Core Faculty Profile

Mark Johnson

Research Interest:

Cellular mechanics and the hydrodynamics of glaucoma; the role of lipids in age-related macular degeneration; transport through connective tissues; esophageal transport; chaos and diffusion.

Cellular Mechanics and the Hydrodynamics of Glaucoma

Glaucoma results from an increase in the intraocular pressure that leads to irreversible damage to the optic nerve, and ultimate, blindness. The increased pressure results from an increased flow resistance in the aqueous outflow pathway. This resistance occurs in or very near a unique endothelium that regulates fluid transport into Schlemm's canal. We are investigating the mechanical forces acting on the cytoskeleton of this endothelium.

The Role of Lipids in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) will likely be the leading cause of blindness in the developed world in the next 20 years. We have shown that lipid accumulation in Bruch's membrane, which is next to the retina, contributes to the development of AMD. These studies involve an examination of why this lipid accumulation occurs and how it might be prevented.

Transport Through Connective Tissues

Fluid flow and diffusion through tissues is important for both nutrients delivery and waste disposal. These process are also essential for drug delivery. The studies are aimed at the understanding of the fundamental mechanisms by which fluid and macromolecules are transported through connective tissues.

Esophageal Transport

Food transport through the esophagus involves peristaltic pumping of a slurry-like material. This involves fluid-solid interactions in the transport of non-newtonian fluids. These studies involve modeling this process and comparing model predictions with experimental measurements.

Chaos and Diffusion

Chaotic systems are known to produce diffusional-like behavior in spite of the deterministic character of the governing equations. This project is involved with the use of diffusional behavior as a marker for the onset of chaos in various low dimensional systems. Using a unique method for detecting diffusional behavior, mathematical modeling is used to determine the validity of this approach, and to investigate the relationship between diffusive and chaotic behavior in low order systems.

Selected Publications:

PUBLICATIONS
Chapters:

1. Johnson, M. and Erickson, K.: Mechanisms and routes of aqueous humor drainage. Principles and Practice of Ophthalmology ,Volume I: Basic Sciences, chapter 11B, Ed. Albert , D.M. and Jakobiec, F.A., WB Saunders Co. Philadelphia, 2000.

2. Johnson, D. and Johnson, M.: How does non-penetrating glaucoma surgery work?, Non-Penetrating Glaucoma Surgery, chapter 4, Ed. Mermoud, A. and Shaarawy, T., Martin Dunitz, Ltd., London, 2001 (reprinted from Journal of Glaucoma).

3. Freddo, T.F. and Johnson, M.: Conventional Aqueous Humor Outflow, in The Eye's Aqueous Humor, Ed. Mortimer Civan, Elsevier, 2009.

4. Johnson, M. and Tamm, E.R.: Biomechanics of aqueous humor outflow resistance, Encyclopedia of the Eye, Chapter 93, Academic Press, 2010.


Papers:

1. Johnson,M.: Turbulent heat transfer to a rotating disk: a review and extension of Dorfman. ASME Journal of Heat Transfer, Nov 1980, 780-1.


2. Johnson,M. and Kamm,R.D.: The role of Schlemm's canal in aqueous outflow from the human eye. Investigative Ophthalmology and Visual Science 24: 320-5, 1983.


3. Johnson,M., Ethier,C.R., Kamm,R.D., Grant,W.M., Epstein,D.E. and Gaasterland,D.: The flow of aqueous humor through micro-porous filters. Investigative Ophthalmology and Visual Science 27: 92-7, 1986.

4. Kamm,R.D., Butcher,R., Froelich,J., Johnson,M., Salzman,E., Shapiro,A. and Strauss,H.W.: Optimization of parameters of external pneumatic compression for prophylaxis against deep vein thr ombosis: radionuclide gated imaging studies. Cardiovascular Research 20: 588-596, 1986.


5. Ethier,C.R., Kamm,R.D., Palaszewski,B.A., Johnson,M. and Richardson,T.M.: Calculations of flow resistance in the juxtacanalicular meshwork. Investigative Ophthalmology and Visual Science 27: 1741-1750, 1986.

6. Johnson,M. and Kamm,R.D.: Numerical studies of steady flow dispersion at low Dean number in a gently curving tube. Journal of Fluid Mechanics 172: 329-345, 1986.


7. Johnson,M., Kamm,R., Ethier,C.R., and Pedley,T.: Scaling laws and the effects of concentration polarization on the permeability of hyaluronic acid. Physicochemical Hydrodynamics 9: 427-441, 1987.

8. Salzman,E.W., McManama,G.P., Shapiro,A.H., Robertson,L.K., Donovan,A.S., Blume,H.W., Sweeney,J., Kamm,R.D., Johnson,M. and Black,P.M.: Effect of optimization of hemodynamics on fibrinolytic activity and antithrombotic efficacy of external pneumatic compression. Annals of Surgery 206: 636-641, 1987.


9. Nguyen,K.P.V., Chung,M.L., Anderson,P.A., Johnson,M. and Epstein,D.L.: Hydrogen Peroxide Removal by the Calf Outflow Pathway. Investigative Ophthalmology and Visual Science 29: 976-981, 1988.

10. Ethier,C.R., Kamm,R.D., Johnson,M., Pavao,A.F. and Anderson, P.J.: Further studies on the flow of aqueous humor through microporous filters. Investigative Ophthalmology and Visual Science 30: 739-745, 1989.


11. Pavao,A.F., Lee,D.A., Ethier,C.R., Johnson,M., Anderson,P.J. and Epstein,D.L.: Two dimensional gel electrophoresis of calf aqueous humor, serum and filter-bound proteins. Investigative Ophthalmology and Visual Science 30: 731-738, 1989.

12. Rosenquist, R., Epstein,D.L., Melamed,S., Johnson,M. and Grant,W.M.: Outflow resistance of enucleated human Eyes at two different perfusion pressures and different extents of trabeculotomy, Current Eye Research 8: 1233, 1989.

13. Johnson,M, Johnson,D.H., Kamm,R.D., deKater,A.W. and Epstein,D.: The filtration characteristics of the aqueous outflow system, Experimental Eye Research 50: 407-418, 1990.


14. Johnson, M., Kamm, R., Ho,L.W., Shapiro,A. and Pedley,T.J.: The nonlinear growth of surface tension-driven instabilities of a thin annular film, Journal of Fluid Mechanics, 233: 141 156, 1991.

15. Johnson,M., Chen,A., Epstein,D.L. and Kamm,R.D.: The pressure and volume dependence of the rate of wash-out in the bovine eye, Current Eye Research 10: 373-375, 1991.


16. Kim,A., Wang,C., Johnson,M. and Kamm,R.D.: The specific hydraulic conductivity of bovine serum albumin, Biorheology, 11: 401-419, 1991.

17. Johnson,M., Shapiro,A., Ethier,C.R. and Kamm,R.D.: The modulation of outflow resistance by the pores of the inner wall endothelium, Investigative Ophthalmology and Visual Science 33: 1670-1675, 1992.


18. Murphy,C.G., Johnson,M. and Alvarado,J.: The juxtacanalicular tissue in pigmentary glaucoma: the hydrodynamic role of pigment and other constituents, Archives of Ophthalmology 110: 1779-1785, 1992.

19. Gong,H., Freddo,T.F. and Johnson,M.: Age-related changes of sulfated proteoglycans in the normal trabecular meshwork, Experimental Eye Research 55: 691-709, 1992.


20. Otis,D., Johnson,M. and Kamm,R.D.: The role of pulmonary surfactant in airway closure: a computational study, Journal of Applied Physiology 75: 1323-1333, 1993.

21. Johnson,M., Gong,H., Freddo,T.F., Ritter,N. and Kamm,R.D.: Serum proteins generate aqueous outflow resistance in bovine eyes, Investigative Ophthalmology and Visual Science 34: 3549-3557, 1993.


22. Otis,D.R. Jr., Ingenito,E.P., Kamm,R.D. and Johnson,M.: Dynamic surface tension of TA surfactant: experiments and theory, Journal of Applied Physiology 77: 2681-2688, 1994.

23. Brown, C.T., Vural, M., Johnson, M. and Trinkaus-Randall, V.: Age-related changes of scleral hydration and sulfated glycosaminoglycans, Mechanisms of Aging and Development 77: 97-101, 1995.


24. Whale, M.D., Grodzinsky, A.J. and Johnson, M.: The effect of aging and pressure on the specific hydraulic conductivity of the aortic wall, Biorheology 33: 17-44, 1996.

25. Sit, A., Gong, H., Ritter, N., Freddo, T.F., Kamm, R.D. and Johnson, M.: The role of soluble proteins in generating aqueous outflow resistance in the bovine and human eye, Experimental Eye Research 64: 813-821, 1997.


26. Sit, A.J., Coloma, F.M., Ethier, C.R. and Johnson, M.: Factors affecting the pores of the inner wall endothelium of Schlemm's canal, Investigative Ophthalmology and Visual Science 38: 1517-1525, 1997.

27. Hubbard, W.C., Johnson, M., Gong, H., Gabelt, B.T., Peterson, J.A., Sawhney, R., Freddo,T.F. and Kaufman, P.L.: Intraocular pressure and outflow facility are unchanged following acute and chronic intracameral chondroitinase ABC and hyaluronidase in monkeys, Experimental Eye Research, 65: 177-190, 1997


28 . Gong, H., Ye,W., Johnson,M., Kamm,R.D. and Freddo,T.F.: The non-uniform distribution of albumin in human and bovine cornea, Experimental Eye Research, 65: 747-756, 1997.

29. Ye, W., Gong, H., Sit, A., Johnson, M. and Freddo, TF: Interendothelial junctions in normal human Schlemm's canal respond to changes in pressure, Investigative Ophthalmology and Visual Science, 38: 2460-2468, 1997.


30. Johnson, M. and Habyarimana, J.: An operational test for distinguishing between complicated and chaotic behavior in deterministic systems, Physica D, 116: 289-300, 1998.

31. Ethier, C.R., Sit, A.J., Coloma, F.M., and Johnson, M.: Two populations of pores of the inner wall endothelium of Schlemm's canal, Investigative Ophthalmology and Visual Science 39: 2041-2048, 1998.


32. Ingenito, E.P., Mark, L., Morris, J., Espinosa, F. F., Kamm,R.D. and Johnson, M.: Biophysical characterization of lung surfactant components, Journal of Applied Physiology 86: 1702-1714, 1999.

33. Johnson, M. and Tarbell, J.M.: A biphasic, anisotropic model of the aortic wall, Journal of Biomechanical Engineering 123: 52-57, 2001.


34. Morris, J., Ingenito, E.P., Mark, L., Kamm, R.D. and Johnson, M.: Dynamic behavior of lung surfactant, Journal of Biomechanical Engineeringg 123: 106-113, 2001.

35. Johnson, D. and Johnson, M.: How does non-penetrating glaucoma surgery work?, Journal of Glaucoma, 10: 55-67, 2001.

36. Russell, P., Tamm, E.R., Grehn, F.J., Picht, G., and Johnson, M.: The presence and properties of myocilin in the aqueous humor, Investigative Ophthalmology and Visual Science 42: 983-986, 2001.


37 . Overby, D., Ruberti, J., Gong, H., Freddo, T.F. and Johnson, M.: Specific hydraulic conductivity of corneal stroma as seen by quick-freeze/deep-etch, Journal of Biomechanical Engineering 123: 154-161, 2001.

38 . Johnson, D.H. and Johnson, M.: Aqueous outflow and glaucoma surgery, Ophthalmo-Chirurgie 13: 88-89, 2001.


39. Johnson, D.H. and Johnson, M.: Glaucoma surgery and aqueous outflow: How does non-penetrating glaucoma surgery work?, Archives of Ophthalmology 120: 67-70, 2001.

40. Johnson, M., Christensen, C., Sit, A., Chen, D., Read, T. and Ethier, C.R. The pore density in the inner wall endothelium of Schlemm's canal of glaucomatous eyes, Investigative Ophthalmology and Visual Science 43:2950-2955, 2002.


41. Gong, H., Overby, D., Ruberti, J., Johnson,M. and Freddo, T.: A new view of the human trabecular meshwork using quick-freeze/deep-etch, Experimental Eye Research 75: 347-358, 2002.

42. Overby, D., Gong, H., Freddo, T.F. and Johnson,M.: The mechanism of increasing outflow facility during washout in the bovine eye, Investigative Ophthalmology and Visual Science 43: 3455-3464, 2002.


43. Ruberti, J.W., Curcio, C.A., Millican, L., Menco, B.Ph.M., Huang, J.-D., and Johnson, M.: Quick-freeze/deep-etch visualization of age-related lipid accumulation in Bruch's membrane, Investigative Ophthalmology and Visual Science 44: 1753-1759, 2003.

44. Ethier, CR, Johnson, M. and Ruberti, J: Ocular Biomechanics and Biotransport, Annual Review of Biomedical Engineering (invited review article), 6:249-73 2004.


45. Seurynck, S.L., Brown, N.J., Wu, C.W., Germino, K.W., Kohlmeir, E.K., Ingenito, E.P., Glucksberg, M.R., Barron, A.E. and Johnson, M.: Optical monitoring of bubble size and shape in a pulsating bubble surfactometer, Journal of Applied Physiology 99: 624-633, 2005.

46. Overby, D and Johnson, M.: Studies on depth-of-field effects in microscopy supported by numerical stimulations, The Journal of Microscopy, Vol 220, 176-189, 2005.

47. Johnson, M.: "What controls aqueous humour outflow resistance?", Experimental Eye Research 82: 545-557, 2006.

48. Johnson, M., Dabholkar, A., Huang, J., Presley J.B., Chimento M.F. and Curcio, C.A.: Comparison of Morphology of Human Macular and Peripheral Bruch's Membrane in Older Eyes, Current Eye Research 32: 791-799, 2007.

49. Huang, J., Presley J.B., Chimento M.F., Curcio, C.A. and Johnson, M.: Age-related changes in human macular Bruch's membrane as seen by quick-freeze/deep-etch, Experimental Eye Research 85: 202-218, 2007.

50. Huang, J-D, Curcio, C.A. and Johnson, M.: Morphometric analysis of lipoprotein-like particle accumulation in aging human macular Bruch's membrane, Investigative Ophthalmology & Visual Science, 49: 2721-2727, 2008.

51. McCarty, W.J. and Johnson, M.: The hydraulic conductivity of Matrigel, Biorheology, 44: 303-317, 2007.

52. McCarty, W.J., Chimento, M.F., Curcio, C.A., and Johnson, M.: Effects of particulates and lipids on the hydraulic conductivity of Matrigel, Journal of Applied Physiology, 105: 621-628, 2008.

53. Zeng, D., Juzkiw, T., Read, A.T., Chan, D., D. W.-H., Glucksberg, M.R., Ethier, C.R. and Johnson, M.: Young's modulus of elasticity of Schlemm's canal endothelial cells, Biomechanics and Modeling in Mechanobiology, 9: 19-33, 2010.

54. Overby, D.R., Stamer, W.D. and Johnson, M.: The changing paradigm of outflow resistance generation: towards synergistic models of the JCT and inner wall (invited review article), Experimental Eye Research, 88: 656-670, 2009.

55. Curcio, C.A., Johnson, M., Huang, J-D and Rudolf, M.: Aging, age-related maculopathy and the response-to-retention of apolipoprotein B-containing lipoproteins, Progress in Retinal and Eye Research 28: 393-422, 2009.

56. Curcio, C.A., Johnson, M., Huang, J-D and Rudolf, M.: Apolipoprotein B-containing lipoproteins in retinal aging and age-related maculopathy, Journal of Lipid Research 51: 451-467, 2010.

57. Johnson, M., Caro, N. and Huang, J-D: Adequacy of exchanging the content of the anterior chamber, Experimental Eye Research 91: 876-880, 2010.