Intravitreal injection (IVI) is the most common treatment for eye posterior segment diseases such as endopthalmitis, retinitis, age-related macular degeneration, diabetic retinopathy, uveitis, and retinal detachment. Most of the drugs used to treat vitreoretinal diseases, have a narrow concentration range in which they are effective, and may be toxic at higher concentrations. Therefore, it is critical to know the drug distribution within the eye following intravitreal injection. Having knowledge of drug distribution, ophthalmologists can decide on drug injection frequency while minimizing damage to tissues. The goal of this study was to develop a computer model to predict intraocular concentrations and pharmacokinetics of intravitreally injected drugs. A finite volume model was created to predict distribution of two drugs with different physiochemical properties in the rabbit eye. The model parameters were obtained from literature review. To validate this numeric model, the in vivo data of spatial concentration profile from the lens to the retina were compared with the numeric data. The difference was less than 5% between the numerical and experimental data. This validation provides strong support for the numerical methodology and associated assumptions of the current study.<\/p>\r\n","references":"[1] J. E. Chastain, \" General considerations in ocular drug delivery,\" in:\r\nOphthalmic Drug Delivery Systems, A. K. Mitra, Ed. New York: Marcel\r\nDekker, 2003, p. 76.\r\n[2] E. Eljarrat-Binstock E, J. Pe'er and A. J. Domb, \" New techniques for\r\ndrug delivery to the posterior eye segment,\" Pharm Res. , vol. 27 (4).\r\n2010, pp. 530-543.\r\n[3] G. A. Peyma, M. E. Lad and M. D. Moshfeghi, \"Intravitreal injection of\r\ntherapeutic agents,\" Retina, The journal of retina and vitreous diseases,\r\nvol. 29(7) 2009, pp. 875-911.\r\n[4] C. Duraira, J. C. Sha, S. Senapati and U. B. Kompella, \"Prediction of\r\nvitreal half-life based on drug physicochemical properties: quantitative\r\nstructure-pharmacokinetic relationships (QSPKR),\" Pharm. Res., vol.\r\n26(5) 2009, pp. 1236-1260.\r\n[5] M. S. Sta, J. X, T. W. Randolph and V. H. Barocas, \"Computer\r\nsimulation of convective and diffusive transport of controlled release\r\ndrugs in the vitreous humor,\" Pharm. Res., vol. 20,2003, pp. 96-102.\r\n[6] S. Friedrich, Y. L. Cheng and B. Saville, \"Finite element modelling of\r\ndrug distribution in the vitreous humor of the rabbit eye,\" Ann. Biomed.\r\nEng. vol. 25,1997, pp. 303-314.\r\n[7] J. Xu, J. J Heys, V. H.Barocas and T. W. Randolph, \"Permeability and\r\ndiffusion in vitreous humor: implications for drug delivery,\" Pharm.\r\nRes., vol. 17, 2000, pp. 664-669.\r\n[8] E. N. Marieb and K. Hoehn, Human Anatomy & Physiology, 7th ed.,\r\nPearson Education Inc,2006.\r\n[9] H. Davson,. in: The Eye, 2nd ed., H. Davson, Ed., New York: Academic\r\nPress, 1969, pp. 88-92\r\n[10] J. Kathawate and S. Acharya, \"Computational modeling of intravitreal\r\ndrug delivery in the vitreous chamber with different vitreous\r\nsubstitutes,\" International Journal of Heat and Mass Transfer, vol. 5,\r\n2008, pp. 5598-5609.\r\n[11] P. L. Kaufman and A. Alm, Adlers-s Physiology of the Eye, 10th ed.\r\nMosby Year book,2003.\r\n[12] P. A. Pearson, G. J. Jaffe, D. F. Martin, G. J. Cordahi, H. Grossniklaus,\r\nE. T. Schmeisser and P. Ashton, \"Evaluation of a delivery system\r\nproviding long-term release of cyclosporine,\"Arch. Ophthalmol. vol.\r\n114, 1996, pp. 311-317.\r\n[13] I. Fatt and B. Hedbys, \"Flow of water in the sclera,\"Exp. Eye Res. Vol.\r\n10, 1970, pp. 243-249.\r\n[14] M. Araie and D. M. Maurice, \"The loss of fluorescein, fluorescein\r\nglucuronide and fluorescein isothiocyanate dextran from the vitreous by\r\nthe anterior and retinal pathways,\" Exp. Eye Res., vol. 52, 1991, pp. 27-\r\n39.\r\n[15] L. Pitk\u251c\u00f1nen, V. Ranta, V. H. Moilanen and A. Urtti, \"Permeability of\r\nRetinal rigment epithelium: effects of permeant molecular weight and\r\nlipophilicity,\" Invest. Ophthalmol. Vis. Sci. vol. 46,2005, pp. 641-646.\r\n[16] D. Maurice,\"Review: practical issues in intravitreal drug delivery,\" J\r\nOcul Pharmacol Ther. Vol. 17(4), 2001, pp. 393-401.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 53, 2011"}