Published: 2018-08-25

Subjective and objective interpretation of tear film interferometry images

Nikhil Sharma, Katherine Oliver


Background: Assessment of the tear film is necessary in routine clinical practice because an unstable tear film can hamper the quality of life by causing vision-related problems and compromising the ocular surface. One of the major concerns related to an unstable tear film is dry eye. Many of dry eye patients suffer from a lack of meibum which forms the lipid layer of the tear film. The lipid layer can be graded and interpreted by using interferometry. However, interpretation and grading of this dynamic layer may be inconsistent in terms of inter- and intra- observations. This study investigated the difficulty of consistent, subjective grading of clinical findings, in general.

Methods: The interferometry images of 30 subjects captured from different equipment were analyzed subjectively. The agreement between intra-observer repeatability was also measured.

Results: A positive Spearman’s correlation of 0.81 was found among different grading patterns observed using the Tearsope to compare right and left eyes. Similarly, a positive Spearman’s correlation of 0.63 was found among different grading patterns observed under interferometer in right and left eye. Correlations were statistically significant, p<0.001. The agreement between intra-observer repeatability calculated using Cohen’s kappa values were also statistically significant, p<0.001.

Conclusions: A correlation between the findings of different equipment could not be made due to the differences in wavelengths of incident light and the image details. However, a new grading pattern has been proposed to describe the thickness of various lipid layer patterns observed under Doane’s interferometer.


Dry eye syndrome, Lipid layer pattern, Tear film lipid layer

Full Text:



Bron AJ, Tiffany JM, Gouveia SM, Yokoi N, Voon LW. Functional aspects of the tear film lipid layer. Exp Eye Res. 2004;78(3):347-60.

Tomlinson A, Khanal S. Assessment of tear film dynamics: Quantification approach. The Ocular Surface. 2005;3(2):81-95.

Cwiklik L. Tear film lipid layer: A molecular level view. Biochimica et Biophysica Acta (BBA) - Biomembranes. 2016;1858(10):2421-30.

Cerretani CF, Ho NH, Radke CJ. Water-evaporation reduction by duplex films: application to the human tear film. Advances in colloid and interface science. 2013 Sep 1;197:33-57.

Werkmeister RM, Alex A, Kaya S, Unterhuber A, Hofer B, Riedl J, et al. Measurement of tear film thickness using ultrahigh-resolution optical coherence tomography. Investigative ophthalmology & visual science. 2013 Aug 1;54(8):5578-83.

Lemp M. Advances in understanding and managing dry eye disease. Am J Ophthalmol. 2008;146(3):350-6.e1.

Nosch DS, Pult H, Albon J, Purslow C. Relationship between corneal sensation, blinking, and tear film quality. Optometry Vision Sci. 01;93(5):471-81.

Craig JP, Craig JP, Tomlinson A. Importance of the lipid layer in human tear film stability and evaporation. Optometry Vision Sci. 01;74(1):8-13.

Borchman D, Foulks GN, Yappert MC, Tang D, Ho DV. Spectroscopic evaluation of human tear lipids. Chem Phys Lipids. 2007;147(2):87-102.

Braun RJ. Dynamics of the tear film. Annu Rev Fluid Mech. 2012;44(1):267-97.

Patel S, Wallace I. Tear meniscus height, lower punctum lacrimale, and the tear lipid layer in normal aging. Optom Vis Sci. 2006;83(10):731-9.

Peng C, Cerretani C, Braun RJ, Radke CJ. Evaporation-driven instability of the precorneal tear film. Adv Colloid Interface Sci. 2014;206:250-64.

Butovich IA, Uchiyama E, Pascuale MAD, McCulley JP. Liquid Chromatography-Mass spectrometric analysis of lipids present in human meibomian gland secretions. Lipids. 2007;42(8):765-76.

Craig JP, Nichols KK, Akpek EK, Caffery B, Dua HS, Joo CK, et al. TFOS DEWS II definition and classification report. The ocular surface. 2017 Jul 1;15(3):276-83.

Sweeney DF, Millar TJ, Raju SR. Tear film stability: A review. Exp Eye Res. 2013;117:28-38.

Nichols KK, Nichols JJ, Zadnik K. Frequency of dry eye diagnostic test procedures used in various modes of ophthalmic practice. Cornea. 2000;19(4):477-82.

Doane MG. An instrument for in vivo tear film interferometry. Optometry and vision science: official publication of the American Academy of Optometry. 1989;66(6):383-8.

Guillon J. Non-invasive tearscope plus routine for contact lens fitting. Contact Lens and Anterior Eye. 1998;21, Supplement 1:S31-S40.

World MA. World medical association declaration of helsinki. ethical principles for medical research involving human subjects. Bull World Health Organ. 2001;79(4):373.

Schiffman RM, Christianson MD, Jacobsen G, Hirsch JD, Reis BL. Reliability and validity of the ocular surface disease index. Arch Ophthalmol. 2000;118(5):615-21.

Bhatnagar KR, Pote S, Pujari S, Deka D. Validity of subjective assessment as screening tool for dry eye disease and its association with clinical tests. Int J Ophthalmol. 2015;8(1):174.

Remeseiro B, Barreira N, García-Resúa C, Lira M, Giráldez MJ, Yebra-Pimentel E, et al. iDEAS: A web-based system for dry eye assessment. Computer methods and programs in biomedicine. 2016 Jul 1;130:186-97.

Remeseiro B, Bolon-Canedo V, Peteiro-Barral D, Alonso-Betanzos A, Guijarro-Berdinas B, Mosquera A, et al. A methodology for improving tear film lipid layer classification. IEEE J Bio and Health Informatics. 2014 Jul;18(4):1485-93.

Guillon JP. Non-invasive tearscope plus routine for contact lens fitting. Cont Lens Anterior Eye. 1998;21 Suppl 1:S31-40.

Thai LC, Tomlinson A, Doane MG. Effect of contact lens materials on tear physiology. Optometry and vision science: official publication of the American Academy of Optometry. 2004;81(3):194-204.

García-Resúa C, Pena-Verdeal H, Miñones M, Giráldez MJ, Yebra-Pimentel E. Interobserver and intraobserver repeatability of lipid layer pattern evaluation by two experienced observers. Contact Lens and Anterior Eye. 2014;37(6):431-7.

Nichols JJ, Nichols KK, Puent B, Saracino M, Mitchell GL. Evaluation of tear film interference patterns and measures of tear break-up time. Optometry and vision science: official publication of the American Academy of Optometry. 2002;79(6):363-369.

Guillon J. Tear film photography and contact lens wear. J British Contact Lens Association. 1982;5(2):84,86-7.

Norn MS. Semiquantitative interference study of fatty layer of precorneal film. Acta Ophthalmol. 1979;57(5):766-74.

Mcdonald JE. Surface phenomena of the tear film. Ame J Ophthalmol. 1969;67(1):56-64.

Barthel KU. 3D-data representation with ImageJ. 2006:63-6.

Willcox MD, Argüeso P, Georgiev GA, Holopainen JM, Laurie GW, Millar TJ, et al. TFOS DEWS II tear film report. The ocular surface. 2017 Jul 1;15(3):366-403.

Yokoi N, Komuro A. Non-invasive methods of assessing the tear film. Exp Eye Res. 2004;78(3):399-407.

Goto E, Tseng SCG. Kinetic analysis of tear interference images in aqueous tear deficiency dry eye before and after punctal occlusion. Invest Ophthalmol Vis Sci. 2003;44(5):1897.