Myopia associated with hyperbaric oxygen therapy.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) involves exposing patients to elevated oxygen pressures and concentrations for the treatment of soft tissue degenerative diseases. As side effects, some patients experience cataract development and/or a significant increase in myopia. SUBJECTS: Eight subjects participated in this project. All were receiving HBOT for health problems. METHODS: For all subjects, acuities and refractive error corrections were measured before and after HBOT sessions at the beginning, midpoint, and end of therapy. For four subjects, A-scan ultrasound and corneal curvature measurements were also made before and after selected HBOT sessions. In addition, susceptibility to free radical damage and indicators of actual damage were measured by blood analyses. During the first half of HBOT therapy, four subjects took placebo tablets; during the second half, antioxidant supplements were given. RESULTS: No subject showed significant acuity or refractive error changes produced by single HBOT sessions. Two of the 8 subjects showed significant increases in myopia over the 20 session course of HBOT. No corresponding changes were found in the ultrasound, corneal curvature, or blood analysis data. DISCUSSION: Theoretically, the increases in myopia could have been caused by lenticular refractive index changes resulting from oxidative damage to lens proteins. However, the biochemical assays used in this project did not predict which subjects were susceptible to increased myopia, nor did they demonstrate elevated levels of free radical activity in a subject who did experience an increase in myopia.

Free radicals and antioxidant supplementation: a review of their roles in age-related macular degeneration.

BACKGROUND: Age-related macular degeneration (ARMD) is a major cause of blindness in the elderly. Unfortunately, no proven form of treatment is currently available for the dry, atrophic form of ARMD seen in more than 90 percent of patients with this condition. METHODS: A recent theory suggests that ARMD is associated with damage to the retina caused by free radicals. If this is correct, it is possible that the damage could be prevented or moderated by supplementing the diet with specific antioxidant vitamins and minerals that enhance the body's natural defenses against free radicals. RESULTS AND CONCLUSION: This paper reviews the literature regarding the pathogenesis of ARMD and presents a rationale for its management or prevention by the use of supplemental vitamins and minerals.

Evaluation of dietary antioxidant levels and supplementation with ICAPS-Plus and Ocuvite.

BACKGROUND: Oxidative damage caused by free radicals has been implicated in the development of age-related macular degeneration (ARMD). Recent studies suggest that antioxidant vitamins and minerals can be useful for the management and/or prevention of this condition. METHODS: To assess the normal dietary intake of the antioxidants, 28 healthy subjects 55 years of age and over completed a diet survey. Then two over-the-counter (OTC) nutritional supplements that make claims about the antioxidant nutrients they contain (ICAPS-Plus and Ocuvite) were evaluated with respect to their ability to raise blood levels of two important antioxidant nutrients: zinc and beta-carotene. RESULTS: Based on the diet survey, 26 of the 28 subjects were found to have deficient intakes; zinc and selenium were the most commonly deficient nutrients. Following a 2-week administration period, both ICAPS-Plus and Ocuvite significantly raised mean serum zinc levels 24.7 percent and 18 percent respectively; ICAPS-Plus significantly raised mean beta-carotene levels by 21.4 percent, but Ocuvite did not change the mean level significantly. CONCLUSIONS: Based on the probable relationship between antioxidant levels and diseases such as ARMD, these results suggest that OTC supplements might be useful for selected patients.

Fluress, fluorescein and benoxinate: recovery from bacterial contamination.

The ability to recover from bacterial contaminations with Staphylococcus auresus and Pseudomonas aeruginosa was determined for three optometric DPAs: Fluress, fluorescein and benoxinate. Results show that Fluress recovers from contamination more rapidly than benoxinate or fluorescein. This ability to recover from contamination and the relative ease of use of Fluress may make it the DPA choice for a number of optometric procedures including applanation tonometry.

Diagnostic pharmaceutical agents: side effects encountered in a study of 15,000 applications.

Data on DPA side effects were gathered from six schools and colleges of optometry for a reporting period from February 1 to April 30, 1979. These data indicate a low incidence of mild and transient side effects caused by several of the DPAs.

Influence of the indigenous gastrointestinal microbial flora on duodenal Mg2+ -dependent and (Na+ + K+) -stimulated adenosine triphosphatase activities in mice.

Mg-dependent and (Na+ + K+)-stimulated adenosine triphosphatase (ATP-ase) activities were assayed in butanol extracts of duodenal tissue from germ-free, specific-pathogen-free, and ex-germfree mice associated with an indigenous microflora from specific-pathogen-free mice. In the germfree mice the levels of both ATPase activities were significantly higher than the levels in specific-pathogen-free mice. By contrast, the ex-germfree animals colonized by an entire indigenous microflora, the values fell to levels close to those for specific-pathogen-free animals. (Na+ + K+)-stimulated ATPase was not inhibited by ouabain in extracts from any of the three kinds of mice. These findings show that the indigenous microbial flora influences the intestinal ATPase activity of mice and, because of the connection between (Na+ + K+-stimulate ATPase and active transpoort, undoubtedly affects the process of absorption in the intestinal tract.