Optic Nerve Head Microvascular Alterations May Explain Ocular Disease in Obesity

Peripapillary choroidal thinning indicates optic nerve head microvascular alterations in women with obesity, according to an investigation published in Photodiagnosis and Photodynamic Therapy. The resulting circulatory impairment may be an underlying cause of ocular pathologies associated with obesity, the report suggests. 

Researchers included 72 women with obesity (mean age, 33.36 years; mean body mass index [BMI], 35.11 kg/m²) and 63 control group participants (mean age, 31.64 years; mean BMI, 20.88 kg/m²) in the cross-sectional analysis designed to investigate the mechanism of obesity-related ocular disease. Study participants underwent ophthalmic examination, enhanced depth imaging-optical coherence tomography (EDI-OCT), measurements of peripapillary and macular choroidal thickness, and lamina cribrosa morphology assessment. 

Peripapillary choroidal thickness was significantly thinner among women with obesity nasally at 1000 and 1500 µm (P =.039 and P =.012, respectively), superiorly at 1500 µm (P =.027), and temporally at 1500 µm (P =.036) compared with control group participants. While inferior and temporal peripapillary choroidal thickness measurements were also thinner at 1000 µm in women with obesity compared with control group individuals, these values did not attain statistical significance (P =.066 for both). 

Intraocular pressure was significantly higher (P =.016) and central corneal thickness was significantly thicker (P =.019) in individuals with obesity. The team did not observe any statistically significant differences among the 2 study groups with respect to Bruch membrane opening, lamina cribrosa thickness, lamina cribrosa depth, or macular choroidal thickness, the report shows.     

The study authors stress that this peripapillary choroidal thinning indicates optic nerve head microvascular impairment. 

“The microvascular disorder, which we discovered in the outer zone of the peripapillary region, indicates impaired blood flow in [the optic nerve head], even in obese individuals who have not yet developed any ocular disease,” according to the researchers. “Our findings suggest that microvascular alteration in the peripapillary region may be the initial event in the pathogenesis of many obesity-related ocular diseases, particularly glaucoma.”

Study limitations include an inability to assess obesity duration.