{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:29:19Z","timestamp":1785403759185,"version":"3.56.0"},"reference-count":31,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T00:00:00Z","timestamp":1778716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013302","name":"King Abdullah International Medical Research Center","doi-asserted-by":"crossref","award":["IRB\/0829\/22"],"award-info":[{"award-number":["IRB\/0829\/22"]}],"id":[{"id":"10.13039\/501100013302","id-type":"DOI","asserted-by":"crossref"}]},{"award":["IRB\/0829\/22"],"award-info":[{"award-number":["IRB\/0829\/22"]}],"id":[{"id":"https:\/\/ror.org\/009p8zv69","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Healthcare"],"abstract":"<jats:p>Background: Dry eye disease (DED) is a multifactorial disease. Numerous risk factors might cause DED, including indoor air pollution, such as incense. Incense (Bakhoor) is widely used in many cultures, including Saudi Arabia, although its smoke contains toxic chemicals that pose serious health hazards. This research investigates the link between the Schirmer II test and tear fluid proteins in DED patients. The study focuses on identifying the ocular examinations, hypothesizing that incense smoke, particularly from synthetic types, exacerbates DED. Methods: This pilot cross-sectional study was conducted at King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia. Participants were recruited from the Cornea and Ophthalmology Clinics. Eye assessments analyzed tear protein concentrations, including tear collection using Schirmer II test strips and tear break-up time (TBUT). The study included DED patients who used incense. Tear fluid from the Schirmer test of 20 randomly selected patients was used for protein analysis of total protein, lactoferrin, and Immunoglobulin E. Inclusion criteria were male and female subjects aged 18 years or older, diagnosed with DED, and using incense. The sample size was 55 participants, selected via convenience sampling. Subjective data were collected through questionnaires, as well as objective data from the tear test and the sample and analyzed with SPSS. Descriptive and inferential statistics were used, with statistical significance set at p-value &lt; 0.05. Results: The Ocular Comfort Index (OCI) categories showed that 21.8% had no symptoms, 40.0% had low symptoms, 30.9% had moderate symptoms, and 7.3% reported high symptoms. TBUT values and Schirmer test scores decreased with increasing OCI severity, with no statistical significance. The mean (SD) of total protein in the right and left eyes for high OCI was 7.19 (1.39) and 7.42 (0.91), respectively, with no statistical significance. The immunoglobulin E levels in the right and left eyes for high OCI were 301.71 (55.97) and 301.71 (47.14), respectively, with no statistical significance. The mean (SD) of lactoferrin in the right and left eyes for high OCI was 163.77 (10.42) and 159.43 (1.68), respectively, with no statistical significance. Conclusions: The study findings demonstrate alignment in incense-using patients between subjective OCI symptom scores and objective clinical diagnostic measures. Specifically, higher OCI scores are associated with lower TBUT and Schirmer II test values, as well as changes in tear biomarkers such as IgE and lactoferrin. These findings emphasize the potential of using simple screening methods combined with bioanalytical markers for early detection of ocular surface disease. This highlights the potential health risks associated with incense exposure, particularly for individuals predisposed to DED. The urgency for further research to explore the long-term effects of incense on ocular health and to raise awareness about its potential impact on populations with high incense usage cannot be overstated.<\/jats:p>","DOI":"10.3390\/healthcare14101351","type":"journal-article","created":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T16:27:56Z","timestamp":1778776076000},"page":"1351","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Assessment of Dry Eye Disease in Incense Users: A Pilot Cross-Sectional Study Integrating Clinical and Tear Biomarker Analysis"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2734-2767","authenticated-orcid":false,"given":"Amani Y.","family":"Alhalwani","sequence":"first","affiliation":[{"name":"College of Science and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"},{"name":"Department of Biomedical Research, King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali S.","family":"Alsudais","sequence":"additional","affiliation":[{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-1612-5139","authenticated-orcid":false,"given":"Abdulaziz S.","family":"Alrashid","sequence":"additional","affiliation":[{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Salma Hamdan","family":"Almarwani","sequence":"additional","affiliation":[{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-5772-3379","authenticated-orcid":false,"given":"Qusay","family":"Aloweiny","sequence":"additional","affiliation":[{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammed","family":"Basendwah","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Ministry of the National Guard-Health Affairs, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alaa Hesham","family":"Mofti","sequence":"additional","affiliation":[{"name":"Department of Biomedical Research, King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia"},{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"},{"name":"Department of Ophthalmology, Ministry of the National Guard-Health Affairs, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6379-590X","authenticated-orcid":false,"given":"Muhammad Anwar","family":"Khan","sequence":"additional","affiliation":[{"name":"Department of Biomedical Research, King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia"},{"name":"College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1016\/j.jtos.2017.05.008","article-title":"TFOS DEWS II Definition and Classification Report","volume":"15","author":"Craig","year":"2017","journal-title":"Ocul. Surf."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1001\/archopht.118.5.615","article-title":"Reliability and validity of the ocular surface disease index","volume":"118","author":"Schiffman","year":"2000","journal-title":"Arch. Ophthalmol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4451","DOI":"10.1167\/iovs.06-1253","article-title":"Measurement of ocular surface irritation on a linear interval scale with the ocular comfort index","volume":"48","author":"Johnson","year":"2007","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1016\/j.jtos.2017.05.001","article-title":"TFOS DEWS II Diagnostic Methodology report","volume":"15","author":"Wolffsohn","year":"2017","journal-title":"Ocul. Surf."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1007\/s00244-025-01119-8","article-title":"Illusion of Incense Smoke and Associated Health Risk: An Investigation of Ocular and Respiratory Particulate Deposition","volume":"88","author":"Muruganandam","year":"2025","journal-title":"Arch. Environ. Contam. Toxicol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1186\/1476-7961-6-3","article-title":"Incense smoke: Clinical, structural and molecular effects on airway disease","volume":"6","author":"Lin","year":"2008","journal-title":"Clin. Mol. Allergy"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"17828","DOI":"10.1038\/s41598-018-36181-x","article-title":"Air pollutant particulate matter 2.5 induces dry eye syndrome in mice","volume":"8","author":"Tan","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/S0048-9697(02)00043-8","article-title":"Characterization of emissions from burning incense","volume":"295","author":"Jetter","year":"2002","journal-title":"Sci. Total Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"113346","DOI":"10.1016\/j.envres.2022.113346","article-title":"Stable C and N isotopes of PM(2.5) and size-segregated particles emitted from incense stick and cigarette burning","volume":"212","author":"Jung","year":"2022","journal-title":"Environ. Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.jscs.2014.10.005","article-title":"Chemical composition and potential health risks of raw Arabian incense (Bakhour)","volume":"20","author":"Elsayed","year":"2016","journal-title":"J. Saudi Chem. Soc."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lin, C.C., Chiu, C.C., Lee, P.Y., Chen, K.J., He, C.X., Hsu, S.K., and Cheng, K.C. (2022). The Adverse Effects of Air Pollution on the Eye: A Review. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19031186"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Mandell, J.T., Idarraga, M., Kumar, N., and Galor, A. (2020). Impact of Air Pollution and Weather on Dry Eye. J. Clin. Med., 9.","DOI":"10.3390\/jcm9113740"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1016\/S0161-6420(99)90170-7","article-title":"Correlation of tear fluorescein clearance and Schirmer test scores with ocular irritation symptoms","volume":"106","author":"Afonso","year":"1999","journal-title":"Ophthalmology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/j.ajo.2025.05.033","article-title":"TFOS DEWS III Diagnostic Methodology","volume":"279","author":"Wolffsohn","year":"2025","journal-title":"Am. J. Ophthalmol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5451","DOI":"10.2147\/JIR.S332771","article-title":"The Adverse impact of incense smoke on human health: From mechanisms to implications","volume":"14","author":"Lee","year":"2021","journal-title":"J. Inflamm. Res."},{"key":"ref_16","first-page":"e18280","article-title":"The Correlation Between Non-Invasive Ventilation Use and the Development of Dry Eye Disease","volume":"13","author":"Shah","year":"2021","journal-title":"Cureus"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Alhalwani, A., Mofti, A.H., Domyati, M.I., Muzian, F., Qadizadah, A.E., Alquhaibi, A.S., Alghamdi, J., Gusti, N., Khan, M.A., and Almhmad, W.M. (2024). The investigation of the effect of incense use on patients with dry eye diseases: A clinical interview-based study. Res. Sq.","DOI":"10.21203\/rs.3.rs-3930822\/v1"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Hwang, H.B., Ku, Y.H., Kim, E.C., Kim, H.S., Kim, M.S., and Hwang, H.S. (2020). Easy and effective test to evaluate tear-film stability for self-diagnosis of dry eye syndrome: Blinking tolerance time (BTT). BMC Ophthalmol., 20.","DOI":"10.1186\/s12886-020-01686-5"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1412","DOI":"10.1016\/S0161-6420(03)00462-7","article-title":"Utility assessment among patients with dry eye disease","volume":"110","author":"Schiffman","year":"2003","journal-title":"Ophthalmology"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1080\/02713683.2020.1801758","article-title":"Gender-Specific Differences in Signs and Symptoms of Dry Eye Disease","volume":"46","author":"Borrelli","year":"2021","journal-title":"Curr. Eye Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.jtos.2021.05.001","article-title":"Demographic and lifestyle risk factors of dry eye disease subtypes: A cross-sectional study","volume":"21","author":"Wolffsohn","year":"2021","journal-title":"Ocul. Surf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1465","DOI":"10.1080\/15287390590967405","article-title":"Adverse respiratory and irritant health effects in temple workers in Taiwan","volume":"68","author":"Ho","year":"2005","journal-title":"J. Toxicol. Environ. Health Part A"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2665","DOI":"10.2147\/JIR.S347489","article-title":"Health and Environmental Risks of Incense Smoke: Mechanistic Insights and Cumulative Evidence","volume":"15","author":"Yadav","year":"2022","journal-title":"J. Inflamm. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6300","DOI":"10.1007\/s11356-015-5819-2","article-title":"Measurements of VOC\/SVOC emission factors from burning incenses in an environmental test chamber: Influence of temperature, relative humidity, and air exchange rate","volume":"23","author":"Manoukian","year":"2016","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"4659","DOI":"10.1007\/s11356-012-1394-y","article-title":"Emission characteristics of air pollutants from incense and candle burning in indoor atmospheres","volume":"20","author":"Manoukian","year":"2013","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1111\/j.1600-0668.2009.00634.x","article-title":"Characterization of particles emitted by incense burning in an experimental house","volume":"20","author":"Ji","year":"2010","journal-title":"Indoor Air"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1167\/tvst.14.9.13","article-title":"Wildfire Smoke Induces Eye Surface Inflammation and Tear Film Changes in a Human Experimental Model","volume":"14","author":"Jaiswal","year":"2025","journal-title":"Transl. Vis. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"498","DOI":"10.1097\/ICL.0000000000001036","article-title":"Human Tear Protein Analysis Using a Quantitative Microfluidic System: A Pilot Study","volume":"49","author":"Casemore","year":"2023","journal-title":"Eye Contact Lens"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.4103\/IJO.IJO_2774_22","article-title":"Optimization and evaluation of tear protein elution from Schirmer\u2019s strips in dry eye disease","volume":"71","author":"Koduri","year":"2023","journal-title":"Indian J. Ophthalmol."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Dermer, H., Theotoka, D., Lee, C.J., Chhadva, P., Hackam, A.S., Galor, A., and Kumar, N. (2019). Total Tear IgE Levels Correlate with Allergenic and Irritating Environmental Exposures in Individuals with Dry Eye. J. Clin. Med., 8.","DOI":"10.3390\/jcm8101627"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1167\/iovs.61.12.9","article-title":"Lactoferrin concentration in human tears and ocular diseases: A meta-analysis","volume":"61","author":"Ponzini","year":"2020","journal-title":"Investig. Ophthalmol. Vis. Sci."}],"container-title":["Healthcare"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9032\/14\/10\/1351\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,16]],"date-time":"2026-05-16T04:22:23Z","timestamp":1778905343000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9032\/14\/10\/1351"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,14]]},"references-count":31,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["healthcare14101351"],"URL":"https:\/\/doi.org\/10.3390\/healthcare14101351","relation":{},"ISSN":["2227-9032"],"issn-type":[{"value":"2227-9032","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,14]]}}}