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

Mao, Xiaogang; Zhang, Shaowei; Hen, Hui; Du, Longting; Li, Guigang; Li, Bin; Zou, Hong

doi:10.1007/s11596-010-0662-7

Cited by 6 publications

(2 citation statements)

References 19 publications

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“…Although gadolinium-based compounds are commonly used as MRI contrast agents to increase recorded signal intensities, the free ion, Gd 3ϩ can be toxic to some tissues, but it is generally regarded as safe when administered as a chelated compound (14,59). Gd-DTPA is a chelated form of Gd 3ϩ with a mol mass of 570 Da and a charge of Ϫ2, which is considered to be safe to administer to the eye to enhance the quality of ocular MRI images (11,40). In this study, we have used gadolinium-based contrast agents to enhance the relaxation rate of water molecules as detected by IR-SE imaging to monitor and compare the time course of Gd-DTPA and Gd 3ϩ movement into the lens (Fig.…”

Section: Ir-se Imaging Of Gd 3ϩ and Gd-dtpa Penetration In The Bovinementioning

confidence: 99%

Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion

Vaghefi

Walker

Pontré

et al. 2012

American Journal of Physiology-Regulatory, Integrative and Comp

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It has been proposed that in the absence of blood supply, the ocular lens operates an internal microcirculation system that delivers nutrients to internalized fiber cells faster and more efficiently than would occur by passive diffusion alone. To visualize the extracellular space solute fluxes potentially generated by this system, bovine lenses were organ cultured in artificial aqueous humor (AAH) for 4 h in the presence or absence of two gadolinium-based contrast agents, ionic Gd(3+), or a chelated form of Gd(3+), Gd-diethylenetriamine penta-acetic acid (Gd-DTPA; mol mass = 590 Da). Contrast reagent penetration into the lens core was monitored in real time using inversion recovery-spin echo (IR-SE) magnetic resonance imaging (MRI), while steady-state accumulation of [Gd-DTPA](-2) was also determined by calculating T1 values. After incubation, lenses were fixed and cryosectioned, and sections were labeled with the membrane marker wheat germ agglutinin (WGA). Sections were imaged by confocal microscopy using standard and reflectance imaging modalities to visualize the fluorescent WGA label and gadolinium reagents, respectively. Real-time IR-SE MRI showed rapid penetration of Gd(3+) into the outer cortex of the lens and a subsequent bloom of signal in the core. These two areas of signal were separated by an area in the inner cortex that limited entry of Gd(3+). Similar results were obtained for Gd-DTPA, but the penetration of the larger negatively charged molecule into the core could only be detected by calculating T1 values. The presence of Gd-DTPA in the extracellular space of the outer cortex and core, but its apparent absence from the inner cortex was confirmed using reflectance imaging of equatorial sections. In axial sections, Gd-DTPA was associated with the sutures, suggesting these structures provide a pathway from the surface, across the inner cortex barrier to the lens core. Our studies have revealed inner and outer boundaries of a zone within which a narrowing of the extracellular space restricts solute diffusion and acts to direct fluxes into the lens core via the sutures.

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Section: Ir-se Imaging Of Gd 3ϩ and Gd-dtpa Penetration In The Bovinementioning

confidence: 99%

Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion

Vaghefi

Walker

Pontré

et al. 2012

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Koefisien partisi (rasio konsentrasi dalam dua bagian kompartemen kornea dan stroma) mampu ditinggikan dengan cara meninggikan pH saat fase air yang menghasilkan obat tidak terionisasi dan membuat obat tersebut menjadi lebih larut dalam lemak. 19 Obat anti-inflamasi non-steroid selama ini dipergunakan sebagai obat yang efektif dalam mengobati peradangan dengan cara penghambat sintesis prostaglandin baik dalam jalur sikooksigenasi atau lipo-oksigenasi. Salah satu obat dari golongan ini adalah natrium diklofenak, yang terdapat untuk sediaan mata dengan konsentrasi 0,1%.…”

Section: Pembahasanunclassified

Efektivitas Penambahan Natrium Diklofenak terhadap Larutan Obat Dilatasi Pupil pada Pasien Retinopati Diabetik

Kartasasmita¹,

Sovani²,

Setyohadji³

et al. 2017

mkb

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AbstrakPemeriksaan fundus memerlukan akses visualisasi yang baik. Pada penderita diabetes melitus, pupil sulit lebar menggunakan obat pelebar pupil standar sehingga perlu ditambahkan agen pelebar pupil. Penelitian ini dilakukan di Rumah Sakit Mata Cicendo periode Januari sampai Juli 2014 menggunakan metode double masked rendomized cotrolled trial terhadap 64 mata dari 32 subjek penelitian yang telah didiagnosis menderita retinopati diabetika dengan tingkat yang sama antara mata kiri dan kanan. Dibuat larutan kombinasi campuran 10 mL tropikamid 0,5%/fenilefrin 0,5%, 10 mL fenilefrin 5% dan 10 ml 0,1% Na diklofenak (larutan I) dan campuran 10 mL tropikamid 0,5%/fenilefrin 0,5%, dan 10 mL fenilefrin 5% (larutan II). Setiap subjek mendapat salah satu larutan pada mata dan larutan yang lain pada sebelahnya secara acak. Dilakukan pemantauan dengan cara memotret pupil pada menit ke-15, 20, dan 25 pada kedua mata. Lebar pupil kedua kelompok perlakuan diukur dengan perangkat lunak khusus (image processing). Dari penenelitian terdapat perbedaan bermakna antara penggunaan larutan I dan larutan II dalam melebarkan pupil baik pada menit ke-15 (t=2,02; p=0,047), menit ke 20 (t=2,23; p=0,029), dan pada menit ke-25 (t=2,041; p=0,045). Larutan kombinasi fenilefrin, tropikamid, dan natrium diklofenak menghasilkan efek dilatasi pupil yang lebih baik dibanding dengan larutan kombinasi fenilefrin dan tropikamid saja pada kasus retinopati diabetes. [MKB. 2017;49(3):199-207] Kata kunci: Dilatasi pupil, natrium diklofenak, retinopati diabetika Effectiveness of Sodium Diclofenac Addition to Pupil Dilatation Agent on Diabetic Retinopathy Patients AbstractFundus examination requires good visualization of fundus. In diabetic patients, it is difficult for the pupil to dilate using the standard pupilarry dilating agent. To achieve proper dilation, special agents have to be added to the standard dilation agent. The study was conducted in Cicendo Eye Hospital from January to July 2014, using double masked randomized controlled trial to 32 patients (64 eyes) who were diagnosed as suffering from diabetic retinopathy with the same grade on both eyes. Eye drop solutions were developed beforehand by mixing 10 mL of 0.5% tropicamide/0.5% phenylephrine, 10 mL of 5% phenylephrine, and 10 mL of 0.1% diclofenac-natrium (solution I) and also by mixing 10 mL of 0.5% tropicamide/0.5% phenylephrine and 10 mL of 5% phenylephrine (solution II). Every subject received one drop of one solution on one eye and the other solution on the other eye in randomly fashion. The observation was performed by taking photographs of the pupil on both eyes 15, 20, and 25 minutes of observation. The resulting pupil photographs were then analyzed and measured using special image processing software and compared. It was revealed that there were statistical differences in pupil dilation between solution I and solution II at 15 minutes (t=2.02; p=0.047), 20 minutes (t=2.23, p=0.029), and 25 minutes (t=2.041, p=0.045). Phenilefrine, tropicamide and diclofenac-natrium combination ...

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