Preoperative Antisepsis With Povidone-Iodine 5% in Cataract Surgery

The ocular surface bacterial contamination and its management in the prophylaxis of post cataract surgery endophthalmitis

Objective: To investigate the recent pieces of evidence regarding the bacterial ocular surface contamination and its treatment in the prophylaxis of post-cataract surgery endophthalmitis. Methods: We conducted a literature research on the topic of interest and selected the most relevant data. Results: The studies reported a relatively high rate of positive conjunctival culture and the most frequently isolated organism was Coagulase negative Staphylococcus, which is also the most common etiological agent of the postoperative endophthalmitis. The bacterial ocular surface load is influenced by age, climate, associated diseases, topical and systemic medication. The use of povidone-iodine alone or in association with levofloxacin eyedrops as prophylactic method is effective in reducing the conjunctival bacterial contamination and consequently decreases the incidence of postoperative endophthalmitis. Conclusions: Based on the current pieces of evidence, adequate treatment of the bacterial ocular surface contamination prior to cataract surgery seems to be effective in preventing endophthalmitis after cataract surgery. Abbreviations: EU = European Union, Spp. = Species, HIV = Human Immunodeficiency Virus.

Comparison of the Effects of Povidone-Iodine 5%, Polyhexamethylene Biguanide, and Chlorhexidine as a Preoperative Antiseptic in Endophthalmitis Prophylaxis in Patients Undergoing Phacoemulsification Cataract Surgery

Background:

This study aims to compare the efficacy and toxicity of povidone-iodine (PI) 5%, polyhexamethylene biguanide (PHMB) 0.02%, and chlorhexidine 0.02% in patients undergoing phacoemulsification cataract surgery.

Materials and Methods:

This single-center, randomized study was done on 330 patients who referred to Feiz hospital in Isfahan and scheduled for cataract surgery. They were assigned randomly to 1 of 3 groups of 110 eyes who received 1 drop of PI 5% in group 1, 1 drop of PHMB 0.02% in group 2 and 1 drop of chlorhexidine 0.02% in group 3. Pre-operative Cultures samples were obtained without any topical application and it was repeated 5 min after use of antiseptic solutions. Cultures were obtained from the inferior conjunctival fornix, using sterile culture swabs while avoiding contact to the eyelids and lashes.

Results:

The numbers of colony-forming units (CFUs) did not differ significantly among the three groups (P = 0.149 and P = 0.260, respectively). After the intervention, CFUs numbers in the three groups were decreased with a significant difference in both blood and chocolate agars (P = 0.304 and P = 0.136, respectively). Of the 317 eyes, 108 (34.1%) showed no bacterial growth in the pre-preparation period, which was similar in the three groups. Staphylococcus epidermidis was the most common isolated bacteria. Conjunctival injection was significantly different among studied groups (P = 0.0001), five patients in iodine group had severe conjunctival injection and no one in the other group. SPE was significantly fewer in chlorhexidine group than PHMB and iodine groups (P = 0.0001).

Conclusion:

Pretreatment with 5% Povidone-Iodine (PVI) for at least 15 min or repeated applications over 10 min is effective in the reduction of conjunctival organisms, and results in less postoperative endophthalmitis.

Cataract

Cataract is the leading cause of reversible blindness and visual impairment globally. Blindness from cataract is more common in populations with low socioeconomic status and in developing countries than in developed countries. The only treatment for cataract is surgery. Phacoemulsification is the gold standard for cataract surgery in the developed world, whereas manual small incision cataract surgery is used frequently in developing countries. In general, the outcomes of surgery are good and complications, such as endophthalmitis, often can be prevented or have good ouctomes if properly managed. Femtosecond laser-assisted cataract surgery, an advanced technology, can automate several steps; initial data show no superiority of this approach over current techniques, but the results of many large clinical trials are pending. The greatest challenge remains the growing 'backlog' of patients with cataract blindness in the developing world because of lack of access to affordable surgery. Efforts aimed at training additional cataract surgeons in these countries do not keep pace with the increasing demand associated with ageing population demographics. In the absence of strategie that can prevent or delay cataract formation, it is important to focus efforts and resources on developing models for efficient delivery of cataract surgical services in underserved regions. For an illustrated summary of this Primer, visit: http://go.nature.com/eQkKll.