Thermal Topographical Rings as a New Tool for Laser Eye Surgery

Khalid A. Joudi¹, Somer M. Nacy^2, and Nebras H. Ghaeb²

¹Mechanical Engineering Department, College of Engineering, University of Baghdad, Baghdad, Iraq

²Biomedical Engineering Department, Al Khwarizmi College of Eng., University of Baghdad, Baghdad, Iraq

Cite this paper:
Khalid A. Joudi, Somer M. Nacy and Nebras H. Ghaeb. Thermal Topographical Rings as a New Tool for Laser Eye Surgery. Journal of Biomedical Engineering and Technology. 2017; 5(1):1-5. doi: 10.12691/jbet-5-1-1

Abstract

Measurement of the corneal surface temperature during the laser surgery have been modified at the last few years, to be used as an extra useful monitoring tool during the dynamic ablation process. While the concentric Placido rings have been used before to measure the refractive errors, here, it have been modified to be used as a new suggested tool to study the thermal response upon the anterior corneal surface during laser eye surgeries. The thermal infrared camera was used to get an image captured at the end of the treatment, where contours with isotherms are derived and examined. The new contour lines introduce the temperature induced per location upon the corneal surface and reflect the biomechanical response behavior. Comparing the contour image with the image generated by the treatment system for the ablated depth showed a new indication for safety limits especially the effect of decentration and other irregular aberrations.

Keywords:
LASIK Placido disc topographic map corneal reshaping

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References:

[1]	G. L. Skuta, L.B. Cantor and J. S. Weiss, “Basic, and Clinical Science, Clinical Optics”, American Academy of Ophthalmology, the Eye M.D. Association, (2011), pp 265-266.
[2]	B. Boyd, S. Agarwal, S. Agarwal and At. Agarwal, “LASIK and Beyond LASIK Wavefront Analysis and Customized Ablation”, Highlights of Ophthalmology, pp 11-12, (2002).
[3]	American Academy of Ophthalmology (AAO), “Ophthalmic Procedure Preliminary Assessment – Corneal Topography”, Ophth. Vol. 106, No. 8, pp 1628-1638, (1999).
[4]	A. Pandolfi, G. Fotia, and F. Manganiello, “Finite element simulations of laser refractive corneal surgery”, Springer, Eng. with Computers (2009), Vol. 25, Issue No. 1, pp 15-24.
[5]	S. H. Mahmoud, N. E. H. Ismail, and A. I. Salem, “A Novel Simulation and Analysis Scheme for Human Eye Ablation”, IEEE, 2007 Int’l. Conf. on Computer Eng. & amp. Systems, pp 262-265.
[6]	R. Mapstone, “Determinants of corneal temperature”, Brit. J. Ophthal. (1968) 52, 729-741.
[7]	M.S. Kitai, V.L. Popkov, V.A. Semchishen and A.A. Kharizov, “The Physics of UV Laser Cornea Ablation”, IEEE, J. of Quantum Ele., Vol. 21, no. (1991), pp 302-307.
[8]	E. J. Berjano, J. M. Ferrero, and J. L. Ali, “Effects of anisotropy in cornea thermal conductivity on temperature profiles in RF thermo keratoplasty”, Proceedings of the 20th Ann. Int’l Conf. of IEEE Eng. in Medicine and Biology, Vol. 20 (4), No. 4, (1998), pp 1953-1955.
[9]	E. J. Berjano and J. Saiz, “Radio-Frequency Heating of the Cornea: Theoretical Model and In Vitro Experiments”, IEEE Transactions on Biom. Eng., Vol. 49, No. 3, (2002), pp 196-205.
[10]	M. Cvetkovic, D. Cavka and D. Poljak, “A Simple Finite Element Model of Heat Transfer in the Human Eye”, IEEE, Int’l Conf. on Tele. and Computer Networks, (2006), pp: 27-31.
[11]	M. Cvetkovic, D. Poljak and A. Peratta, “Thermal Modelling of the Human Eye Exposed to Laser Radiation”, IEEE, 16th Int’l Conf. on Software, Tele. and Computer Networks: (2008), pp: 16-20.
[12]	E.Y.K. Ng, E.H. Ooi, “FEM simulation of the eye structure with bioheat analysis”, Computational methods and programs in biomedicine issue, 82, (2006), pp 268-276.
[13]	E. H. Ooi, E. Y. K. Ng, “Simulation of aqueous humor hydrodynamics in human eye heat transfer”, ELSEVIER, Computers in Biology and Medicine Vol.. 38 (2008). pp252-262.
[14]	K.J. Chua, J.C. Ho, S.K. Chou and M.R. Islam, “On the study of the temperature distribution within a human eye subjected to a laser source”, ELSEVIER, Int’l Comm. in Heat and Mass Transfer Vol. 32 (2005), pp 1057-1065.
[15]	E. H. Ooi, W.T. Ang and E.Y.K. Ng, “Bioheat transfer in the human eye: A boundary element approach”, Eng. Analysis with Boundary Elements Vol. 31 (2007), pp 494-500.
[16]	E. H. Ooi, W.T. Ang and E.Y.K. Ng, “A boundary element model of the human eye undergoing laser Thermo keratoplasty”, Computers in Biology and Medicine Vol. 38 (2008), pp 727-737.
[17]	E. H. Ooi, W.T. Ang, and E.Y.K. Ng, “A boundary element model for investigating the effects of eye tumor on the temperature distribution inside the human eye”, ELSEVIER, Computers in Biology and Medicine, Vol. 39, (2009), pp 667-677.
[18]	K. A. Joudi, S. M. Nacy and N. H. Ghaeb, “One-Dimensional solution for temperature distribution upon corneal surface during laser surgery”,6th Cairo Int’l Biom. Eng. Conf., (2012).
[19]	M.A. Khanday, Aasma Rafiq and Mir Aijaz, “Mathematical Study of Transient Heat Distribution in Human Eye Using Laplace Transform”, International Journal of Modern Mathematical Sciences, 2014, 9(2): 118-127.
[20]	Press center, Schwind, “Dynamic heat propagation in the cornea considered ITEC–SCHWIND AMARIS features a unique thermal control system”. Kleinostheim, Germany, Feb. 2009.
[21]	Ioannis M. Aslanides, S. Padroni, D. de Ortueta, J. Tan, M. Tomita and D. Uthoff, “Intelligent Thermal Effect Control”, cataract and refractive surgery today, refractive surgery at the cutting edge, Sponsored by Schwind, 2011.
[22]	Specifications of LASIK system of ALCON on website www.alcon.com.
[23]	C. Purslow and J.S. Wolffsohn, “Ocular surface temperature, a review”, Eye & Contact Lens, Vol. 31, No. 3, (2005), pp 117-123.
[24]	A. Merla and G. L. Romani, “Biomedical applications of functional infrared imaging”, Proc. Of the 2005 IEEE Engineering in Medicine and Biology, 27th Annual Conference, Shanghai, China, September 1-4, (2005), pp 690-693.
[25]	G. Singh and H. S. Bhinder, “Comparison of noncontact IR and remote sensor thermometry in normal and dry eye patients”, Euro. J. of Oph. V. 15, N.6, (2005), pp 668-673.
[26]	L. Tan, Z. Q. Cai and N. S. Lai, “Accuracy and sensitivity of the dynamic ocular thermography and inter-subjects ocular surface temperature (OST) in Chinese young adults”, ELSEVIER, Contact Lens & Anterior Eye, 32, (2009), pp 78-83.
[27]	R. Acharya U, E. Y. K. Ng and G. C. Yee, “Analysis of Normal Human Eye with Different Age Groups using Infrared Images”, ELSEVIER, J Med system (2009) 33: pp 207-213.
[28]	J. H. Tan, E.Y.K. Ng, R. Acharya U and C. Chee, “Automated study of ocular thermal images: Comprehensive analysis of corneal health with different age group subjects and validation”, ELSEVIER, Digital Signal Processing 20 (2010), pp 1579-1591.
[29]	U. Brunsmann, U. Sauer, S. A. Mosquera, T. Magnago and N. Triefenbach, “Evaluation of thermal load during laser corneal refractive surgery using infrared thermography”, ELSEVIER, Infrared Physics & Technology 53 (2010) pp 342-347.
[30]	J. H. Tan, E.Y.K. Ng, U. R. Acharya, “Evaluation of topographical variation in ocular surface temperature by functional infrared thermography”, ELSEVIER, Infrared Physics & Technology 54 (2011) pp 469-477.
[31]	T. Y. Su, C. K. Hwa, P. H. Liu, D. O. Chang, P. F. Su, S. W. Chang and H. K. Chiang,” Noncontact detection of dry eye using a custom designed infrared thermal image system”, Journal of Biomedical Optics 16 (4), (2011), pp 1-9.
[32]	S. A. Mosquera and S. Verma, “Analysis of the change in peak corneal temperature during excimer laser ablation in porcine eyes”, J. of Biomedical Optics, 20 (7), (July 2015), pp 1-13.
[33]	K. A. Joudi, S. M. Nacy and N. H. Ghaeb, “Temperature Distribution upon Corneal Surface during Laser Eye Surgery, a Comparative Study”, American Journal of Biom. Eng., Vol.3, No.6, (2013), pp 1-6.