Preoperative Treatment of Meibomian Gland Dysfunction with a Vectored Thermal Pulsation System Prior to Extended Depth of Focus IOL Implantation.

INTRODUCTION: Patients implanted with a range-of-vision intraocular lens (IOL) (multifocal or extended depth of focus, EDOF) may be more susceptible to visual disturbances from poor tear film quality, and prophylactic treatment of meibomian gland dysfunction (MGD) has been recommended. The purpose was to evaluate whether vectored thermal pulsation (LipiFlow™) treatment prior to cataract surgery with a range-of-vision IOL safely improves postoperative outcomes. METHODS: This is a prospective, randomized, open-label, crossover, multicenter study of patients with mild-to-moderate MGD and cataract. The test group underwent LipiFlow treatment prior to cataract surgery and implantation of an EDOF IOL, while the control group did not. Both groups were evaluated 3 months postoperatively, after which the control group received LipiFlow treatment (crossover). The control group was re-evaluated 4 months postoperatively. RESULTS: A total of 121 subjects were randomized, with 117 eyes in the test group and 115 eyes in the control group. At 3 months after surgery, the test group had a significantly greater improvement from baseline in total meibomian gland score compared with the control group (P = 0.046). At 1 month after surgery, the test group had a significant decrease in corneal (P = 0.04) and conjunctival (P = 0.002) staining compared to the control group. At 3 months after surgery, the test group had significantly lower incidence of being bothered by halos compared with the control group (P = 0.019). The control group had a significantly lower incidence of being bothered by multiple or double vision compared with the test group (P = 0.016). After crossover, patients had significant improvement in vision (P = 0.03) and total meibomian gland score (P < 0.0001). No safety concerns or relevant safety findings were uncovered. CONCLUSION: Presurgical LipiFlow treatment of patients implanted with range-of-vision IOLs improved meibomian gland function and postoperative ocular surface health. This supports guidelines recommending proactive diagnosis and management of MGD in patients with cataracts to improve patient experience. TRIAL REGISTRATION: The study was registered on www. CLINICALTRIALS: gov (NCT03708367).

Clinical performance of a hybrid presbyopia-correcting intraocular lens in patients undergoing cataract surgery in a multicenter trial.

PURPOSE: To compare the clinical performance of TECNIS Synergy intraocular lens (IOL), model ZFR00V, vs TECNIS IOL, model ZCB00, in cataract patients. SETTING: Multicenter clinical setting. DESIGN: Prospective, randomized, subject/evaluator-masked clinical trial. METHODS: Cataract patients aged ≥22 years were randomly assigned 1:1 to bilateral implantation with ZFR00V or ZCB00. Key end points at 6 months postsurgery included monocular and binocular visual acuities at 4 m, 66 cm, 33 cm, and/or 40 cm, binocular distance-corrected defocus testing, patient-reported outcomes, and safety. RESULTS: 272 patients were implanted with ZFR00V (135) or ZCB00 (137). At 6 months, 83/131 (63.4%) ZFR00V patients demonstrated 20/25 or better combined monocular distance-corrected vision at far, intermediate, or near, compared with 5/130 (3.8%) ZCB00 patients. ZFR00V demonstrated excellent binocular uncorrected vision at intermediate (0.022 logMAR) and distance-corrected vision at 40 cm (0.047 logMAR). Strong ZFR00V performance persisted under mesopic conditions (0.244 logMAR or ∼20/32 Snellen), where improvement over ZCB00 with distance-corrected vision at near was 3.5 lines. ZFR00V provided a broad range of functional vision (20/32 or better) through -3.5 diopters of defocus (29 cm). Most ZFR00V patients reported no spectacle wear overall (93.1%) or at all 4 viewing distances combined (87.8%), and 55.7% qualified as completely spectacle independent. Relatively low proportions of ZFR00V patients reported being very/extremely bothered by halos (13.7%), starbursts (11.5%), or night glare (8.4%). The safety profile was similar between IOL groups. CONCLUSIONS: TECNIS Synergy ZFR00V demonstrated improved intermediate and near vision, increased range of vision, and greater spectacle independence vs TECNIS monofocal ZCB00.

Clinical Evaluation of a Modified Light Transmission Short-Wavelength Filtering Intraocular Lens Compared to a Colorless Control.

INTRODUCTION: The aim of this study was to evaluate the safety and efficacy of a violet-light filtering intraocular lens (IOL) compared to a colorless IOL control. METHODS: This was a prospective, bilateral, randomized, comparative, patient/evaluator-masked multi-center clinical trial at 12 sites in the USA. Patients underwent standard small-incision phacoemulsification cataract extraction. Visual acuity, contrast sensitivity, and color vision were tested 12 months postoperatively. Patient satisfaction and vision-related quality of life were evaluated based on directed patient responses obtained from a binocular subjective questionnaire. RESULTS: A total of 250 subjects were bilaterally implanted with the violet-light filtering TECNIS monofocal ZV9003 (n = 126) and colorless TECNIS monofocal ZA9003 (n = 124). Mean uncorrected distance visual acuity (UDVA) was 0.123 LogMAR for ZV9003 and 0.116 LogMAR for the ZA9003 group. Mean corrected distance visual acuity (CDVA) was 0.00 LogMAR for both groups. No significant difference was found between the groups for 22/25 questionnaire categories, including color perception. A significant difference was found in favor of the ZV9003 group for day driving, night driving, and frustration with vision. Contrast sensitivity mean difference was < 0.05 log units across all lighting conditions and spatial frequencies. CONCLUSION: No difference was found between groups for visual acuity, contrast sensitivity, color testing, and adverse events as well as with the majority of optical/visual symptoms. A statistical difference was noted in driving and frustration with eyesight that may be related to benefits of using a violet-light filtering chromophore. Overall, the violet-light filtering ZV9003 showed excellent visual acuity and contrast sensitivity results with a low incidence of optical/visual symptoms.

Effect of Violet Light-Filtering and Manufacturing Improvements in an Extended Depth-of-Focus Intraocular Lens on Visual Performance.

Purpose: To assess the experimental visual performance and dysphotopsia characteristics of the new Tecnis Symfony OptiBlue extended-depth-of-focus with violet light-filtering (ZXR00V) intraocular lens (IOL) compared with the colorless Tecnis Symfony (ZXR00) IOL. Methods: Range of vision was assessed with simulated visual acuity defocus curves, predicted by white light through focus modulation transfer function (MTF) measurements. The clinical visual acuity defocus curve of the ZXR00 IOL was used to validate the predicted range of vision. Image quality was compared by measuring white light MTF at a spatial frequency of 15 cycles per degree (c/deg) for 3 mm and 5 mm pupil diameters with optical powers of 5 D, 20 D, and 34 D using the average corneal eye (ACE) model with the average spherical and chromatic aberration of the cataract population. Effects on dysphotopsias were predicted by measurement and computer simulation of light scatter (straylight parameter) and subsequent determination of retinal veiling luminance (RVL) in vitro. Contrast enhancement under challenging light conditions was calculated based on the effects in RVL. Results: The simulated visual acuity defocus curves and image quality outcomes were comparable between the ZXR00V and ZXR00 IOLs. The area under the straylight curve for the straylight parameter showed a 19% improvement in halo performance with ZXR00V versus ZXR00. A 12% to 17% reduction in RVL was achieved in favor of ZXR00V over ZXR00, which enhanced contrast vision by 9% to 13% under challenging light conditions. Conclusion: The violet light-filtering technology and improved manufacturing of ZXR00V delivers a comparable range of vision and tolerance to refractive error to ZXR00 while mitigating dysphotopsias and enhancing contrast vision.

Post-Market Evaluation of Rotational Stability and Visual Performance of a New Toric Intraocular Lens with Frosted Haptics.

Purpose: To evaluate 3-month rotational stability, and visual and refractive outcomes of a toric intraocular lens (IOL) with frosted haptics. Patients and Methods: A post-market, prospective, multi-center, single-arm, open-label study conducted at seven clinical sites in the United States. Two hundred and two eyes of 133 subjects with unilateral or bilateral cataracts and corneal astigmatism were implanted with the Tecnis Toric II IOL, Models ZCU150 to 600 (Johnson & Johnson Surgical Vision, Inc.). Lens axis misalignment/rotation, visual acuity, manifest refraction, and surgeon and patient satisfaction were evaluated 3 months postoperatively. Lens rotation was determined with operative and postoperative visit photographs and was analyzed by two independent masked analysts. Results: Mean absolute lens rotation was 0.82° ± 1.00° and 0.94° ± 0.71° at 1 day (n = 189 eyes) and 3 months (n = 185 eyes), respectively. Absolute lens rotation was ≤5° in 98.9% and 100% of eyes at 1 day and 3 months, respectively. At 3 months, postoperative monocular uncorrected and corrected distance visual acuities were 0.004 ± 0.115 LogMAR (20/20) and -0.066 ± 0.092 LogMAR (20/17), mean spherical equivalent was -0.25 D ± 0.35 D and residual refractive cylinder was +0.27 D ± 0.33 D. Surgeons were satisfied/very satisfied with overall clinical outcomes and rotational stability in 99% of eyes, and with uncorrected distance vision in 98.5% of eyes. Conclusion: The study results demonstrate that the Tecnis Toric II IOL has excellent rotational stability with a high percentage of study eyes being within 5° of intended orientation. The study lens demonstrated excellent uncorrected distance visual acuity, reduction of cylinder, and exceptional patient and surgeon satisfaction.

Clinical Performance and Surgeon Acceptability of a New Dual Mode Phacoemulsification System.

Purpose: The purpose of this first in-human study was to evaluate the overall clinical performance of the VERITAS™ Vision System in patients scheduled to undergo cataract extraction and to confirm overall surgeon acceptability. Patients and methods: This prospective, open-label multinational study included adults with cataracts scheduled for planned cataract extraction and posterior chamber IOL implantation. Standard small-incision phacoemulsification cataract surgery with the VERITAS Vision System was conducted. Surgeons completed a questionnaire regarding their clinical experience with the VERITAS Vision System for each patient following surgery and 1-day postoperative. Corneal clarity and adverse events (AEs) were assessed. Surgeon acceptability was scored on a 5-point scale, with acceptability considered favorable for scores of 4 and 5. Results: A total of 115 eyes (79 patients) were treated. The El Salvador site treated 41 patients (58 eyes), and the US site treated 38 patients (57 eyes). Overall, surgeons were satisfied with the clinical performance regardless of the cataract grade. The satisfaction with anterior chamber stability, post-occlusion surge, followability, holdability, cutting efficiency, usability, and overall satisfaction with the VERITAS Vision System was clinically favorable in ≥99% of cases. Overall satisfaction with the swivel handpiece, foot pedal, and enhanced ergonomics were clinically favorable in ≥97% of cases regardless of the cataract grade. Satisfaction with corneal clarity at same-day postoperative and 1-day postoperative, and 1-day overall clinical results of surgery with the VERITAS Vision System were clinically favorable in ≥94% of cases regardless of cataract grade. Conclusion: The new dual-mode phacoemulsification system with dual-durometer tubing, gas forced infusion, new swivel handpiece, and ergonomics improvements resulted in a high rate of user satisfaction with clinical performance and ergonomics. The VERITAS Vision System is safe and effective when used as indicated.

Performance of a Translucent Activator for LipiFlow Vectored Thermal Pulse (VTP) Treatment of Meibomian Gland Dysfunction.

Purpose: Investigator feedback was used to assess the clinical use of the LipiFlow® System with the new translucent Activator Clear to successfully complete LipiFlow® treatments. Patients and Methods: This was a prospective, open-label clinical investigation. A total of 88 eyes (44 subjects) were treated using the LipiFlow® System with the new Activator Clear. Subjects diagnosed with bilateral meibomian gland dysfunction (MGD) were enrolled in the study. Each investigator performed a complete LipiFlow® treatment with the translucent Activator on both eyes of each subject. Investigators completed a questionnaire assessing the clinical use of the Activator Clear on a 5-point scale (1 - very difficult or strongly disagree, 3 - neutral, 5 - very easy or strongly agree). Results: The new translucent Activator provided successful LipiFlow® treatments in 100% of cases, with 95% confidence interval of (96%, 100%). Additionally, the investigators agreed or strongly agreed that the translucent components of the Activator Clear made it easy to access and position the activator with confidence on the subject's eye. Conclusion: The overall investigators' impressions on usage and functionality of LipiFlow® System with the translucent Activator were very positive. The Activator Clear enables doctors with efficient and confident positioning around patient eyelids to ensure successful LipiFlow® treatment when used as indicated.

Visual outcomes and safety of an extended depth-of-focus intraocular lens: results of a pivotal clinical trial.

PURPOSE: To compare the effectiveness and safety of the TECNIS Symfony intraocular lens (IOL; ZXR00) with the TECNIS 1-piece monofocal IOL (ZCB00). SETTING: 15 sites in the United States. DESIGN: Prospective, randomized, patient-masked/evaluator-masked clinical trial. METHODS: Randomized participants received either the ZXR00 or ZCB00 IOL bilaterally. The 6-month postoperative outcomes included monocular and binocular distance, intermediate, and near visual acuity (VA), spherical equivalent refraction and refractive cylinder, spectacle wear, and visual symptoms. RESULTS: Overall, 299 patients were implanted with a study IOL (ZXR00 IOL, n = 148; ZCB00 IOL control, n = 151). At the 6-month follow-up, mean binocular uncorrected distance VA was comparable between ZXR00 and ZCB00 IOL recipients (P = .1011). The ZXR00 IOL group had significantly better mean binocular uncorrected intermediate VA and uncorrected near VA (both P < .0001) than the ZCB00 IOL group. The mean binocular distance-corrected intermediate VA and distance-corrected near VA were also better in the ZXR00 IOL group (both P < .0001). More ZXR00 IOL recipients reported wearing spectacles none of the time or a little of the time for overall vision at 6 months compared with the ZCB00 IOL group (85.0% vs 59.9%, P < .0001). In the ZXR00 IOL-implanted patients, low incidence rates of night glare (mild to moderate, 2.7%), halo (mild to moderate, 13.6%; severe, 2.7%), and starbursts (mild to moderate, 7.5%; severe, 1.4%) were reported. CONCLUSIONS: The TECNIS Symfony IOL provided comparable distance vision and improved uncorrected and distance-corrected intermediate and near vision, along with decreased spectacle wear and low incidence rates of dysphotopsia, compared with the TECNIS 1-piece monofocal IOL.

Presbyopia Treatments by Mechanism of Action: A New Classification System Based on a Review of the Literature.

Presbyopia, a loss of accommodative ability associated with aging, is a significant cause of vision impairment globally. At the clinical level, it is a frustrating and difficult issue that negatively impacts patients' quality of life. Less appreciated is the fact that loss of accommodative ability and its current treatments methods may present safety concerns, for example, increasing the risk of falls. Therefore, a more complete understanding of treatment options with respect to how they relate to the natural ability of the eye is needed to improve decision making and to aid clinicians in individualizing treatment options. This article reviews the options for expanding functional through focus-a term coined to describe the ability of the eye to see at all distances with minimal latency-by how they vary the refractive power over time, across the visual field, between eyes, or across a range of distances.

Multifocal Spectacle and Monovision Treatment of Presbyopia and Falls in the Elderly.

Presbyopia is an age-related condition that affects approximately 1.8 billion people worldwide. Strategies to correct presbyopia include both nonsurgical and surgical approaches. Although eye care providers assume that multifocal spectacles and monovision have lower risks than surgical interventions, there is evidence to suggest that the use of these nonsurgical approaches in the older population increases the risk for trips and falls. Each year, fall-related injuries and deaths are reported in a substantial portion of the population, both globally and in the United States. Previous studies have shown a link between visual acuity, contrast sensitivity, stereoacuity, and visual field impairments and falls. More recent mechanistic and epidemiological studies have shown that multifocal spectacles and monovision can increase the risk for falls as well. Although evidence on the financial burden of falls related to multifocal spectacles or monovision is limited, total direct medical costs related to falls associated with multifocal spectacles are estimated to be approximately $11 billion annually in the United States. Therefore, it is important that eye care providers consider the risk for falls associated with multifocal spectacles and monovision when making decisions on the best strategy for correcting presbyopia in older adults. [J Refract Surg. 2021;37(6 Suppl):S12-S16.].

Correlation of Intraoperative Optical Coherence Tomography of Crystalline Lens Diameter, Thickness, and Volume with Biometry and Age.

PURPOSE: To characterize crystalline lens dimensions derived from in vivo spectral-domain optical coherence tomography (SD-OCT) and identify associations among these parameters, ocular biometry, and age. METHODS: In this retrospective study, lens thickness (LT), lens diameter (LD), and lens volume (LV) were measured intraoperatively using SD-OCT in 293 eyes undergoing lens surgery. Correlations among LT, LD, LV, age, axial length (AL), and anterior chamber depth (ACD) were analyzed. Multiple regression analysis was performed to determine whether a combination of biometric data could predict LD and LV. RESULTS: Wide variations were observed in LT (3.6-5.7 mm), LD (7.5-11.9 mm), and LV (119.9-312.4 mm3) of aging eyes. Correlations among the 3 lens dimensions were statistically significant (LV-LT: r = 0.785; P < .001; LV-LD: r = 0.696; P < .001; and LT-LD: r = 0.121; P = .039). With age, the correlation coefficients of LT, LD, and LV were 0.526, 0.326, and 0.573, respectively (P < .001). Although there was significant correlation of AL with LT (r = -0.137; P = .002) and LD (r = 0.268; P < .001), it was not significant with LV (r = 0.084; P = .15). Subgroup analysis revealed that 19.8% of long eyes had LD >1 standard deviation (SD) above and that 5.2% had LD <1 SD below the mean LD. CONCLUSIONS: Dimensions of the aging lens vary considerably and are most accurately characterized by direct measurement of LT, LD, and LV, rather than making assumptions based on AL. These findings challenge historically proposed relationships between LD and AL and represent a normative dataset of contemporary geometric features of the aging lens, possibly aiding in surgical decision making and future developments in lens surgery.

Clinical evaluation of a bacterially derived sodium hyaluronate 2.3% ophthalmic viscosurgical device.

PURPOSE: To compare the safety and effectiveness of bacterially derived and animal-derived sodium hyaluronate 2.3% ophthalmic viscosurgical devices (OVD) (Healon5 PRO and Healon5, respectively) in cataract surgery. SETTING: United States multicenter study. DESIGN: Prospective, randomized, masked, controlled study. METHODS: Adult patients having bilateral cataract extraction and posterior chamber intraocular lens implantation were randomly assigned to receive Healon5 PRO OVD in 1 eye (study group) and Healon5 OVD in the fellow eye (control group). The endothelial cell count (ECC) was measured preoperatively and 3 months postoperatively. Tonometry was performed preoperatively and at the 6-hour, 1-day, 1-week, 1-month, and 3-month timepoints. The cumulative rate of postoperative intraocular pressure (IOP) spikes (≥30 mm Hg) was calculated. Changes from baseline in IOP, edema, inflammation, serious adverse events, and visual acuity were also assessed. RESULTS: The study comprised 213 and 208 treated and paired-eye patients, respectively. At 3 months, there was no statistically significant difference in the mean percentage ECC change from baseline between study group and the control group (-5.55% versus -6.66%; mean difference 1.11% ± 11.89% [SD]; 95% confidence interval (CI), -0.52 to 2.74) or the cumulative IOP spike rate (8.2% versus 6.3%; mean percentage difference -1.9%; 95% CI, -5.46% to 1.61%). At 3 months, both OVD groups had significant reductions in IOP from baseline (-1.37 mm Hg and -1.32 mm Hg, respectively; both P < .0001). The distribution of edema, inflammation, serious adverse events, and visual acuity outcomes was also similar between the groups. CONCLUSION: The 2 OVDs were clinically similar in terms of safety and effectiveness for cataract surgery.

Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens.

PURPOSE: The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. METHODS: In this retrospective-prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50-81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70-80 cm), and near (35-40 cm) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. RESULTS: At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. CONCLUSION: Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction.

Intraocular lens optics and aberrations.

PURPOSE OF REVIEW: This review outlines concepts in intraocular lens (IOL) optics and aberrations important both for current IOLs and for new IOLs in development. RECENT FINDINGS: Optical aberrations make a significant impact on the laboratory and clinical performance of IOLs, especially under mesopic and low-contrast conditions. Minimizing or correcting these aberrations can potentially improve visual function. Strategic management of aberrations can have clinical utility for extended depth of focus and presbyopia correction. SUMMARY: All IOLs affect ocular aberrations in some manner. It is important for clinicians and researchers to understand the implications how any residual aberrations could affect visual quality, visual side-effects, and depth of focus.

The subject-fixated coaxially sighted corneal light reflex: a clinical marker for centration of refractive treatments and devices.

PURPOSE: To describe the inconsistencies in definition, application, and usage of the ocular reference axes (optical axis, visual axis, line of sight, pupillary axis, and topographic axis) and angles (angle kappa, lambda, and alpha) and to propose a precise, reproducible, clinically defined reference marker and axis for centration of refractive treatments and devices. DESIGN: Perspective. METHODS: Literature review of papers dealing with ocular reference axes, angles, and centration. RESULTS: The inconsistent definitions and usage of the current ocular axes, as derived from eye models, limit their clinical utility. With a clear understanding of Purkinje images and a defined alignment of the observer, light source/fixation target, and subject eye, the subject-fixated coaxially sighted corneal light reflex can be a clinically useful reference marker. The axis formed by connecting the subject-fixated coaxially sighted corneal light reflex and the fixation point, the subject-fixated coaxially sighted corneal light reflex axis, is independent of pupillary dilation and phakic status of the eye. The relationship of the subject-fixated coaxially sighted corneal light reflex axis to a refined definition of the visual axis without reference to nodal points, the foveal-fixation axis, is discussed. The displacement between the subject-fixated coaxially sighted corneal light reflex and pupil center is described not by an angle, but by a chord, here termed chord mu. The application of the subject-fixated coaxially sighted corneal light reflex to the surgical centration of refractive treatments and devices is discussed. CONCLUSION: As a clinically defined reference marker, the subject-fixated coaxially sighted corneal light reflex avoids the shortcomings of current ocular axes for clinical application and may contribute to better consensus in the literature and improved patient outcomes.

Consistency of breast density measured from the same women in four different MR scanners.

PURPOSE: To compare the breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) measured from breast MRI of the same women using four different MR scanners. METHODS: The study was performed in 34 healthy Asian volunteers using two 1.5T (GE and Siemens) and two 3T (GE and Philips) MR scanners. The BV, FV, and PD were measured on nonfat-suppressed T1-weighted images using a comprehensive computer algorithm-based segmentation method. The scanner-to-scanner measurement difference, and the coefficient of variation (CV) among the four scanners were calculated. The measurement variation between two density morphological patterns presenting as the central type and the intermingled type was separately analyzed and compared. RESULTS: All four scanners provided satisfactory image quality allowing for successful completion of the segmentation processes. The measured parameters between each pair of MR scanners were highly correlated, with R(2) ≥ 0.95 for BV, R(2) ≥ 0.99 for FV, and R(2) ≥ 0.97 for PD in all comparisons. The mean percent differences between each pair of scanners were 5.9%-7.8% for BV, 5.3%-6.5% for FV, 4.3%-7.3% for PD; with the overall CV of 5.8% for BV, 4.8% for FV, and 4.9% for PD. The variation of FV was smaller in the central type than in the intermingled type (p = 0.04). CONCLUSIONS: The results showed that the variation of FV and PD measured from four different MR scanners is around 5%, suggesting the parameters measured using different scanners can be used for a combined analysis in a multicenter study.

Comparison of breast density measured on MR images acquired using fat-suppressed versus nonfat-suppressed sequences.

PURPOSE: To investigate the difference of MR percent breast density measured from fat-suppressed versus nonfat-suppressed imaging sequences. METHODS: Breast magnetic resonance imaging (MRI) with and without fat suppression was acquired from 38 subjects. Breasts were divided into subgroups of different morphological patterns ("central" and "intermingled" types). Breast volume, fibroglandular tissue volume, and percent density were measured. The results were compared using nonparametric statistical tests and regarded as significant at p < 0.05. RESULTS: Breast volume, fibroglandular volume, and percent density between fat-suppressed and nonfat-suppressed sequences were highly correlated. Breast volumes measured on these two sequences were almost identical. Fibroglandular tissue volume and percent density, however, had small (<5%) yet significant differences between the two sequences-they were both higher on the fat-suppressed sequence. Intraobserver variability was within 4% for both sequences and different morphological types. The fibroglandular tissue volume measured on downsampled images showed a small (<5%) yet significant difference. CONCLUSIONS: The measurement of breast density made on MRI acquired using fat-suppressed and nonfat-suppressed T1W images was about 5% difference, only slightly higher than the intraobserver variability of 3%-4%. When the density data from multiple centers were to be combined, evaluating the degree of difference is needed to take this difference into account.