The effect of povidone iodine flush versus drops on conjunctival colonization before intravitreal injections.
ABSTRACT To determine the most effective method of applying povidone iodine 5% to decrease conjunctival colonization before intravitreal injections.
Twenty-eight patients from two tertiary care centers undergoing intravitreal injection for diffuse diabetic macular edema, exudative age-related macular degeneration, venous occlusive disease, or refractory pseudophakic cystoid macular edema were prospectively randomized to two study arms. One arm received 2-3 drops of 5% povidone iodine (drops group) and the second received a 10 ml flush of the same solution (flush group). The inferior conjunctival fornix was cultured before and after antiseptic technique was performed in all patients. Three culture media, thioglycollate broth, chocolate agar and blood agar, were used for each sample.
Each study group had 14 patients. Prior to antisepsis, 22 of the 28 (78.6%) subjects had positive conjunctival cultures. 16 and 14 bacterial organisms were isolated in the first and second groups, respectively. After using 2-3 drops of 5% povidone iodine in the first study arm of patients, three of 16 (18.7% reduction) bacterial organisms were no longer isolated in thioglycollate broth media. With flush irrigation of 10 ml of 5% povidone iodine, seven of 14 (50% reduction) bacterial organisms were no longer isolated (P-value 0.07) in broth media. No difference in reduction of bacterial colonization was found on plated media (chocolate agar and blood agar).
Irrigating the conjunctival fornix with 5% povidone iodine results in greater reduction of bacterial colonization compared with drop application of the same solution. Flush irrigation may provide better protection against the risk of endophthalmitis with intravitreal injections.
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ABSTRACT: Introduction: Endophthalmitis is an uncommon but potentially devastating complication of cataract surgery and often carries a poor prognosis. The incidence of endophthalmitis varies considerably in the literature, ranging from 0.05% to 0.35%. Some measures routinely used as prophylaxis have not been proven to be of benefit. This article reviews the current literature on the common prophylactic measures used to prevent endophthalmitis. Methods: A search of the literature in Medline and critical review of the study design, sample size, and analysis of outcomes. Results: Clinical studies on prophylactic measures suggest that using povidone-iodine 5% to clean the eyelids and conjunctiva before cataract surgery has a significant benefit both in reducing the actual rate of endophthalmitis and reducing the bacterial load after surgery. A bolus dose of intracameral cefazolin or cefuroxime has a significant benefit on reducing infection rate, with evidence for the latter drug coming from a large, prospective, randomised clinical trial. There is some evidence to suggest that subconjunctival antibiotics may reduce the incidence of endophthalmitis, although much of the evidence comes from case-control studies. Although the current evidence on the efficacy of topical antibiotic drops is mixed, this is commonly practiced both pre-and postoperatively. Conclusions: The most useful prophylactic measures to reduce the rate of endophthalmitis are the use of 5% povidone-iodine and intracameral injection of antibiotics after surgery. Subconjunctival antibiotics may be of benefit, while topical antibiotics alone may not reduce the rate of endophthalmitis significantly.
Article: Clinical and antiviral efficacy of an ophthalmic formulation of dexamethasone povidone-iodine in a rabbit model of adenoviral keratoconjunctivitis.[show abstract] [hide abstract]
ABSTRACT: To determine the efficacy of a new formulation of topical dexamethasone 0.1%/povidone-iodine 0.4% (FST-100) in reducing clinical symptoms and infectious viral titers in a rabbit model of adenoviral keratoconjunctivitis. Rabbit corneas were inoculated bilaterally with 2×10(6) plaque-forming-units (PFU) of adenovirus type 5 (Ad5) after corneal scarification. Animals were randomized 1:1:1:1 (five rabbits per group) to FST-100, 0.5% cidofovir, tobramycin/dexamethasone (Tobradex; Alcon Laboratories, Fort Worth, TX) ophthalmic suspension, and balanced salt solution (BSS; Alcon Laboratories). Treatment began 12 hours after viral inoculation and continued for 7 consecutive days. The eyes were clinically scored daily for scleral inflammation (injection), ocular neovascularization, eyelid inflammation (redness), friability of vasculature, inflammatory discharge (pus), and epiphora (excessive tearing). Eye swabs were collected daily before treatment for the duration of the study. Virus was eluted from the swabs and PFU determined by titration on human A549 cells, according to standard procedures. The FST-100 treatment resulted in significantly lower clinical scores (P<0.05) than did the other treatments. The 0.5% cidofovir exhibited the most ocular toxicity compared with FST-100, tobramycin/dexamethasone, and balanced salt solution treatments. FST-100 and 0.5% cidofovir significantly (P<0.05) reduced viral titers compared with tobramycin/dexamethasone or balanced salt solution. FST-100 was the most efficacious in minimizing the clinical symptoms of adenovirus infection in rabbit eyes. FST-100 and 0.5% cidofovir were both equally effective in reducing viral titers and decreasing the duration of viral shedding. By providing symptomatic relief in addition to reducing infectious virus titers, FST-100 should be a valuable addition to treatment of epidemic adenoviral keratoconjunctivitis.Investigative ophthalmology & visual science 01/2011; 52(1):339-44. · 3.43 Impact Factor
Article: Intravitreal injection technique.[show abstract] [hide abstract]
ABSTRACT: As the intravitreal injection of therapeutic medication plays an increasingly large role in ophthalmology, its implementation continues to be modified and refined. Variations in injection technique are discussed, and the authors combine their clinical and research experience with a review of the literature to propose a recommended intravitreal injection protocol.Seminars in ophthalmology 05/2011; 26(3):104-13.