Preoperative characteristics and a potential mechanism of chronic dry eye after LASIK.

Purpose: To determine whether measurable preoperative characteristics predispose patients to chronic dry eye after laser in situ keratomileusis (LASIK).

Methods: The study consisted of 24 eyes of 24 patients who underwent LASIK. Tear breakup time, Schirmer testing with and without anesthesia, rose bengal staining, central corneal sensitivity, nucleus-to-cytoplasmic ratio, and goblet cell density were evaluated 2 weeks before and 1 week, 3 months, and 9 months after surgery.

Nitric oxide and cGMP mediate alpha1D-adrenergic receptor-Stimulated protein secretion and p42/p44 MAPK activation in rat lacrimal gland.

Purpose: To determine whether alpha(1)-adrenergic receptors use the nitric oxide (NO)/cGMP pathway to stimulate protein secretion by rat lacrimal gland.

Methods: Identification and cellular location of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) were determined by Western blot and immunofluorescence techniques, respectively. Rat lacrimal gland acini were isolated by collagenase digestion, and protein secretion stimulated by phenylephrine, an alpha(1)-adrenergic agonist, was measured with a fluorescence assay system.