Smoking is the most significant modifiable risk factor for the development and progression of age-related macular degeneration (AMD). But a patient’s cigarette habit doesn’t appear to trigger significant increases in fundus autofluorescence (FAF), a new study reports.

Since increased FAF has been previously linked to increased retinal pigment epithelium lipofuscin deposition in the retina and in eyes with AMD, researchers sought to determine if a relationship existed between smoking and autofluorescence, which they hypothesized could provide insight into the pathogenic mechanism of AMD.

The cross-sectional study compared quantitative FAF in the retina of healthy non-smokers and smokers. Investigators enrolled 105 individuals, including 54 smokers. Sixty-one participants were female and the mean age was 41. 

Participants self-reported past medical and ocular history and underwent eye exams in addition to quantitative FAF imaging with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference. Investigators took two sets of images per eye, and they used a regression model to examine the relationship between mean quantitative FAF values and smoking status. Researchers analyzed images from 161 eyes (80 right and 81 left).

The study found older age and female gender were independently associated with higher quantitative FAF. Additionally, positive smoking history tended to result in higher quantitative FAF values after adjusting for age and gender but was not statistically significant. Among smokers, the number of packs and years smoked were not significantly associated with higher quantitative FAF either.

“Our study’s results are consistent with existing literature in which older age is predictive of intensified autofluorescence, while smoking history does not have as important of an impact on autofluorescence as hypothesized,” researchers wrote in their paper.

 Several large epidemiological studies have shown that smoking is significantly associated with AMD, but quantitative FAF is likely not the appropriate modality to clinically assess smoking’s impact on the retina, they added.