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Ocular Surface Research Group


SERI’s Ocular Surface research group engages in highly competitive, world-class research related to the ocular surface. The main focus is on the diagnosis and treatment of ocular surface diseases, such as dry eye, meibomian gland dysfunction and pterygium. They are also focused on understanding the molecular basis of these diseases. This type of research ranges from epidemiology, health services, biochemicals, cell- and animal-based research to imaging and human clinical trials.

In recent years, the group has performed research related to conjunctival T cells, induction of immune-mediated ocular surface inflammation in animals, the effects of S100 calcium-binding proteins and the regulation of wound healing by molecules such as transglutaminase-2. The group is dedicated to the evaluation and use of state-of-the-art technologies in dry eye, such as tear protein biomarkers, non-invasive meibography, tear evaporimetry, and tear eicosanoid lipid analysis by mass spectrometry. It is currently very active in various projects with commercial potential, such as the preclinical evaluation of anti-inflammatory drugs and tear stabilising formulations.

As part of the effort to translate research findings into clinical care, the Ocular Surface research group has published in topics, such as autologous plasma drops for recalcitrant dry eye, thermopulsation treatment, eyelid warming, moisture chamber glasses, patient focus groups and education on use of eyelid wipes. The Principal Investigator actively contributes to the international Dry Eye Workshop, the Meibomian Gland Dysfunction International Workshop, the Asia Dry Eye Society Council and the Asia Cornea Society. He is a global ambassador for the Tear Film and Ocular Surface Society. The emphasis, therefore, is not only on innovative research, but also in the promotion and education of the public and health professionals to champion the healthcare needs of patients with ocular surface diseases.


In addition to the ocular surface clinical trial centre, the ocular surface research lab houses cutting edge facilities and equipment, such as centricollation system (Prospect Biosystems), flow cytometry facility (BD), cell impedence tracking device (xCELLigence, Roche), microscopy imaging station and basic laboratory setups, including qPCR machines (Roche), film development and cell culture facilities.

Selected Publications

  1. Ambaw YA, Timbadia DP, Raida M, Torta F, Wenk MR, Tong L. Profile of tear lipid mediator as a biomarker of inflammation for meibomian gland dysfunction and ocular surface diseases: Standard operating procedures. Ocul Surf. 2020 Oct 3:S1542-0124(20)30148-8. doi: 10.1016/j.jtos.2020.09.008. Epub ahead of print. PMID: 33022413.

  2. Ambaw YA, Fuchs D, Raida M, Mazengia NT, Torta F, Wheelock CE, Wenk MR, Tong L. Changes of tear lipid mediators after eyelid warming or thermopulsation treatment for meibomian gland dysfunction. Prostaglandins Other Lipid Mediat. 2020 Dec;151:106474. doi: 10.1016/j.prostaglandins.2020.106474. Epub 2020 Aug 9. PMID: 32783924.

  3. Teo CHY, Ong HS, Liu YC, Tong L. Meibomian gland dysfunction is the primary determinant of dry eye symptoms: Analysis of 2346 patients. Ocul Surf. 2020 Oct;18(4):604-612. doi: 10.1016/j.jtos.2020.06.008. Epub 2020 Jul 15. PMID: 32682082.

  4. Ambaw YA, Wong T, Chong R, Ah H, Ji S, Raida M, Torta F, Wenk MR, Tong L. Change of tear lipid mediators in a post-trabeculectomy cohort. Ocul Surf. 2020 Oct;18(4):565-574. doi: 10.1016/j.jtos.2020.06.004. Epub 2020 Jul 3. PMID: 32622916.

  5. Tong L, Hou AH, Wong TT. Altered expression level of inflammation-related genes and long-term changes in ocular surface after trabeculectomy, a prospective cohort study. Ocul Surf. 2018 Oct;16(4):441-447. doi: 10.1016/j.jtos.2018.06.005. Epub 2018 Jun 21. PMID: 29935986.

  6. Wolffsohn JS, Arita R, Chalmers R, Djalilian A, Dogru M, Dumbleton K, Gupta PK, Karpecki P, Lazreg S, Pult H, Sullivan BD, Tomlinson A, Tong L, Villani E, Yoon KC, Jones L, Craig JP. TFOS DEWS II Diagnostic Methodology report. Ocul Surf. 2017 Jul;15(3):539-574. doi: 10.1016/j.jtos.2017.05.001. Epub 2017 Jul 20. PMID: 28736342.

  7. DA Schaumberg, JJ Nichols, EB Papas, L Tong, M Uchino, KK Nichols. The international workshop on meibomian gland dysfunction: Report of the subcommittee on the epidemiology of, and associated risk factors for, MGD. Invest Ophthalmol Vis Sci. 2011; 52 (4): 1994-2005.

  8. Tong L, Seow G, Tan J, Thumboo J. Dry eye practice pointer. BMJ. 2012; 345:e7533.

  9. Tong L et al. The eye: A window of opportunity in rheumatoid arthritis? Nature Reviews Rheumato.2014 Jun 10.doi: 0.1038/nrrheum.2014.85.

  10. Lim A, Wenk MR, Tong L. Lipid-Based Therapy for Ocular Surface Inflammation and Disease. Trends Mol Med. 2016 Jul;22(7):629. doi: 10.1016/j.molmed.2016.05.008. Epub 2016 Jun 6. Erratum for: Trends Mol Med. 2015 Dec;21(12):736-48. PMID: 27282088.

  11. Bose T, Lee R, Hou A, Tong L, Chandy KG. Tissue resident memory T cells in the human conjunctiva and immune signatures in human dry eye disease. Sci Rep. 2017 Mar 27;7:45312. doi: 10.1038/srep45312. PMID: 28345628; PMCID: PMC5366884.

  12. Tong L, Zhou L, Beuerman R, Simonyi S, Hollander DA, Stern ME. Effects of punctal occlusion on global tear proteins in patients with dry eye. Ocul Surf. 2017 Oct;15(4):736-741. doi: 10.1016/j.jtos.2017.04.002. Epub 2017 Apr 19. PMID: 28433820.

  13. Tong L, Beuerman R, Simonyi S, Hollander DA, Stern ME. Effects of Punctal Occlusion on Clinical Signs and Symptoms and on Tear Cytokine Levels in Patients with Dry Eye. Ocul Surf. 2016 Apr;14(2):233-41. doi: 10.1016/j.jtos.2015.12.004. Epub 2016 Jan 13. PMID: 26774908.

  14. Lam SM, et al. Extensive characterization of human tear fluid collected using different techniques unravels the presence of novel lipid amphiphiles. J Lipid Res. 2014 Feb;55(2):289-98. doi: 10.1194/jlr.M044826.

  15. Lan W, Hou A, Lakshminarayanan R, Lim YP, Tong L. Linc-9432 is a novel pterygium lincRNA which regulates differentiation of fibroblasts. FEBS Lett. 2018 Apr;592(7):1173-1184. doi: 10.1002/1873-3468.13027. Epub 2018 Mar 23. PMID: 29513395.

  16. Tong L, Png E, Hou AH, Yong SS, Yeo HL, Riau A, Mendoze E, Charausiaa SS, Lim CT, Yiu TW, Iismaa SE. Molecular Mechanism of Transglutaminase-2 in Corneal Epithelial Migration and Adhesion. BiochimBiophysActa 2013;1833:1304-1315.

  17. Png E, Samivelu GK, Yeo SH, Chew J, Chaurasia SS, Tong L. Hyperosmolarity mediated mitochondrial dysfunction requires transglutaminase-2 in human corneal epithelial cells. J Cell Physiol. 2011; 226: 693–699.

  18. Lan, Wanwen; Chen, Silin; Tong, Louis. MicroRNA-215 Regulates Fibroblast Function: Insights from a Human Fibrotic Disease. Cell Cycle. 2015 Jun 18;14(12):1973-84. doi: 10.1080/15384101.2014.998077.

  19. Riau AK, Wong TT, Finger SN, Lan WW, Chaurasia SS, Hou AH, Chen SL, Yu SJ, Tong L. Aberrant DNA methylation of matrix remodeling and cell adhesion related genes in pterygium. PLOS One. 2011; 6(2): e14687.

  20. Selva KJ, Liu YC, Siak JK, Lan WW, Tong L, Yawata M, Mehta JS, Yawata N, Dynamic change in natural killer cell type in the human ocular mucosa in situ as means of immune evasion by adenovirus infection. Mucosal Immunol 2015 Jun 17. doi: 10.1038/mi.2015.47.

  21. Gong L, Sun XH, Ma ZZ, et al, Tong L. A Randomized, Parallel-Group Comparison Study of Diquafosol Ophthalmic Solution in Patients with Dry Eye (Comparison with 0.1% sodium hyaluronate ophthalmic solution) in China and Singapore. Br J Ophthalmol. 10.1136/bjophthalm ol-2014-306084.Waduthantri S, Yong SS, Htoon HM, Tong L. Randomised controlled trial of Systane Ultra® vs Refresh Tears® in Asian dry eye patients. Optom Vis Sci. 2012; 89: 1647-53.

  22. Jerkins G, Greiner JV, Tong L, Tan J, Tauber J, Mearza A, Srinivasan S. A Comparison of Efficacy and Safety of Two Lipid-Based Lubricant Eye Drops for the Management of Evaporative Dry Eye Disease. Clin Ophthalmol. 2020 Jun 18;14:1665-1673. doi: 10.2147/OPTH.S256351. PMID: 32606581; PMCID: PMC7308126.

  23. Koh YW, Celik T, Lee HK, Petznick A, Tong L. Detection of meibomian glands and classification of meibography images. J Biomed Opt. 2012; 17(8):086008.

  24. Husain R, Tong L, Fong A, Cheng JF, How A, Chua WH, Lee L, Gazzard G, Tan DT, Koh D, Saw SM. Prevalence of cataract in rural Indonesia. Ophthalmology. 2005 Jul;112(7):1255-62. doi: 10.1016/j.ophtha.2005.02.015. PMID: 15993241.


The Ocular Surface research team is led by a clinician scientist, Professor Louis Tong, and currently comprises of a post-doctoral research fellow, two graduate students, two research optometrists and one research assistant. The group is dedicated to nurturing post-graduate and undergraduate medical students, undergraduate final year project students as well as polytechnic students who are welcome to join the lab for long or short term attachments.

Grant Support
Our research is supported by national competitive grants (e.g. National Medical Research Council) including three clinician-scientist awards, one individual research grant, the Biomedical Research Council Translational Clinical Research Project grant, two international awards, as well as various sources of industrial funding.


Prof Louis Tong

Senior Research Fellow

Dr Hou Ai Hua

Senior Research Technologist

Tin Min Qi

Project Coordinators

  • Cynthia Boo

  • Sharon Yeo