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Objective: To assess the efficacy of an orally administered antioxidant dietary supplement for managing marginal dry eye., Design: A prospective, randomised, placebo controlled trial with cross-over., Setting: Eye Clinic, Department of Vision Sciences, Glasgow Caledonian University., Subjects: Forty marginal dry eye sufferers composed of 30 females and 10 males (median age 53 y; range 38-69 y)., Interventions: Baseline assessments were made of tear volume sufficiency (thread test), tear quality (stability), ocular surface status (conjunctival impression cytology) and dry eye symptoms (questionnaire). Each subject was administered courses of active treatment, placebo and no treatment, in random order for 1 month each and results compared to baseline., Results: Tear stability and ocular surface status were significantly improved following active treatment (P<0.05). No changes from baseline were detected following administration of placebo and no treatment (P>0.05). Absolute increase in tear stability correlated with absolute change in goblet cell population density. Tear volume was not improved following any treatment period and dry eye symptom responses were subject to placebo effect., Conclusions: Oral antioxidants improved both tear stability and conjunctival health, although it is not yet understood whether increased ocular surface health mediates increased tear stability or vice versa., Sponsors: This study was supported by a PhD scholarship funded by the Department of Vision Sciences, Glasgow Caledonian University, Scotland. Antioxidant supplements and placebos were kindly donated by Vitabiotics.

Variations in sex hormones due to the menstrual cycle (and oral contraceptives) were evaluated for their effect on tear physiology. Subjects were 18 females taking oral contraceptives or their age matched controls (no medication), aged 21-33 years. Symptoms of ocular discomfort (visual analog scale), tear film structure (TearScope), non-invasive tear thinning time (HirCal grid), evaporation rate (ServoMed evaporimeter), osmolality (Nanolitre Osmometer), tear turnover rate, tear volume (Fluorotron Master), and tear protein levels (HPLC) were measured around day 2 (D2), actually day 1-4 and day 19 (D19) actually day 18-21 of the cycle. No significant differences were found for any tear parameters between D2 and D19 for either pill users or controls alone, or in the comparison of pill users with controls. No effect on tear physiology was found for serum hormone changes induced by oral contraceptive use or by normal cyclic variations in healthy young females.

Purpose: To assess whether the size of the cells obtained by conjunctival impression cytology can be quantitatively assessed by measurement of the longest dimension of the cells., Methods: Under topical benoxinate anaesthesia, cells were removed from the normally exposed nasal bulbar conjunctival surface using a 0.4 micron pore diameter filter (Biopore filter; type Millcell-CM). The filters were stained with haematoxylin after ethanol denaturation, photographed at 40 x magnification, and 35 mm slides prepared. An optical overlay method was used to outline the borders of sets of 30-35 contiguous cells on each image. The cell area, longest and shortest dimensions were measured by planimetry to an accuracy of +/- 3%., Results: Analyses of 20 sets of samples, from individuals aged 21 to 48 years and without clinically significant ocular surface disease, revealed a median cell area of 133 micron 2 (n = 621, range 46-1602 micron 2; average 212 micron 2), a median longest dimension of 13.9 microns (range 6.6-68.8 microns; average 16.9 microns) and a shorter dimension of 10.0 microns (range 4.7-43.0 microns; average 11.9 microns); the distributions of values indicated bimodality. Most cells had a long:short ratio (L:S ratio) value between 1.00 and 1.80, but 11.9 +/- 6.1% of the cells had L:S ratios between 1.80 and 4.60. The overall relationship between the longest dimension and the area of the cells was nonlinear, with cells having larger L:S ratios having disproportionately smaller areas., Conclusions: The superficial conjunctival cells are small, and their longest dimensions are systematically related to area. Analyses of cell shape indicate further possible ways of identifying different cells on the bulbar conjunctiva. Compared to literature values, there is a substantial overlap in longest dimensions of the conjunctival cells with those of cells that can be collected off the corneal surface. This means that superficial conjunctival and corneal cells cannot be distinguished simply on the basis of measurements of the long dimension.

Purpose: To quantitatively assess the measured nucleus-to-cytoplasm (N/C) ratios for sets of bulbar conjunctival cells categorised by a subjective grading scheme (0-3)., Methods: Impression cytology samples were taken from the nasal bulbar conjunctiva of 37 individuals (aged 22 to 74 years) without any significant eye disease. The sheets of cells were generally stained with Giemsa, photographed and 35 mm slides prepared. The images were graded 0 to 3 according to the scheme of Nelson [Cornea 7, 71-81 (1988)] and approximately 35 contiguous cells from each image measured by planimetry from an overlay., Results: Analysis of 1097 cells revealed that the N/C ratios ranged from 1.395 to 0.056 and correlated well with the grading. The average N/C ratio (range for +/- 1.96 SD) for each grade was 0.607 (0.983 to 0.531) for grade 0, 0.533 (0.759 to 0. 333) for grade 1, 0.291 (0.427 to 0.155) for grade 2, and 0.154 (0. 228 to 0.080) for grade 3., Conclusions: N/C ratios can be assessed from conjunctival impression cytology samples and appear to be sufficiently consistent to allow for a designated range of cell N/C ratios to be specified for each grade.

This survey article provides a current update on a variety of new cardioactive and vasoactive drugs that have recently been added to the anesthesia armamentarium. Included are discussions of pharmacologic agents, their effects on cardiovascular physiology, and mechanisms of each as they relate to specific uses of anesthesia care and general clinical practice. The cardioactive and vasoactive drugs discussed encompass sympathetic agonists, sympathetic antagonists, vasodilators, and calcium channel blockers.