Evaluation of mycelium extent within the corneal stroma in keratomycosis: experimental study

E. V. Boyko; N. V. Vasilyeva; E. M. Trunin; N. V. Shchemerov; V. V. Tatarkin; I. A. Bosak; E. V. Presnyakov; I. Sorochanu; A. S. Sidina; D. E. Zhumabek; V. S. Tomazova; R. V. Deev; Э. В. Бойко; Н. В. Васильева; Е. М. Трунин; Н. В. Щемеров; В. В. Татаркин; И. А. Босак; Е. В. Пресняков; И. Сорочану; А. С. Сидина; Д. Е. Жумабек; В. С. Томазова; Р. В. Деев

doi:10.29413/ABS.2026-11.2.18

Evaluation of mycelium extent within the corneal stroma in keratomycosis: experimental study

https://doi.org/10.29413/ABS.2026-11.2.18

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Abstract

Background. The diagnosis and management of fungal keratitis remain major challenges in routine ophthalmic practice. This is largely attributable to the severe, treatment-resistant course of the disease and the high risk of recurrence, even when appropriate antifungal therapy is administered. A distinctive feature of keratomycosis is the ability of filamentous fungi to extend beyond the clinically visible margins of the lesion, which may significantly compromise treatment efficacy.

The aim. To determine the true extent of mycelial fungal spread within the corneal stroma in keratomycosis.

Materials and Methods. The study was performed using an experimental rabbit model of keratitis induced with Fusarium solani isolates. To assess the actual extent of the pathological process, slit-lamp biomicroscopy, anterior segment optical coherence tomography (OCT), and histological examination were employed. Measurements were obtained with consideration of corneal anatomical features.

Results. On days 7–9 after keratitis induction, in 9 cases demonstrated a well-defined biomicroscopic appearance consistent with fungal keratitis, with confirmed fungal etiology. Histological examination revealed fungal cells in 17 of 45 sections. A quantitative visual assessment using a corneal microscope and histological examination revealed a difference between these parameters (p = 0.0036), with the median area of proliferation in the corneal stroma being greater than the visually detectable infiltrate. Fungal cells also penetrated the entire corneal thickness in all samples, with detection in the aqueous humor of the anterior chamber.

Conclusion. The findings indicate that by day 8 of keratitis progression, the spread of fungal cells along stromal collagen lamellae may exceed the clinically visible lesion by nearly half and extend in depth to involve anterior chamber structures. These growth characteristics of filamentous fungi should be considered when planning the extent of surgical intervention in fungal keratitis.

Keywords

keratitis, ophthalmomycosis, fungal infection, Fusarium solani, keratomycosis, optical coherence tomography, diagnosis of keratomycosis, corneal histology, fungal keratitis recurrence

About the Authors

E. V. Boyko

North-Western State Medical University named after I.I. Mechnikov; S. Fyodorov «Eye Microsurgery» Federal State Institution, St. Petersburg Branch
Russian Federation

Ernest V. Boyko – Dr. Sc. (Med.), professor, head of the Department of Ophthalmology of the NWSMU named after I. I. Mechnikov; director of the S. Fyodorov «Eye Microsurgery» Federal State Institution, St. Petersburg Branch.

Kirochnaya Street, 41, St. Petersburg 191015; Yaroslav Gashek Str., 21, St. Petersburg 192283

N. V. Vasilyeva

P.N. Kashkin Research Institute of Medical Mycology, North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Natalia V. Vasilyeva – Dr. Sc. (Biol.), professor, director of the Kashkin Research Institute of Medical Mycology.

Santiago-de-Cuba Str., 1/28, St. Petersburg 194291

E. M. Trunin

North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Evgeny M. Trunin – Dr. Sc. (Med.), professor, head of the Department of Operative and Clinical Surgery with Topographic Anatomy named after S.A. Simbirtsev, NWSMU named after I.I. Mechnikov.

Kirochnaya Street, 41, St. Petersburg 191015

N. V. Shchemerov

North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Nikolay V. Shchemerov – postgraduate student of the Department of Ophthalmology, NWSMU named after I.I. Mechnikov.

Kirochnaya Street, 41, St. Petersburg 191015

V. V. Tatarkin

North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Vladislav V. Tatarkin – Cand. Sc. (Med.), associate professor of the Department of Operative and Clinical Surgery with Topographic Anatomy named after S.A. Simbirtsev, NWSMU named after I.I. Mechnikov.

Kirochnaya Street, 41, St. Petersburg 191015

I. A. Bosak

P.N. Kashkin Research Institute of Medical Mycology, North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Ilya A. Bosak – Cand. Sc. (Med.), senior researcher at the Kashkin Institute of Medical Mycology.

Santiago-de-Cuba Str., 1/28, St. Petersburg 194291

E. V. Presnyakov

Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery
Russian Federation

Evgenii V. Presnyakov – researcher at the Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery.

Fotiev Str., 10, Moscow 119991

I. Sorochanu

Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery
Russian Federation

Irina Sorochanu – researcher at the the Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery.

Fotiev Str., 10, Moscow 119991

A. S. Sidina

North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Anastasia S. Sidina – 1st year clinical resident of the Department of Ophthalmology, NWSMU named after I.I. Mechnikov.

Kirochnaya Street, 41, St. Petersburg 191015

D. E. Zhumabek

RUDN University named after Patrice Lumumba
Russian Federation

Dauren E. Zhumabek – 2^nd year clinical resident of the Department of Eye Diseases of the Medical Institute of RUDN University named after Patrice Lumumba.

Miklukho-Maklaya Str., 6, Moscow 117198

V. S. Tomazova

North-Western State Medical University named after I.I. Mechnikov
Russian Federation

Veronika S. Tomazova – a 6^th year student of the Faculty of Medicine, NWSMU named after I.I. Mechnikov.

Kirochnaya Street, 41, St. Petersburg 191015

R. V. Deev

Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery
Russian Federation

Roman V. Deev – Cand. Sc. (Med.), Acting Director of the Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery.

Fotiev Str., 10, Moscow 119991

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Review

For citations:

Boyko E.V., Vasilyeva N.V., Trunin E.M., Shchemerov N.V., Tatarkin V.V., Bosak I.A., Presnyakov E.V., Sorochanu I., Sidina A.S., Zhumabek D.E., Tomazova V.S., Deev R.V. Evaluation of mycelium extent within the corneal stroma in keratomycosis: experimental study. Acta Biomedica Scientifica. 2026;11(2):187-195. (In Russ.) https://doi.org/10.29413/ABS.2026-11.2.18

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