Initial Loading Phase Research Articles

Gait Analysis in Kinematic Versus Mechanical Alignment in Total Knee Joint Arthroplasty (TKA) - A Randomized Trial

We found no significant differences across the KA and MA procedures in relation to bilateral limb symmetry during walking (p > 0.05) across all variables studied. The theoretical advantage of KA technique in restoring a more natural gait was not observed in this study. Traditional mechanical alignment (MA) attempts to position femoral and tibial components perpendicular to the mechanical axis of each bone. Kinematic alignment (KA) attempts to match implant position to the prearthritic anatomy of individual patients, with the aim of restoring more normal gait kinematics for that patient and potentially improving functional outcome. The aim of this study was to compare MA and KA techniques in restoring bilateral limb symmetry during walking following unilateral TKA. Twenty-seven patients with unilateral osteoarthritis who had been randomised to receive a MA (n=14) or KA (n=13) procedure underwent gait analysis in a biomechanics laboratory at a minimum of 24 months post operation. Eligible patients had a well-functioning native knee on the contralateral side to their TKA. In the KA group, patient-specific cutting-blocks were manufactured using individual pre-operative magnetic resonance imaging data. In the MA group, computer navigation was used to ensure neutral mechanical alignment accuracy. Subjects attended a biomechanics laboratory where a nine camera motion analysis system was used to collect 3D kinematic data of the left and right limbs as subjects performed five trials of walking at a self selected speed. During these trials, 3D ground reaction forces and moments during the stance phase were recorded with a force platform. Kinematic and kinetic data were analyzed using the Visual 3D biomechanics software program. The kinematic variables of interest were sagittal and frontal plane knee angle at footstrike, and the change in these angles in the initial loading phase following footstrike. The kinetic analysis was focused on the initial loading phase and the dependent variables were the peak moment and peak power calculated in sagittal and frontal planes. Differences in these variables across legs were calculated, and these differences were then compared across groups in the statistical analysis (independent t-tests). We observed no difference in the kinematic variables of frontal plane knee angle at footstrike (mean difference -0.12°, 95% confidence interval [CI] -4.41° to 4.17°, p = 0.95), sagittal plane knee angle at footstrike (mean difference -0.47°, 95% CI -4.69° to 3.75°, p = 0.82), frontal plane maximum flexion in loading (mean difference -0.41°, 95% CI -3.75° to 2.92°, p = 0.80), and sagittal plane maximum flexion in loading (mean difference 1.40°, 95% CI -2.88° to 5.67°, p = 0.51). Likewise, we observed no difference in the kinetic variables of frontal plane peak moment (Nm/kg) in initial loading (mean difference -0.22, 95% CI -0.53 to 0.08, p = 0.14), sagittal plane peak moment in initial loading (mean difference 0.03, 95% CI -0.12 to 0.18, p = 0.65), and sagittal plane power (W/kg) at the knee (mean difference -0.16, 95% CI -0.35 to 0.03, p = 0.10). We found no significant differences across the KA and MA procedures in relation to bilateral limb symmetry during walking (p > 0.05) across all variables studied. The theoretical advantage of KA technique in restoring a more natural gait was not observed in this study.

In-situ characterization of microstructural changes in a carbon nanotube sheet under sustained load

The present study characterizes the creep behavior of carbon nanotube (CNT) sheets under externally applied sustained loads. Creep loads at levels ranging from 85% to 98% of the ultimate tensile strength of the CNT sheet were applied using a tensile tester inside a scanning electron microscope chamber. The microscope enabled in-situ characterization of the microstructural changes in the CNT sheet under the influence of the applied load. The loads were sustained for 1,000,000s or failure, whichever occurred first. A computational pattern recognition technique was also developed that enabled quantitative approximation of the time dependent changes in distribution of individual CNT orientation with reference to the loading direction. It was observed that the CNTs increasingly aligned along the loading direction during the initial loading phase when the CNT sheet was ramped up to the desired load level. Further microstructural changes by way of individual CNTs continuing to gradually align along the loading direction was observed after the loads were sustained at the desired levels. The pattern recognition computational results validated the experimental findings. Slight relaxation of the CNTs was also observed upon the removal of load once 1,000,000s was reached.

The Interval between Treatments of Bevacizumab and Dexamethasone Implants for Diabetic Macular Edema Increased over Time in the BEVORDEX Trial

To report increasing retreatment interval of intravitreal bevacizumab and dexamethasone implants for diabetic macular edema (DME) in the BEVORDEX trial. Multicenter randomized clinical trial. Sixty-eight eyes from 47 patients who completed 2 years of follow-up. The BEVORDEX study (www.clinicaltrials.gov identifier, NCT01298076), set in Australia, was the first head-to-head trial of bevacizumab (Avastin; Genentech, South San Francisco, CA), with retreatment considered after 4 weeks, versus a slow-release dexamethasone implant (Ozurdex; Allergan Inc., Irvine, CA), with retreatment possible after 16 weeks, for center-involving DME. Study eyes were assessed every 4 weeks for retreatment according to prespecified visual acuity and central macular thickness criteria. In this post hoc analysis, changes in treatment interval over time were examined using mixed-effects regression models. We assessed whether the mean treatment interval changed over time and if this depended on baseline characteristics or the treatment received. Of the 68 eyes from 47 patients, 67 study eyes received at least 1 retreatment (1 eye in the dexamethasone implant group did not require retreatment over 24 months). Thirty-two eyes received bevacizumab and 35 eyes received dexamethasone implants. Study eyes received a mean of 14.6 injections (standard deviation [SD], 7.8 injections) and 5.6 injections (SD, 1.4 injections) in the bevacizumab and dexamethasone groups, respectively, over 2 years. The mean retreatment interval over the 2-year follow-up period was 70.8 days (SD, 43.8 days) for the bevacizumab group and 145 days (SD, 45.4 days) for the dexamethasone implant group. The mean treatment interval increased over time for both drugs (P= 0.016), independent of which treatment was received (P= 0.808). Longer treatment interval over time was associated with younger age (P=0.037) and better baseline visual acuity (P= 0.026), but not with gender (P= 0.907) or baseline central macular thickness (P= 0.900). The increase in treatment interval for both intravitreal bevacizumab and dexamethasone implants over time has implications when informing patients about potential treatment burden for DME, planning intravitreal injections services, and designing future clinical trials. For drugs with a disease-modifying effect, fixed-interval dosing may not be required beyond an initial loading phase.

某国产复合材料层压板压缩稳定性研究

分别用工程算法和有限元软件MSC.Patran2008/Nastran2008,分析了受压缩载荷作用下某国产复合材料层压板四边简支约束下的失稳情况，并展开了四边简支情况下的复合材料层压板压缩稳定性试验。试验表明在加载的初始阶段试件发生的局部屈曲，层压板后屈曲承载能力较大；研究了层压板的破坏模式。工程理论计算、有限元分析、试验结果进行对比，发现三种方式得到层压板的一阶屈曲载荷接近，说明了数值模型的合理及有限元计算可以为复合材料结构的研究提供一定的参考。 The mis-stability condition of simply supported domestic composite lamination at four sides af-fected by compressive load is analyzed by engineering algorithm and finite element software MSC. Patran 2008/Nastran 2008, respectively. And a compression stability test of simply supported composite laminates on four sides is conducted. The tests show a local buckling during the initial phase of loading; the post-buckling load-bearing capability is large. The failure mode of the laminate was studied. The contrast of engineering theory calculation, finite element analysis, and the test results shows that the first-order buckling loads from three methods are close, which indicates the finite element model is rational and the finite element calculation could provide reference to the research of composite structure.

Permeability Evolution of Granite Gneiss During Triaxial Creep Tests

Permeability is an important factor for seepage analysis of rock material, and a key factor in ensuring the safety of underground works. In this study, the permeability evolution of granite gneiss during triaxial creep tests was investigated. In the context of an underground oil storage cavern in China, a series of hydro-mechanical coupling creep tests were conducted on rock cores of granite gneiss at three different pore pressures to reveal the effect of pore pressure on the permeability evolution and to investigate the correlation between the permeability and volumetric strain during the creep process. During the creep tests, the permeability decreases in the initial loading phase. At all deviatoric stress levels, the permeability remains stable in the steady creep stage and increases rapidly in the accelerated creep stage. Based on the test data, the initial permeability, steady permeability and peak permeability at various stress levels are defined. The effect of pore pressure on the permeability is captured by a linear model. In addition, the relationship between permeability and volumetric strain can be described as a process divided into three phases, with different functions in each phase.

En Face Spectral-Domain Optical Coherence Tomography Imaging of Outer Retinal Hard Exudates in Diabetic Macular Edema Based on Optical Coherence Tomography Patterns.

To evaluate en face spectral-domain optical coherence tomography (SD-OCT) findings of the outer retinal hard exudates in diabetic macular edema (DME). Exploratory analyses of prospective and consecutive case series. Fifty-five eyes treated with intravitreal ranibizumab (IVR) (Lucentis; Genentech, South San Francisco, CA) for 12 months were classified according to OCT features of DME: diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD). Area fraction of outer nuclear layer (ONL) hard exudates (HEs) was assessed from en face OCT images. Area fraction of ONL HEs increased from 1.45% ± 1.22% to 2.24% ± 1.31% in DRT and from 2.24% ± 1.85% to 3.25% ± 1.52% in CME. HE gain was greatest during first 3 months (DRT = 0.83%; CME = 1.25%). SRD showed no difference in HEs (P = .462). ONL HEs increased in DRT and CME at month 12 following IVR. Rapid gain of HEs was found during the initial loading phase of IVR.

Obesity Is Associated With the Development of Interstitial Pneumonia Under Long-Term Administration of Amiodarone in Refractory Atrial Fibrillation Patients

Although oral amiodarone (AMD) has been used for the management of atrial fibrillation (AF), serious complications such as interstitial pneumonia (IP) occur very occasionally. We evaluated which factors were associated with the development of IP under the long-term administration of AMD in patients with refractory AF.This study included 122 consecutive patients (65.8 ± 11.4 years, mean body mass index [BMI] of 23.2 ± 4.3 kg/m(2)) who orally received AMD to inhibit AF between January 2004 and December 2013. Administration of AMD was begun at 400 mg daily as a loading dose, and was continued at a dosage of 50-400 mg daily after the initial loading phase, determined by the control of the arrhythmias and occurrence of side-effects. The clinical factors were compared between the patients with and without adverse effects, especially IP.During an average follow-up period of 49.2 ± 28.2 months, 53 patients (43.4%) were determined to have converted and maintained sinus rhythm. In contrast, adverse effects were detected in 46 patients (37.7%) with AMD. IP occurred in 8 patients (6.6%), thyrotoxicosis in 35 (28.7%), and others in 5 (4.1%). Four (50.0%) out of 8 patients complicated with IP had obesity (BMI > 27 kg/m(2)). Among the clinical factors, only obesity was significantly associated with the development of IP (P = 0.026).In patients with refractory AF, AMD had an antiarrhythmic effect with long-term administration, but greater adverse effects were also observed. Obesity was the most significant factor associated with the development of IP.

Missed Hospital Appointments of Patients Receiving Ranibizumab Therapy for Neovascular Age-Related Macular Degeneration.

IntroductionThe aim of this study was to investigate the frequency and duration of missed hospital appointments (MHAs) in a consecutive cohort of patients treated with ranibizumab for neovascular age-related macular degeneration (nAMD) and to assess their impact on outcomes of therapy in a real-world clinical setting.MethodsRetrospective, cross-sectional study of consecutive patients attending medical retina clinics for nAMD treatment with ranibizumab.ResultsSeventy-eight eyes of 78 patients met the inclusion criteria for data analysis. Mean age was 78 years with mean follow-up of 27 months. Mean visual acuity (VA) was 52 ± 16 letters at baseline, 56 ± 17 letters at year 1 and 58 ± 16 letters at year 2. At the end of the second year, 90% of the patients had lost <15 letters, 26% had gained ≥15 letters and 10% had lost ≥15 letters. Nineteen patients had at least one MHA (24%) over 2 years. There were 26 MHA episodes in total leading to a median duration of 79 days (range 35–159) between attended hospital visits. None of these MHAs occurred during the first 3 months after treatment initiation. Mean VA and central retinal thickness difference between 2 years and baseline for the MHA group was not statistically different compared with the non-MHA group.ConclusionsOur data suggest that MHA may be a relatively common occurrence in AMD treatment clinics, but good outcomes of treatment can be achieved over 2 years despite missed hospital visits if patients are reviewed on average six times in the first year after an initial loading phase of three injections and nine times in the second year of treatment.Electronic supplementary materialThe online version of this article (doi:10.1007/s40123-015-0031-5) contains supplementary material, which is available to authorized users.

Results from the treatment of refractory diabetic macular oedema with Bevacizumab in a clinical setting

AbstractPurpose To evaluate the outcome of the treatment of patients with refractory diabetic macular oedema with intravitreal bevacizumab (Avastin).Methods Prospective data was entered into an in house database of all patients being treated for refractory diabetic macular oedema at the Ophthalmology Department, Central Middlesex Hospital, London, UK. All patients received bevacizumab on a pro re nata basis after an initial loading phase of three injections. Best corrected visual acuity (BCVA) on the logMAR chart and the central retinal thickness (CRT) on the optical coherence tomography (OCT) scan were recorded at each visit. OCT was performed with the Spectralis OCT device (Heidelberg Engineering, Heidelberg, Germany) using the standard protocol of the clinic. Statistical analysis involved the Wilcoxon signed rank test and Spearman correlation test.Results 64 eyes of 48 patients were included in this study. The mean age was 68 years (range 45 ‐ 87). Patients received a mean of 3 bevacizumab (range 1‐10) injections. The follow‐up time was up to 15 months. The mean logMAR BCVA at baseline for Avastin was 0.74. At 2, 3, 7, and 11 months the mean BCVA was 0.77, 0.75, 0.67, and 0.69 respectively (p=0.01, 0.006, 0.02 and 0.05). There was no significant difference between baseline and any period thereafter during follow‐up to 15 months. Mean CRT at baseline was 527μm. The mean CRT at months 1‐4 were 456, 491, 490 and 480μm respectively and were significantly different for baseline, (p=0.001, 0.01, 0.03 and 0.04). CRT for months 5 to 15 were not significantly different from baseline.Conclusion The treatment of refractory diabetic macular oedema with intravitreal bevacizumab made little difference to improving the BCVA and CRT of the patients.

Experimental Investigation of PC-Films Using Optical Measurements

Abstract The alignment of polymer chains is a well known microstructural evolution effect due to straining of polymers. This has a drastic influence on the macroscopic properties of the initially isotropic material. In this work, cold forming is performed at room temperature on a tensile testing machine. Polycarbonate films are examined in two loading phases. In the first phase, the specimen is loaded to induce anisotropy, and in the second, it is re-loaded, while the material direction is varied. The investigations are supported by an optical measurement system to gain knowledge about the inhomogeneous material behavior in the initial loading phase and about the anisotropic homogeneous behavior during the re-loading phase. Two dimensional strain contours are obtained from the test data. Additionally, we propose a method for approximation of the macroscopic true stress and compare the results with a common approach based on volume consistency. In the future, the test data will set a basis for parameter identification of constitutive equations taking into account a combination of inhomogenous and homogenous material behavior, exhibiting strain induced anisotropy.

About the applicability of a simple model to predict the fatigue life and behavior of woven-ply thermoplastic laminates at T > Tg

Through the application of a simple model, the concept of damage accumulation has been used to predict the fatigue life of TP-based composite materials at a test temperature higher than its glass transition temperature. This work was aimed at studying the off-axis tension–tension fatigue behavior of woven-ply C/PPS laminates which consists of three primary stages: (i) In the initial phase of cyclic loading, damage accumulates rapidly along with a matrix plasticization under the form of intra-laminar cracking which may initiate in multiple locations, but preferably at the interfaces between fibers and matrix at the crimps – (ii) The second stage is characterized by a steady damage growth rate and little damage accumulation – (iii) Damage (mostly debonding and interlaminar cracks) generalizes rapidly during the last stage ultimately resulting in extensive delamination and fiber bundles pull-out. It also appears that the fatigue behavior is ascribed to the highly ductile and time-dependent behavior of matrix-rich regions due to the non-planar structure of woven plies. Finally, a simple analytical model was applied, and proved to be adequate to capture the different stages of damage scenario, with excellent correlation to the experimental data.

In situ tests simulating traffic-load-induced settlement of alluvial silt subsoil

In China, The Yellow River delta is the youngest large river delta, and the low liquid limit alluvial silt is widely distributed there. The silt is easy to liquefy so that the silt subsoil shows large settlement under traffic load. At present, few in situ model tests were conducted to study the traffic-load-induced settlement of silt subsoil. Therefore, a falling-weight simulation equipment of traffic load was developed. By adjusting the technical parameters such as the falling height of the weight, different types of traffic loads can be well simulated. With the equipment, in situ tests were carried out to study cumulative settlement of silt subsoil in the Yellow River delta. Tests indicate that the settlement and excess pore water pressures rapidly grow initially and then tend to be stable with increasing the number of load cycles, and they also increase with the magnitude of the traffic load. When the load attains a threshold value, liquefaction takes place in the silt subsoil. After terminating loading, the pore water pressure rapidly decreases and the settlement increases simultaneously, while after one hour they tend to stabilize. Based on Chai–Miura cumulative deformation model of soil, the traffic-load-induced cumulative settlement of silt subsoil was calculated and compared with the test results. The calculated cumulative settlement with increasing number of load cycles agrees well with the test results, except the initial phase of cyclic loading where the settlement observed in the situ tests is overestimated. This is mainly because Chai–Miura model assumes undrained conditions while the subsoil under traffic loads is partly drained.

Vitamin D supplementation in a healthy, middle-aged population: actual practices based on data from a French comprehensive regional health-care database

The debate surrounding recommendations for vitamin D supplementation in middle-aged patients (that is, 20-60 years of age) with low serum concentrations of 25-hydroxyvitamin D (25(OH)D) is growing. Our aim was to describe practices regarding vitamin D supplementation in this age group, which are basically unknown. We performed an analysis using exhaustive reimbursement data from the individuals in Rhône-Alpes area, a French region regrouping more than 6 million of inhabitants. The data were collected from the French Insurance Health-care System. Patients who were 20-60 years of age, had no severe comorbidities, had a 25(OH)D assay between 1 December 2008 and 31 January 2009 were identified. Those who received a subsequent prescription for vitamin D were included in this analysis. We described patterns of vitamin D supplementation by frequency and daily dose. The sample in this study included 1311 patients. The mean age was 47.7 years (s.d.: 9.5) and the median age was 50.2 years. Most of the participants (that is, 85.9%) were women. A total of 372 distinct prescription patterns for vitamin D supplementation were observed. The two most frequent (that is, 32.6% in total) involved a unique dispensation of a high dose of either 200,000 (17.5%) or 100,000 IU (15.1%). Most prescribed supplements were based on vitamin D3 (65%), and the most prescribed forms were high dose ampoules (81.6%). Only 48.9% of the participants were given a maintenance prescription after the initial loading phase. Our results reveal a significant variability in the prescriptions for vitamin D supplementation from physicians in the French population. Moreover, less than half of the patients receive maintenance therapy after the initial loading phase of supplementation.

Experimental characterization of strain localization in rock

Abstract In this study, damage evolution and strain localization in sandstone have been experimentally investigated in uniaxial compression tests. A digital image correlation technique has been applied to obtain apparent strain fields which can visually display the deformation and damage evolution of rock. The experimental results show that regions with apparent strain concentration (RASC) develop at the initial loading stage and distribute diffusely on the sample surface which may correspond to the damaged areas. With incremental load, the RASCs localize spatially, probably via coalescence into a line-shaped area that behaves like a macroscopic crack leading to the eventual failure of the specimen. A factor DRASC representing the deviation of the average apparent strain in RASCs from the average on the whole sample surface and a localization factor Lf, are proposed to characterize the evolution of damage and localization. DRASC increases slowly in the initial phase of loading and rises rapidly after the onset of localization. Lf decreases during loading which indicate the localization of spatial distribution of damage. The two factors can be used to well reflect the damage evolution and strain localization of rock specimens under compression.

EFFECTS OF VEGF INHIBITION ON RETINAL MORPHOLOGY, NEOVASCULAR NETWORK SIZE, AND VISUAL ACUITY IN PATIENTS WITH VASCULARIZED PIGMENT EPITHELIUM DETACHMENT BECAUSE OF OCCULT CHOROIDAL NEOVASCULARIZATION

To report the results of vascular endothelial growth factor inhibition for vascularized pigment epithelium detachment associated with choroidal neovascularization secondary to age-related macular degeneration. We performed a retrospective analysis of patients affected by vascularized pigment epithelium detachment treated with intravitreal anti-vascular endothelial growth factor (0.5 mg of ranibizumab or 1 mg of bevacizumab) and a follow-up of 12 months. Retinal angiomatous proliferations were excluded. Treatment was conducted with an initial loading phase followed by a pro re nata phase. Fluorescein angiography and indocyanine green angiography were performed at baseline and every 3 months. Forty eyes were included in this study. After a follow-up of 12 months and 5.5 treatments on average, best-corrected visual acuity did not vary significantly. Central retinal thickness and pigment epithelium detachment height were significantly reduced, whereas the choroidal neovascularization area remained constant. In vascularized pigment epithelium detachment, anti-vascular endothelial growth factor therapy shows visual stabilization but not best-corrected visual acuity gain. However, it is associated with significant morphologic improvements, and it may offer a benefit over the natural course of the disease.

Особенности начального этапа работы активной зоны реактора БН-1200

Особенности начального этапа работы активной зоны реактора БН-1200

Long-term effects of ranibizumab treatment delay in neovascular age-related macular degeneration

Intravitreal injections of ranibizumab are the standard of care for neovascular age-related macular degeneration (AMD). In clinical trials, comparable efficacy has been shown for either monthly injections or as needed injections upon monthly controls. Unlike in trial settings, treatment in clinical routine is often delayed by complex approval procedures of health insurance and limited short-term surgical capacities. Eighty-nine patients with neovascular AMD were followed for 12 months. Early treatment diabetic retinopathy study (ETDRS) visual acuity (VA), Radner reading VA and spectral domain optical coherence tomography were performed monthly, with additional fluorescein angiography if needed. After an initial loading phase of three consecutive monthly intravitreal injections with ranibizumab, re-injections were performed when recurrent activity of choroidal neovascularization (CNV) was detected. After an initial increase to a value of +5.0 ± 11.87 ETDRS letters from baseline, VA constantly decreased over 12 months to a value of -0.66 ± 16.82 ETDRS letters below baseline. Central retinal thickness (CRT) decreased from a value of 438.1 ± 191.4 μm at baseline to a value of 289.9 ± 138.6 μm after initial therapy and stabilized at a value of 322.4 ± 199.5 μm. Loss of VA during latency between indication to treat and treatment was significantly greater than re-gain of VA after re-initiation of therapy (-2.2 ± 5.0 versus 0.4 ± 7.4 letters; p = 0.046). Latency between indication to treat and treatment is responsible for irreversible VA deterioration. A successful PRN treatment regimen for neovascular AMD requires immediate access to therapy after indication.

Combination therapy with low-dose transpupillary thermotherapy and intravitreal ranibizumab for neovascular age-related macular degeneration: a 24-month prospective randomised clinical study

AimTo compare the effect of combined low-dose transpupillary thermotherapy (TTT) and intravitreal ranibizumab with sham TTT and intravitreal ranibizumab in patients with neovascular age-related macular degeneration (AMD).MethodsA 24-month, double-masked, randomised,...

Biomechanical comparison of strategies to adjust axial stiffness of a hybrid fixator

To evaluate strategies for increasing the axial stiffness of a hybrid external bone fixator. Type Ia hybrid fixators, consisting of a uniplanar linear component connected to a circular ring, were tested in displacement controlled loading in axial compression. The basic hybrid construct was modified to explore strategies considered to increase fixator stiffness including: decreasing ring diameter, increasing ring thickness, adding pins to the ring fixation, and adding struts between the ring and vertical post components of the device. Stiffness in the initial phase of loading was compared between the groups. The addition of a single diagonal bar between the ring and linear connecting rail did not significantly improve the stiffness of constructs. However, the addition of two half-pins to the ring, the addition of two struts between the ring and linear connecting rail, or decreasing the internal ring diameter from 115 to 85 mm progressively increased the stiffness of the frame. The most effective strategy consisted of increasing the thickness of the ring from 6 to 12 mm, thereby increasing the stiffness of the control frame by 335%. Modulating the ring thickness, adding two struts between the ring and linear connecting rail, and reducing the ring diameter appear to be the most effective, simple, and clinically versatile ways to increase axial stiffness, most likely due to their impact on reducing ring bending.

Choroidal thickness after intravitreal ranibizumab injections for choroidal neovascularization

PurposeTo study changes in choroidal thickness with ranibizumab treatment for choroidal neovascularization (CNV).DesignProspective case series.MethodsThis prospective study consisted of 60 CNV-affected eyes of 60 patients treated with intravitreal injections of ranibizumab using an on-demand protocol after an initial loading phase. The eyes studied included 20 with age-related macular degeneration (AMD), 20 with polypoidal choroidal vasculopathy (PCV), and 20 with myopic CNV. In the eyes with AMD and PCV, choroidal thickness at the fovea was measured with optical coherence tomography using enhanced depth imaging. In eyes with myopic CNV, the choroidal thickness was measured using standard optical coherence tomography without the enhanced depth imaging technique.ResultsWith ranibizumab treatment, central retinal thickness decreased significantly (P < 0.001) and visual acuity improved significantly (P < 0.001). However, central choroidal thickness (167.2 ± 108.3 μm) showed no significant change at 1 month after the loading phase (165.2 ± 107.8 μm, P = 0.120) or at final examination (164.8 ± 107.7 μm, P = 0.115). At baseline, central retinal thickness in eyes with AMD was significantly greater that those with PCV (P = 0.005) or high myopia (P = 0.029). However, central choroidal thickness in eyes with myopic CNV was significantly thinner than in eyes with AMD (P < 0.001) or PCV (P < 0.001). In each type of disease, there was no significant change in central choroidal thickness with ranibizumab treatment.ConclusionThe effect of ranibizumab on the choroidal thickness is minimal, if any.