Topical ophthalmic antibiotics are common prescribed just prior to eye surgery to lower the risk of infection. Previous studies have suggested that antibiotics containing a preservative (Zymar) kill bacteria much quicker than those without a preservative (Vigamox). The purpose of this research is to compare how quickly to the two commonly prescribed antibiotics eliminate bacteria from the eye surface.

• Ta CN, He L, Nguyen E, De Kaspar HM. Prospective randomized study determining whether a 3-day application of ofloxacin results in the selection of fluoroquinolone-resistant coagulase-negative Staphylococcus. Eur J Ophthalmol. 2006 May-Jun;16(3):359-64.
• Mino de Kaspar H, Koss MJ, He L, Blumenkranz MS, Ta CN. Antibiotic susceptibility of preoperative normal conjunctival bacteria. Am J Ophthalmol. 2005 Apr;139(4):730-3.
• de Kaspar HM, Kreidl KO, Singh K, Ta CN. Comparison of preoperative conjunctival bacterial flora in patients undergoing glaucoma or cataract surgery. J Glaucoma. 2004 Dec;13(6):507-9.
• Ta CN, Chang RT, Singh K, Egbert PR, Shriver EM, Blumenkranz MS, Mino de Kaspar H. Antibiotic resistance patterns of ocular bacterial flora: a prospective study of patients undergoing anterior segment surgery. Ophthalmology. 2003 Oct;110(10):1946-51.
• Ta CN, Egbert PR, Singh K, Shriver EM, Blumenkranz MS, Mino De Kaspar H. Prospective randomized comparison of 3-day versus 1-hour preoperative ofloxacin prophylaxis for cataract surgery. Ophthalmology. 2002 Nov;109(11):2036-40; discussion 2040-1.

Inclusion Criteria:

• Age- older than 50 years of age
• Diagnosis- Cataract or had cataract surgery

Exclusion Criteria:

• Systemic or topical antibiotic treatment within 30 days
• Use of systemic or topical steroids
• Active ocular infection
• Ocular surgery in the past 6 months
• Allergy to fluoroquinolones