Intraocular Lens Decentration Research Articles

Optical bench simulation for intraocular lenses using field-tracing technology.

To evaluate the image quality of intraocular lenses (IOLs) using field-tracing optical simulation and then compare it with the image quality using conventional ray-tracing simulation. We simulated aspheric IOLs with a decenter, tilt, and no misalignment using an aspheric corneal eye model with a positive spherical aberration. The retinal image, Strehl ratio, and modulation transfer function (MTF) were compared between the ray-tracing and field-tracing optical simulation and confirmed by the results reported in an in vitro experiment using the same eye model. The retinal image showed interference fringes from target due to diffraction from the object in a field-tracing simulation. When compared with the experimental results, the field tracing represented the experimental results more precisely than ray tracing after passing over 400 μm of the decentration and 4 degrees of the tilt of the IOLs. The MTF values showed similar results for the case of no IOL misalignment in both the field tracing and ray tracing. In the case of the 200-μm decentration or 8-degree tilt of IOL, the field-traced MTF shows lower values than the ray-traced one. The field-tracing optical bench simulation is a reliable method to evaluate IOL performance according to the IOL misalignment. It can provide retinal image quality close to real by taking into account the wave nature of light, interference and diffraction to explain to patients having the IOL misalignment.

Evaluation of Decentration, Tilt and Angular Orientation of Toric Intraocular Lens.

PurposeThe aim of this study was to develop software for the universal objective evaluation of factors influencing intraocular correction of astigmatism, such as decentration, tilt, axial position and angular orientation the toric intraocular lens (IOL).Patients and MethodsSoftware was developed using the MS Visual Studio environment. The analysis was presented using images of 67 eyes with an implanted IOLs of the SN6ATx model series. Decentration and angular position of the lens were obtained from images of the anterior segment of the eye, using a Visucam unit. Tilt was measured on tomographic images from OCT Avanti (in meridian of highest tilt and perpendicular meridian) and preoperative biometry parameters of eye (axial length, anterior chamber depth – ACD, ocular lens thickness – LT, limbus diameter and mean keratometry value) including postoperative anterior chamber depth (pACD) were measured using Lenstar LS900.ResultsApplying the software methodology to the evaluation of individual toric IOL parameters, the following results were obtained: mean decentration 0.25 ± 0.17 mm which was observed in 61.19% of eyes, mean misalignment to the planned axis equal to 3.8 ± 3.6 degrees, mean highest inclination equal to 3.7 ± 1.2 degrees and mean difference of pACD and ACD was equal to 1.46 ± 0.31 mm. There was only a weak nonsignificant correlation between preoperative ACD versus decentration and tilt of IOL or a weak significant correlation between preoperative LT and both decentration and misalignment of IOL.ConclusionThe use of the presented methodology for determining the positional parameters of the toric IOL provided comparable results with the results of recent studies. Software design can be considered as a suitable alternative to previously published techniques, with the significant advantage of the possibility of using universal input images, their graphical editing and especially the possibility of comprehensive analysis of all parameters.

Efficacy of Large Optic Intraocular Lenses in Myopic Eyes with Posterior Segment Pathology.

We report a case series of patients with high myopia (axial length 25.04–27.59 mm) diagnosed with cataract and maculopathy who underwent a combined procedure of phacoemulsification with implantation of a large optic intraocular lens (IOL) and intravitreal injection. Six patients with a mean (± standard deviation) age of 73.20 ± 7.19 years received the 7.0-mm optic ASPIRA-aXA IOL (HumanOptics AG, Erlangen, Germany) and intravitreal injection of aflibercept at the end of the surgery. The corrected distance visual acuity (CDVA) improved significantly (p = 0.001) from a preoperative logMAR of 0.87 ± 0.28 logMAR to 0.49 ± 0.18 logMAR at 10 weeks postoperatively. Even though all patients had a persisting central scotoma due to their maculopathy, there was a significant improvement in their subjective quality of life and self-autonomy. Patients reported no postoperative dysphotopsia. During surgery and postoperative examinations, the wide IOL optic permitted an enhanced view of the fundus. The IOLs remained stable after implantation, especially during the intravitreal injection at the end of the surgery. No IOL displacement or shift of the lens was observed. Retinal diseases are sight-threatening and diminish the patient’s quality of life due to reduced visual acuity and visual field defects. When cataract surgery is performed in this patient group, a reduced prognosis can be assumed. Our results show that implantation of the large optic IOL enables a wide view of the fundus during and after surgery without any additional risks or negative effects. It may also reduce the risk of dysphotopsia in cases of IOL decentration in large capsular bags, but comparative studies with a higher number of cases are needed to confirm this. A large rhexis and large IOL optic seem to be advantageous for the retinal surgeon in follow-up surgeries on the posterior segment of the eye.

In-the-Bag Versus Ciliary Sulcus Secondary Intraocular Lens Implantation for Pediatric Aphakia: A Prospective Comparative Study

To compare outcomes of in-the-bag vs ciliary sulcus secondary intraocular lens (IOL) implantation for pediatric aphakia. Prospective interventional case series. This institutional study was conducted in 202 children (355 aphakic eyes) diagnosed as having congenital cataracts and who underwent cataract extraction before age 24 months. Pediatric aphakic eyes underwent in-the-bag or ciliary sulcus secondary IOL implantation according to the amount of residual lens capsule and were monitored for 3 years postoperatively. The main outcome measures were adverse events (AEs), IOL tilt and decentration, and best corrected visual acuity (BCVA) in the operative eye. A total of 144 eyes (40.6%, 89 children) received in-the-bag IOL implantation (capsular group), and 211 eyes (59.4%, 132 children) underwent ciliary sulcus IOL implantation (sulcus group). Kaplan-Meier curves showed that the time-dependent incidence of glaucoma-related AEs (GRAEs) (P=.005) and any AEs (P=.002) were higher in the sulcus group. In-the-bag IOL implantation was a strong protective factor against GRAE (hazard ratio, 0.08; 95% CI, 0.01-0.53; P=.009) and any AEs (hazard ratio, 0.21; 95% CI, 0.08-0.57; P=.002). Clinically significant IOL decentration (>0.4 mm) was more common in the sulcus group compared with the capsular group (vertical decentration: 29.8% vs 15.7%, P=.005; horizontal decentration: 30.3% vs 9.35%, P < .001). BCVA in the capsular group was better than that in the sulcus group (logMAR, 0.56 vs 0.67, P=.014). Compared with ciliary sulcus secondary IOL implantation, in-the-bag IOL implantation reduced AEs and yielded better IOL centration and BCVA for pediatric aphakia.

Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: comparison of internal aberrations and visual quality.

To compare the internal aberrations and optical quality after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS). This study included patients who received FLACS or CPCS from January 2016 to July 2019. Postoperative examinations included wavefront measurements under pupil diameters of 3.0mm and 5.0mm, intraocular lens (IOL) decentration, visual acuity (VA), and refractive outcomes. Visual quality was measured with Strehl ratio and modulation transfer function (MTF). Subgroup analyses were conducted based on monofocal or multifocal-extended depth of focus (EDOF) IOL. The study consisted of 221 eyes (105 eyes in FLACS and 116 eyes in CPCS). With a pupil diameter of 5.0mm, FLACS demonstrated a significantly lower root mean square of total internal aberration (P = 0.004), higher order aberrations (HOAs) (P = 0.034), tilt (P = 0.049), coma (P = 0.004), and spherical aberration (P = 0.014). IOL tilt was found to be positively correlated with total internal aberration (P < 0.001), HOAs (P < 0.001), and coma (P < 0.001). The FLACS group presented significantly smaller IOL decentration than the CPCS group (P < 0.001), but there were no significant differences in terms of VA and refractive outcomes between groups. In the multifocal-EDOF subgroup, Strehl ratio and MTF values were significantly higher in the femtosecond group with a 3.0-mm pupil. FLACS induced significantly lower values of IOL tilt, decentration, and internal aberrations compared with the CPCS group with a pupil diameter of 5.0mm, while no significant differences were found in the VA or optical quality over long-term observation. This trial was registered at www.chictr.org.cn (registration number ChiCTR2000038965).

Анализ влияния наклона и децентрации ИОЛ на индуцированный астигматизм при исследовании методом трассировки лучей на модели глаза

Purpose. Determination of the influence of the intraocular lens (IOL) inclination and decentration on the magnitude of induced astigmatism in a theoretical study using software on an eye model. Material and methods. An eye model with the specified parameters was performed to carry out the calculation. Modulation of the change in the wavefront was carried out using the Zemax program (LLC, USA). In the model eye, the probability of induction of astigmatism was analyzed depending on the change in the position of the aspherical IOL Acrysof IQ 16.0, 22.0 and 24.0 diopters and the toric model Acrysof IQ Toric SN6AT3, SN6AT4 and SN6AT5. The angle of inclination of the IOL relative to the horizontal plane was examined from 0° to 10° with a step of 1°, decentration from 0.1 to 1.5 mm with a step of 0.1 mm. At each IOL position, aberration data of the 2nd order Z (2, 2) were recorded. The obtained results were used to calculate the critical tilt angle and decentration. Results. The magnitude of induced astigmatism increased with the rise of the degree of inclination and decentration, corresponding to an increase in the optical power of the IOL. Accordingly, critically significant were the values of 3.0° inclination for the aspherical IOL with an optical power of 22.0 and 22.0 diopters and 3.5° for 16.0 diopters, decentration – 0.7 mm and 1.0 mm. The inclination of the TIOL relative to the horizontal plane revealed the induction of the magnitude of inverse astigmatism, according to an increase in the inclination angle of 0.3 diopters at a slope of 3–4°. Conclusions. The tilt and decentration of the aspherical and TIOL patterns induce astigmatism depending on the increase in IOL power. The inclination of the TIOL in relation to the horizontal plane set at 90 ° promotes the induction of astigmatism. Key words: astigmatism, toric intraocular lenses, tilt and decentration of the intraocular lens, ray tracing

Clinically Significant Intraocular Lens Decentration and Tilt in Highly Myopic Eyes: A Swept-Source Optical Coherence Tomography Study

To investigate the occurrence and risk factors of clinically significant intraocular lens (IOL) decentration and tilt in highly myopic eyes using swept-source anterior segment optical coherence tomography (SS-AS-OCT). Cross-sectional study. This study included 334 participants (334 eyes) with high myopia, defined as axial length (AL) ≥26 mm, who underwent phacoemulsification with IOL implantation. Decentration and tilt of IOL were assessed by SS-AS-OCT. Clinically significant IOL decentration and tilt was defined as decentration ≥0.4 mm and tilt ≥7°. Routine preoperative and postoperative examinations included visual acuity, refraction, biometric measurement using IOLMaster 700 (Carl Zeiss Meditec), and objective visual quality evaluated by OPD-Scan III (Nidek Technologies). Among the 334 highly myopic participants, 71 (21.3%) had clinically significant IOL decentration, and 26 (7.78%) had clinically significant IOL tilt. The proportion of clinically significant IOL decentration (37.1% vs 14.0%, P < .001) and tilt (16.2% vs 3.90%, P < .001) in those with AL ≥30 mm was significantly higher than in those with AL <30 mm. The multivariable logistic regression model showed only AL ≥30 mm was associated with clinically significant IOL decentration (odds ratio, 1.65; P=.002). AL ≥30 mm (odds ratio, 2.09; P=.001) was an independent risk factor for clinically significant IOL tilt after adjusting for confounders. AL ≥30.3 mm could effectively predict IOL decentration ≥0.6 mm (area under the curve, 0.802). Participants with AL >30 mm have a higher risk of clinically significant IOL decentration and tilt, thus caution should be taken to implant multifocal or toric IOL for these patients.

Stability of Intraocular Lens With Different Haptic Design: A Swept-Source Optical Coherence Tomography Study.

Purpose: To investigate the stability of intraocular lens (IOLs) with different haptics by swept-source anterior-segment optical coherence tomography (AS-OCT).Methods: Sixty-eight eyes from 55 patients received the implantation of Rayner 920H (Closed C-loop Group), Zeiss 509M (Plate Group) or Lenstec SOFTEC HD (C-loop Group) IOLs. The tilt and decentration of IOLs were evaluated using AS-OCT at least 1 month postoperatively.Results: Mean decentration and tilt of IOLs were 0.18 ± 0.12 mm (range 0.02 to 0.59 mm) and 5.63 ± 1.65° (range 2.2 to 9.6°) respectively. Decentration was significantly smaller in the plate haptic group (0.12 ± 0.06 mm) as compared to the C-loop group (0.22 ± 0.13 mm, P = 0.02). The tilt of IOL was also significantly smaller in the plate haptic group (4.96 ± 0.89°) as compared to the C-loop group (6.28 ± 1.83°, P = 0.01). There was marginal difference between the Closed C-loop group (5.52 ± 1.74°) and C-loop group (6.28 ± 1.83°, P = 0.07).Conclusions: The Plate-haptic IOLs should have better stability for the decentration and tilt than the C-loop design IOLs.

One Year Outcomes and Stability of a Novel Scleral Anchored Intraocular Lens.

Purpose To assess one year results and stability of the implantation of a scleral anchored intraocular lens (IOL). Design Interventional prospective case series. Methods Sixty eyes of 60 patients affected by either aphakia or IOL dislocation were included in this study. Patients underwent vitrectomy, scleral fixation of the IOL, and, if present, dislocated IOL removal. Patients were evaluated preoperatively and at 1, 3, 6, and 12 months after surgery by best-corrected distance visual acuity (BCVA) assessment, intraocular pressure (IOP) measurement, corneal specular microscopy, and optical coherence tomography (OCT) of both the macula and anterior segment. Results At twelve months, mean BCVA significantly improved (p < 0.0001), and none of the patients experienced a decrease of visual acuity. A 10% decrease of endothelial cell count occurred after surgery. Cystoid macular edema occurred in three patients (5%). A transient increase of intraocular pressure was noted in 7 cases (12%). At one month, horizontal and vertical IOL tilt was 1.04 ± 0.87 and 0.74 ± 0.71 degrees, respectively, and did not significantly change in the follow-up (p > 0.05). None of the patients had decentration or dislocation of scleral-fixated IOL during the follow-up. Conclusion Implantations of scleral plug fixated IOL provide good visual results, low complication rate, and excellent stability of the lens until one-year follow-up.

Simulations of Decentration and Tilt of a Supplementary Sulcus-Fixated Intraocular Lens in a Polypseudophakic Combination Using Ray-Tracing Software

This study aimed to assess image quality after the tilt and decentration of supplementary intraocular lenses (IOLs) in a two-lens configuration. One was designed for sulcus fixation with a nominal power range of 1D–10D and was combined with a capsular fixation 20D IOL. The optical performance of a ray-tracing model was tested under IOL misalignment through the area under the modulation transfer function (MTFa) and wave aberrations. Tilting by 10° resulted in a 4% reduction of the MTFa for a 10D IOL as compared to 9% for the 20D lens. The two models demonstrated good tolerance to a 1 mm decentration; as for the 10D sulcus-fixated lens, the MTFa loss was 2%, and 4% for the capsular fixation lens. Coma and astigmatism increased three- and four-fold, respectively, after a 10° tilt compared to the aberration level induced by the 1 mm decentration. Both analyses showed a trend towards a lower MTF impact and fewer optical errors with decreasing nominal power. In conclusion, when misaligned, low-power sulcus-fixated IOLs might retain their good optical quality. An extreme tilt of 10° has a more detrimental effect on the IOL performance than a 1 mm decentration. The proper alignment of a high-power capsular fixation lens is important in achieving a desirable postoperative outcome.

Changes in Optical Quality Induced by Tilt and Decentration of a Trifocal IOL and a Novel Extended Depth of Focus IOL in Eyes With Corneal Myopic Ablations.

To assess the effect of decentration and tilt combined with prior myopic ablations on the optical performance of a trifocal intraocular lens (IOL) and a novel IOL with an extended depth of focus (EDOF) design. The XACT Mono-EDOF ME4 (Santen Pharmaceutical Co Ltd) and the trifocal FineVision (PhysIOL) IOLs were analyzed with and without simulated previous myopic ablations. The optical quality of the IOLs was evaluated with the PMTF optical bench (LAMBDA-X). The through-focus modulation transfer function (MTF) curves were recorded. Measurements were done for three situations: centered, 0.4 mm decentered, and 4 degrees tilted. The trifocal IOL showed three peaks of vision and the EDOF IOL showed a far distance peak with intermediate addition. When decentration or tilt were induced, the trifocal IOL showed negligible changes but the EDOF IOL showed a -0.50 diopters (D) shift of the overall curve. With simulated myopic ablation, the trifocal IOL showed a -0.50 D shift of the curve. When tilt or decentration were also induced, the better optical results were found at -1.00 D. With myopic ablations, the EDOF IOL showed a -0.50 D shift of the optical quality and when decentration or tilt were then induced, negative shifts over -1.00 D were found. The trifocal IOL was less affected by mis-alignments. When myopic ablations were induced, both lenses decreased their optical quality and the effects of misalignments were higher. In patients who have undergone corneal myopic ablation procedures, proper alignment of the implanted IOL and obtaining effective emmetropia becomes even more critical. [J Refract Surg. 2021;37(8):532-537.].

Outcomes and Complications of Sutured Scleral-Fixated Foldable Intraocular Lens Implantation: A Retrospective Study of 5-Year Follow-Up.

Purpose To evaluate long-term outcomes and complications of sutured scleral-fixated foldable intraocular lens (IOL) implantation. Design Retrospective study. Methods Patients who underwent sutured scleral-fixated foldable IOL implantation using 10-0 polypropylene suture were followed up for at least 5 years at one Chinese tertiary hospital and two primary hospitals. Results 52 eyes among 48 patients (35 male and 13 female) were evaluated. The mean age (years) was 50.27 ± 20.08 (range: 6 to 81). The mean postoperative follow-up time (months) was 79.70 ± 18.84 (range: 60 to 121). The mean best-corrected visual acuity (BCVA) improved from 0.83 ± 0.69 logarithm of the minimum angle of resolution (logMAR) at baseline to 0.50 ± 0.45 logMAR at the last follow-up visit. There was improved or unchanged BCVA in 44 eyes (84.62%) and reduced BCVA in 8 eyes (15.38%). Mild intraoperative intravitreal hemorrhage was observed in 3 eyes (5.77%). Early postoperative complications included transient elevated intraocular pressure (IOP) in 5 eyes (9.62%) and hypotony in 1 eye (1.92%). Secondary epimacular membrane occurred in 5 eyes (9.62%) and retinal detachment (RD; 3 years postsurgery), subconjunctival suture knot exposure (5 years postsurgery), and persistent elevated IOP (in a GRAVES patient) occurred in 1 eye (1.92%) each. No suture erosion or breakage nor IOL dislocation was observed. No visually threatening IOL tilt or decentration was reported in any patient. Conclusion Sutured scleral-fixated foldable IOL implantation demonstrated satisfactory long-term outcomes and rare suture-related complications. This technology was safe and did not require complicated equipment and is of considerable interest in the setting of aphakia without adequate capsule support.

Comparison of decentration, tilt and lenticular astigmatism of ıntraocular lens between sutured and sutureless scleral fixation techniques

To evaluate at six months the intraocular lens (IOL) decentration, tilt and lenticular astigmatism between foldable sutured and sutureless scleral fixation IOLs compared to conventional phacoemulsification surgery. We retrospectively reviewed records for 22 eyes with sutureless scleral fixation, 16 eyes with sutured scleral fixation and 23 eyes with conventional phacoemulsification. IOL decentration and angle of IOL tilt were compared on Scheimpflug images 6 months after surgery. Lenticular astigmatism is described as the difference between refractive and net corneal astigmatism. The angle of tilt in both meridians was significantly lower in the sutureless group than in the sutured group (P=0.008 horizontally and P=0.002 vertically). IOL decentration did not show a significant difference between the three groups in either horizontal or vertical meridians (P˃0.05). Lenticular astigmatism was significantly lower in the sutureless and control groups than in the sutured group (P=0.003 and P<0.001). In addition to being relatively quick and easy to perform, the sutureless scleral fixation technique showed superior results in terms of IOL tilt and lenticular astigmatism at the six-month follow-up compared to the sutured technique.

Knot-free suture scleral fixation of dislocated intraocular lenses: clinical results of a novel surgical technique.

To describe and report surgical outcomes of a novel, knot-free technique to manage dislocated intraocular lenses (IOLs). Beyoglu Eye Education and Research Hospital, Istanbul, Turkey. Retrospective observational clinical study. The files of 47 patients were retrospectively reviewed, and the patients who had a follow-up time of 6 months or more were included in this study. The surgery of every case was watched for the surgical complications and calculation of the surgical time. The postoperative complications and success rate were specifically tabulated. Thirty-five eyes of 35 patients were included in this study (23 men, 12 women; mean age 63.1 ± 19.2 years). The mean follow-up time was 22.5 ± 9.9 months. The mean surgical time was 28.2 ± 6.8 minutes. Corrected distance visual acuity improved significantly after surgery (P = .001). Anatomic success rate was 97.1% after a single surgery. Most common complications included transient intraocular pressure (IOP) elevation (n = 2), persistent IOP elevation (n = 1), mild IOL tilt (n = 1), mild IOL decentration (n = 1), secondary IOL dislocation requiring intervention (n = 1), transient corneal edema (n = 1), and bullous keratopathy (n = 1). Knot-free suture scleral fixation of dislocated IOLs was a minimally invasive approach for the management of dislocated IOLs and required only two 20-gauge corneal incisions without the need for scleral flaps or incisions. This technique had a low complication rate and delivered successful results in most cases.

Double-Needle Yamane Technique Using Flanged Haptics in Ocular Trauma-A Retrospective Survey of Visual Outcomes and Safety.

To evaluate visual outcomes and safety of the double-needle technique using flanged haptics (Yamane technique) in patients with aphakia caused by ocular trauma at a trauma referral center. Retrospective: Consecutive interventional case series of 30 patients who underwent the Yamane technique due to posttraumatic aphakia. The double-needle technique using flanged haptics was combined with anterior vitrectomy (group A) in 14 patients, and with pars plana vitrectomy (PPV) (group B) due to retinal detachment, nucleus dislocation into the vitreous cavity, or intraocular lens (IOL) displacement in 16 patients. No intraoperative complications were noted. There was significant improvement in the visual acuity in both groups at the second postoperative visit. However, the visual acuity was significantly worse in the group treated with the Yamane technique combined with PPV. Silicone oil tamponade in PPV group was associated with worse visual acuity, whereas post lensectomy status was associated with poor visual function result in the anterior vitrectomy group. There was one case of slight IOL decentration and one retinal detachment during the postoperative follow-up period in the group with PPV. In this case series, the Yamane technique applied in traumatized eyes was found to be an efficacious and safe procedure. Combining the Yamane technique with PPV due to posterior segment ocular trauma was associated with worse functional results in the follow-up at three months. Further studies with longer follow-up evaluations are required to verify long-term complications.

Influence of anterior capsulorhexis shape, centration, size, and location on intraocular lens position: finite element model.

To evaluate the influence of anterior capsulorhexis shape, dimension, and eccentricity on intraocular lens (IOL) position. Laboratory investigation. Computational model. A finite element model of the human crystalline lens capsule and zonule was created and the anterior capsule opened to simulate centered and decentered circular and elliptic rhexis. The model calculated capsular bag stress, IOL rotation, tilt, decentration, and vaulting, related to both capsular landmarks (absolute) and a reference IOL position defined as that obtained with a 5.0 mm circular and centered rhexis. Mean von Mises stress along the IOL major z-axis was significantly higher than that along the perpendicular x-axis in all cases (P < .001), both at the equator and at the rhexis edge. Stress at the equator was always greater than that at the rhexis edge (P < .001) regardless of the rhexis shape and position. As rhexis eccentricity increased, the stress difference between the z- and x-axes increased. Absolute IOL tilt (range 10-1 to 10-7 degrees), decentration (10-3 to 10-7 mm), rotation (10-2 to 10-3 degrees), and vaulting (10-1 mm) were negligible from an optical standpoint, but all of them were significantly greater for decentered rhexis (both round and elliptic) compared with centered (P < .05). Anterior capsulorhexis irregularity and/or eccentricity increase IOL tilt, decentration, rotation, and vaulting in a numerically significant but optically negligible way. Von Mises stress is much greater at the capsular bag equator compared with the rhexis edge and highly asymmetrically distributed in all cases. Stress asymmetry may influence postoperative biologic processes of capsular bag shrinking and further IOL tilting or decentration.

Stability of Various Types of Aspheric Intraocular Lenses After Implantation: A One-Year Retrospective Study.

ObjectiveThe aim of the present study was to evaluate the stability of four different types of aspheric intraocular lenses (IOLs) after implantation.MethodsThis retrospective study included 124 eyes implanted with four different types of aspheric IOLs including a one-piece four-loop fixed hydrophilic acrylic IOL, a one-piece flat fixed acrylic IOL, a one-piece two-loop fixed acrylic IOL, and a three-piece two-loop fixed silicone IOL. IOL decentration, tilt, and ocular coma‐like aberration (coma) at one-week, one-month, three-month, and one-year time points were evaluated postoperatively.ResultsIOL decentration, tilt, and coma in the AO, 36A, IQ, and KS-AiN implantation groups were statistically significantly different one week and one year postoperatively (p < 0.01). There were significant differences between each of the pairs of groups (p < 0.01), except for coma between the AO and 36A implantation groups one week postoperatively (p > 0.05). When comparing the different time points (ie, one week, one month, three months, and one year postoperatively), IOL decentration, tilt, and coma were significantly different in each group (p < 0.05). IOL decentration, tilt, and coma in each group increased over the period from one week to one year postoperatively. A positive linear correlation was observed between IOL decentration or tilt and coma one year postoperatively (p < 0.01).ConclusionOne-piece multi-point fixed acrylic IOLs demonstrate better stability when compared with three-piece two-point fixed silicone IOLs. IOL decentration, tilt, and coma increase gradually over time. Ocular coma‐like aberrations are influenced by the stability of IOLs.

Full-Diffractive Multifocal Intraocular Lens Posterior Optic Capture for Selected Pediatric Cataracts.

To evaluate the short-term outcomes of implantation of a full-diffractive multifocal intraocular lens (IOL) with optic capture for selected pediatric cataracts. In this prospective study, patients with pediatric cataract aged 3 to 14 years were selected to receive multifocal IOL (Tecnis ZMB00; Abbott Medical Optics) posterior optic capture. Visual acuity, stereopsis, visual quality, and complications were assessed. Forty-five patients (66 eyes) were recruited with a follow-up of 9.09 ± 5.93 months (range: 6 to 24 months). The cataract was bilateral in 21 patients and unilateral in 24 patients. At the last follow-up visit, the mean distance-corrected distance, intermediate, and near visual acuity was 0.28 ± 0.25, 0.43 ± 0.24, and 0.39 ± 0.27 logMAR, respectively. Among the patients with bilateral cataract, postoperative corrected distance visual acuity (CDVA) was 20/40 or better in 79% (33 of 42) of the eyes and 20/20 in 26% (11 of 42) of the eyes. Of the patients with unilateral cataract, 54% (13 of 24) achieved a CDVA of 20/40 or better but none obtained a CDVA of 20/20. All patients developed stereopsis postoperatively (P < .05). There was no significant difference in modulation transfer function cut-off and Strehl ratio between the eyes with a multifocal IOL and the healthy eyes of patients with unilateral cataract (P > .05). Objective Scatter Index values were significantly better in the healthy eyes (P < .05). No posterior capsule opacification, posterior synechiae, secondary glaucoma, pigmentary IOL deposits, or IOL decentration was observed during the follow-up period. Short-term follow-up results suggest full-diffractive multifocal IOL optic capture may benefit appropriately selected patients with pediatric cataract. [J Refract Surg. 2021:37(6):390-397.].

English

BACKGROUND Visual rehabilitation of aphakic patients include spectacle correction, contact lenses, and primary or secondary intra ocular lens (IOL) implantation. Spectacles are rarely used nowadays because of limited visual field, aniseikonia and peripheral refractive errors. Contact lenses are other options for correcting aphakia but can cause a lot of corneal complications. Options for correction of aphakic patients with lack of adequate capsular support include anterior chamber IOL (ACIOL), scleral fixated IOL (SFIOL), and iris fixated IOL. Implantation of a retropupillary IC-IOL provides the benefits of a PCIOL, and the duration of the surgery is also less. The retropupillary IC-IOL because of its position lowers the risk of endothelial decompensation is a better option. We wanted to evaluate the functional outcomes of retropupillary iris claw lens implantation. METHODS Secondary implantation of IC-IOL was done in 50 surgical aphakic eyes as a result of intraoperative posterior capsular rent with zonular dialysis (N = 43, 86 %) &amp; large (&gt; 7 clock hours) zonular dehiscence (N = 7, 14 %). Follow up was done on 1 st day, 7th day, 1 month, 3 months and 6 months. RESULTS 22 males and 28 females in the age group 40 - 78 years were operated. 78 % eyes (N = 39) had vision better than 6 / 12 while only 10 % eyes (N = 5) had &lt; 6 / 60 vision and the remainder 12 % (N = 6) had vision between 6 / 18 &amp; 6 / 36. Complications like acute postoperative iritis (N = 18, 36 %) pupillary distortion (N = 15, 30 %), pigment clumping (N = 10, 24 %), iris chaffing (N = 9, 21 %), secondary glaucoma (N = 5, 12 %) and IOL decentration (N = 3, 7 %) were seen. The mean difference in central endothelial counts before surgery and 6 months after surgery was 109 cell / mm2 (5.92 %). CONCLUSIONS Iris claw lens gives the dual benefit of good visual acuity and less complication rate in aphakic patients with lack of adequate capsular support. KEYWORDS Retropupillary Iris Claw Lens, Surgical Aphakia, Secondary implantation, Zonular Dialysis, Aneisokonia

Characteristics and Risk Factors of Intraocular Lens Tilt and Decentration of Phacoemulsification After Pars Plana Vitrectomy.

PurposeThe purpose of this study was to investigate the characteristics and risk factors of intraocular lens (IOL) tilt and decentration of phacoemulsification after pars plana vitrectomy (PPV) using swept-source optical coherence tomography (SS-OCT).MethodsOne hundred four eyes with prior PPV and 104 eyes without PPV undergoing uneventful cataract surgery were enrolled in this study. IOL tilt and decentration were measured by SS-OCT (CASIA2) 3 months postoperatively.ResultsThe mean IOL tilt and decentration were greater in the PPV group (5.36 ± 2.50 degrees and 0.27 ± 0.17 mm, respectively) than in the non-PPV group (4.54 ± 1.46 degrees, P = 0.005; 0.19 ± 0.12 mm, P < 0.001, respectively). Multiple logistic regression showed that silicone oil (SO) tamponade (odds ratio [OR] = 5.659, P = 0.021) and hydrophilic IOL (OR = 5.309, P = 0.022) were associated with IOL tilt over 7 degrees, and diabetes mellitus (DM; OR = 5.544, P = 0.033) was associated with IOL decentration over 0.4 mm. Duration of SO tamponade was positively correlated with IOL tilt (P = 0.014) and decentration (P < 0.001). The internal total higher-order aberration, coma, trefoil, and secondary astigmatism in the PPV group were higher than in the non-PPV group, and positively correlated with IOL tilt (P < 0.05).ConclusionsPatients with prior vitrectomy had greater IOL tilt and decentration than the non-PPV group. Longer duration of SO tamponade, hydrophilic IOL, as well as DM were the risk factors of greater IOL tilt and decentration in patients with prior PPV.Translational RelevanceOptically sophisticated designed IOLs should be used cautiously in vitrectomized eyes.