Magnetic Resonance Imaging in Patients Implanted with Ex-PRESS Stainless Steel Glaucoma Drainage Microdevice

Feo, F. De; Roccatagliata, Luca; Bonzano, Laura; Castelletti, Lara; Mancardi, Gianluigi; Traverso, Carlo Enrico

doi:10.1016/j.ajo.2008.12.011

Cited by 15 publications

(12 citation statements)

References 26 publications

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“…Moreover, it is unknown whether the conclusions reached in the rabbit can be directly used in human eyes, as the intravital studies in human beings are limited. Furthermore, these methods fail to sufficiently reveal the theoretical system of drug metabolism in eyes [13,14] .…”

Section: Discussionmentioning

confidence: 93%

Corneal permeability assay of topical eye drop solutions in rabbits by MRI

Mao

Zhang

Hen

et al. 2010

J. Huazhong Univ. Sci. Technol. [Med. Sci.]

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This study examined the corneal permeability of topical eye drop solutions added with various corneal penetrating accelerators and gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) by nuclear magnetic resonance imaging (MRI). Twenty-four New Zealand rabbits were randomly divided into 3 groups according to the random digits table: Gd-DTPA group, in which the rabbits received 23.45% Gd-DTPA; hyaluronic acid group, in which 23.45% Gd-DTPA plus 0.2% hyaluronic acid was administered; azone group, in which 23.45% Gd-DTPA with 0.2% azone was given. Fifty microliters of the eye drops was instilled into the conjunctive sac every 5 min, for a total of 6 applications in each group. Contrast medium signals in the cornea, anterior chamber, posterior chamber, and vitreous body were scanned successively by MRI. The morphology and cell density of the corneal endothelium were examined before and 24 h after the treatment. The results showed that the residence time of Gd-DTPA in the conjunctival sac in the hyaluronic acid and azone groups was longer than that in the Gd-DTPA group. The signals in the anterior chamber of the Gd-DTPA and hyaluronic acid groups were increased slightly, and those in the azone group strengthened sharply. The signal intensity continuously rose over 80 min before reaching plateau. The strengthening rate of signals in the anterior chamber was 19.63% in the Gd-DTPA group, 53.42% in the sodium hyaluronate group, and 226.94% in the azone group. No signal was detected in the posterior chamber or vitreous body in all the 3 groups. Corneal morphology and cell density did not show any significant changes after the treatment in all the 3 groups. It was concluded that azone can significantly improve the corneal permeability of drugs that are similar to Gd-DTPA in molecular weight and molecular size, and MRI is a noninvasive technique that can dynamically detect eye drop metabolism in real time.

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Section: Discussionmentioning

confidence: 93%

Corneal permeability assay of topical eye drop solutions in rabbits by MRI

Mao

Zhang

Hen

et al. 2010

J. Huazhong Univ. Sci. Technol. [Med. Sci.]

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“…8 demonstrated immediate movement of the device across a wet petri dish at both 1.5 and 3 T, but no movement of the device when placed on a dry petri dish at both 1.5 and 3 T. They went on to test the device when placed into the anterior chamber of a human cadaver eye (intracameral test) and when implanted through the sclera (scleral fixation test) with no movement detected at 3 T. De Feo et al . 9 published a series of five patients with a total of seven implants who underwent MRI at 1.5 T without adverse event or artefact affecting interpretation of brain MRI but some degree of artefact in the region of the optic nerve. Consistent with De Feo et al ., susceptibility artefact related to the orbital implants in the present cases did not significantly obscure visualization of the brain, optic nerves, or posterior globes with conventional T1- and T2-weighted spin echo sequences at 1.5 T (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Investigation of the literature yielded no information in the radiology literature. A few papers from the ophthalmology literature were identified, which suggested MRI compatibility up to 1.5 T. 7-9 The MRI was approved and performed under close supervision at 1.5 T. The patient tolerated the MRI examination without ill effect or complication, and subsequent slit lamp examination in the ophthalmology clinic revealed no evidence of dislocation of the shunts or other side effects related to imaging.…”

Section: Introductionmentioning

confidence: 99%

Ex-PRESS glaucoma filter: an MRI compatible metallic orbital foreign body imaged at 1.5 and 3T

et al. 2015

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AIM To report on the MRI compatibility of the Ex-PRESS glaucoma filtration device, a tiny metallic implant placed into the anterior chamber of the eye that is much smaller than traditional glaucoma shunts, and to educate the radiology community regarding its appearance. MATERIALS AND METHODS Seven patients with Ex-PRESS glaucoma filtration devices were identified that had undergone MRI at San Francisco General Hospital/University of California San Francisco Medical Center by searching and cross-referencing the radiology reporting system and the electronic medical record. MRI images were reviewed for artefact interfering with interpretation. Ophthalmology examinations were reviewed for evidence of complications. RESULTS Eighteen individual MRI examinations were performed during 12 unique MRI events on these 7 patients. 13/18 individual MRI examinations and 7/12 MRI events were performed at 3 T with the others performed at 1.5 T. Mean time from Ex-PRESS implantation to MRI was 17.5 months. Mean time from MRI to first ophthalmology examination was 1.1 months and from MRI to latest ophthalmology examination was 6.6 months. Susceptibility artefact did not interfere with image interpretation and no complications related to MRI were encountered. CONCLUSION The Ex-PRESS glaucoma filtration device appears to be safe for MRI at 1.5 and 3 T and does not produce significant susceptibility artefact to affect diagnostic interpretation adversely.

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“…In a recent report, De Feo and colleagues evaluated MRI brain images taken in patients with the Ex-PRESS device in place. Although no safety concerns arose, they did note imaging artifacts generated by the device potentially compromising diagnostic evaluation 10. Even more recently, Geffen et al found that the Ex-PRESS device does experience some movement under 1.5 and 3.0 T conditions.…”

Section: Introductionmentioning

confidence: 99%

“…As the popularity of the Ex-PRESS device has grown, concerns have been raised about the safety of the metallic implant in MRI conditions 10 11. The device is composed of 316L grade stainless steel considered to be austenitic and non-ferromagnetic 12.…”

Section: Introductionmentioning

confidence: 99%

MRI of the Ex-PRESS stainless steel glaucoma drainage device

Seibold

Rorrer

Kahook

2010

British Journal of Ophthalmology

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The Ex-PRESS glaucoma drainage device, manufactured from grade 316L stainless steel, does move in the presence of high magnetic fields. The clinical significance of this finding and translation to in vivo conditions are not currently known. Further studies are needed to better understand how patients might be affected by the magnetic properties of this device post implantation and how patients should be counselled in regards to safety of MRI in the early and late postoperative period.

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Magnetic Resonance Imaging in Patients Implanted with Ex-PRESS Stainless Steel Glaucoma Drainage Microdevice

Cited by 15 publications

References 26 publications

Corneal permeability assay of topical eye drop solutions in rabbits by MRI

Corneal permeability assay of topical eye drop solutions in rabbits by MRI

Ex-PRESS glaucoma filter: an MRI compatible metallic orbital foreign body imaged at 1.5 and 3T

MRI of the Ex-PRESS stainless steel glaucoma drainage device

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