The retinal thickness and choroidal vascularity index in smokers

(Image credit: AdobeStock/Nopphon)

Miguel A. Quiroz-Reyes, MD, PhD, and colleagues found that cigarette smoking negatively affects the choroidal vascularity, as indicated by a significant reduction of the choroidal vascularity index (CVI).¹

The investigators are from The Retina Department of Oftalmologia Integral ABC Medical and Surgical Nonprofit Organization, National Autonomous University of Mexico, Lomas de Chapultepec, and the Juarez Hospital, Public Assistance Institution, both in Mexico City, Mexico.

They explained that smoking seems to have major ocular effects in that it “increases oxidative stress that affects the vascular endothelium by decreasing the antioxidant vitamin C and disrupting regular nitric oxide activity. Smoking reduces blood flow in the retina and choroid due to increased vascular resistance and compromised choroidal blood flow regulation compared to nonsmokers."²

The negative effects of smoking on ocular tissues are well known and include age-related macular degeneration (AMD), diabetic retinopathy, cataracts, contact lens-related keratitis, Graves’ ophthalmopathy,^3,4 ischemic optic neuropathy, and glaucoma.^5-7 Although the specific pathophysiological mechanism involved remains unclear, endothelial dysfunction is believed to play a pivotal role in the development of smoking-induced vascular diseases, according to Wimpissinger et al.², the authors commented.

They carried out a meta-analysis that included numerous studies identified in Web of Science, Medline, PubMed, and Embase. They included observational studies to explore the relationships between smoking and ocular parameters such as the CVI and full retinal/choroidal thicknesses.

Meta-analysis results

Four out of the 743 identified articles, involving 702 eyes, met the inclusion criteria. The analysis revealed a significant reduction in the CVI among smokers (standard mean difference:

-0.61, 95% confidence interval [CI]: -0.78 to -0.43, p < 0.00001), indicating compromised choroidal vascularity,” the authors reported.

In contrast, the impact of smoking on the subfoveal choroidal thickness (SFCT) did not reach significance (mean difference: 3.88 μm, 95% CI: -7.34-15.10, p = 0.50), with high heterogeneity (I² = 79%). The full-retinal thickness (FRT) also did not differ significantly between smokers and nonsmokers.

They also suggested that the mean CVI values decreased as the smoking intensity increases, suggests dose-dependency.

“Cigarette smoking negatively affects choroidal vascularity, as indicated by a significant reduction in the CVI. However, its impact on the FRT and SFCT remains unclear and requires further research. These findings highlight the importance of smoking cessation for eye health and suggest that CVI is a valuable noninvasive predictive biomarker for monitoring vascular changes in smokers,” the investigators concluded.

References

1. Quiroz-Reyes MA, Quiroz-Gonzalez EA, Quiroz-Gonzalez MA, Lima-Gomez V. Effects of cigarette smoking on retinal thickness and choroidal vascularity index: a systematic review and meta-analysis. Int J Retin Vitr. 2025;11. https://doi.org/10.1186/s40942-025-00646-9

2. Wimpissinger B, et al. Effects of isometric exercise on subfoveal choroidal blood flow in smokers and nonsmokers. Invest Ophthalmol Vis Sci. 2003;44:4859–4863.

3. Asfar T, Lam BL, Lee DJ. Smoking causes blindness: time for eye care professionals to join the fight against tobacco. Invest Ophthalmol Vis Sci. 2015;56:1120–1121.

4. Galor A, Lee DJ. Effects of smoking on ocular health. Curr Opin Ophthalmol. 2011;22:477–482.

5. Nita M, Grzybowski A. Smoking and eye pathologies. A systemic review. Part II. Retina diseases, uveitis, optic neuropathies, thyroid-associated orbitopathy. Curr Pharm Design. 2017;23:639–654.

6. Mitchell P,LiewG, Gopinath B,Wong TY. Age-related macular degeneration. Lancet. 2018;392(10153):1147–1159.

7. Pérez-de-Arcelus M, Toledo E, Martínez-González MA, Martin-Calvo N, Fernandez-Montero A, Moreno-Montañés J. Smoking and incidence of glaucoma: the SUN cohort. Medicine. 2017;96; https://doi.org/10.1097/md.0000000000005761