Cigarette Smoking As An Independent Predictor Of Endothelial Cell Loss After Cataract Surgery: A Prospective Cohort Study

Purpose: To evaluate effects of cigarette smoking on corneal endothelial cell density after cataract surgery and whether smoking predicts endothelial loss.

Methods: Prospective cohort study of patients >40 years undergoing phacoemulsification, classified as smokers or non-smokers. ECD was measured preoperatively and at 1 and 3 months. Analyses included t-tests and multivariate regression.

Results: Eighty eyes were analyzed. Smokers had lower baseline ECD (p ≤ 0.004). Postoperative ECD loss was greater in smokers (p < 0.001). Smoking independently predicted endothelial reduction (β = −0.48; p < 0.001).

Conclusions: Smoking is associated with endothelial vulnerability after cataract surgery and should be considered in perioperative assessment.

This prospective, single-center cohort study was performed at a high-volume tertiary academic ophthalmology center in Italy (University of Modena and Reggio Emilia) between January and December 2024. The institution functions as a referral center for complex anterior segment surgery, with standardized perioperative protocols and procedures performed exclusively by experienced surgeons.

This prospective observational cohort study was conducted at University of Modena and Reggio Emilia (Italy) and approved by local Ethics Committee. Patients >40 years with senile cataract were classified as smokers (combusted tobacco users) or non-smokers; vaping/oral tobacco users and those with prior ocular surgery or corneal/systemic disease were excluded. Preoperative and 1- and 3-month assessments included specular microscopy (ECD, CCT, CV, HEX%) and BCVA. Smoking exposure was quantified in pack-years. All surgeries were standardized phacoemulsification performed by two experienced surgeons. Comparisons used t-tests; multivariate regression adjusted for age, sex, and pack-years; effect sizes were calculated with Cohen’s d (p < 0.05).

Eighty eyes (40 smokers, 40 non-smokers) were analyzed. Baseline age and gender were comparable. Smokers showed lower baseline ECD (2294.8 vs 2523.9 cells/mm²; p = 0.0005) and higher CCT (556.2 vs 538.4 µm; p = 0.004). Postoperative ECD loss was significantly greater in smokers at 1 and 3 months (p < 0.001). Smoking independently predicted endothelial reduction (β = −0.48; p < 0.001) and increased odds of ECD < 2000 cells/mm² and CCT > 550 µm. HEX% was lower and CV% higher in smokers (p < 0.001; Cohen’s d up to 1.96). BCVA improved similarly in both groups. Smoking is an independent risk factor for impaired endothelial recovery after cataract surgery.

In conclusion, cigarette smoking emerges as a strong, independent risk factor for impaired corneal endothelial recovery following cataract surgery. These findings should encourage a more proactive approach in managing patients with a smoking history, ultimately aiming to optimize surgical outcomes and long-term corneal health.