Changes in corneal thickness and corneal endothelial cell density after phacoemulsification cataract surgery: a double-blind randomized trial

BACKGROUND: Age-related cataract is a leading cause of visual impairment, considered a global health burden, it is responsible for over 47% of blindness worldwide. Surgical intervention is usually the treatment of choice and phacoemulsification cataract surgery with implantation of an intraocular lens is the most common procedure, which may have several complications. OBJECTIVES: To determine the effects of phacoemulsification surgery on corneal endothelial cell density and corneal thickness in patients undergoing cataract surgery. METHODS: The present study was conducted on patients diagnosed with immature senile cataract requiring surgical intervention from November 2013 to 2014 in Khatam al Anbia Hospital (a tertiary ophthalmology center). Physical examination included best-corrected visual acuity using the Snellen chart, refraction, slit-lamp bio-microscopy for anterior chamber evaluation, keratometry, Goldman tonometry, gonioscopy, and dilated indirect ophthalmoscopy, pachymetry, specular microscopy and biometry. Surgery was performed by similar method and technique in all patients. The change in the corneal endothelial cell count or density and central corneal thickness (CCT) number were compared preoperatively and one day, one week, one month, and three months post–operatively. RESULTS: A total of 92 eyes of 85 patients (43 females and 42 males with mean age of 62.1±12.2 years) were studied. Patients’ visual acuity improved (log MAR: 1±0.5 preoperatively to 0.45±0.34 post-operatively) (p=0.001). There was 11.4% endothelial cell loss (ECL) and significant decrease in ECC (from 2,791.15±99.86 to 2,472.87±472.14) (p=0.04). The central corneal thickness increased significantly (from 530.47±2.60 to 540.91±36.07). Diabetic patients (12.9%) had a statistically significant higher ECL rate after phacoemulsification (14.6% versus 8.7% respectively, p=0.002). CONCLUSION: Phacoemulsification resulted in significant corneal endothelial damage, which is particularly important in patients with a borderline reservoir of endothelial cell, such as diabetic patients, which highlights the necessity of refining the current surgical methods and instruments to minimize the endothelial damage. TRIAL REGISTRATION: The trial was registered in the Thai clinical trial registry (http://www.clinicaltrials.in.th) with the ID: TCTR20171122001. FUNDING: The study was supported by a research grant of Mashhad University of Medical Sciences.