Effects of lacrimal drainage occlusion with nondissolvable intracanalicular plugs on hydrogel contact lens wear.

PURPOSE: To investigate effects of lacrimal drainage occlusion with intracanalicular silicone plugs in hydrogel lens wearers with the symptom of dryness. Effects of rewetting drops in combination with the plugs were also evaluated. METHODS: A 6-week, prospective, double masked, placebo-controlled study design was followed. Thirty-five patients (26 females and 9 males) were entered into the study based on specific symptoms and signs of dry eye with hydrogel lens wear. Baseline symptoms, noninvasive prelens tear film break-up time, lens water content, fluorescein, and rose bengal staining were recorded. Herrick Lacrimal Plugs were inserted into both canaliculi of one previously randomized eye by an independent investigator. The fellow eye was manipulated in a sham procedure. Symptoms and signs were followed over 4 weeks. Nonpreserved rewetting drops were used in both eyes during the 5th week. Symptoms and signs were again followed. RESULTS: Symptoms improved more significantly in the plugged eye than the control eye after insertion of the plugs, and again after use of the drops. This improvement diminished in some of the patients. Prelens tear film break-up time was not significantly changed. Water content of all lenses combined increased only in the plugged eye with the use of drops. Fluorescein staining decreased significantly in the plugged eye. Rose bengal staining showed a slight decrease in the plugged eye. CONCLUSIONS: Intracanalicular silicone plugs offer improvement of symptoms and signs of dryness in this population. There seems to be some decrease in improvement of symptoms with the plugs over time. Concurrent use of rewetting drops increases the benefits.

Toxicity of insulin administered chronically to human eye in vivo.

Insulin administered in eyedrop from with a surfactant agent has been shown to be clinically effective in treating diabetes in animal models. Concentrations of insulin as high as 100 U/ml in saline were shown to produce no detectable clinical toxicity to human eyes in single-dose administration. We sought to investigate the local toxicity of insulin in human eyes during long-term, multidose administration. A prospective, randomized, placebo controlled, double-masked study was conducted involving eight healthy volunteers. Subjects were given 50 microliters sterile saline containing 100 U/ml crystalline porcine insulin randomized to one eye and 50 microliters placebo (sterile saline) to the fellow eye administered twice daily for 8 weeks. Subjective ocular irritation and visual acuity and objective assessment of the eyelids, conjunctiva, cornea, anterior chamber, crystalline lens, pupil size, and intraocular pressure were evaluated. Blood D-glucose levels were monitored to assess glycemic levels. There was no statistically significant difference (p > 0.05) observed between insulin-treated and placebo-treated eyes. Eyedrops containing insulin were subjectively as comfortable and objectively as clinically innocuous as sterile saline alone. The results of this study demonstrate that insulin (100 U/ml) in saline is nontoxic to the human eye after long-term, multi-dose exposure. Topical administration of insulin combined with an absorption-promoting agent may be a practical and feasible alternative to multiple daily subcutaneous injections or implanted pump devices currently used in the long-term treatment of diabetes mellitus if a nonirritating absorption-promoting agent can be identified.(ABSTRACT TRUNCATED AT 250 WORDS)