Microsporidial Stromal Keratitis: A Rare Entity in Central Europe

 

 Buy Article Permissions and Reprints

Background

Recent data analyses account for corneal opacities as the fifth leading cause of blindness worldwide [1], with infectious keratitis being the most common condition [2], [3]. Microsporidia are obligate intracellular, spore-forming fungi that may cause such infectious keratitis. Their ubiquitous presence in the environment leads to frequent human exposure [4], although the exact pathogenesis of keratitis remains unclear. Direct inoculation with contaminated water, food, soil, and ocular trauma has been postulated [5], [6]. There are two different corneal manifestations of microsporidial keratitis: multifocal epithelial keratitis, which mainly affects immunosuppressed patients as in human immunodeficiency virus (HIV), and stromal keratitis, largely seen among immunocompetent individuals [7]. The disease entity is endemic in Asian countries and has rarely been reported in Europe [8]. We describe a case of histopathologically confirmed stromal microsporidial keratitis diagnosed at a tertiary care hospital in Switzerland.

Publication History

Received: 16 October 2022

Accepted: 09 January 2023

Article published online:
25 April 2023

© 2023. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

• References

• 1 Flaxman SR, Bourne RRA, Resnikoff S. et al. Global causes of blindness and distance vision impairment 1990–2020: a systematic review and meta-analysis. Lancet Glob Health 2017; 5: e1221-e1234 DOI: 10.1016/S2214-109X(17)30393-5.
  CrossrefPubMedGoogle Scholar
• 2 Ung L, Bispo PJM, Shanbhag SS. et al. The persistent dilemma of microbial keratitis: Global burden, diagnosis, and antimicrobial resistance. Surv Ophthalmol 2019; 64: 255-271 DOI: 10.1016/j.survophthal.2018.12.003.
  CrossrefPubMedGoogle Scholar
• 3 Ting DSJ, Ho CS, Deshmukh R. et al. Infectious keratitis: an update on epidemiology, causative microorganisms, risk factors, and antimicrobial resistance. Eye (Lond) 2021; 35: 1084-1101 DOI: 10.1038/s41433-020-01339-3.
  CrossrefPubMedGoogle Scholar
• 4 Didier ES, Stovall ME, Green LC. et al. Epidemiology of microsporidiosis: sources and modes of transmission. Vet Parasitol 2004; 126: 145-166 DOI: 10.1016/j.vetpar.2004.09.006.
  CrossrefPubMedGoogle Scholar
• 5 Didier ES, Snowden KF, Shadduck JA. Biology of microsporidian species infecting mammals. Adv Parasitol 1998; 40: 283-320 DOI: 10.1016/s0065-308x(08)60125-6.
  CrossrefPubMedGoogle Scholar
• 6 Taju S, Tilahun Y, Ayalew M. et al. Diagnosis and treatment of microsporidial keratoconjunctivitis: literature review and case series. J Ophthalmic Inflamm Infect 2011; 1: 105-110 DOI: 10.1007/s12348-011-0025-y.
  CrossrefPubMedGoogle Scholar
• 7 Singh P, Tripathy K. Microsporidial Keratitis. Treasure Island (FL): StatPearls Publishing; 2022
  Google Scholar
• 8 Leroy J, Cornu M, Deleplancque AS. et al. Case Report: Ocular Microsporidiosis: Case in a Patient Returning from India and Review of the Literature. Am J Trop Med Hyg 2018; 99: 90-93 DOI: 10.4269/ajtmh.18-0015.
  CrossrefPubMedGoogle Scholar
• 9 Thomas PA. Current perspectives on ophthalmic mycoses. Clin Microbiol Rev 2003; 16: 730-797 DOI: 10.1128/CMR.16.4.730-797.2003.
  CrossrefPubMedGoogle Scholar
• 10 Sabhapandit S, Murthy SI, Garg P. et al. Microsporidial Stromal Keratitis: Clinical Features, Unique Diagnostic Criteria, and Treatment Outcomes in a Large Case Series. Cornea 2016; 35: 1569-1574 DOI: 10.1097/ICO.0000000000000939.
  CrossrefPubMedGoogle Scholar
• 11 Matoba A, Goosey J, Chevez-Barrios P. Microsporidial Stromal Keratitis: Epidemiological Features, Slit-Lamp Biomicroscopic Characteristics, and Therapy. Cornea 2021; 40: 1532-1540 DOI: 10.1097/ICO.0000000000002704.
  CrossrefPubMedGoogle Scholar
• 12 Moshirfar M, Somani SN, Shmunes KM. et al. A Narrative Review of Microsporidial Infections of the Cornea. Ophthalmol Ther 2020; 9: 265-278 DOI: 10.1007/s40123-020-00243-z.
  CrossrefPubMedGoogle Scholar
• 13 Coca M, Kim J, Shenoy S. et al. Microsporidial Stromal Keratitis: Successful Treatment with Topical Voriconazole and Oral Itraconazole. Cureus 2016; 8: e934 DOI: 10.7759/cureus.934.
  CrossrefPubMedGoogle Scholar
• 14 Joseph J, Vemuganti GK, Garg P. et al. Histopathological evaluation of ocular microsporidiosis by different stains. BMC Clin Pathol 2006; 6: 6 DOI: 10.1186/1472-6890-6-6.
  CrossrefPubMedGoogle Scholar
• 15 Huang HY, Wu CL, Lin SH. et al. Microsporidial stromal keratitis: characterisation of clinical features, ultrastructural study by electron microscopy and efficacy of different surgical modalities. Br J Ophthalmol 2020; 104: 613-620 DOI: 10.1136/bjophthalmol-2019-315094.
  CrossrefPubMedGoogle Scholar
• 16 Ueno S, Eguchi H, Hotta F. et al. Microsporidial keratitis retrospectively diagnosed by ultrastructural study of formalin-fixed paraffin-embedded corneal tissue: a case report. Ann Clin Microbiol Antimicrob 2019; 18: 17 DOI: 10.1186/s12941-019-0316-y.
  CrossrefPubMedGoogle Scholar
• 17 James TY, Kauff F, Schoch CL. et al. Reconstructing the early evolution of Fungi using a six-gene phylogeny. Nature 2006; 443: 818-822 DOI: 10.1038/nature05110.
  CrossrefPubMedGoogle Scholar
• 18 Corsaro D, Michel R, Walochnik J. et al. Molecular identification of Nucleophaga terricolae sp. nov. (Rozellomycota), and new insights on the origin of the Microsporidia. Parasitol Res 2016; 115: 3003-3011 DOI: 10.1007/s00436-016-5055-9.
  CrossrefPubMedGoogle Scholar
• 19 Khandelwal SS, Woodward MA, Hall T. et al. Treatment of microsporidia keratitis with topical voriconazole monotherapy. Arch Ophthalmol 2011; 129: 509-510 DOI: 10.1001/archophthalmol.2011.54.
  CrossrefPubMedGoogle Scholar
• 20 Sangit VA, Murthy SI, Garg P. Microsporidial stromal keratitis successfully treated with medical therapy: a case report. Cornea 2011; 30: 1264-1266 DOI: 10.1097/ICO.0b013e31821d876d.
  CrossrefPubMedGoogle Scholar
• 21 Loh RS, Chan CM, Ti SE. et al. Emerging prevalence of microsporidial keratitis in Singapore: epidemiology, clinical features, and management. Ophthalmology 2009; 116: 2348-2353 DOI: 10.1016/j.ophtha.2009.05.004.
  CrossrefPubMedGoogle Scholar