[Study of tear function and the conjunctival surface in diabetic patients]

Area of Science:

• Ophthalmology
• Diabetology
• Ocular Surface Disease

Background:

• Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus.
• Patients with diabetes are at increased risk for dry eye disease.
• Ocular surface dysfunction can occur in diabetic patients even without subjective dry eye symptoms.

Purpose of the Study:

• To investigate the correlation between different grades of diabetic retinopathy and tear film and ocular surface function.
• To assess ocular surface health in diabetic patients who do not report dry eye symptoms.

Main Methods:

• Recruited 72 patients (129 eyes) with diabetes but no dry eye symptoms (McMonnies questionnaire).
• Evaluated tear film and ocular surface using Schirmer test, tear film break-up time (BUT), fluorescein and lissamine green staining, and conjunctival impression cytology.
• Analyzed results to correlate DR grades with ocular surface parameters.

Main Results:

• Normal Schirmer test and BUT were observed in 51% and 67% of eyes, respectively.
• Fluorescein and lissamine green staining were negative in 81% and 95% of eyes, indicating minimal epithelial damage.
• Conjunctival impression cytology revealed pathological squamous metaplasia in patients with DR, despite normal tear function tests.

Conclusions:

• Diabetic retinopathy patients without subjective dry eye symptoms can exhibit pathological ocular surface changes.
• Normal tear function tests (Schirmer, BUT) do not exclude ocular surface pathology in diabetic patients with retinopathy.
• These findings highlight the importance of comprehensive ocular surface evaluation in diabetic patients, irrespective of reported symptoms.