ABSTRACT.Purpose: To investigate the effects of chronic smoking on the ocular surface and tear characteristics. Methods: The Schirmer I-test, tear film break-up time, rose Bengal staining scores, impression cytology, tear lysozyme concentration, eye irritation symptoms, and eye irritation indices were determined for 44 eyes in 44 healthy, chronic smokers who had smoked six or more cigarettes per day for the previous year. Thirty-seven eyes in 37 healthy, non-smokers were assessed in the same masked manner for comparison. Cytological specimens were obtained from the temporal interpalpebral bulbar conjunctiva by 'impression' technique. Goblet cells were counted in the specimens obtained and squamous metaplasia was graded following epithelial cell morphology assessment. Results: In chronic smokers, we found decreased tear film break-up time (p = 0.022) and tear lysozyme concentration (p = 0.013), and increased Schirmer I-test values (p = 0.047), squamous metaplasia scores (p = 0.016), eye irritation scores (p < 0.001) and eye irritation indices (p = 0.013), as compared with the control group. There were no statistically significant differences in goblet cell counts (p = 0.710) or rose Bengal staining scores (p = 0.827). Conclusion: These findings suggest that chronic smoking has a negative effect on the ocular surface and affects some tear characteristics. The chronic ocular irritative effects of cigarette smoking may lead to defects in ocular surface defence.

Selective LT was followed by an immediate increase in the aqueous humour LPO concentration and decreases of SOD and GST in the rabbit, probably due to photovaporization and photodisruption caused by the frequency-doubled Nd:YAG laser. The increased aqueous LPO levels suggest that free oxygen radicals are formed in the pigmented trabecular meshwork during LT, and may be responsible for the inflammatory complications of this procedure.

The aim of this study is to demonstrate the spectrum of conditions encompassed by the term ‘trachomatous cicatrization of eyelid tissue’, to discuss the mechanisms of scar tissue formation and to describe sequelae in this potentially blinding condition. Specimens of eyelid tissues were taken from 27 upper eyelids of 21 patients with entropion who underwent surgical procedures and 2 post-mortem upper eyelids with severe trachomatous entropion. Upper palpebral conjunctival swabs and biopsy specimens were taken from 5 patients with active trachoma and they were examined by fluorescence microscopy and routine histopathological methods. Conjunctival impression cytology samples were collected in all patients. In specimens taken from patients with active trachoma the inflammatory infiltrate was organized as lymphoid follicles in the underlying stroma and impression cytology showed cytoplasmic elementary bodies. In specimens taken from patients with scarring trachoma light microscopy studies showed subepithelial fibrous membrane formation, squamous metaplasia and loss of goblet cells, pseudogland formation in conjunctiva, degeneration of orbicularis oculi muscle fibres, subepithelial vascular dilatation, localized perivascular amyloidosis and subepithelial lymphocytic infiltration. Accessory lachrymal glands and the ducts of glands were compromised by subepithelial infiltration and scarring. The contraction of the subepithelial fibrous tissue formed by collagen fibres and anterior surface drying are the main factors contributing to the chronic cicatrization and entropion formation.

Topical CsA was effective in the treatment of severe trachomatous dry eye, yielding improvements in both objective and subjective measurements with a safety profile.

Oxygen free radicals may be implicated as a mediator of inflammation in endotoxin-induced uveitis. The increase in free radicals in the aqueous humor may play a role in the pathogenesis of endotoxin-induced uveitis.