Histological findings in experimental macular surgery with indocyanine green

PURPOSE: To analyze the effect of different concentrations and application intervals of indocyanine green (ICG) on the retina in an experimental setting of macular surgery. METHODS: Twenty-one porcine eyes were used within 5 hours after enucleation. The eyes were hemisected and the vitreous removed. Different doses of ICG (up to 1 mg) were applied over the trephined macula, and the remainder of the eyecup was filled with a balanced salt solution (BSS). Both the ICG solution and the BSS were drained after 30 or 60 seconds and the complete eyecup irrigated and filled with fresh BSS. The posterior pole was then illuminated with a standard surgical light pipe and light source at maximum power for 3 minutes. Both the ICG-treated retina and the nontreated surrounding retina were processed for histology. RESULTS: Exposure of the retina at different concentrations of ICG either for 30 or 60 seconds, followed by illumination, caused no histologically detectable damage compared with the controls. No microarchitectural disorganization or cellular disruption was detected. The vitreoretinal interface seemed unaffected. CONCLUSIONS: Previously described severe damage to the inner retina of human donor eyes could not be found with even higher doses of ICG in this porcine model. Although differences within the species may contribute to these contradictory results, it is conceivable that the postmortem time and the vitality of the tissue influence the outcome in this ex vivo system.     

Indications for extra-oral implants: strategic methods apropos of a clinical case

We report the case of a 73-year-old man with an extensive tumor of the external ear, describing the criteria that led us to use an extra-oral implant and not reconstructive surgery. Each criteria was evaluated comparatively to another option and also on the prosthesis level.     

The role of observational studies in assessing the impact of antiviral therapies

During the past year many observational studies have reported on the impact of highly active antiretroviral therapy on their patient populations. Care should be taken when interpreting these findings because of possible biases due to reporting delay and loss to follow-up. The results are very encouraging, however, suggesting dramatic reductions in the incidence of AIDS and death, and resulting hospitalizations.     

Clinical measures of adiposity and percentage fat loss: which measure most accurately reflects fat loss and what should we aim for?

OBJECTIVE: To determine which clinical measure of childhood obesity should be monitored to best reflect change in adiposity in a weight management programme and estimate the degree of change needed to be relatively certain of fat reduction. SUBJECTS: 92 obese children with a mean (range) age of 12.8 (6.9-18.9) years and a mean body mass index standard deviation score (BMI SDS) of +3.38 (+2.27 to +4.47) attending a hospital-based clinic on a regular, 3 monthly basis. Measurements: Pairs of weight and height measured up to 2.41 years apart used to derive BMI as kg/m2, and adjusted for age and gender to give weight and BMI SDS (BMI-z score) using British 1990 Growth Reference Data. Contemporaneous adiposity estimated by fatness measured by a bioimpedance segmental body composition analyser. RESULTS: Changes in BMI-z scores, compared to BMI, weight and weight SDS, most accurately reflected loss of fat. Reductions of 0.25, 0.5, 0.75, and 1 BMI SDS equate to expected mean falls in total body fat percentage of 2.9%, 5.8%, 8.7% and 11.6%. Approximate 95% prediction intervals indicated that a fall in BMI SDS of at least 0.6 over 6-12 months (or 0.5 over 0-6 months) is consistent with actual fat loss. CONCLUSION: Change in BMI-z score best reflects percentage fat loss compared to BMI, weight and weight SDS. The wide variation in likely percentage fat loss for a given BMI SDS reduction means a loss of 0.5-0.6 is required to be relatively certain of definite percentage fat reduction.