RESUMO
Medical treatment of ophthalmic diseases relies primarily on the use of multidose drugs. Short term use is highly effective usually with little local toxicity. However, chronic use of these preparations not only increases the likelihood of microbial contamination and secondary ocular infection, but also of toxicity from the drug formulation itself. Increasing awareness of the toxicity of ophthalmic preservatives has led to an increasing variety of preservative schemes ranging from [self-preservation] to ionic buffer systems. Beyond outdated testing methods, the anti-microbial efficacy of most of these systems is poorly defined, potentially placing these preparations at an unknown risk of contamination by unmonitored, untested organisms. No uniformity in toxicity testing exists which further complicates the clinician's judgment of the risk-benefit of using a particular drug formulation. In this manuscript we examine in detail each of the current employed ophthalmic preservative regimens with respect to their known antimicrobial activity and potential toxicity, where known. We also survey the most popular ophthalmic preparations, detailing their preservation schemes as well as concentrations to help the clinician in choosing an appropriate formulation for the treatment of various ophthalmic diseases
RESUMO
Bleb dysesthesia is a common but under recognized late complication of trabeculectomy, sometimes requiring surgical revision if conservative measures fail. We describe in detail a surgical technique for closure of a large conjunctival defect following bleb excision for refractory dysesthesia. Two subconjunctival 5-fluorouracil injections were given to improve bleb function. Eight months post-operatively, the intraocular pressure is well controlled on two agents, and the patient has had resolution of dysesthesia