Purpose: Obesity is associated with eye diseases, but the underlying structural changes and pathogenic mechanisms have not been examined in detail. Here, we assessed the effects of morbid obesity on the morphometric indices of eye disease.
Methods: Morbidly obese volunteers (n=101, body mass index [BMI] ≥40) and healthy individuals (n=95, BMI: 18.50-24.99) were examined by Goldman applanation tonometry, pachymetry, and spectral domain optical coherence tomography. Intraocular pressure, anterior chamber depth, axial length, central corneal thickness, retinal nerve fiber layer thickness, central foveal thickness, and choroidal thickness were compared between groups.
Results: Uncorrected intraocular pressure was significantly greater in the morbidly obese group than in the healthy control group (15.5 ± 2.5 vs. 14.5 ± 2.6 mmHg, p=0.009), whereas axial length, anterior chamber depth, and central corneal thickness did not differ between the groups. The mean retinal nerve fiber layer thickness at the temporal quadrant was reduced in the morbidly obese group (72.7 ± 13.6 vs. 85.05 ± 52.6 µm, p=0.024). Similarly, the mean retinal thicknesses at nasal and temporal 1500-µm locations were lower in the morbidly obese group (346.6 ± 18.2 vs. 353.7 ± 18.8 µm, p=0.008; 323.1 ± 20.3 vs. 330.0 ± 18.9 µm, p=0.001). The mean choroidal thickness was also reduced in almost all measurement locations (fovea, temporal 500 and 1000 µm, and nasal 500, 1000, and 1500 µm) of the obese group (p<0.05). Weight and BMI were negatively correlated with subfoveal choroidal thickness (r=-0.186, p=0.009; r=-0.173, p=0.015).
Conclusion: Morbid obesity is associated with elevated uncorrected intraocular pressure and signs of neuropathy and retinopathy. Obesity may thus increase the risks of glaucoma and glaucomatous optic neuropathy.
Keywords: Morbid obesity; Intraocular pressure; Nerve fibers; Corneal pachymetry; Anterior eye segment; Posterior eye segment