Rheometric and stability analysis of additive infused magnetorheological fluids: a comparative study.

Magnetorheological fluid (MRF) is a smart responsive fluid, when exposed to the magnetic field, reflects a noticeable transformation in fluid viscosity due to the presence of field responsive particles in the fluid. MRF has been utilized in variety of applications, which despite possess significant concerns regarding on sedimentation due to the density mismatch between the carrier fluid and the suspended magnetic particles. To improve the resistance of rapid sedimentation, this research aims to incorporate one of the component (additive/surfactants) blended into the fluid. The objective of the study focuses to determine the efficient incorporate-infused fluid for further application and sedimentation resistance. In this study, MRF is infused with siloxane, lithium, oleic acid and SDBS (Sodium Dodecyl Benzene Sulfonate) as additive and surfactants along with silicon oil as a carrier fluid. The significant repercussion parameters such as rheology behavior of the samples, temperature and particle sedimentation has been examined and interpreted. Substantially, the effective sample and performance has been comprehended with the insightful comparative results obtained.

Spontaneous central retinal artery occlusion in a teenager with sickle cell trait.

Sickle cell trait (SCT) is traditionally considered a benign condition by ophthalmologists. Several studies have reported ocular complications in SCT, but these complications have been described as a consequence of trauma, exertion, and associated systemic disorders. We here in the report a case of an Arab teen boy, who presented with a sudden loss of vision in his left eye of 1 h duration. The ocular examination revealed acute central retinal artery occlusion. He underwent a series of laboratory and radiological investigations. The blood investigations revealed SCT and abnormal partial thromboplastin time. The fundus fluorescein angiography revealed abnormal retinal vascular perfusion. Marked blood rheological impairment and activation of the coagulation pathway can occur without any contributing factors in SCT leading to severe ocular complications. This is one of the young patients with spontaneous vascular occlusion in SCT.

Volcano like pattern in optical coherence tomography in chronic diabetic macular edema.

In this article we herein report an interesting vitreo-macular interface abnormality associated with chronic diabetic cystoid macular edema. It is an observational case study of three diabetic patients examined in the diabetic clinic. All the patients had proliferative diabetic retinopathy with chronic macular edema. A serial cross sectional OCT examination and tracking of both the longitudinal progression of macular thickening and vitreo-macular interface revealed cystoid macular edema with a characteristic hyperreflective vitreous shadow emerging from the vitreofoveal interface. All the patients had dehiscence of inner retinal layers. This particular morphological feature at the vitreo-foveolar interface, which we name as "volcano sign", has not been described earlier. The probable mechanism of such a finding probably could be due to slow progressive leakage of chronic cytoid fluid into the vitreous with condensation of the overlying vitreous. Vitreo-macular traction followed by posterior vitreous detachment probably would have contributed to such a morphological event.

Management of recurrent inflammatory choroidal neovascular membrane secondary to Vogt-Koyanagi-Harada syndrome, using combined intravitreal injection of bevacizumab and triamcinolone acetate.

The purpose of this report is to evaluate the efficacy and safety of combined intravitreal injection of bevacizumab and intravitreal triamcinolone acetonide (IVTA) for recurrent inflammatory choroidal neovascular membrane (CNVM). It was a prospective interventional study of a young female, who was a known case of Vogt-Koyanagi-Harada syndrome. She presented with an inflammatory choroidal neovascualar membrane and signs of panuveitis in the right eye. She underwent a complete ophthalmic examination. She was given intravitreal injection of bevacizumab and IVTA at different sites. There was complete regression of CNVM and ocular inflammation within a week. After six months, she had recurrence of CNVM in the same eye, which was treated similarly. There was a complete resolution of CNVM and ocular inflammation after the combination therapy and systemic steroids, until one year of follow-up. No serious systemic or ocular adverse events were noted. Combination therapy appears to be an effective and safe method in the management of recurrent inflammatory CNVM.

Retinal vascular events after intravitreal bevacizumab.

PURPOSE: To record retinal vascular events following intravitreal bevacizumab injection. METHODS: Collaborative multi-centre retrospective case series. RESULTS: Eight patients were documented to have central retinal artery occlusion (four patients), branch retinal artery occlusion, capillary occlusion, central retinal vein occlusion and branch retinal vein occlusion (one patient each) within 0-55 days (median 2 weeks) of intravitreal bevacizumab. All patients had several ocular and systemic risk factors for retinal vascular events: elevated intraocular pressure on discharge (four patients), pre-existent glaucoma (one patient), pre-existent ischaemic retinal vascular disorder (four patients), systemic hypertension (five patients), diabetes mellitus (three patients), coronary artery disease (four patients), carotid disease (three patients), smoking (two patients) and migraine (one patient). CONCLUSION: The retinal vascular events may be associated with the underlying ocular disease under treatment or with the underlying systemic disease, may be related to an increased intraocular pressure post-injection constraining further an already poor retinal perfusion, the vasoconstrictor effect of bevacizumab, or a combination of all three.

Intravitreal bevacizumab in inflammatory ocular neovascularization.

PURPOSE: To assess the role of bevacizumab in inflammatory ocular neovascularization. DESIGN: Retrospective, multicenter, consecutive case series of inflammatory ocular neovascularization. METHODS: Patients with inflammatory ocular neovascularization of varying causes for whom standard therapy failed were treated with intravitreal injection of bevacizumab. Main outcome measures included improvement of best-corrected visual acuity (BCVA) expressed in logarithm of minimum angle of resolution units, response of inflammatory ocular neovascularization by funduscopy and angiography, and decrease in central foveal thickness as measured by optical coherence tomography at the three-month follow-up. RESULTS: At the three-month follow-up, 84 eyes of 79 patients had been treated with a mean of 1.3 injections (range, one to three). Thirty-four eyes showed juxtafoveal choroidal neovascularization (CNV), 34 eyes showed subfoveal CNV, eight eyes showed peripapillary CNV, and 11 eyes showed neovascularization of the disc (NVD) or neovascularization elsewhere (NVE). BCVA improved 2.4 lines from 0.68 (6/28 or 20/94) to 0.44 (6/17 or 20/55) (P < .001). BCVA improved by one to three lines in 34.5% of the eyes, by four to six lines in 16.7% of the eyes, and by more than six lines in 14.2% of the eyes. Function was unchanged in 23.8% of the eyes. BCVA worsened in 10.7% (zero to three lines in 7.1%, more than four lines in 3.6%). Central foveal thickness decreased from baseline 346 to 252 microm (P < .001). For CNV, 32 eyes (43.2%) had complete regression after the injection, 27 (36.5%) had partial regression, five (6.8%) had no response, and 10 eyes (13.5%) were not evaluated by the contributors. For NVD or NVE, seven eyes (63.6%) had complete regression of new vessels and four eyes (36.4%) had partial regression after the injection. CONCLUSIONS: Intravitreal bevacizumab led to short-term significant visual improvement and regression of inflammatory ocular neovascularization in a wide variety of inflammatory ocular diseases.

Electrophysiological and structural assessment of the central retina following intravitreal injection of bevacizumab for treatment of macular edema.

PURPOSE: To evaluate with electrophysiological responses and Optical Coherence Tomography (OCT), the short term functional and structural effects at the macula following intravitreal injection of bevacizumab for macular edema. METHODS: Prospective, non-randomized, interventional case study. In total, 17 eyes of 17 patients with macular edema due to vein occlusions and diabetic retinopathy received intravitreal bevacizumab. All Patients underwent complete ophthalmic examination including Snellen visual acuity testing, Multifocal Electroretinography (mfERG) and Full Field Electroretinography (FERG), OCT scanning at baseline at 1 week and 2 months after intravitreal bevacizumab. RESULTS: FERG did not show any change in waveform parameters following intravitreal injection of bevacizumab. Average mfERG macular responses within central 20 degrees showed increased P(1) amplitude (P < 0.05) at 2 months after treatment as compared to the baseline recordings in all subjects. No changes were seen in the implicit time. There was 22% improvement in central retinal thickness (CRT) at 2 months compared to the baseline (P < 001). CONCLUSION: Intravitreal injection bevacizumab resulted in reduction in the central retinal thickness and mild to moderate improvement in the mfERG amplitudes in this short-term study. The visual acuity changes did not directly correlate with the reduced central retinal thickness or improvement in mfERG. The short-term results showed no serious ocular adverse effects. Therefore on short-term follow up the off label drug showed improvement of macular edema secondary to vein occlusion and diabetic retinopathy with no demonstrable toxic effects.

Clinical, anatomic, and electrophysiologic evaluation following intravitreal bevacizumab for macular edema in retinal vein occlusion.

PURPOSE: To investigate clinical, anatomic, and electrophysiologic response after single intravitreal injection of bevacizumab for macular edema attributable to retinal vein occlusion. DESIGN: Prospective nonrandomized, interventional case series. METHODS: Twenty-one patients with macular edema attributable to vein occlusion received intravitreal injection of bevacizumab 1.25 mg. Nine patients had central retinal vein occlusion (CRVO), and 12 patients had branch retinal vein occlusion (BRVO). Complete ophthalmic examination including optical coherence tomography (OCT) was done at baseline and follow-up visits. Fifteen patients underwent fluorescein angiography at baseline. Selected patients underwent electroretinography (ERG) and visual evoked potential (VEP) at baseline and follow-up. Follow-up was for 12 weeks. RESULTS: At baseline, mean visual acuity was 20/381 (median, 20/400) and showed improvement to mean 20/135 (median, 20/60) after one month, (P = .001). At 12 weeks, mean visual acuity was 20/178 (median, 20/80) (P = .001). The mean central retinal thickness (CRT) was 647.81 microm (median, 609.00 microm) at baseline and decreased to mean 293.43 microm (median, 222.00 microm) at one month (P = .001). At 12 weeks, mean CRT was 320.90 mum (median, 280.00 microm) (P = .001). ERG and VEP showed no worsening of the waveforms. There was no significant difference in the visual outcome between the BRVO and CRVO groups. CONCLUSION: Intravitreal injection of bevacizumab appears to result in significant short-term improvement of visual acuity and macular edema secondary to vein occlusion. The present report confirms the previous studies. No ocular toxicity or adverse effects were observed. However, prospective, randomized, controlled long-term studies are required with an adequate number of patients.