Risk of visual impairment according to the comorbidity of systemic and ocular diseases.

HTN, DM, and DR, either alone or in combination, increase the risk of VI. Glaucoma also increases the risk when combined with DR; however, it has a negative correlation with VI in the absence of DR. Periodic ophthalmologic examinations for glaucoma, which primarily affects the peripheral visual field and not central visual acuity, might help prevent VI caused by other diseases.