same IOL models were implanted.ResultsThe mean amount of scattered light, between 1.0° and 5.1°, generated by each IOLs were, in deg2sr–1 units: (1) 1.2, (2) 12.1, and (3) 33.4. Lens (3) present a high amount of straylight related to a halo of an approximate diameter of 2°.ConclusionsIn vitro measurements of the angular distribution of the point spread function of different types of IOLs showed important aspects related to their manufacturing quality. These results are in line with previous clinical findings where glare sensitivity was tested in the same angular range.Translational RelevanceIn vitro measurement of angular dependence of straylight in IOLs, regardless their design, provides a valuable feedback to improve their optical quality. The minimization of the amounts of straylight positively impacts the recurrence of photic phenomena.