Evaluation of the Relationship Between Orbital Dimensions Measured Using Computed Tomography Scans with Primary Open-angle Glaucoma
Nuraddeen Ibrahim JaafarAbstract
Background:
As the leading cause of irreversible blindness, primary open-angle glaucoma (POAG) poses a significant health issue worldwide. While elevated intraocular pressure (IOP) is the key established risk factor, many patients continue to show glaucomatous damage even without statistically high IOPs. This prompted investigations into other potential anatomical markers, like orbital dimensions, that could be implicated in the pathophysiology of the disease. This study was done to evaluate orbital dimensions in patients diagnosed with POAG and examine their associations with glaucoma severity parameters.
Methodology:
The study comprised 350 volunteers who were newly diagnosed with POAG. Glaucoma-defining parameters (GDPs) such as IOP, vertical cup-to-disc ratio (vCDR), and visual field mean deviation (VF-MD) were measured. The orbital dimensions, height, width, depth, volume, and orbital index (OI) were measured using computed tomography. Statistical analyses included correlation analysis and multivariable linear regression, reporting 95% confidence intervals (95% CI).
Results:
Mean orbital height, width, depth, and volume were 34.1 ± 2.2 mm, 38.8 ± 2.5 mm, 44.7 ± 3.1 mm, and 29.6 ± 3.7 cm 3 , respectively. Orbital depth, width, and volume demonstrated statistically significant positive associations with vCDR and inverse associations with VF-MD. The OI showed significant linear associations with all evaluated GDPs, and regression models showed reliable indices for GDP estimation.
Conclusion:
Specific orbital dimensions were significantly associated with POAG structural and functional parameters. The findings suggest that orbital anatomy may play a role in POAG susceptibility and severity. We have demonstrated, for the first time, a strong statistical association between OI and POAG severity. However, these anatomical relationships could be only baseline traits rather than causal associations. Therefore, prospective, case–control studies incorporating healthy comparison groups and longitudinal follow-up are required to confirm these observed associations.