Smoking Cessation May Reduce Risk of Visual Field Progression in Heavy Smokers

Abstract

Prcis: The earlier a person quits smoking the more likely is the optic nerve be spared from damage.

Purpose: To investigate the effect of smoking cessation on visual field (VF) progression in glaucoma.

Methods: Primary open angle glaucoma patients with a minimum of 3 years follow-up and 5 VFs were included. Linear mixed models were used to investigate the effects of smoking on the rates of 24-2 VF mean deviation loss after adjusting for confounding factors. Cox proportional hazard regression was used to identify whether different levels of smoking intensity were associated with VF progression with respect to different duration of quitting.

Results: Five hundred eleven eyes of 354 patients were included over the mean follow-up of 12.4 years. Mean baseline age (95% confidence interval) was 62.3 (61.2, 63.4) years. One hundred forty nine (42.1%) patients were smokers. In a multivariable model, smoking intensity was associated with faster VF loss (-0.06, 95% confidence interval (-0.10, -0.01) dB/year per 10 pack-years, P =0.01) among smokers. Heavy smokers (≥20 pack-years) who had quit ˂25 years prior had significantly greater odds of VF progression compared with never smokers (odds ratio=2.49 (1.01, 6.08); P =0.046). There was no significant difference in odds of VF progression in heavy smokers who had quit smoking more than 25 years compared with never smokers ( P =0.43). A significantly higher proportion of VF progression was found in heavy smokers who quit < 25 years compared with heavy smokers who quit ≥25 years by Kaplan-Meier analysis ( P =<0.001).

Conclusions: After ≥25 years of smoking cessation, the risk of VF progression in former heavy smokers becomes similar to never smokers. Long-term smoking cessation may be associated with lower VF progression in glaucoma patients.

Figure 1.

Hazard event risk associated with visual field progression among former smokers vs. never smokers is displayed, containing data from 52 eyes (39 subjects). This plot provides a stable estimate for relative risk of hazard event across a range of 0 to 30 years since quitting smoking. Former smokers are limited to those with at least 20 cumulative pack-years and are adjusted for age, alcohol consumption, body mass index, and mean intraocular pressure (IOP).

Figure 2.

Kaplan-Meier analysis of the probability to detect visual field (VF) progression in glaucoma eyes. Log-rank tests comparing heavy smokers (≥20 pack-years) who quit smoking within 25 years vs. heavy smokers who quit more than 25 years showed a statistically significant difference. (P= <0.001, log-rank test).