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Purpose: To validate the use of noncontact scanning slit pachymetry and OCT pachymetry measurements without contact lens (CL) removal, to determine corneal swelling variations during extended wear (EW)., Methods: Central corneal thickness (CCT) was measured with ultrasonic (US) pachymetry, noncontact scanning slit pachymetry (Orbscan II; Bausch & Lomb, Tampa, FL), and optical coherence tomography (OCT) 1 week before the wearing of CLs and during 1 week of EW. High-Dk (lotrafilcon A) and low-Dk (etafilcon A) soft CLs were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health. Orbscan and OCT were also performed without CL removal after 3 and 7 days of wear., Results: CCT measured with Orbscan and OCT showed a high correlation with US pachymetry. There were corneas with edema and without edema. Bland-Altman analysis showed a high level of agreement between Orbscan and OCT, with and without CL removal and with US pachymetry. High repeatability of Orbscan (r(2) = 0.000) and OCT (r(2) = 0.001) measurements without CL removal was also found. Etafilcon A lenses induced significantly higher corneal swelling than did lotrafilcon A lenses measured with Orbscan and OCT., Conclusions: Orbscan and OCT are accurate, noninvasive, and reproducible techniques for evaluation of CCT without CL removal. OCT has more accuracy and repeatability than does Orbscan. Both techniques allowed for measurement throughout the study period of the CCT differences induced by CL wear.

Purpose: To report the ocular surface pathology of patients suffering from acute/subacute mercury vapor intoxication. Design: Cross-sectional study. Participants: Male workers intoxicated with inorganic mercury referred for ophthalmic involvement and healthy control subjects. Methods: The following tests were performed: dry eye (DE)-related symptoms indicated by the ocular surface disease (OSDI) index questionnaire; tear osmolarity; analysis of 23 tear cytokine concentrations and principal component and hierarchical agglomerative cluster analyses; tear break-up time (T-BUT); corneal fluorescein and conjunctival lissamine green staining; tear production by Schirmer and tear lysozyme tests; mechanical and thermal corneal sensitivity (non-contact esthesiometry); and corneal nerve analysis and dendritic cell density by in vivo confocal microscopy (IVCM). Results: Twenty-two out of 29 evaluated patients entered the study. Most had DE-related symptoms (OSDI values > 12), that were severe in 63.6% of them. Tear osmolarity was elevated (>308 mOsms/L) in 83.4% of patients (mean 336.23 (28.71) mOsm/L). Corneal and conjunctival staining were unremarkable. T-BUT was low (<7 s) in 22.7% of patients. Schirmer test and tear lysozyme concentration were low in 13.6% and 27.3% of cases, respectively. Corneal esthesiometry showed patient mechanical (mean 147.81 (53.36) mL/min) and thermal thresholds to heat (+2.35 (+1.10) °C) and cold (−2.57 (−1.24) °C) to be significantly higher than controls. Corneal IVCM revealed lower values for nerve density (6.4 (2.94) n/mm2), nerve branching density (2 (2.50) n/mm2), and dendritic cell density (9.1 (8.84) n/mm2) in patients. Tear levels of IL-12p70, IL-6, RANTES, and VEGF were increased, whereas EGF and IP-10/CXCL10 were decreased compared to controls. Based on cytokine levels, two clusters of patients were identified. Compared to Cluster 1, Cluster 2 patients had significantly increased tear levels of 18 cytokines, decreased tear lysozyme, lower nerve branching density, fewer dendritic cells, and higher urine mercury levels. Conclusions: Patients suffering from systemic mercury intoxication showed symptoms and signs of ocular surface pathology, mainly by targeting the trigeminal nerve, as shown by alterations in corneal sensitivity and sub-basal nerve morphology. [ABSTRACT FROM AUTHOR]