The effects of electronic cigarette smoking on retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, and choroidal thickness.

Purpose: To compare the thickness of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and choroid in healthy electronic cigarette smokers and non-smokers using spectral domain optical coherence tomography (SD-OCT).

Material and method: 25 healthy electronic cigarette smokers and 25 age- and gender-matched healthy non-smokers were included in the study. RNFL, GCL, IPL and choroidal thickness were measured by SD-OCT using an automated programme. After normality tests, an independent sample t-test was used to analyse the differences in RNFL, GCL, IPL, and choroidal thickness values between the groups.

Results: The mean age of electronic cigarette smokers and non-smokers was 33.68 and 33.64 years, respectively. The mean smoking history was 6.6 years (range 5-8 years). Most of the participants smoked 2-5 ml of e-liquid per day (52%), while 36% smoked more than 5 ml and 12% smoked less than 2 ml per day. The mean intraocular pressure in the electronic cigarette smoker group was 15.0 mmHg, while the non-smoker group was 15.32 mmHg. The mean axial length in the electronic cigarette smoker group and non-smoker group was 23.36 and 23.63 mm, respectively. No significant difference was observed regarding RNFL, GCL, IPL or choroidal thickness between both groups.

Conclusion: The thickness of the RNFL, GCL, IPL, and choroid was found to be similar in both the healthy electronic cigarette smokers and non-smokers groups.