Optical and aberrometric evaluation of a new enhanced monofocal intraocular lens with isofocal optic design.

PURPOSE: To evaluate the optical and aberrometric outcomes of an enhanced monofocal intraocular lens (ISOPure) compared with those of a standard monofocal lens (MicroPure) having the same platform and material. METHODS: A prospective, comparative and randomised clinical study. A total of 28 eyes of 28 patients were randomly assigned to either group. Monocular visual acuity (VA) was measured at distance and intermediate under photopic and mesopic conditions. Aberrometry was analysed for 3.0-, 4.0-, 4.5- and 5.0 mm pupils. The contrast sensitivity defocus curve was measured for 3.0- and 4.5-mm pupils, while the modulation transfer function (MTF) and Strehl ratio (SR) were assessed with a double-pass system. All measurements were performed monocularly 3 months after surgery. RESULTS: No significant differences were found for distance VA. Under photopic conditions, intermediate VA was better with the ISOPure lens, while no significant differences were found between the lenses under mesopic conditions. Internal and total aberrations were higher for the ISOPure lens. No significant differences were found for corneal aberrations. Additionally, both the contrast sensitivity defocus curve and optical quality showed similar behaviour for each lens, with the MTF cut-off frequency exceeding 30 c/deg in both cases. CONCLUSION: The isofocal ISOPure lens enhanced intermediate VA without affecting distance VA under photopic conditions. Moreover, there were no significant differences in visual quality between the ISOPure and MicroPure lenses, despite the former exhibiting higher internal and total aberrations than the monofocal model.

Prospective Randomized Single-Masked Study of Bilateral Isofocal Optic-Design or Monofocal Intraocular Lenses.

Purpose: To assess refractive and visual outcomes of bilateral implantation of an isofocal optic-design intraocular lens (IOL) or a monofocal IOL following cataract surgery. Methods: A total of 127 patients were recruited into a prospective, single-masked, randomized trial. Sixty-five patients bilaterally implanted with the Isopure Isofocal IOL and 62 patients with the Micropure Monofocal IOL were followed for 4-6 months. Refraction, monocular and binocular uncorrected-distance-visual acuity, corrected-distance-visual acuity (CDVA), uncorrected-intermediate-visual acuity and distance-corrected-intermediate-visual acuity (DCIVA, 66/80 cm), uncorrected-near-visual acuity, and distance-corrected-near-visual acuity (DCNVA, 40 cm) were evaluated. Binocular defocus curve, binocular contrast sensitivity (photopic, mesopic with/without glare), and glare and halo phenomena were also measured. Results: 99.23% of eyes were within ±1.00D and 84.62% of eyes within ±0.50D for the Isopure patients and 98.39% and 82.26% for the Micropure patients, respectively. The mean spherical-equivalent was -0.06 ± 0.36D and 0.10 ± 0.32D for the Isopure and Micropure patients, respectively. 98.5% and 100% of patients implanted with the Isopure and Micropure IOLs showed a cumulative binocular CDVA value ≥20/20, respectively. 80% and 67.70% of patients implanted with the Isopure presented a binocular DCIVA ≥20/25 at 80 and 66 cm, respectively. These percentages were 46.8% and 40.3% with the Micropure IOL, respectively. For Isopure, 7.7%, 30.8%, and 58.5% of patients presented a DCNVA ≥20/25, ≥20/32 and ≥20/40, respectively. These values were lower for the Micropure: 1.6%, 19.4% and 46.8%, respectively. Defocus curves showed similar good visual acuity at distance for both lenses with better intermediate vision for the Isopure. Both groups presented good contrast sensitivity, and the size and intensity of halo and glare phenomena were similar between the two. No adverse-events were reported. Conclusion: Our trial shows that both IOLs provide excellent visual acuity and contrast sensitivity for far vision with similar photic phenomena, and the Isopure IOL improved unaided intermediate vision performance.

Influence of isofocal intraocular lenses on objective refraction based on autorefraction and aberrometry.

PURPOSE: To evaluate and compare the objective refractions obtained by autorefraction and aberrometry under different lighting conditions with an isofocal intraocular lens (Isopure, BVI medical, Liége, Belgium) compared to a monofocal control lens (Micropure, BVI medical, Liége, Belgium) with the same platform and material. METHODS: Prospective, comparative and randomized study on patients undergoing cataract surgery and bilateral isofocal or monofocal IOL implantation. A total of 44 subjects were randomly assigned to either the isofocal group (n = 22) or the Micropure (n = 22). Manifest refraction (MR) was always performed under the same lighting conditions for all the patients. For objective refraction the autorefractor KR8800 and the aberrometer OPD-Scan III (Nidek Inc., Tokyo, Japan.) were used. For each eye included in the study, six result sets were collected: MR, AR (autorefraction measured with the autorefractor), WF-P and WF-M (Zernike-coefficients-based objective refraction, photopic and mesopic pupil size), OPD-C and OPD-M (autorefraction measured with the aberrometer in photopic and mesopic conditions). RESULTS: The mean sphere for MR was 0.03 ± 0.32D for the Isopure group and 0.24 ± 0.22D for the monofocal group (p = 0.013). For the Isopure group, Friedman analysis showed statistically significant differences for sphere measured with WF-P (p = 0.035), WF-M (p = 0.018) and OPD-M (p = 0.000), and SE measured with OPD-M (p = 0.004). In the Micropure lens group, the Friedman analysis showed differences for all values studied (p < 0.05). Correlation coefficients showed that AR is the objective method with the strongest correlation values for all components of refraction for both groups. CONCLUSION: The modification of the surfaces of the isofocal lens does not have a negative impact on the refraction obtained by AR compared to a standard monofocal intraocular lens.

Comparison of visual performance between two aspheric monofocal intraocular lens models.

CLINICAL RELEVANCE: It is important to distinguish between visual acuity, optical quality and quality of vision when outcomes obtained with intraocular lenses are evaluated. These parameters, that includeobjective and subjective tests, should be assessed to obtain results that are not biased. BACKGROUND: To assess the difference in visual and optical quality between two monofocal intraocular lens models. METHODS: : This was a prospective, parallel and randomised clinical study conducted at Miranza IOA, a private clinic in Madrid, Spain. Sixty patients were implanted bilaterally, 30 per group, with two aspheric IOLs with induced spherical aberration of -0.27 µm for Group A and -0.20 µm for Group B. Visual outcomes obtained at 1 and 3 months after surgery included both uncorrected (UCVA) and corrected monocular distance visual acuity (DCVA), objective scattering index (OSI), modulation transfer function (MTF) cut-off, Strehl Ratio (SR), contrast sensitivity defocus curve (CSDC), intraocular lens spherical aberration (SA), and longitudinal chromatic aberration of the eye. Activity limitations in daily life were assessed using CatQuest-9SF questionnaire. RESULTS: There were statistically significant differences for DCVA (0.04 LogMAR; p = .008) and SR (0.03; p = .003) between groups. Outcomes related to CSDC showed statistically significant differences for vergences between -0.50 D and +1.00 D (3 mm pupil) and for vergences of 0.00 D and +0.50 D (4.5 mm pupil) between groups. Overall, Group A showed better results regarding visual and optical quality, including a lower longitudinal chromatic aberration result in comparison to Group B. Patient satisfaction evaluated with CatQuest-9SF showed that Group A achieved better outcomes, although the differences were statistically significant only for the 'Reading text on television' item (p = 0.027). CONCLUSIONS: Both intraocular lens models showed excellent quantity of vision, optical and visual quality as well as high patient satisfaction. Despite this, the the Group A model provided slightly better outcomes than the Group B model.

Changes in Accommodative and Binocular Function following Phakic Intraocular Lens for High and Low-to-Moderate Myopia.

The aim was to evaluate accommodative and binocular function of phakic intraocular lens implantable collamer lens (ICL) in high and low-to-moderate myopia. Prospective comparative cohort study with 38 myopic patients who underwent ICL implantation were divided into two groups of 19 patients, each one based on the spherical equivalent (SE): high-power (SE ≤ −6 D) and low-to-moderate (SE > −6 D). The push-up amplitude of accommodation (AA), monocular accommodative facility (MAF), distance and near ocular deviation, near convergence amplitude, near point convergence (NPC), stereopsis, and accommodative convergence/accommodation (AC/A) ratio were assessed before surgery and 1 week and 1 month postoperatively. The mean residual refractive error at 1 month after surgery improved in both groups, 0.18 ± 0.34 D and 0.09 ± 0.26 D, respectively (p < 0.001). There was a significant decrease in AA in both groups between preoperatively and at 1-week (p = 0.001; p = 0.008, respectively) and 1-month follow-up (p = 0.001; p = 0.008). For the rest of the binocular measurements, no statistically significant postoperative changes were found in any group. This finding suggests follow-up studies on amplitude of accommodation in phakic intraocular lens ICL implantation.

Agreement between the biometric measurements used to calculate the size of the implantable collamer lenses measured with four different technologies.

Purpose: To evaluate the agreement between the biometric measurements used to calculate the size of the implantable collamer lenses (ICL) with different technologies: swept-source optical coherence tomography, spectral domain optical coherence tomography, and Scheimpflug tomography. Methods: This retrospective observational study included subjects undergoing refractive surgery with posterior chamber phakic IOL implantation to correct their myopia. The anterior chamber depth (ACD) and the horizontal white to white (WTW) or the angle to angle (ATA) distance were measured with the following four devices: the IOLMaster 700 biometer (Carl Zeiss Meditec, Jena, Germany), based on swept-source optical coherence tomography; the Cirrus and Visante optical coherence tomographs (Carl Zeiss Meditec) based on low-coherence interferometry; and the Pentacam rotating Scheimpflug camera (Oculus, Wetzlar, Germany). Results: In the horizontal corneal diameter measurements, there were statistically significant differences between Pentacam-IOLMaster 700 pair (P < 0.001) and Pentacam-Visante pair (P < 0.001). WTW from CIRRUS showed the lowest correlation when paired with Pentacam and IOLMaster 700 (R2 = 0.452 and 0.385 for Visante and R2 = 0.494 and 0.426 for Cirrus). Regarding the linear correlation of the ACD measurements, all pairs of devices were statistically significant and all of them showed a very good correlation index. Conclusion: There is a good agreement between the different devices under evaluation for ACD measurements. As for WTW, the values measured with the different devices showed large discrepancies with low correlation levels, especially when comparing the tomographs with the other devices under evaluation.

Visual and optical quality of enhanced intermediate monofocal versus standard monofocal intraocular lens.

PURPOSE: Intraocular lens designs are constantly evolving, trying to obtain more spectacle independence after cataract surgery. This advantage can be linked to some disadvantages, such as optical quality decrease. For that reason, it is important to assess, not only the amount of vision provided but also the quality of vision once they are implanted. The purpose of the present work was to compare the visual performance between two monofocal intraocular models: a standard model and a monofocal with enhanced intermediate vision lens. METHODS: Prospective, randomized, comparative study. Sixty adult subjects scheduled to undergo bilateral cataract surgery and IOL implantation were randomized to receive one of the two IOLs in both eyes at Miranza IOA, Madrid, Spain (group A: monofocal with enhanced intermediate vision lens and group B: standard monofocal lens). Monocular outcomes (right eyes) determined 1 and 3 months postoperatively were photopic corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), perceived halo, corrected intermediate-distance contrast sensitivity, and higher-order aberrations. The impact of the new IOL in the postoperative management with autorefraction devices was also evaluated. RESULTS: No differences were found in CDVA between the two groups. Significant differences were detected between the two lenses evaluated in both total HOA (p = 0.028) and internal HOA (p = 0.037). Contrast sensitivity and halometry results obtained at 1 month were similar across the two IOL groups. CONCLUSION: In patients undergoing cataract surgery, monofocal with enhanced intermediate vision IOL offered similar distance performance and contrast sensitivity along with perceived HOA and halos compared with the standard monofocal IOLs tested.

Impact of Lens Material on Objective Refraction in Eyes with Trifocal Diffractive Intraocular Lenses.

PURPOSE: Compare subjective (Rx) and objective (ObjRx) refractions outcomes with two autorefractors models and an aberrometer in eyes implanted with a hydrophobic trifocal IOL (FineVision POD F GF, Physiol, Liége, Belgium) and a hydrophilic one (FineVision POD F, Physiol, Liége, Belgium). METHODS: Prospective comparative cohort study, with 100 subjects randomly assigned to either the POD F group (n = 50) or the POD F-GF group (n = 50). Postoperative eye examinations at 1-month visit included seven result sets, one for each assessment method: Rx, AR (automated refraction measured with the autorefractor KR8800), WF-P (Zernike-coefficients-based objective refraction, photopic pupil size), WF-M (Zernike-coefficients-based objective refraction, mesopic pupil size), WF-4 (Zernike-coefficients-based objective refraction, 4 mm pupil), OPD-C (automated refraction measured with the aberrometer OPD in the central pupil/photopic conditions), and OPD-M (automated refraction measured with the aberrometer OPD under mesopic conditions). RESULTS: Mean differences between ObjRx and Rx reached statistical significance for sphere and spherical equivalent (M) only with OPD-C in the POD F-GF group. All ObjRx methods showed significant differences with Rx in the POD F group, with some values differing by more than 0.50 D (-0.58 D in M for the WF-P). Bland Altman plots showed better agreement for the astigmatic components, and for sphere and spherical equivalents in both IOL groups measured with AR and OPD-M. CONCLUSIONS: None of the objective methods of refraction evaluated in this study were as reliable as the subjective refraction, irrespective of the lens material, but POD F-GF ObjRx seems to differ less with Rx than POD F ObjRx values.

Interocular biometric parameters comparison measured with swept-source technology.

PURPOSE: In the event that any ocular parameter involved in the calculation of intraocular lens power could not be properly measured in one eye, it is important to know whether clinically relevant differences between both eyes can be expected. The aim of this work is to evaluate the symmetry of interocular biometric parameters. METHODS: This was a prospective, cross-sectional study involving 4090 subjects. Patients underwent consecutive swept-source optical biometry performed with an IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany). The biometric parameters that were evaluated were: axial length (AL), mean anterior curvature (Rm), anterior chamber depth (ACD), crystalline lens thickness (LT), central corneal thickness (CCT) and white-to-white (WTW). The Chang-Waring chord distance (CWC-D) and the Chang-Waring chord angle (CWC-A) were also evaluated. RESULTS: There is an excellent correlation between both eyes for almost all the biometric parameters under study, with the exception of the CWC. Agreement for AL was better for eyes shorter than 24 mm. The linearity of the OD-vs-OS relationship can be correctly assumed for all parameters (Cusum test: p > 0.05 in all cases). CONCLUSION: There are no clinically significant interocular differences for the biometric parameters under study, although for all of them, except the LT, statistically significant differences did arise. In the case of AL, moderate differences can be expected in eyes larger than 24 mm.

Multicountry clinical outcomes of a new nondiffractive presbyopia-correcting IOL.

PURPOSE: To evaluate the effectiveness and safety of a new presbyopia-correcting intraocular lens (IOL) with a nondiffractive design, DFT015, compared with an aspheric monofocal IOL, SN60WF. SETTING: 19 investigational sites in 4 countries: Australia, Canada, Spain, and the United Kingdom. DESIGN: Prospective, randomized, parallel-group, controlled, assessor- and patient-masked clinical study. METHODS: Participants aged ≥22 years with bilateral cataracts were randomized to DFT015 or SN60WF in a 5:4 ratio and masked until final postoperative follow-up at month 6. The primary effectiveness objective was superiority of DFT015 over SN60WF in mean monocular photopic distance-corrected intermediate visual acuity (DCIVA) at month 3. Secondary effectiveness objectives included noninferiority of DFT015 to SN60WF in mean monocular photopic corrected distance visual acuity (CDVA) and superiority in the mean monocular photopic distance-corrected near visual acuity (DCNVA) at month 3. Visual disturbances were assessed at month 6. RESULTS: 282 patients were randomized to DFT015 (n = 159) or SN60WF (n = 123). All effectiveness objectives were achieved at month 3 in first eyes. For monocular photopic results in first eyes, DFT015 demonstrated superior mean DCIVA (least squares means of -0.139 logMAR in favor of DFT015, P < .001), noninferior mean CDVA (97.5% upper confidence limit [UCL] of the difference was <0.1 logMAR) and superior mean DCNVA (95% UCL of the difference was <0.0 logMAR) compared with SN60WF at month 6. DFT015 exhibited a similar visual disturbance profile to that of SN60WF. CONCLUSIONS: DFT015 provided superior intermediate and near vision and a similar visual disturbance profile compared with an aspheric monofocal IOL.

First Results after Implantation of Hydrophilic and Hydrophobic Trifocal Intraocular Lenses: Visual and Optical Performance.

PURPOSE: To compare postcataract surgery visual and optical performance between two trifocal intraocular lenses (IOLs) with the same optical design: a hydrophobic acrylic glistening-free IOL and a hydrophilic acrylic IOL. METHODS: Patients were bilaterally implanted with either the hydrophobic or the hydrophilic IOL. The data of the patients' right eyes were evaluated. Visual quality assessments included refractive outcomes, monocular visual acuity (VA) at far, intermediate, and near distances, defocus curve, aberrations (spherical aberration (SA)), root mean square (RMS) of corneal, internal, and total higher-order aberrations (HOAs)), and tilt of IOL. RESULTS: Fifty-one patients were included in the analysis: 26 patients implanted with the hydrophobic IOL and 25 patients implanted with the hydrophilic IOL. At 1 month, no statistically significant differences were found for monocular uncorrected and corrected VA at distance, distance-corrected VA at intermediate and near, defocus curve, manifest spherical equivalent, total SA, and RMS of the total, internal, and corneal HOA. The defocus curve of both groups showed a visual acuity of 0.3 logMAR or better in the intermediate range from 0.5 to -2.5 D of vergence level with no significant differences between the groups. Compared to the hydrophilic group, y-direction tilt was significantly higher in the hydrophobic group (p=0.027). The total tilt and x-axis tilt did not differ between the groups. CONCLUSION: Both IOLs demonstrated an excellent quality of vision and provided the patient with a wide range of vision.

Longitudinal Chromatic Aberration in Patients Implanted With Trifocal Diffractive Hydrophobic IOLs.

PURPOSE: To measure the in vivo longitudinal chromatic aberration (LCA) from the chromatic difference of focus (480 to 700 nm) using psychophysical methods in patients bilaterally implanted with a hydrophobic trifocal intraocular lens (IOL). METHODS: Psychophysical best focus was measured in both eyes at different wavelengths (480 to 700 nm) and at three different viewing distances (0.00, +1.75, and +3.50 diopters [D]) using a custom-developed polychromatic adaptive optics set-up provided with a supercontinuum laser, a Hartmann-Shack wavefront sensor, a deformable mirror, a motorized Badal system, a pupil monitoring system, and a psychophysical channel with monochromatically illuminated stimuli. Measurements were performed on 10 patients (20 eyes) bilaterally implanted with hydrophobic trifocal diffractive IOLs (FineVisionHP POD F GF; PhysIOL). LCA was computed from the chromatic difference of focus curves as the difference between 480 and 700 nm at near, intermediate, and far. RESULTS: The LCA from psychophysical measurements was significantly higher for far vision (0.99 ± 0.06 diopters [D]), than for intermediate (0.67 ± 0.10 D) and near (0.23 ± 0.08 D) vision (one-way analysis of variance, P < .05). CONCLUSIONS: LCA for far vision was significantly higher than for intermediate and near vision in hydrophobic trifocal diffractive IOLs, in agreement with a previous study with the same optical design but hydrophilic material IOLs. The LCA for the hydro-phobic IOL is slightly higher than for the hydrophilic IOL at far. Different combinations of refractive and diffractive LCA will allow optimizing IOL designs to improve polychromatic image quality. [J Refract Surg. 2020;36(12):804-810.].

The influence of surgeons and technicians on the learning curve of femtosecond-laser cataract surgery / Influencia de los cirujanos y técnicos en la curva de enseñanza de la cirugía de cataratas con láser de femtosegundo

PURPOSE: To demonstrate the influence of the surgeon's and the operating room (OR) technicians' experience upon the outcome of femtosecond laser-assisted cataract surgery (FLACS). MATERIALS AND METHODS: Our study included 250 eyes from 156 patients who had undergone either cataract surgery or clear-crystalline-lens extraction and where capsulorhexis and lens fragmentation had been performed using the CATALYS® Precision System femtosecond platform (Abbott Medical Optics Inc., Santa Ana, CA, USA).The patients were operated either by an experienced surgeon in the use of femtosecond laser or by an inexperienced surgeon in that field and two technicians. The quantitative outcome measures were: Suction loss rate, vacuum time, number of consumables used by the patient and intraoperative complication rate. RESULTS: Both for the experienced and the inexperienced surgeons, suction loss rates as well as vacuum time decreased progressively as time went by and more surgical procedures had been completed by that surgeon. For a given surgeon suction time decreased significantly, going from 137 to 99s, as the assisting technician gradually gained experience. The number of consumables used in each procedure by the experienced surgeon ranged from 1.10 (for the first 50 cases) to 1.02 from those initial cases onwards. Regarding intraoperative complications, they also decreased progressively as the number of procedures completed by the surgeon increased. CONCLUSIONS: The experience of each team member involved in such procedures-be it surgeons or technicians-have an impact, to a greater or lesser extent, upon the surgery's outcome, as quantified by the outcome variables of choice

OBJETIVO: Demostrar la influencia de la experiencia del cirujano y los técnicos de quirófano en los resultados de la cirugía de cataratas asistida por láser de femtosegundo (FLACS). MATERIALES Y MÉTODOS: Nuestro estudio incluyó 250 ojos de 156 pacientes sometidos a cirugía de cataratas o extracción de cristalino transparente, en las que la capsulorrexis y la fragmentación de lente se habían realizado utilizando la plataforma de femtosegundo CATALYS(R) Precision System (Abbott Medical Optics Inc., Santa Ana, CA, EEUU). Los pacientes fueron operados, bien por un cirujano con experiencia en el uso del láser de femtosegundo, o bien por un cirujano sin experiencia en dicho campo, y dos técnicos. Las medidas del resultado cuantitativo fueron: tasa de pérdida de succión, tiempo de vacío, número de consumibles utilizados por el paciente, y tasa de complicación intraoperatoria. RESULTADOS: Tanto para cirujanos expertos como inexpertos, las tasas de pérdida de succión, así como el tiempo de vacío disminuyeron progresivamente a medida que transcurría el tiempo, y que se incrementaba el número de intervenciones quirúrgicas completadas por el cirujano. Para un cirujano dado, el tiempo de succión disminuyó significativamente, pasando de 137 a 99 segundos, a medida que el técnico asistente ganaba experiencia gradualmente. El número de consumibles utilizados en cada procedimiento por un cirujano experto oscilaba entre 1,10 (para los primeros 50 casos) y 1,02 desde los casos iniciales en adelante. En cuanto a complicaciones intraoperatorias, también disminuyeron progresivamente a medida que aumentaba el número de intervenciones completadas por el cirujano. CONCLUSIONES: La experiencia de cada miembro del equipo involucrado en dichos procedimientos-bien fueran cirujanos o técnicos-tiene un impacto, en mayor o menor medida, sobre el resultado de la cirugía, según lo cuantificado por las variables de elección del resultado

Comparison of Visual Performance and Patient Satisfaction Outcomes with Two Trifocal IOLs with Similar Optical Design but Different Materials.

PURPOSE: To compare clinical outcomes in a prospective trial of cataract surgery patients bilaterally implanted with two different trifocal intraocular lenses (IOLs) with very similar optical designs but consisting of different IOL materials (hydrophobic and hydrophilic). PATIENTS AND METHODS: Fifty-one patients (102 eyes) were randomized to receive trifocal IOLs bilaterally - FineVision POD F (hydrophilic) or FineVision POD F GF (hydrophobic) (both PhysIOL, Liége, Belgium). The follow-up period was 3 months. Outcome measurements included uncorrected distance (UDVA), corrected distance (CDVA), distance-corrected intermediate (DCIVA), and distance-corrected near visual acuity (DCNVA), refraction, negative dysphotopsia, optical quality of vision, contrast sensitivity under photopic and mesopic conditions, halometry (discrimination index), and patient-reported outcomes. RESULTS: At the final study visit, mean (SD) values for binocular UDVA, CDVA, DCIVA (80 cm), and DCNVA (40 cm) were -0.01 (0.06), -0.04 (0.04), 0.09 (0.10), and 0.10 (0.09) logMAR, respectively, for POD F, and 0.01 (0.08), -0.03 (0.03), 0.08 (0.1), and 0.13 (0.11) respectively, for POD F GF. Defocus assessments showed a continuous curve with a functional range of visual acuity (≤0.15 logMAR) from ~30 cm to infinity in both groups. The discrimination index was >0.85 for all patients, and both groups showed similar contrast sensitivity under photopic and mesopic conditions. At 3 months, no patient reported negative dysphotopsia, and high satisfaction rates were observed. CONCLUSION: Clinical outcomes showed no significant difference between each lens when measured at 1 month and 3 months after implantation. This equally good clinical performance of hydrophilic and hydrophobic trifocal lenses allows the surgeon to choose the IOL material based on personal preferences or patients' needs.

Biomechanical Stability of Three Intraocular Lenses With Different Haptic Designs: In Silico and In Vivo Evaluation.

PURPOSE: To assess the biomechanical stability of three different marketed intraocular lenses (IOLs) with different haptic designs (four-loop IOL [Micro F FineVision model] and double C-loop IOL [POD F and POD FT models], all manufactured by PhysIOL), in silico (computer simulation) and in vivo (in the context of lens surgery). METHODS: An in silico simulation investigation was performed using finite element modeling (FEM) software to reproduce the compression test defined by the International Organization for Standardization and in vivo implantation in patients in the context of lens surgery was evaluated 1 day and 3 months postoperatively. IOL decentration and rotation were tested. In addition, the stress and strains were analyzed with the finite element method. RESULTS: In the in silico evaluation, the compression force for the POD F IOL was slightly lower than for the POD FT IOL and Micro F IOL for all compression diameters. The axial displacement was maximum for the POD FT IOL and the tilt, rotation, and lateral decentration were substantially lower than the acceptable tolerance limits established in ISO 11979-2. In the in vivo evaluation, a total of 45 eyes from 45 patients were selected, 15 eyes for each IOL model under assessment. Statistically significant differences were found between the Micro F and POD F IOLs for lateral decentration in x-direction (in absolute value) at 3 months postoperatively (P = .03). CONCLUSIONS: Although statistically significant differences have been found when comparing the displacement, tilt, and rotation between the different lenses, these differences cannot be considered clinically relevant, which would suggest that all three IOL models yield excellent stability in those terms. FEM appears to be a powerful tool for numerical studies of the biomechanical properties of IOLs. [J Refract Surg. 2020;36(9):617-624.].

Influence of angle κ on visual and refractive outcomes after implantation of a diffractive trifocal intraocular lens.

PURPOSE: To evaluate changes in angle κ after the implantation of a trifocal intraocular lens (IOL) and to assess the postoperative outcomes of patients with different angle κ values. SETTING: IOA Madrid Innova Ocular, Madrid, Spain. DESIGN: Prospective trial. METHODS: Sixty-three eyes from 63 patients who had bilateral implantation of a diffractive trifocal IOL (POD F, PhysIOL) were included. Pupil offset was used as the best estimate of angle κ and was measured using Pentacam (Oculus) preoperatively and at 3 months postoperatively. Postoperative refractive outcomes (sphere, cylinder, and manifest refraction spherical equivalent) and visual outcomes at far, intermediate, and near distance were assessed and compared between eyes with small pupil offset and eyes with large pupil offset. Quality of vision was assessed using a subjective questionnaire. RESULTS: There was a significant decrease in pupil offset values postoperatively (mean: 0.197 ± 0.12 mm) compared with those preoperatively (mean: 0.239 ± 0.12 mm), with a mean decrease of -0.042 mm (P = .0002). The same significant decrease was found for both right and left eyes, when analyzed separately. No statistically significant difference was found in any of the refractive and visual acuity outcomes between eyes with small pupil offset and eyes with large pupil offset. The majority of patients (14 of 16) complaining of significant halos had eyes with small pupil offset. CONCLUSIONS: Large pupil offset did not negatively affect visual and refractive outcomes. The tolerance to larger pupil offset might be due to the IOL optical design, with the first diffractive ring being larger than other commonly used multifocal IOLs. More studies comparing various diffractive IOL models would be useful to confirm such hypothesis.

Intraocular lens power calculation in eyes with keratoconus.

The purpose was to review and document the methods used to calculate the power of the intraocular lens (IOL) to be implanted in cataract surgery in the specific scenario of eyes with keratoconus. This review included all scientific articles published in English that focused on the parameters and formulas used to calculate the power of the IOL to be implanted in eyes with keratoconus undergoing cataract surgery. There are few publications that show in detail how IOL power is calculated in these particular cases. If the keratometric value used was based on the standard refractive index (1.3375), it resulted in a postoperative refractive error with a tendency to hyperopia. The SRK/T formula yielded the best outcomes. The greater the severity of keratoconus the greater was the deviation of the postoperative refractive status from the target outcome.

Comparing Medium-Term Clinical Outcomes following XEN® 45 and XEN® 63 Device Implantation.

PURPOSE: To evaluate medium-term clinical outcomes with XEN® 45 or XEN® 63 Gel Stent (Allergan, Dublin, Ireland) for treatment of primary open angle glaucoma (POAG). Materials and Methods. Retrospective, descriptive, and observational study involving 40 patients implanted with a XEN® 45 Gel Stent and 34 implanted with a XEN® 63 Gel Stent who had undergone POAG surgery and had been followed up and controlled between 12 and 36 months. RESULTS: IOP dropped from 18.02 ± 5.23 mmHg preop to 13.81 ± 1.88, 14.80 ± 2.23, and 14.62 ± 1.90 at 1, 2, and 3 years after surgery (p < 0.001) consecutively with XEN® 45 and from 19.00 ± 6.11 mmHg preop to 15.47 ± 2.45, 14.66 ± 2.45, and 15.46 ± 2.48 at 1, 2, and 3 years after surgery (p < 0.001) with XEN® 63. The number of drugs used by patients to treat their glaucoma decreased after undergoing surgery in both groups. Within the XEN® 45 group, mean changes at 1 year, 2 years, and 3 years amounted to 70%, 74.3%, and 37.5%, respectively, whereas within the XEN® 63 group, the mean reduction was 75%, 79.8%, and 71.9%. When comparing the outcomes for two groups, the differences did not prove to be statistically significant. More than 90% of the procedures included in the study (using either gel-stent device) were completed without any noteworthy complications. CONCLUSION: POAG surgical procedures with either XEN® 45 or XEN® 63 Gel Stent implantation could be a safe and effective treatment approach.

New method to assess the accuracy of intraocular lens power calculation formulas according to ocular biometric parameters.

PURPOSE: To develop a new method that makes it easy to detect accuracy deficiencies of any intraocular lens (IOL) power calculation formulas and to test it on 9 different formulas. SETTING: IOA, Madrid, Spain. DESIGN: Retrospective observational case series. METHODS: This study's first stage included 3519 eyes from 3519 candidates for cataract surgery for which frequency distributions for the following biometric eye parameters were computed: axial length (AL), anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW), and mean corneal radius (Rm). The resulting data for each parameter were fifth, 25th, 75th and 95th percentiles, which allowed definition of the corresponding normality range. In a second stage, the new graphic-representation method was tested for 9 different formulas in a sample of 70 eyes undergoing cataract surgery with multifocal IOL (mIOL) implantation. RESULTS: Normality ranges (defined as the 25th to 75th percentile interval) were 22.84 to 24.42 mm for AL, 2.86 to 3.39 mm for ACD, 4.36 to 4.88 mm for LT, 11.64 to 12.19 mm for WTW, and 7.52 to 7.87 mm for Rm, with lower sizes in women. No significant differences were found among the 9 formulas for percentage of eyes in ±0.50 diopters (D) (P = .82) or ±1.00 D (P = .97). The graphical method showed less accuracy in ±0.50 D for ACDs from 2.46 to 2.85 mm (5th to 25th percentile) for several formulas (P < .05). CONCLUSIONS: Nine formulas showed nonsignificant differences in the general predictability for a sample of eyes that were candidates to mIOL implantation. Predictability in this sample decreased for short ACDs.

The influence of surgeons and technicians on the learning curve of femtosecond-laser cataract surgery.

PURPOSE: To demonstrate the influence of the surgeon's and the operating room (OR) technicians' experience upon the outcome of femtosecond laser-assisted cataract surgery (FLACS). MATERIALS AND METHODS: Our study included 250 eyes from 156 patients who had undergone either cataract surgery or clear-crystalline-lens extraction and where capsulorhexis and lens fragmentation had been performed using the CATALYS® Precision System femtosecond platform (Abbott Medical Optics Inc., Santa Ana, CA, USA).The patients were operated either by an experienced surgeon in the use of femtosecond laser or by an inexperienced surgeon in that field and two technicians. The quantitative outcome measures were: Suction loss rate, vacuum time, number of consumables used by the patient and intraoperative complication rate. RESULTS: Both for the experienced and the inexperienced surgeons, suction loss rates as well as vacuum time decreased progressively as time went by and more surgical procedures had been completed by that surgeon. For a given surgeon suction time decreased significantly, going from 137 to 99s, as the assisting technician gradually gained experience. The number of consumables used in each procedure by the experienced surgeon ranged from 1.10 (for the first 50 cases) to 1.02 from those initial cases onwards. Regarding intraoperative complications, they also decreased progressively as the number of procedures completed by the surgeon increased. CONCLUSIONS: The experience of each team member involved in such procedures-be it surgeons or technicians-have an impact, to a greater or lesser extent, upon the surgery's outcome, as quantified by the outcome variables of choice.