Compression of the Lid Margin Increase Microbial Contamination Risk of Patients Undergoing Cataract Surgery

Inclusion Criteria: * (1) Age \> 60 years; (2) clinical diagnosis of age related cataract, without previous recent ocular surgery; (3) undergoing phacoemulsification with implantation of intraocular lens ; (4) able to give informed consent. Exclusion Criteria: * (1) any inflammation of the eye or other parts of the body within the previous 3 months; (2) chronic use of any types ophthalmic medication; (3) contact lens wear; (4) ocular surgery within the past 3 months; (5) use of systemic antibiotics within 30 days; (6) use of eyedrops in either eye within 3 days of enrollment; (7) need for concurrent glaucoma, cornea or other surgery.