AcrySof SN60WF Research Articles

Spectral-Domain OCT Lens Meridian Position as a Metric to Estimate Postoperative Anatomical Lens Position.

To evaluate the prediction of postoperative anatomical lens position (ALP) using intraoperative spectral-domain optical coherence tomography (SD-OCT) lens anatomy metrics in patients who underwent femtosecond laser-assisted cataract surgery. Intraoperative SD-OCT (Catalys; Johnson & Johnson Vision) and postoperative optical biometry (IOLMaster 700; Carl Zeiss Meditec AG) were used to assess anterior segment landmarks, including lens thickness, lens volume, anterior chamber depth, lens meridian position (LMP), and measured ALP. LMP was defined as the distance from the corneal epithelium to the lens equator, and ALP was defined as the distance from the corneal epithelium to the IOL surface. Eyes were divided into groups according to axial length (> 22.5 mm, 22.5 to 24.5 mm, and > 24.5 mm) and IOL type (Tecnis ZCB00 [Johnson & Johnson Vision]; AcrySof SN-60WF [Alcon Laboratories, Inc], or enVista MX60E [Bausch & Lomb]) to further analyze the correlation between LMP and ALP. Theoretical effective lens position was back-calculated using a specific formula. Primary outcome was correlation between postoperative measured ALP and LMP. A total of 97 eyes were included in this study. Linear regression analysis displayed a statistically significant correlation between intraoperative LMP and postoperative ALP (R2 = 0.522; P < .01). No statistically significant correlation was observed between LMP and lens thickness (R2 = 0.039; P = .06) or between ALP and lens thickness (R2 = 0.02; P = .992). The greatest predictor for ALP was LMP (β = 0.766, P < .001; R2 = 0.523). Intraoperative SD-OCT-measured LMP correlated better than anterior chamber depth and axial length to postoperative ALP. Further studies are necessary to analyze the impact of preoperative or intraoperative LMP measurements on postoperative refractive outcomes. [J Refract Surg. 2023;39(3):165-170.].

Ophthalmic viscosurgical device interaction with two hydrophobic acrylic intraocular lenses of different equilibrium water content

Ophthalmic viscosurgical device (OVD) is used during intraocular surgery to protect ocular tissue. It requires complete removal from the eye by the end of surgery to avoid postoperative complications. This study compares the interaction of a cohesive OVD with two different intraocular lenses (IOLs) of different equilibrium water content. In this laboratory study on porcine cadaver eyes, the capsular bags and anterior chambers of each eye were filled with fluorescein-stained OVD. Following implantation of 10 IOLs each of Clareon CNA0T0 and AcrySof SN60WF (Alcon Laboratory, Fort Worth, USA) IOLs, the OVD was removed using the irrigation/aspiration mode. The OVD removal was timed and differences between the both IOL groups were compared. OVD removal time ranged from 18 to 40 s (mean ± SD, 26.4 ± 6.8 s) and from 16 to 39 s (mean ± SD, 23.6 ± 6.6 s) for eyes implanted with a CNA0T0 and a SN60WF IOL, respectively, without a statistically significant difference between the groups, P > 0.05. Cohesive OVD removal times were similar between the CNA0T0 and SN60WF groups. Surgeons should experience no differences regarding the interaction between cohesive OVDs and IOLs made from the new Clareon material compared to the established AcrySof material.

Accuracy of IOL Power Calculation Formulas for AcrySof SN60WF versus Tecnis ZCB00 Intraocular Lenses.

PurposeTo compare the accuracy of various intraocular lens power formulas for two monofocal hydrophobic foldable lenses, the AcrySof SN60WF and the Tecnis ZCB00.MethodsThis retrospective study included 409 eyes from 409 patients who underwent uncomplicated cataract surgery (299 eyes with SN60WF and 110 eyes with ZCB00). Biometry was performed for all eyes with an IOLMaster 700. Predicted refraction from five different IOL power formulas (Barrett Universal II, Haigis, Hoffer-Q, Holladay 2, and SRK/T) was compared to postoperative refraction at one to three months for the following axial length strata: short eyes (22.5 mm), medium eyes (22.5–25.5 mm), and long eyes (25.5 mm).Results In patients with medium eyes, there were no significant differences in the mean absolute error (MAE) and the percentage of eyes within 0.5 D (%0.5 D) between both IOLs. In short eyes, although MAE was similar between both lenses, %0.5 D was significantly higher for Barrett Universal II in ZCB00 than in SN60WF (P = 0.01) while Hoffer-Q and Holladay 2 performed equally for both lenses. In long eyes, ZCB00 had a higher MAE than SN60WF for Barrett Universal II, Haigis, and Hoffer-Q. Additionally, in long eyes, the percentage of eyes within %0.5 D was significantly higher for SN60WF than ZCB00 for all formulas (P 0.001).ConclusionAlthough there were no significant differences in the formula accuracy between these two lenses in medium eyes for all formulas and in short eyes for most formulas, the accuracy decreased significantly in long eyes for ZCB00 compared to SN60WF. The effect of IOL model on the postoperative outcomes should be further investigated.

Long-term incidence of posterior capsular opacification in patients with non-infectious uveitis

Little is known about the long-term incidence of posterior capsule opacification (PCO) after cataract surgery in patients with uveitis. This retrospective study included 211 eyes of 146 patients with non-infectious uveitis who underwent cataract surgery and implantation of an Acrysof SN60WF (Surface: plasma-treated, Optic and Haptic: hydrophobic acrylic), iSert XY-1 (Surface: UV-ozone-treated, Optic and Haptic: hydrophobic acrylic), or iSert 251/255 (Surface: UV-ozone-treated, Optics: hydrophobic acrylic, Haptic: polymethyl methacrylate). The cumulative incidences of PCO and subsequent yttrium–aluminum-garnet (Nd:YAG) capsulotomy over the 5-year follow-up were analyzed, and patients who were implanted with different intraocular lenses (IOLs) were compared. Mixed-effects Cox proportional hazard models showed that, compared with the Acrysof group, the iSert XY-1 group had higher risks of PCO (adjusted HR, 7.26; 95% CI, 1.82–28.8) and Nd:YAG capsulotomy (adjusted HR, 6.50; 95% CI, 1.55–27.2). Similar results were obtained when the Acrysof group was compared with the iSert 251/255 group for PCO (adjusted HR, 8.22; 95% CI, 2.35–28.7) and Nd:YAG capsulotomy (adjusted HR, 8.26; 1.90–36.0). These data suggest that a plasma-treated surface, hydrophobic acrylic optic and hydrophobic acrylic haptic, of the IOL could enhance biocompatibility even under inflammatory conditions, thus suppressing PCO development.

Vision-related Quality of Life after Bilateral Implantation of Monofocal and Multifocal Intraocular Lenses.

PurposeTo evaluate vision-related quality of life in two sets of patients after routine cataract surgery implanting with traditional versus multifocal intraocular lens (IOLs).MethodsIn a cross-sectional prospective study, 58 and 33 candidates for cataract surgery were divided into traditional (Acrysof SN60WF, Alcon Laboratories, Inc) and multifocal IOL (AcrySof IQ PanOptix IOL TFNT00, Alcon Laboratories, Inc.) groups, respectively. The primary outcome was VFQ-25 scores. The secondary outcomes were making comparisons between the two IOL types in the near vision and the driving items.Resultsmean patients' age in traditional and multifocal IOL groups was 60.85 7.40 (55% female) and 59.85 8.95 (36% female) years, respectively. The mean VFQ-25 total scores in traditional and multifocal IOL groups before and after surgery were 63.69 4.95 and 72.15 9.66, and 98.08 0.70 and 95.70 1.30, respectively (P = 0.001 & 0.001). The mean scores of night driving in traditional and multifocal IOL groups were 38.79 20.50 and 44.35 21.12 (P = 0.1) before surgery which improved to 97.41 7.68 and 56.45 11.12 after surgery, respectively (P = 0.001). The mean scores of near vision in traditional and multifocal IOL groups were 46.83 10.56 and 50.53 8.58 (P = 0.2) before surgery which improved to 89.94 4.87 and 100.00 0.00 after surgery, respectively (P = 0.001).ConclusionVision-related quality of life after cataract surgery with either type of traditional or multifocal (PanOptix) IOLs improved to an excellent level. Traditional IOLs provided more satisfaction in nighttime driving while multifocal IOLs provided increased satisfaction in near and intermediate vision.

Silicone Oil Adhesion to Hydrophobic Acrylic Intraocular Lenses: A Comparative Laboratory Study of a New versus an Established Hydrophobic Acrylic Intraocular Lens Material.

Background In vitro assessment of silicone oil adhesion to a new hydrophobic acrylic intraocular lens (IOL) material, the Clareon model CNA0T0, compared with the established AcrySof model SN60WF was carried out. Methods Silicone oil adhesion was assessed for two types of IOLs, Clareon CNA0T0 (n = 10) and AcrySof SN60WF (n = 10). Lenses were immersed in an aqueous sodium chloride solution for 12 hours and then incubated at room temperature in silicone oil for 12 hours. The lenses were washed with distilled water and photographed at 25x magnification using a microscope. The percent coverage was calculated by dividing the area of oil coverage by the total surface area of the lens. Results Silicone oil adhesion to the surface of the CNA0T0 lens ranged from 4% to 22%, with a mean ± SD coverage of 8% ± 4%. Silicone oil adhesion to the surface of the SN60WF lens ranged from 1% to 17%, with a mean coverage of 9% ± 4%. The silicone oil adhesion of CNA0T0 was equivalent to that of SN60WF (P > 0.05). Conclusions The new Clareon model CNA0T0 IOL has silicone oil adhesion and interaction that are equivalent to the established AcrySof IOL.

Axial Length Change in Pseudophakic Eyes Measured by IOLMaster 700.

PurposeThe purpose of this study was to investigate the change in axial length (AL) after cataract surgery measured by swept source optical coherence tomography (IOLMaster 700), and explore ways to eliminate this AL measurement error in pseudophakic eyes.MethodsPatients with cataract who underwent unilateral phacoemulsification with four types of intraocular lens (IOLs) implantation (Asphina 509M, Tecnis PCB00, enVista MX60, and Acrysof SN60WF) were enrolled. Bilateral AL measurements were performed before and 1 month after cataract surgery utilizing IOLMaster 700. The postoperative AL of the operated eye was evaluated using three different modes (phakic, aphakic, and pseudophakic), and the fellow eye was measured by phakic mode. Associations among the AL change and cataract grade, lens thickness, preoperative AL, or refractive index of IOL were investigated using stepwise multivariate linear regression.ResultsA total of 305 patients with cataract with mean age of 65.97 ± 13.39 years were recruited. The mean postoperative AL was 0.10 mm and 0.21 mm shorter than the pre-operative AL utilizing pseudophakic and phakic modes, respectively (P < 0.001). No significant difference was observed between pre-operative and postoperative AL using aphakic mode (P = 0.264). There were no significant associations among AL change in pseudophakic eye and cataract grade, lens thickness, pre-operative AL, or refractive index of IOL (P > 0.05).ConclusionsA correction factor of 0.10 mm is suggested to eliminate AL measurement error of IOLMaster 700 in pseudophakic eyes before further improvement of AL measurement accuracy.Translational RelevanceOur study may help to eliminate the AL measurement error of IOLMaster 700 in pseudophakic eyes.

In-vitro glistening formation in six different foldable hydrophobic intraocular lenses

BackgroundGlistenings describe small, refractile microvacuoles that may arise within the intraocular lens (IOL) material and reduce the patients’ quality of vision. Lenses composed of hydrophobic acrylic material are particularly affected by glistening formation. In this study, we compared the tendency of glistening formation in six different types of hydrophobic acrylic intraocular lenses (IOLs).MethodsWe used a well-established accelerated laboratory method to develop glistenings in the following IOLs: Vivinex XY1 (Hoya), AcrySof SN60WF (Alcon), Tecnis ZCB00 (AMO), Avansee PN6A (Kowa), Aktis SP NS-60YG (Nidek), and CT Lucia 601P (Zeiss). IOLs were first immersed in saline at 45 °C for 24 h and then at 37 °C for 2.5 h in a water bath. Microvacuole (MV) density and size (Miyata grading) were documented and calculated using an image analysis program.ResultsThe mean glistening density [MV/mm2] and mean Miyata grading (in brackets) were: Vivinex: 11.6 ± 5.7 (0), SN60WF: 264.4 ± 110.3 (2.6), Tecnis: 6.0 ± 2.8 (0), Avansee: 2.2 ± 0.7 (0), Aktis: 851.4 ± 59.4 (3+) and CT Lucia: 71.0 ± 71.6 (1).ConclusionsWhile all tested IOLs showed glistenings with the accelerated laboratory method, the Aktis and SN60WF showed the highest microvacuole density, followed by the CT Lucia. In comparison, the Vivinex, Tecnis, and Avansee IOLs showed far fewer number of glistenings.

Accuracy of New Intraocular Lens Power Calculation Formulas: A Lens Thickness Study.

To investigate whether using lens thickness measurement as an optional input improves the refractive accuracy of four new generation formulas. Consecutive patients scheduled for cataract surgery were enrolled. Preoperative biometry was performed with an OA-2000 optical biometer (Tomey). All patients received the same monofocal intraocular lens (AcrySof SN-60WF; Alcon Laboratories, Inc). The Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO), Kane, and Radial Basis Function (RBF) formulas were analyzed with and without the inclusion of lens thickness as an input. Postoperative refraction was measured at 1 month. The mean prediction error (PE), the median absolute error (MedAE), and the percentage of eyes with a PE within ±1.00 diopters (D) or less were calculated after constant optimization. The final analysis was performed on 169 eyes of 169 patients. Comparison of the mean PE, MedAE, and the percentage of eyes with a PE within ±0.25, ±0.50, ±0.75, and ±1.00 D resulting from each formula with and without lens thickness did not reveal any statistically significant difference. Cochran's Q test showed a statistically significant difference among formulas in the percentage of eyes with a PE of less than ±0.50 D (P = .042). However, Dunn's post-hoc test did not show any statistically significant difference between any pair of formulas. Lens thickness measurement did not improve the accuracy of the BUII, EVO, Kane, or RBF formulas. The RBF formula yielded the same results with and without lens thickness, thus making this input useless. [J Refract Surg. 2021;37(3):202-206.].

Outcomes of IOL power calculation using measurements by a rotating Scheimpflug camera combined with partial coherence interferometry.

To evaluate the accuracy of the measurements provided by a Scheimpflug camera combined with partial coherence interferometry for intraocular lens (IOL) power calculation. I.R.C.C.S.-G.B. Bietti Foundation, Rome, Italy. Prospective case series. Consecutive patients scheduled for cataract surgery were enrolled. Preoperative biometry was performed with a Pentacam AXL. All patients received the same IOL (AcrySof SN60WF). Measurements were entered into the following formulas: Barrett Universal II, Emmetropia Verifying Optical 2.0, Haigis, Hoffer Q, Holladay 1, Holladay 2 with axial length adjustment, Kane, Ladas Super Formula (LSF) 2.0, Næser 2, Pearl-DGS, SRK/T, T2, and VRF. When refraction was measured at 1 month postoperatively, the mean prediction error (PE), the median absolute error (MedAE), and the percentage of eyes with a PE within ±0.25, ±0.50, and ±1.00 diopter (D) were calculated after constant optimization. Ninety-one eyes of 91 patients were analyzed. Comparison of the mean PE and MedAE did not reveal any statistically significant difference. However, the Pearl DGS formula achieved the lowest MedAE (0.19 D), followed by the LSF 2.0 (0.22). Twelve of the 13 formulas obtained a PE within ±0.50 D in at least 80% of eyes (range 80%-87%) and 7 of them in at least 85%. Twelve formulas yielded a PE within ±0.25 D in at least 50% of eyes (range 51%-64%). All the investigated formulas performed well using the Pentacam AXL measurements. The newest Pearl DGS formula version and LSF 2.0 showed promising results.

Comparison of Long-Term Rotational Stability of Three Commonly Implanted Intraocular Lenses

To compare rotational stability and its influencing factors in 3 different widely used hydrophobic acrylic intraocular lenses (IOLs) from the end of surgery (EoS) to 4-7months (6months) in over 380 eyes. Prospective interventional comparative clinical study. Setting: Department of Ophthalmology, Medical University of Vienna. A total of 381 eyes of 199 patients with age-related cataract received an IOL Acrysof SN60WF, Tecnis ZCB00, or Envista MX60 in a consecutive order. Implantation of an Acrysof, Tecnis, or Envista IOL randomized to the 0 ± 10, 45 ± 10, 90 ± 10, or 135 ± 10° axis in 1 or both eyes. Baseline measurement was performed with patients supine still on the operating table. Postoperative follow-ups were conducted after 1 hour, 1week, 1month, and 6months. Difference of absolute rotation from the EoS to 6months. Absolute rotations from the EoS to 6months were 1.65 ± 2.1, 2.65 ± 4.1, and 3.18 ± 5.8° for the Acrysof, Tecnis, and Envista group, respectively. Rotational stability was statistically significantly superior in the Acrysof compared with the Envista group (P= .014), but not compared with the Tecnis group (P= .10). No significant difference was found between the Tecnis and Envista groups (P= .761). Maximum values of 15.8, 38.6, and 44.9° were observed for the Acrysof, Tecnis, and Envista group, respectively. The Acrysof IOL showed the least amount of absolute rotation compared with the Tecnis and Envista IOLs. Outliers possibly requiring secondary intervention were observed in all groups. The amount of rotation was greatest during the first postoperative hour.

Posterior Capsule Opacification With Two Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

To compare the incidence and intensity of posterior capsule opacification (PCO) and neodymium-yttrium-aluminum-garnet (Nd:YAG) capsulotomy rates between 2 similar open-loop single-piece hydrophobic acrylic intraocular lenses (IOLs) that differ in the proprietary material characteristics and design features, over a period of 3 years. Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison. Setting: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Eighty patients (160 eyes) had bilateral cataract surgery and received a Vivinex XY1 IOL in 1 eye and an AcrySof SN60WF IOL in the other eye. Follow-up examinations were performed 3 years after surgery. Digital retroillumination images were taken of each eye. The amount of PCO (score: 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software (AQUA). PCO score (scale, 0-10). The mean objective PCO score of the Vivinex XY1 IOLs was 0.9 ± 0.8 compared to the PCO score of 1.4 ± 1.1 for the AcrySof SN60WF IOLs (P < .001). Three years postoperatively, 11.4% of patients had an Nd:YAG capsulotomy in the Vivinex XY1 eye and 18.6% had a capsulotomy in the AcrySof SN60WF eye (P= .23). The new hydrophobic acrylic Vivinex XY1 IOL showed significantly lower PCO rates and lower YAG rates compared to the AcrySof SN60WF IOL. The interaction of various factors such as hydrophobic material, smooth optic surface, and sharp posterior optic edge plays a key role in PCO development.

Refractive results after cataract surgery using Optical biometry

Purpose: To assess the refractive outcome of optical biometry (Nidek AL-scan) after elective phacoemulsification in a study of 30 eyes.&#x0D; Study Design: Descriptive case series.&#x0D; Place and Duration of Study: Elective cataract surgeries done at a private clinic from July 2015 to June 2016 were selected and their records were analyzed.&#x0D; Material Methods: The measurements of IOL calculation was done using optical biometry with partial coherence interferometry (Nidek AL-scan) that provides information about axial length, central keratometry, white to white diameter and anterior chamber anatomical depth. SRK-T formula was used to calculate IOL power. All patients underwent a complete ophthalmological examination. Phacoemulsification with clear corneal incision of 2.75 mm was done and IOL was implanted in the bag (Alcon Acrysof SN60WF IOL and MA60AC IOL). Post-operative refraction was taken with autorefractor (Huvitz HRK-7000) after 4 weeks and it was compared with pre-operative objective refraction. Comparison of K readings taken by AL-scan and autorefractor were done.&#x0D; Results: We studied 30 eyes of 23 patients who underwent elective cataract surgery with foldable IOL. Post-operative spherical equivalent was plano in 53% of cases with mean of -0.05 after 4 weeks postoperatively. The mean keratometric power using autorefractor was 44.4 D while with AL-scan it was 44.7 D. There were no intraoperative complications or postoperative subjective complaints (such as halo or glare) in our patients.&#x0D; Conclusion: Intraocular lens power calculations done by optical biometry are easy to use, reliable and result in excellent refractive outcomes. Ultrasound biometry may still be required in case of mature and dense posterior subcapsular cataract.

Comparison of glistenings formation and their effect on forward light scatter between the Acrysof SN60WF and Eternity Natural Uni NW-60 intraocular lenses

AimsTo compare the characteristics of glistenings and forward light scatter between the Alcon Acrysof SN60WF and Santen Eternity Natural Uni NW-60 intraocular lenses (IOLs).MethodsFive Acrysof SN60WF and five Eternity Natural...

Intrasession Repeatability of Biometric Measurements Obtained with a Low-Coherence Interferometry System in Pseudophakic Eyes

ABSTRACTPurpose: To evaluate the intrasession repeatability of the biometric measurements obtained with a low-coherence reflectometry optical biometer in pseudophakic eyes implanted with two different types of intraocular lens (IOL).Methods: Prospective, single-center, comparative study including 69 eyes of 69 patients with ages ranging from 51 to 92 years. Previous uncomplicated cataract surgery had been performed in all patients 1 to 2 months before measurements, with implantation of the Acrysof SN60WF IOL in 35 eyes (35 patients, group 1) and the IOL Akreos MI60 in 34 eyes (34 patients, group 2). A complete postoperative ophthalmological examination was performed including three consecutive measurements with the “Aladdin” system from (Topcon, Japan). Intrasession repeatability of axial length (AXL), anterior chamber depth (ACD) and IOL thickness (IOLT) were assessed with the within-subject standard deviation (Sw), intraobserver precision (1.96 × Sw), coefficient of variation (CV) and intraclass correlation coefficient (ICC). Results: The Sw for AXL measurements was 0.03 and 0.05 mm in groups 1 and 2, respectively, with ICC of 1.000 and 0.999 (CV: 0.14% and 0.22%) (p ≤ 0.031). Concerning pseudophakic ACD, the Sw was 0.03 and 0.09 mm in groups 1 and 2, respectively, with ICC of 0.992 and 0.956 (CV: 0.55% and 1.75%) (p ≤ 0.021). The variability of IOLT measurements was high in both groups, with Sw of 0.12 and 0.29 mm for groups 1 and 2 (p = .008), respectively, and ICC of 0.065 and 0.770 (CV: 20.84% and 62.39%).Conclusions: The optical biometer “Aladdin” (Topcon, Japan) provides consistent measurements of AXL and ACD in pseudophakic eyes. However, there is a limitation in the consistency of IOLT measurements that should be investigated further.

Evaluation of intraocular lens mechanical stability

To compare mechanical characteristics and stability of Clareon CNA0T0 intraocular lens (IOL) with 4 currently marketed monofocal IOLs and to evaluate axial displacement and simulated dioptric power shift using a range of compression diameters. Alcon Laboratories, Inc., Fort Worth, Texas, USA. Experimental study. Clareon CNA0T0, AcrySof SN60WF, enVista MX60, Tecnis ZCB00, and Vivinex iSert XY1 IOLs (10 per group) were assessed using standardized methods for axial displacement, optic decentration, and optic tilt per the International Organization for Standardization ISO11979-3. Axial displacement was also measured over a range of compression diameters (9.0 to 11.0mm). At 10.0mm compression, the mean axial displacement for the CNA0T0 IOL (0.02mm±0.01 [SD]) was significantly lower than for the MX60, ZCB00, and XY1 IOLs (P<.005). At all compression diameters, the CNA0T0 and SN60WF IOLs had the lowest levels of axial displacement and corresponding simulated dioptric power shift at the corneal plane versus other IOL models. At 10.0mm compression, the mean optic decentration was within ±0.06mm for all models, and there were no significant differences between the CNA0T0 IOL and other IOLs. At 10.0mm compression, the mean optic tilt was no greater than 1.2 degrees for all IOL models evaluated; however, the mean optic tilt for the CNA0T0 IOL was significantly lower than for the MX60 IOL (P<.005). The CNA0T0 and SN60WF IOLs showed the lowest levels of axial displacement and corresponding simulated dioptric power shift over all tested compression diameters, indicating they might provide the most consistent refractive outcomes.

In vivo evaluation of a new hydrophobic acrylic intraocular lens in the rabbit model

To evaluate the uveal and capsular biocompatibility as well as positioning stability of a new hydrophobic acrylic intraocular lens (IOL) invivo in the rabbit model and compare it with a commercially available IOL. John A Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Fifteen New Zealand rabbits had the new test IOL(Clareon CNA0T0) implanted in one eye and a control IOL (Acrysof SN60WF) implanted in the contralateral eye. The testIOL is manufactured from a new hydrophobic acrylic material incorporating ultraviolet blocker and blue light filter. Its design is based on the control IOL's platform. The rabbits were followed up with weekly slitlamp evaluations, which assessed inflammatory reactions as well as capsular bag opacification. Anterior chamber depth was measured at 1 and 4weeks post-implantation (high-frequency ultrasound). After 4weeks, the rabbits were killed humanely and the eyes were enucleated. The anterior segment was evaluated from the posterior or Miyake-Apple view, and was then processed for complete histopathology. There were no statistically significant differences between test and control eyes in terms of postoperative inflammation and capsular biocompatibility, including posterior capsule opacification (P=.34, paired t test), and anterior capsule opacification (P=.53, paired t test), as observed during clinical and pathological evaluation. Invivo axial positioning for the test IOL was comparable to the control IOL and stable over time (P=.531 versus P=.788). The new IOL showed biocompatibility and stability comparable to the control IOL.

Comparison of visual performance after three different aspheric intraocular lenses implantation

Objective To compare visual performance after three types of spherically aberrated aspheric intraocular lens (IOL) implantation. Methods Total 115 eyes of 115 patients with age-related cataract were randomly divided into 3 groups. One type of aspheric IOLs: Tecnis ZA9003 of negative spherical aberration (SA), AcrySof SN60WF or Akreos Adapt AO of zero SA was implanted in different groups. The followed up time was 3 months after operation. Results The difference of best corrected visual acuity and contrast sensitivity(CS) after operation were not significant among 3 groups (P>0.05). With 5 mm and 6 mm pupil, the SA and mean high order aberrations(HOA) in Akreos Adapt AO group were higher than those of other two groups(P 0.05). With 6 mm pupil, the total aberrations of the other two groups were significantly lower than that of Akreos Adapt AO group(P=0.000, 0.001). Coma, visual function and quality of life survey showed similar results among groups (P>0.05). Conclusion Negative SA aspheric IOL can significantly reduce SA and HOA. However, the difference of postoperative visual acuity, CS and quality of life are not significant among groups. Key words: Lens, intraocular, aspheric; Contrast sensitivity; Aberration, spherical; Aberration, high order

A Method to Improve the Accuracy of Optimized A-Constant for IOL Calculation Formulas

Objective: To achieve more accurate IOL calculation results using multiple A-constants for SRK/T formula. Methods: This is a retrospective clinical study. The study includes 650 cases of phacoemulsification with an Acrysof SN60WF IOL (Alcon, TX). The study excluded eyes that had corneal refractive surgery, eyes with any condition that precluded accurate and consistent keratometry. The study used the average of 5 valid measurements of axial length (AL) and corneal curvature using IOLMaster (Carl Zeiss Meditec, Inc. Germany) prior to surgery and manifest refraction measured at least 3 months after surgery. Patients were divided into 7 groups based on AL from less than 22 mm to greater than 27 mm. The average A-constant with standard deviation was calculated in each group, and these groups were compared to each other using independent two-sample t-test (p<0.05). Results: The A-constants changed with AL. The A-constant of the four groups with AL less than 25 mm did not differ significantly each other (P<0.05). The two groups with AL less than 26 mm and less than 27 mm also did not differ statistically. Both are different than the first four groups. The A-constant for the group of AL 27 mm and more were different from all other groups. Second order polynomial described the relationship of the A-constant to AL. Conclusion: Our results suggest that using different A-constants for eyes with different ALs, especially longer than 26 mm, may improve the accuracy of post-operative refraction results.

Accuracy of Intraocular Lens Calculation Formulas

To compare the accuracy of intraocular lens (IOL) calculation formulas (Barrett Universal II, Haigis, Hoffer Q, Holladay 1, Holladay 2, Olsen, and SRK/T) in the prediction of postoperative refraction using a single optical biometry device. Retrospective consecutive case series. A total of 13 301 cataract operations with an AcrySof SN60WF implant and 5200 operations with a SA60AT implant (Alcon Laboratories, Inc., Fort Worth, TX). All patients undergoing cataract surgery between July 1, 2014, and December 31, 2015, with Lenstar 900 optical biometry were eligible. A single eye per patient was included in the final analysis, resulting in a total of 18 501 cases. We compared the performance of each formula with respect to the error in predicted spherical equivalent and evaluated the effect of applying the Wang-Koch (WK) adjustment for eyes with axial length >25.0 mm on 4 of the formulas. For the SN60WF, the standard deviation of the prediction error, in order of lowest to highest, was the Barrett Universal II (0.404), Olsen (0.424), Haigis (0.437), Holladay 2 (0.450), Holladay 1 (0.453), SRK/T (0.463), and Hoffer Q (0.473), and the results for the SA60AT were similar. The Barrett formula was significantly better than the other formulas in postoperative refraction prediction (P < 0.01) for both IOL types. Application of the WK axial length modification generally resulted in a shift from hyperopic to myopic outcomes in long eyes. Overall, the Barrett Universal II formula had the lowest prediction error for the 2 IOL models studied.