This study examines the use of Trypan Blue staining of the corneal endothelium in patients undergoing phacoemulsification. It is a single-center prospective, randomized individual cohort study. One eye in each patient with diabetic retinopathy will undergo phacoemulsification without Trypan Blue capsule staining (control eye) while the other eye will undergo phacoemulsification with Trypan Blue capsule staining (study eye). Both eyes will undergo intraocular lens implantation. Preoperative and four-week postoperative quantitative and qualitative morphometric endothelial cell analyses of the cornea will be performed using noncontact specular microscopy.

Inclusion Criteria:

• Patients with bilateral cataract and diabetic retinopathy

Exclusion Criteria:

• History of ocular surgery Active
• ocular inflammation Corneal opacities
• Pseudoexfoliation syndrome
• Anterior chamber flare and (or) other signs of possibly altered blood - queous barrier
• Iris neovascularization (rubeosis)
• Uncontrolled glaucoma
• Congenital or traumatic cataracts
• History or present chronic use of topical or systemic steroids
• Poor papillary dilatation (<6 mm)
• Specular microscopy cell density < 2000 cell/mm2
• Patients who experienced complications fromphacoemulsification

Randomization was done using an envelope technique wherein, after each patient was placed on the operating bed, the surgeon opened the patient's corresponding envelope, which contained information about whether Trypan Blue should be used for anterior capsular staining or not.