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    Course Summary

    Tear ferning – Christine Purslow & Helen Tilley (17:29)

    The pre-ocular tear film (POTF) is an important measure of the health of the surface of the eye. There are a number of pre-existing techniques for the assessment of the POTF, and one of the less well-known ones is the tear ferning test. This differs from other methods as it evaluates the composition of tears. The reasons for the different patterns of crystallization and ‘ferning’ that result are not currently fully understood, but research in the area is ongoing. In this interview, Helen Tilly talks to Dr Christine Purslow about tear ferning and its application in research and clinical diagnosis.

    First published in DOCET OQ82 (2012).

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      Learning objectives

      To provide listeners with:

      • An understanding of the pre-ocular tear film's (POTF) use as an important measure of the health of the surface of the eye
      • An outline of the tear ferning test as a technique for the assessment of the POTF 
      • An understanding of how the tear ferning test differs from other methods in its evaluation of the composition of tears
      • An outline of the application of tear ferning in research and clinical diagnosis
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        More information and references


        • Bitton E (2007) Tear ferning: a valuable tool in determining dry eye. Optician 21.09.07, 32-35
        • Evans KSE, North RV, Purslow C (2009) Tear ferning in contact lens wearers. Ophthal. Physiol. Opt. 29, 199-204
        • Golding TR, Baker AT, Rechberger J (1994) X-ray and scanning electron microscopic analysis of the structural composition of tear ferns. Cornea 13, 58-66
        • Golding T, Brennan N (1989) The basis of tear ferning. Clin. Exp. Optom. 72, 102-122
        • Norn M (1994) Quantitative tear ferning; clinical investigations. Acta Ophthalmol. (Copenh) 72, 369-372
        • Pensyl C, Dillehay S (1998) The repeatablility of tear mucus ferning grading. Optom. Vis. Sci. 75, 600-604
        • Ravazzoni L, Ghini C, Macri A (1997) Tear ferning as a predictive test for contact lens tolerance. Investigative Ophthal. & Vis. Sci. 38, 753-753

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