The newly-introduced Touch Tear Micro Assay System is perhaps the first objective measure of aqueous deficient dry eyes and will help catch those patients who test borderline with other techniques such as the Schirmer's test or corneal staining. The Touch Tear Micro Assay System detects aqueous deficiency by measuring the concentration of lactoferrin in a tear sample taken from the patient. A reduced level of this lacrimal protein has been shown to directly correlate with reduced tear production by the lacrimal gland. It has been suggested that deficiency of lacrimal protein may be the earliest sign of an aqueous deficient dry eye. Top Of Page Viagra Causes Visual Symptoms.
Visual symptoms can last several hours and include light sensitivity and a bluish color tinge.
Relaxation of this tissue allows more blood to flow into the penis producing an erection. The retina contains a similar enzyme, PDE type 6, which is critical to the normal functioning of the photoreceptor cells. Viagra has a 10-times weaker inhibitory action on retinal PDE, thus accounting for the visual symptoms. The significance of these symptoms is unclear, and it is not known if Viagra causes any permanent damage in patients with pre-existing retinal disease. Studies appear to show that the drug is safe in patients with diabetes as well as macular degeneration .