Diagnosis of chlamydial lesions of the anterior eye segment

Ocular involvement may be caused by various members of the family Chlamydiaceae, among which Chlamydia trachomatis plays the leading role. Chlamydial infection caused by this pathogen represents a significant medical and social challenge for contemporary public health, affecting more than 129 million people worldwide annually. The rising incidence of urogenital chlamydiosis is naturally accompanied by an increasing frequency of ocular involvement, with chlamydial conjunctivitis identified in more than 50% of patients with established urogenital infection. The absence of specific clinical symptoms, marked polymorphism of manifestations, and the pathogen’s capacity for prolonged tissue persistence considerably impede timely diagnosis. Chronic forms of infection frequently follow a latent course, remain undetected on routine examination, and lead to serious complications affecting both the reproductive system and the eye. Particular diagnostic complexity is presented by mixed infections and generalized forms of chlamydial infection involving various ocular structures, including the anterior segment. Laboratory diagnosis of chlamydial eye disease requires a comprehensive approach employing modern investigative methods, including molecular biological, immunofluorescence, immunohistochemical, and serological techniques. Diagnostic outcomes are substantially influenced by appropriate patient preparation, specimen collection technique, transport and storage conditions, and the competence of medical personnel. According to published data, pathogen verification requires the use of at least two complementary diagnostic methods to ensure the reliability of results. The rapid development of novel diagnostic technologies offers additional opportunities for improving pathogen identification, particularly in cases of atypical presentation and treatment-resistant disease. An optimal diagnostic strategy is an essential prerequisite for the timely detection of chlamydial eye disease, initiation of adequate systemic therapy, and prevention of serious complications in patients of reproductive age.

1. Lobzin YuV, Pozniak AL, Sidorchuk SN. Hlamidijnye infekcii, diagnostika, klinika, lechenie, reabilitacija: rukovodstvo dlja vrachej. SPb.: Foliant; 2010. (In Russ.)

2. Sidorchuk, S. N. Sovremennaya taksonomiya mikroorganizmov poryadka Chlamydiales kak «vershina aisberga» /s. N. Sidorchuk, A. L. Poznyak, T. R. Akhmedzhanov // Nereshennye voprosy ehtiotropnoi terapii aktual’nykh infektsii : Materialy Vserossiiskoi ezhegodnoi nauchno-prakticheskoi konferentsii, posvyashchenoi 75-letiyu akademika RAN Lobzina Yu.V., Sankt-Peterburg, 09–10 dekabrya 2025 goda. – Sankt-Peterburg: Sankt-Peterburgskaya obshchestvennaya organizatsiya «Chelovek i ego zdorov’e», 2025. – S. 277-289.

3. Boiko EV, Pozniak AL, Karev VE, et al. Current aspects of clinical and laboratory diagnosis of chlamydia infection of the posterior eye segment. Ophthalmology Reports. 2026;19(1):91-98. doi: 10.17816/OV692462

4. Tagini F, Puolakkainen M, Greub G, On Behalf Of The Escmid Study Group For Mycoplasma And Chlamydia Infections Esgmac. From coughs to complications: the story of Chlamydia pneumoniae. J Med Microbiol. 2025;74(4):002006. doi:10.1099/jmm.0.002006

5. Collina F, De Chiara A, De Renzo A, De Rosa G, Botti G, Franco R. Chlamydia psittaci in ocular adnexa MALT lymphoma: a possible role in lymphomagenesis and a different geographical distribution. Infect Agent Cancer. 2012;7:8. doi:10.1186/1750-9378-7-8

6. Wons J, Meiller R, Bergua A, Bogdan C, Geißdörfer W. Follicular Conjunctivitis due to Chlamydia felis-Case Report, Review of the Literature and Improved Molecular Diagnostics. Front Med (Lausanne). 2017;4:105. doi:10.3389/fmed.2017.00105

7. World Health Organization [Internet]. Sexually transmitted infections (STIs); 2022– . [cited 2026 March 10]. Available from: https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)

8. Hocking JS, Geisler WM, Kong FYS. Update on the Epidemiology, Screening, and Management of Chlamydia trachomatis Infection. Infect Dis Clin North Am. 2023;37(2):267-288. doi:10.1016/j.idc.2023.02.007

9. Rodrigues R, Sousa C, Barros A, Vale N. Chlamydia trachomatis: From Urogenital Infections to the Pathway of Infertility. Genes (Basel). 2025;16(2):205. doi:10.3390/genes16020205

10. Volodina TA, Saskova PV, Ivanova EV. Urogenital chlamydiosis: current state (review). Pharmacy & Pharmacology. 2014;2(6):66-73. (In Russ.)

11. Rodrigues R, Sousa C, Vale N. Chlamydia trachomatis as a Current Health Problem: Challenges and Opportunities. Diagnostics (Basel). 2022;12(8):1795. doi:10.3390/diagnostics12081795

12. Abedifar Z, Fallah F, Asadiamoli F, Bourrie B, Doustdar F. Chlamydia trachomatis Serovar Distribution in Patients with Follicular Conjunctivitis in Iran. Turk J Ophthalmol. 2023;53(4):218-221. doi:10.4274/tjo.galenos.2022.12080

13. Zur NV, Mironov AYu, Aleshkin VA, et al. Actual aspects of laboratory diagnostics of urogenital chlamydial infections. Astrakhan Medical Journal. 2016;1(2):16-32. (In Russ.)

14. Kaptilnyy VA, Lystsev DV. Modern methods of diagnostics and treatment of chlamydia infection. V.F. Snegirev Archives of Obstetrics and Gynecology. 2019;6(1):8-14. (In Russ.) doi:10.18821/2313-8726-2019-6-1-8-14.

15. Gladin DP, Korolyuk AM, Drobot IV, et al. Chlamydia and chlamydiosis. Russian Biomedical Research. 2021;6(4):37-46. (In Russ.)

16. Markina AN, Kapustina TA, Parilova OV, Belova EV. Pathogenic characteristics of intracellular infection in chlamydiosis. Russian Journal of Infection and Immunity. 2021;11(3):423-432. (In Russ.) doi:10.15789/2220-7619-PCO-1213.

17. Bikbov MM, Malkhanov VB, Babushkin AE. Kon’yunktivity: differentsial’naya diagnostika i lecheniye [Conjunctivitis: differential diagnosis and treatment: monograph]. M.: Aprel’; 2015. (In Russ.)

18. Vakhova ES, Krichevskaya GI, Yani EV, Svetlova EV. Current aspects of chlamydia trachomatis infection of the anterior eye segment: pathogenesis, clinical forms, laboratory diagnosis, treatment. Russian ophthalmological journal. 2014;7(4):5-11. (In Russ.)

19. Zigangirova NA, Rumyantseva YP, Morgunova EY, et al. Detection of C. trachomatis in the serum of the patients with urogenital chlamydiosis. Biomed Res Int. 2013;2013:489489. doi:10.1155/2013/489489

20. Babushkin AE, Shеvchuk NE. Chlamydial conjunctivitis: clinic, diagnosis, treatment (literature review). Point of View. East – West. 2021;1:102-106. (In Russ.) doi:10.25276/2410-12572021-1-102-106.

21. Chentsova OB, Mezhevova IIu. New clinical forms and diagnostics of ophthalmoclamidiosis. Russian Annals of Ophthalmology. 2003;119(5):25-28. (In Russ.)

22. Kovalevskaya MA, Filina LA, Halayqa AIA. Chronic infectious processes in ophthalmology // Modern technologies in ophtalmology. 2024;58(6):70-79. (In Russ.) doi:10.25276/23124911-2024-6-70-79.

23. Boiko EV, Pozniak AL, Maltsev DS, et al. High Frequency of Latent Conjunctival C. trachomatis, M. hominis, and U. urealyticum Infections in Young Adults with Dry Eye Disease. J Ophthalmol. 2014;2014:154627. doi:10.1155/2014/154627

24. Abdelfattah MM, Khattab RA, Mahran MH, Elborgy ES. Evaluation of patients with dry eye disease for conjunctival Chlamydia trachomatis and Ureaplasma urealyticum. Int J Ophthalmol. 2016;9(10):1457-1465. doi:10.18240/ijo.2016.10.15

25. Pozniak AL, Sidorchuk SN, Drigina LB, Goreiko TV. Modern aspects of urogenital chlamydia diagnosis. Klinikolaboratornyj konsilium. 2009;3:57-71. (In Russ.)

26. Boiko EV, Karev VE, Pozniak AL, et al. Chronic conjunctivitis as an extragenital focus of genitourinary chlamydial infection. Russian Annals of Ophthalmology. 2026;141(1):95100. (In Russ.) doi:10.17116/oftalma202614201195

27. Barton A, Faal N, Ramadhani A, et al. Longitudinal changes in tear cytokines and antimicrobial proteins in trachomatous disease. PLoS Negl Trop Dis. 2023;17(10):e0011689. doi:10.1371/journal.pntd.0011689

28. Letafati A, Ghafari P, Mobarezpour N, et al. Prevalence of Chlamydia trachomatis in eye specimens of patients suspected of having viral keratitis: a cross-sectional study. New Microbes New Infect. 2025;66:101604. doi:10.1016/j.nmni.2025.101604

29. Sidorovich Syu, Latypova MF, Kolikova TG, et al. Sravnitel’nyj analiz metodov laboratornoj diagnostiki urogenital’nogo hlamidioza. Vestnik Dermatologii i Venerologii. 2001;(1):9-10.

30. Rodrigues R, Silva AR, Sousa C, Vale N. Addressing Challenges in Chlamydia trachomatis Detection: A Comparative Review of Diagnostic Methods. Medicina (Kaunas). 2024;60(8):1236. doi:10.3390/medicina60081236

31. Shetty S, Kouskouti C, Schoen U, et al. Diagnosis of Chlamydia trachomatis genital infections in the era of genomic medicine. Braz J Microbiol. 2021;52(3):1327-1339. doi:10.1007/s42770-021-00533-z

32. Ripa T, Nilsson P. A variant of Chlamydia trachomatis with deletion in cryptic plasmid: implications for use of PCR diagnostic tests. Euro Surveill. 2006;11(11):E061109.2. doi:10.2807/esw.11.45.03076-en

33. Hokynar K, Rantakokko-Jalava K, Hakanen A, et al. The Finnish New Variant of Chlamydia trachomatis with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test. Microorganisms. 2019;7(8):227. doi:10.3390/microorganisms7080227

34. Roy F, Beirnes J, LeBlanc JJ, et al. Surveillance for Chlamydia trachomatis variants escaping detection with the Aptima Combo 2 assay in Canada from 2019 to 2021. Microbiol Spectr. 2025;13(3):e0206224. doi:10.1128/spectrum.02062-24

35. Domeika M, Savicheva A, Sokolovskiy E, et al. Guidelines for the laboratory diagnosis of Chlamydia trachomatis infections in East European countries. J Eur Acad Dermatol Venereol. 2009;23(12):1353-1363. doi:10.1111/j.1468-3083.2009.03328.x

36. Agaeva GI. Comparative evaluation of the efficiency of modern methods of diagnostics of ophthalmochlamidiosis. Meditsinskie novosti. 2019;9:51-54. (In Russ.)

37. Magaki S, Hojat SA, Wei B, et al. An Introduction to the Performance of Immunohistochemistry. Methods Mol Biol. 2019;1897:289-298. doi:10.1007/978-1-4939-8935-5_25

38. Arévalo F, Rayme S, Zurita F, et al. Immunohistochemical detection of chlamydia trachomatis in sexually transmitted infectious proctitis. BMC Gastroenterol. 2022;22(1):171. doi:10.1186/s12876-022-02233-w

39. Rahman KS, Darville T, Russell AN, et al. Comprehensive Molecular Serology of Human Chlamydia trachomatis Infections by Peptide Enzyme-Linked Immunosorbent Assays. mSphere. 2018;3(4):e00253-18. Published 2018 Aug 1. doi:10.1128/mSphere.00253-18

40. Tošić-Pajić J, Sazdanović P, Nikolov A, et al. Combination of Individual Tests to Improve Diagnostic Accuracy in Chlamydia trachomatis Detection. Medicina (Kaunas). 2025;61(4):714. doi:10.3390/medicina61040714

41. Sarkar K, Saini V. Current Topics in Chlamydia trachomatis Infections [Internet]. Understanding Sexually Transmitted Diseases – Prevention, Symptoms, and Treatment Options [Working Title]. IntechOpen; 2024. DOI: 10.5772/intechopen.1007204

42. Chemisova OS, Tsyrulina OA, Trukhachev AL, Noskov AK. Comparative analysis of methods for isothermal amplification of nucleic acids. Journal of microbiology, epidemiology and immunobiology. 2022;99(1):126-138. doi:10.36233/0372-9311-176.