The Effects of Smoking on Retinal Layer Thickness in Relapsing Remitting Multiple Sclerosis Patients Using Optical Coherence Tomography
Sophia Tessema1, Eman Dannawey1, Muhammad Raghib2, Zaima Liaquat2, Fen Bao2, Carla Santiago-Martinez2, Jacob Rube3, Evanthia Bernitsas4
1Neurology, Wayne State University, 2Wayne State University, 3University Health Center, 4Wayne State School of Medicine
Objective:
This study aimed to compare the thickness of retinal layers of patients with relapsing remitting multiple sclerosis (RRMS) in ever smokers to never smokers using spectral domain optical coherence tomography (SD-OCT).
Background:
Recent research suggests retinal nerve fiber and macular retinal ganglion cell-inner plexiform layers may be useful and inexpensive biomarkers for progression of disability and neurodegeneration in RRMS. Smoking is a known risk factor for onset and progression of MS and may modify retinal thinning in these patients.
Design/Methods:
A cross-sectional analysis of 48 patients who met the 2017 McDonald diagnostic criteria for RRMS were recruited. Smoking history use was obtained from the medical record as well as interviews with patients. Retinal imaging was obtained by SD-OCT performed by a trained examiner. OCT was performed to evaluate the thickness of the retinal layers comparing those who ever smoked and those who were never smokers.
SPSS v29 software using independent paired sample t-tests were used to compare thickness of retinal layers between ever-smokers and non-smokers.
Results:
Out of 48 patients with RRMS, 27 (56.25%) were ever-smokers and 21 (43.75%) were never-smokers.
The mean global peripapillary retinal quadrant (G layer) thickness was 87.78 µm (± 12.53) in smokers and 95.09 µm (± 10.78) in nonsmokers ( p= 0.038). Inferior peripapillary retinal quadrant (I layer) thickness was 112.20 µm (± 17.47) in smokers and 123.51 µm (± 18.33) in nonsmokers (p=0.017). Papillomacular bundle layers (PMB) was 44.24 µm (± 9.53) in smokers and 50.95 µm( ± 9.94) in nonsmokers (p=0.022). No statistically significant thinning in all other retinal layers.
Conclusions:
Our results show statistically significant retinal thinning in ever-smokers compared to non-smokers in the G, I and PMB layers of the retina. All other layers were not statistically significant. The findings suggest smoking may contribute to localized or segmental retinal thinning in RRMS patients.