A parametric approach to measuring limbus corneae from digital images
(2006) A parametric approach to measuring limbus corneae from digital images. IEEE Transactions on Biomedical Engineering 53(6):pp. 1134-1140.
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Abstract
It is difficult to demarcate the limbus borders in standard intensity images of the eye since the transition from the cornea (iris) to sclera is gradual. Non-parametric techniques that are currently used for this task are not sufficiently precise to be adopted in those ophthalmic applications where high precision in determining the limbus/pupil characteristics is required. This is the case, for example, in customized refractive corrections. Another aspect of limbus corneae characterization is the inability of measuring in vivo the outer outline of the limbus annulus without specialized illumination techniques. To overcome these limitations, we propose a parametric approach that utilizes a sigmoidal function fitted to radial intensity profiles of the limbus corneae. By the way of simulations, we show the superiority of the proposed parametric approach when compared to an optimized nonparametric technique. Further, we review the techniques for fitting ellipses to the estimated points of the limbus annulus and discuss clinical aspects of the proposed methodology. Initial clinical experiments showed close agreement between the proposed approach and limbus corneae estimates manually obtained by experienced clinicians.
| Item Type: | Journal Article |
|---|---|
| Status: | Published |
| Keywords: | horizontal corneal diameter;horizontal visible iris diameter;limbus size;pupillometry;sigmoidal function;white-to-white corneal diameter |
| Subjects: | 240000 Physical Sciences > 249900 Other Physical Sciences > 249902 Medical Physics 290000 Engineering and Technology > 291500 Biomedical Engineering > 291501 Clinical Engineering 320000 Medical and Health Sciences > 321000 Clinical Sciences > 321016 Opthalmology and Vision Science 320000 Medical and Health Sciences > 320900 Optometry > 320901 Optical Technology 280000 Information, Computing and Communication Sciences > 280300 Computer Software > 280301 Programming Techniques |
| ID Code: | 4426 |
| Deposited By: | Pritchard, Nicola |
| Deposited On: | 05 July 2006 |
| Alternative Locations: | http://dx.doi.org/10.1109/TBME.2006.873387 |
| Copyright Owner: | Copyright 2006 IEEE |
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