Diabetic Ocular Surface Has Defects in Oxygen Uptake Revealed by Optic Fiber Microsensor

Area of Science:

• Ophthalmology
• Diabetology
• Biomedical Engineering

Background:

• Diabetes mellitus can lead to diabetic keratopathy (DK), an ocular surface disorder affecting patients and cornea recipients.
• DK and other diabetic ocular surface issues are often underdiagnosed, necessitating noninvasive diagnostic methods.
• Previous research indicates diabetic corneas have reduced oxygen (O2) uptake compared to healthy corneas, but a comprehensive ocular surface assessment is lacking.

Purpose of the Study:

• To investigate the impact of diabetes on the spatiotemporal O2 consumption profile of the ocular surface.
• To determine if diabetes alters the unique O2 consumption patterns observed in healthy ocular surfaces.
• To explore potential noninvasive diagnostic markers for diabetic ocular surface abnormalities.

Main Methods:

• Utilized an optic-fiber O2 micro-sensor (optrode) to measure O2 consumption across the ocular surface.
• Employed streptozotocin (STZ)-induced diabetic mice as a model for diabetes mellitus.
• Compared O2 consumption patterns in diabetic mice with age-matched healthy controls.

Main Results:

• Diabetic mice exhibited diminished O2 uptake across the ocular surface, losing the characteristic spatiotemporal pattern seen in controls.
• A significant reduction in O2 consumption was observed in the bulbar conjunctiva and limbus of diabetic corneas, but not the central or peripheral cornea.
• Unlike healthy corneas, diabetic corneas did not show an increased O2 consumption at the limbus during the evening.

Conclusions:

• Diabetes mellitus impairs O2 uptake at the ocular surface, revealing a novel aspect of diabetic keratopathy pathophysiology.
• O2 consumption mapping of the ocular surface presents a potential noninvasive method for diagnosing diabetic ocular surface abnormalities.
• These findings suggest a new mechanism contributing to the development of diabetic eye complications.