Fast and easy visualization method of impression cytology probe
with microbiota detection on the ocular surface
Yugay, N.Y. (Nikolay)1, Novikov, N.I. (Ivan)2, Subbot, S.A. (Anastasia) PhD2, Khalatyan, K.S. (Anait)3
1 I.M. Sechenov First Moscow State Medical University (Sechenovskiy University), Ophthalmology, Moscow,
2 Research Institute of Eye Diseases, Laboratory of Basic Research in Ophthalmology, Moscow, Russian
3 Research Institute of Eye Diseases, Ophthalmology, Moscow, Russian Federation
Impression cytology is non- or minimally invasive technique used for ocular surface examination.
This technique is in constant expansion due to its advantages and high diagnostic potential.
Usually the conjunctival cavity and its microbiota are examined by light microscopy or
bacteriological culture methods. However, limitations of the light microscopy method do not
allow to visualize properly the bacterial component of the probe. After that, microbiological
culture methods are time consuming and some types of bacteria can’t be cultivated in standard
conditions, what can lead to false negative results. Identication of the pathogen is crucial on
behalf of choosing an antibacterial therapy. This challenge can be solved by scanning electron
microscopy. At the same time, conventional sample preparation is quite a long process. We
aimed to use a new fast two-step lanthanoid contrasting method with subsequent visualization
on scanning electron microscope.
Materials & Methods
12 patients participated in the study. 6 of them had specic signs of infectious inammatory
process on the ocular surface. Other patients didn’t suer from ocular surface diseases. Topical
anesthesia was not required, because exible plastic cover slips didn’t cause any discomfort to
the patients. The specimen preparation included 2 stages: treatment with neodymium and with
plumbum (BioREE-B staining kit). Further, these specimens were examined on the scanning
In visualized samples we found squamous epithelial cells, mucosal components and microbiota.
Epithelial cells seemed to enter the apoptotic process (karyopicnosis and cytoplasm vacuolation).
In two out of six cases with supposed infectious process increased density of coccomorphic
organisms compared with “healthy” donors was detected. Sometimes it was possible to visualize
It is the rst time, when pictures of ocular surface were obtained so fast and with so high
resolution. New contrasting method with neodymium and plumbum treatment enable to give
the morphological assessment of the most supercial layers. Furthermore, quality of the images
allows to evaluate not only functional status of corneal cells, but also microbiota activity.