Impact of Well-Controlled Type 2 Diabetes on Corneal Endothelium Following Cataract Surgery: A Prospective Longitudinal Analysis.

The aim of this study was to evaluate corneal endothelial changes following phacoemulsification cataract surgery with intraocular lens implantation in patients with type 2 diabetes (study group) and without diabetes (control group). The study aimed to determine the extent of endothelial cell damage and the regenerative capacity of the cornea in patients with well-controlled diabetes. This study compared corneal endothelial parameters in 80 eyes (80 patients) with well-controlled type 2 diabetes and 80 eyes (80 patients) without diabetes, all of whom underwent uneventful phacoemulsification cataract surgery. Patients were examined preoperatively and at 14 days, 3 months, and 6-8 months postoperatively. Endothelial cell density (ECD), percentage of hexagonal cells (%HEX), cell size variability (CV), and central corneal thickness (CCT) were assessed using a specular microscope. Visual acuity, intraocular pressure (IOP), and cumulative dissipated energy (CDE) during phacoemulsification were also measured. The study and control groups were matched for age and sex. Preoperatively, patients with type 2 diabetes had significantly lower endothelial cell density (2480.76 ± 303.48 cells/mm) compared to the control group (2629.64 ± 304.73 cells/mm, = 0.002). Visual acuity was also significantly lower in the study group (0.44 ± 0.18) than in the control group (0.50 ± 0.19, = 0.049). No significant preoperative differences were observed in IOP, CV, %HEX, or CCT. Postoperatively, both groups experienced ECD decline: -18.44%, -18.77%, and -19.05% in the study group and -15.12%, -16.42%, and -16.73% in the control group at 14 days, 3 months, and 6-8 months, respectively. Differences between groups were not statistically significant ( = 0.285). A significant %HEX decrease was observed in both groups at all time points, with a greater decline in the study group at 14 days and 3 months. CV significantly increased in both groups at 14 days and 3 months postoperatively, but no significant difference was found between groups. A significant increase in CCT was observed at 14 days and 3 months postoperatively, with a greater increase in the study group at 14 days. Preoperative visual acuity negatively correlated with CDE in both groups. Additionally, CDE negatively correlated with ECD at all time points. Endothelial cell density is lower in patients with well-controlled type 2 diabetes than in non-diabetic individuals. Both groups are at risk of endothelial cell loss during phacoemulsification. Despite good glycemic control and comparable preoperative endothelial morphology, the cornea in diabetic patients is more vulnerable to damage, with a prolonged regeneration process. The impaired regenerative capacity of the corneal endothelium suggests the need for additional precautions during cataract surgery in diabetic patients. Despite ECD decline and delayed endothelial regeneration, the functional status of the cornea, as indicated by visual acuity and CCT, remains stable. The adequate corneal endothelial cell reserve in well-controlled type 2 diabetes patients allows for cataract surgery without significant corneal complications.