Review Article
Volume 12 Issue 9 - 2021
Tear Ferning Test as a Valuable Tool to Determine the Quality of Tear Film in Animals and Human
Mana A Alanazi1*, Gamal A El-Hiti2, Rahaf Almaymuni1, Mashaaer A Baashen1, Raied Fagehi1 and Ali M Masmali2
1Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
2Cornea Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
*Corresponding Author: Mana A Alanazi, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Received: July 28, 2021; Published: August 30, 2021


Background: Tear film stability is essential for healthy vision. More than one test should be used to examine tear film status. The tear ferning test is used as a valuable and repeatable tool to examine the quality of tears in animals and human. The current study aimed to report and discuss the most recent use of the tear ferning test to diagnose dry eye in animals and human.

Main text: The tear ferning test involves the collection of a tear sample using a capillary tube. The tears were allowed to dry in a controlled environment, and the patterns produced were observed and inspected using a light microscope. The four-point tear ferning grading scale that included type I or II (normal eye) and types III or IV (dry eye) is used to grade tear ferning patterns. Another grading scale is developed, which consists of five grades and is used in 0.1 increments. A grade > 2 is defined as dry eye. The tear ferning test has been applied to assess the quality of tears among birds, reptiles, and other animals, such as rabbits, cats, dogs, monkeys, horses, and camels. The tear ferning test has been used to investigate the effect of various disorders, such as the thyroid gland, diabetes, high body mass index, high blood cholesterol level, and vitamin deficiency on tear film. The effect of beverages such as green tea and peppermint that are rich in polyphenols on the tear film have been evaluated. Moreover, the effect of eyedrops on the tear film and addition of electrolytes on tear ferning patterns of eyedrops was studied.

Conclusion: The tear ferning test is an easy-to-perform and inexpensive tool to evaluate the quality of tears in animals and human. It can be used in combination with other tests to detect dry eye symptoms.

Keywords: Tear Ferning Test; Ferning Patterns; Tear Ferning Grading Scales; Tear Film Stability; Dry Eye


  1. Sweeney DF., et al. “Tear film stability: a review”. Experimental Eye Research 117 (2013): 28-38.
  2. Mcmonnies CW. “Tear instability importance, mechanisms, validity and reliability of assessment”. Journal of Optometry4 (2018): 203-310.
  3. Li N., et al. “Tear film instability and meibomian gland dysfunction correlate with the pterygium size and thickness pre- and postexcision in patients with pterygium”. Journal of Ophthalmology (2019): 5935239.
  4. Yokoi N and Georgiev GA. “Tear film–oriented diagnosis and tear film–oriented therapy for dry eye based on tear film dynamics”. Investigative Ophthalmology and Visual Science14 (2018): DES13-DES22.
  5. Sun C-C., et al. “Effect of warming eyelids on tear film stability and quality of life in visual display terminal users: a randomized controlled trial”. Scientific Reports 10 (2020): 16919.
  6. McGill JI., et al. “Normal tear protein profiles and age-related changes”. British Journal of Ophthalmology5 (1984): 316-320.
  7. Johnson ME and Murphy PJ. “Changes in the tear film and ocular surface from dry eye syndrome”. Progress in Retinal and Eye Research4 (2004): 449-474.
  8. McCulley JP and Shine WE. “The lipid layer of tears: dependent on meibomian gland function”. Experimental Eye Research3 (2004): 361-365.
  9. Holly FJ. “Tear film physiology”. American Journal of Optometry and Physiological Optics4 (1980): 252-257.
  10. Korb DR., et al. “The Tear Film”. Structure, Function and Clinical Examination”. 1st edition, Elsevier (2002).
  11. Milder B. “The Lacrimal Apparatus”. In: Moses RA and Hart WM. Adler’s Physiology of the Eye”. St Louis, Missouri: The CV Mosby Co (1987).
  12. Dilly PN. “Structure and function of the tear film”. Advances in Experimental Medicine and Biology 350 (1994): 239-247.
  13. Brewitt H and Sistani F. “Dry eye disease: the scale of the problem”. Survey of OphthalmologyS2 (2001): S199-S202.
  14. Baudouin C. “The pathology of dry eye”. Survey of OphthalmologyS2 (2001): S211-S220.
  15. McGinnigle S., et al. “Evaluation of dry eye”. Survey of Ophthalmology4 (2012): 293-316.
  16. Kaštelan S., et al. “Diagnostic procedures and management of dry eye”. BioMed Research International (2013): 309723.
  17. Tomlinson A., et al. “The International Workshop on Meibomian Gland Dysfunction: Report of the Diagnosis Subcommittee”. Investigative Ophthalmology and Visual Science4 (2011): 2006-2049.
  18. Stapleton F., et al. “TFOS DEWS II epidemiology report”. The Ocular Surface3 (2017): 334-365.
  19. Bhavsar AS., et al. “A review on recent advances in dry eye: pathogenesis and management”. Oman Journal of Ophthalmology2 (2011): 50-56.
  20. Phadatare SP., et al. “A comprehensive review on dry eye disease: diagnosis, medical management, recent developments, and future challenges”. Advances in Pharmaceutics (2015): 704946.
  21. Lin H and Yiu SC. “Dry eye disease: a review of diagnostic approaches and treatments”. Saudi Journal of Ophthalmology3 (2014): 173-181.
  22. Thulasi P and Djalilian AR. “Update in current diagnostics and therapeutics of dry eye disease”. Ophthalmology 11S (2017): S27-S33.
  23. Willcox MDP., et al. “TFOS DEWS II Tear film report”. The Ocular Surface3 (2017): 366-403.
  24. Masmali A., et al. “Comparative study of repeatability of phenol red thread test versus Schirmer's test in normal adults in Saudi Arabia”. Eye and Contact Lens3 (2014): 127-131.
  25. Pauk SV., et al. “Noninvasive tear film break-up time assessment using handhold lipid layer examination instrument”. Acta Clinica Croatica1 (2019): 63-71.
  26. Masmali A., et al. “Investigation of tear film using the TearLabTM osmolarity system in normal adults in Saudi Arabia”. Eye and Contact Lens2 (2014): 74-78.
  27. Fagehi R., et al. “Correlation between tear osmolarity measurements using TearLab and I-Pen osmolarity systems in normal young Saudi subjects”. EC Ophthalmology2 (2021): 40-46.
  28. Abusharaha A., et al. “Assessment of tear-evaporation rate in thyroid-gland patients”. Clinical Ophthalmology 13 (2019): 131-135.
  29. Alanazi SA., et al. “Assessment of the tear evaporation rate in chronic smokers using Delfin Vapo Meter”. International Journal of Ophthalmology and Visual Science2 (2019): 37-41.
  30. Kyei S., et al. “Association between dry eye symptoms and signs”. Journal of Current Ophthalmology4 (2018): 321-325.
  31. Wood SD and Mian SI. “Diagnostic tools for dry eye disease”. European Ophthalmic Review2 (2016): 101-107.
  32. Rolando M. “Tear mucus ferning test in normal and keratoconjunctivitis sicca eyes”. Chibret International Journal of Ophthalmology4 (1984): 32-41.
  33. Masmali A., et al. “Development of a new grading scale for tear ferning”. Contact Lens and Anterior Eye3 (2014): 178-184.
  34. Masmali A., et al. “The tear ferning test: a simple clinical technique to evaluate the ocular tear film”. Clinical Experimental Optometry5 (2014): 399-406.
  35. Tabbara KF and Okumoto M. “Ocular ferning test: a qualitative test for mucus deficiency”. Ophthalmology 6 (1982): 712-714.
  36. Golding TR and Brennan NA. “The basis of tear ferning”. Clinical Experimental Optometry4 (1989): 102-112.
  37. Murube J. “Tear crystallization test: two centuries of history”. The Ocular Surface1 (2004): 7-9.
  38. Vaikoussis E., et al. “Tear mucus ferning in patients with Sjögren’s syndrome”. Documenta Ophthalmologica2 (1994): 145-151.
  39. Norn M. “Quantitative tear ferning. Clinical investigations”. Acta Ophthalmologica3 (1994): 369-372.
  40. Ravazzoni L., et al. “Forecasting of hydrophilic contact lens tolerance by means of tear ferning test”. Graefe's Archive for Clinical and Experimental Ophthalmology 236 (1998): 354-358.
  41. Buckley HE. “Crystal Growth”. New York: Wiley; London: Chapman and Hall Ltd (1951).
  42. Kogbe O., et al. “Factors responsible for tear ferning”. Cornea5 (1991) :433-444.
  43. Pearce EI and Tomlinson A. “Spatial location studies on the chemical composition of human tear ferns”. Ophthalmic and Physiological Optics4 (2000): 306-313.
  44. Rolando M., et al. “The effect of hyperosmolarity on tear mucus ferning”. Fortschritte der Ophthalmologie6 (1986): 644-646.
  45. Horwath J., et al. “Ocular ferning test – Effect of temperature and humidity on tear ferning patterns”. Ophthalmologica 2 (2001): 102-107.
  46. Norn M. “Ferning in conjunctival-cytologic preparations. Crystallisation in stained semiquantitative pipette samples of conjunctival fluid”. Acta Ophthalmologica1 (1987): 118-122.
  47. Pensyl CD and Dillehay SM. “The repeatability of tear mucus ferning grading”. Optometry and Vision Science8 (1998): 600-604.
  48. Tang Y-J., et al. “Establishment of a tear ferning test protocol in the mouse model”. Translational Vision Science and Technology 13 (2020): 1.
  49. Oriá AP., et al. “Comparison of electrolyte composition and crystallization patterns in bird and reptile tears”. Frontiers in Veterinary Science 7 (2020): 574.
  50. Lantyer-Araujo NL., et al. “Rabbit as an animal model for ocular surface disease, tear osmolarity, electrolyte, and tear ferning profiles”. Optometry and Vision Science10 (2020): 847-851.
  51. Veloso JF., et al. “The use of tear ferning test in cats for evaluation of ocular surface”. Acta Veterinaria Scandinavica 62 (2020): 23.
  52. Williams D and Hewitt H. “Tear ferning in normal dogs and dogs with keratoconjunctivitis sicca”. Open Veterinary Journal3 (2017): 268-272.
  53. Oriá AP., et al. “Tear ferning test in healthy dogs”. Veterinary Ophthalmology4 (2018): 391-398.
  54. Raposo ACS., et al. “Evaluation of lacrimal production, osmolarity, crystallization, proteomic profile, and biochemistry of capuchin monkeys tear film”. Journal of Medical Primatology6 (2018): 371-378.
  55. Silva LR., et al. “Tear ferning test in horses and its correlation with ocular surface evaluation”. Veterinary Ophthalmology2 (2016): 117-123.
  56. Masmali AM., et al. “Structure and microanalysis of tear film ferning of camel tears, human tears and refresh plus”. Molecular Vision 24 (2018): 305-314.
  57. Tabbara KF and Okumoto M. “Ocular ferning test”. Ophthalmology6 (1982): 712-714.
  58. Norn M. “Quantitative tear ferning. Methodologic and experimental investigations”. Acta Ophthalmologica 2 (1988): 201-205.
  59. Puderbach S and Stolze HH. “Tear ferning and other lacrimal tests in normal persons of different ages”. International Ophthalmology6 (1991): 391-395.
  60. Horwath J., et al. “Ocular ferning test - effect of temperature and humidity on tear Ferning patterns”. Ophthalmologica2 (2001): 102-107.
  61. Nebbioso M., et al. “Tear ferning test and pathological effects on ocular surface before and after topical cyclosporine in vernal keratoconjunctivitis patients”. Journal of Ophthalmology (2018): 1061276.
  62. Sharanjeet-Kaur., et al. “The relationship between tear ferning patterns and non-invasive tear break-up time in normal Asian population”. Journal of Optometry3 (2016): 175-181.
  63. Masmali A., et al. “Assessment of tear film quality among smokers using tear ferning patterns”. Journal of Ophthalmology (2016): 8154315.
  64. Alanazi SA., et al. “Effect of short-term oral vitamin D3 supplementation on tear film in dry eye subjects”. International Journal of Ophthalmology and Visual Science 4 (2019): 51-57.
  65. Alanazi SA., et al. “Effects of short-term oral vitamin A supplementation on the ocular tear film in patients with dry eye”. Clinical Ophthalmology 13 (2019): 599-604.
  66. Alanazi SA., et al. “An assessment of the ocular tear film in patients with thyroid disorders”. Clinical Ophthalmology 13 (2019): 1019-1026.
  67. Alanazi SA. “Assessment of tear film in subjects with a high body mass index”. Clinical Optometry 11 (2019): 77-84.
  68. Alanazi SA. “Assessment of ocular tear film stability in subjects with high total cholesterol levels”. The Medical Journal of Cairo University9 (2019): 3109-3116.
  69. Alanazi SA., et al. “A comparative study of the quality of non-stimulated and stimulated tears in normal eye male subjects using the tear ferning test”. Clinical Optometry 11 (2019): 65-71.
  70. Masmali AM., et al. “The acute effect of a single dose of green tea on the quality and quantity of tears in normal eye subjects”. Clinical Ophthalmology 13 (2019): 605-610.
  71. Cheng H., et al. “Epicatechin regulates blood lipids and attenuates hepatic steatosis in rats fed high-fat diet”. Molecular Nutrition and Food Research 61 (2017): 1700303.
  72. Muramatsu K., et al. “Effect of green tea catechins on plasma cholesterol level in cholesterol-fed rats”. Journal of Nutritional Science and Vitaminology 32 (1986): 613-622.
  73. Masmali AM., et al. “Assessment of the tear film in normal eye subjects after consumption of a single dose of hot peppermint drink”. Clinical Optometry 11 (2019): 39-45.
  74. Chacko SM., et al. “Beneficial effects of green tea: a literature review”. Chinese Medicine 5 (2010): 8546513.
  75. Alanazi SA., et al. “Effect of Refresh Plus® preservative-free lubricant eyedrops on tear ferning patterns in dry eye and normal eye subjects”. Clinical Ophthalmology 13 (2019): 1011-1017.
  76. Norn MS. “Tear fluid pH in normals, contact lens wearers, and pathological cases”. Acta Ophthalmologica5 (1988): 485-489.
  77. Simmons PA and Vehige JG. “2Investigating the potential benefits of a new artificial tear formulation combining two polymers”. Clinical Ophthalmology 11 (2017): 1637-1642.
  78. Simmons PA., et al. “Efficacy and safety of two new formulations of artificial tears in subjects with dry eye disease: a 3-month, multicenter, active-controlled, randomized trial”. Clinical Ophthalmology 9 (2015): 665-675.
  79. Labetoulle M., et al. “Carboxymethylcellulose and hyaluronic acid multiingredient eye drop: a randomized controlled trial in moderate to severe dry eye”. Eye10 (2017): 1409-1416.
  80. Masmali AM. “Improvement of ferning patterns of lubricant eye drops mixed with various electrolytes and carboxymethylcellulose”. Contact Lens and Anterior Eye6 (2019): 633-639.
Citation: Mana A Alanazi., et al. “Tear Ferning Test as a Valuable Tool to Determine the Quality of Tear Film in Animals and Human”. EC Ophthalmology 12.9 (2021): 41-55.

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