Reconstituted human corneal epithelium: a new alternative to the Draize eye test for the assessment of the eye irritation potential of chemicals and cosmetic products.

The aim of this study was to evaluate the interest of a new three-dimensional epithelial model cultivated from human corneal cells to replace animal testing in the assessment of eye tolerance. To this end, 65 formulated cosmetic products and 36 chemicals were tested by means of this in vitro model using a simplified toxicokinetic approach. The chemicals were selected from the ECETOC data bank and the EC/HO International validation study list. Very satisfactory results were obtained in terms of concordance with the Draize test data for the formulated cosmetic products. Moreover, the response of the corneal model appeared predictive of human ocular response clinically observed by ophthalmologists. The in vitro scores for the chemicals tested strongly correlated with their respective scores in vivo. For all the compounds tested, the response of the corneal model to irritants was similar regardless of their chemical structure, suggesting a good robustness of the prediction model proposed. We concluded that this new three-dimensional epithelial model, developed from human corneal cells, could be promising for the prediction of eye irritation induced by chemicals and complex formulated products, and that these two types of materials should be tested using a similar protocol. A simple shortening of the exposure period was required for the chemicals assumed to be more aggressively irritant to the epithelial tissues than the cosmetic formulae.

Speech perception skills and speech production intelligibility in French children with prelingual deafness and cochlear implants.

OBJECTIVE: To examine speech perception and production intelligibility in French children with prelingual deafness who received multichannel cochlear implants. DESIGN: Within-subject, repeated-measures design for assessing speech perception and a cross-sectional design for assessing overall speech intelligibility. SETTING: A pediatric cochlear implant center. SUBJECTS: Sixty-four French children with prelingual deafness who received multichannel cochlear implants (mean age at time of implantation, 3 years 11 months) underwent assessment for speech perception. A subset of 16 children who received implants by 3 years of age underwent assessment for speech intelligibility. MAIN OUTCOME MEASURES: Speech perception skills were assessed using phoneme detection, closed-set word and sentence recognition, and modified open-set (MOS) recognition. Speech intelligibility was assessed by asking 50 listeners to identify recorded speech samples from the subjects. Dependent variables for the studies consisted of percent of correct items. RESULTS: After implantation, all children were able to detect phonemes by 3 months. Closed-set word and sentence identification reached 100% accuracy by 48 months (7 children with 4 years of implantation experience). Some children (8 of 48) demonstrated some MOS recognition after 1 year. Modified open-set recognition averaged 67.9% by 42 months (12 children available) and 80% by 48 months (7 children available). Overall speech intelligibility was 4.2% after 1 year, 30.7% after 2 years, 55.2% after 3 years, and 74.2% after 4 years. Within-subject comparison of MOS recognition and overall speech intelligibility scores revealed an insignificant trend for high perceptual performance to be associated with higher speech intelligibility scores (P = .17). There also was a tendency for higher performance to be associated with longer implantation experience. CONCLUSIONS: Speech perception scores appear to increase with increased experience using a cochlear implant. Overall speech intelligibility appears to steadily improve with increased experience and appears to be poorly related to perceptual performance on MOS recognition tasks.