Which systemic condition can lead to ocular complications?

Diabetes is well-documented as a systemic condition that can lead to a variety of ocular complications. High blood sugar levels associated with diabetes can result in damage to the blood vessels in the retina, leading to diabetic retinopathy. This condition is a significant cause of vision loss among adults, as it can progress to more severe stages involving macular edema and retinal detachment if not managed properly. Additionally, individuals with diabetes are also at an increased risk for cataracts and glaucoma.

The other conditions listed (hyperthyroidism, allergy, and asthma) can have some effects on the eyes, such as dry eyes or eye strain, but they are not primarily associated with severe ocular complications like those related to diabetes. Hyperthyroidism can cause issues such as Graves' disease, which may lead to eye symptoms, but again, the systemic implications and the severity of vision-related complications are more significant in diabetes. Allergies and asthma may cause temporary discomfort or irritation but do not typically lead to lasting or severe eye complications.