Assessment of conjunctival goblet cell density using laser scanning confocal microscopy versus impression cytology

Purpose: To determine the association between conjunctival goblet cell density (GCD) assessed using in vivo laser scanning confocal microscopy and conjunctival impression cytology in a healthy population. Methods: Ninety (90) healthy participants undertook a validated 5-item dry eye questionnaire, non-invasive tear film break-up time measurement, ocular surface fluorescein staining and phenol red thread test. These tests where undertaken to diagnose and exclude participants with dry eye. The nasal bulbar conjunctiva was imaged using laser scanning confocal microscopy (LSCM). Conjunctival impression cytology (CIC) was performed in the same region a few minutes later. Conjunctival goblet cell density was calculated as cells/mm(2). Results: There was a strong positive correlation of conjunctival GCD between LSCM and CIC (rho = 0.66). Conjunctival goblet cell density was 475 +/- 41 cells/mm(2) and 466 +/- 51 cells/mm(2) measured by LSCM and CIC, respectively. Conclusions: The strong association between in vivo and in vitro cellular analysis for measuring conjunctival GCD suggests that the more invasive CIC can be replaced by the less invasive LSCM in research and clinical practice. (C) 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.