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Bulgarian Review of Ophthalmology

Clinical application of impression cytology

Rozaliya Hristova, Georgi Markov, Yani Zdravkov, Alexandrina Vlahova, Ivan Tanev


Introduction: Impression cytology is an alternative to excisional biopsy minimally invasive method of histological examination of the ocular surface.

Aim: The purpose of this study was to determine changes in impression cytology samples of patients with ocular surface disease and to assess the diagnostic capabilities of the classical method introduced by Tseng et al. and standard histological techniques.

Materials and Methods: Analysis of 31 patients (36 eyes) and 15 healthy controls (30 eyes) from the Department of Ophthalmology, Alexandrovska University Hospital was conducted.

Results and Discussion: The pathology included mainly limbal stem cell deficiency in 77.42% (n=24) of the patients, 18 of whom had associated neurotrophic keratopathy. Optical coherence tomography demonstrated epithelial defects in 80.65% (n=25), stromal hyperreflectivity in all patients and specific changes. Samples processed using the classic method of Tseng et al., demonstrated hypercellularity and characteristic morphology of conjunctival and corneal cells. PAS+ cells in the corneal epithelium is a hallmark of conjunctivalization, which was present in 87.09% (n=27) of the patients. In some cases, the stratified squamous epithelium was keratinizing (keratinization). Inflammatory infiltration was found in 67.74% (n=21) of patients. However, due to hypercellularity the assessment of the reaction type was ambiguous. Standard histological samples demonstrated hypocellularity, stratified squamous non-keratinizing epithelium, and in 31.25% typical finds of regenerative processes were present. Cellular morphology in inflammatory reactions allowed defining the cells as lymphocytes or neutrophils.

Conclusion: The method of choice for processing the samples should be tailored to the investigated pathology and an individualized approach to every patient is required in order to obtain optimal diagnostic and therapeutic results.


impression cytology, neurotrophic keratopathy, ocular surface

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About The Authors

Rozaliya Hristova
Medical University Sofia

Medical University Sofia

Georgi Markov
Department of Ophthalmology, University Hospital Alexandrovska

Medical University Sofia

Yani Zdravkov
Department of Ophthalmology, University Hospital Alexandrovska

Medical University Sofia

Alexandrina Vlahova
Department of General and Clinical Pathology, University Hospital Alexandrovska

Medical University Sofia

Ivan Tanev
Department of Ophthalmology, Medical University Sofia