Impression cytology in the evaluation of ocular surface tumors: review article

Abstract

Impression cytology (IC) has been widely used as a method for evaluating the ocular surface and superficial cells layers in the diagnosis and follow-up after treatment of several ocular surface tumors of both epithelial and melanocytic origin. Information regarding this can be found in the English-language literature since 1992. Using either cellulose acetate or Biopore membranes for specimen collection, a high correlation has been found between IC and tissue histology. Compared with exfoliative cytology with spatula, IC is less traumatic to the patient's eye, provides a precise location of the area being studied, and allows accurate observation of the cells the way they exist in vivo. The additional advantage of IC is the preservation of limbal stem cells responsible for continuous corneal epithelium renewal; these can be affected after incisional or excisional biopsy at the corneoscleral limbus, which is the most frequent site of appearance of tumors in the stratified epithelium. Treatment for ocular surface squamous neoplasia has historically included surgery, but nonsurgical interventions have also been adopted. Hence, in certain cases, ophthalmologists may prefer interventions less invasive than surgical biopsy such as of impression cytology for both initial diagnosis and therapeutic monitoring of treatment for ocular surface lesions. Nevertheless, it should be considered that IC may be less helpful if the results conflict with the clinical picture or if the clinical diagnosis is uncertain and results are negative. In such cases, surgical biopsy is required for accurate diagnosis. The purpose of this review is to examine the published literature on the utilization of IC for the diagnosis and management of ocular surface tumors and to discuss the requirement for further investigation on the subject.

Impression cytology as diagnostic tool in horses with and without ocular surface disease

“…ICS collects the most superficial layers of the ocular surface due to the adhering property of the sampling device [4]. ICS is now widely used in human ophthalmology to examine the healthy ocular surface [5] and to assess conjunctival and corneal alterations in contact lens wearers [6][7][8] Examination of eyes with ocular surface neoplasia [9,10] and keratoconjunctivitis sicca [11,12] are other indications for ICS. A major advantage of ICS is the arrangement of harvested cells in their natural layout; thus enabling clinical pathologists to examine an exact copy of the area of interest.…”

Impression cytology in a series of clinically diagnosed ocular surface melanocytic lesions

“…The atypical cells expressed different sizes, with or without cytoplasmic pigment, irregular nuclear chromatin pattern, anisokaryosis characterized by large and irregular nuclei with prominent nucleoli, and mitoses. [5617] PAM with atypia, defined by Folberg et al [18] was diagnosed on IC when the relative proportion of atypical melanocytes were low. Malignant ocular surface melanocytic lesions, equivalent to malignant melanoma, were diagnosed cytologically when an abundant number of atypical melanocytes were observed.…”

“…Distinguishing benign from malignant or potentially malignant melanocytic lesions of the conjunctiva is of high significance for proper management of such lesions, monitoring the progression of a melanocytic lesion, and following up the effect of a therapeutic intervention. [156] For instance, avoiding an unnecessary excisional biopsy in the perilimbal areas is pivotal for the preservation of limbal stem cells which are responsible for renewal of corneal epithelium. [78]…”

“…[5] The exfoliative or brush cytology may also induce morphologic changes in cellular structure. [6] Impression cytology (IC), however, has been used as a noninvasive, rapid, inexpensive, outpatient-based, and easy to perform method for sampling superficial epithelium in various ocular surface disorders such as dry eyes, limbal stem cell deficiency, microbiological infections, and ocular surface neoplasms. [91011121314]…”

“…Additionally, although this method may not replace the gold standard mode of histopathology, it can play an essential role in the diagnosis and management of patients with ocular surface melanocytic lesions. [615] In the present study, the application of IC for the diagnosis of clinically diagnosed ocular surface melanocytic disorders was evaluated.…”