Morphometry of surgically removed internal limiting membrane during vitrectomy in diabetic macular edema.

ABSTRACT

BACKGROUND: Histopathologic and morphometric analysis of the internal limiting membrane (ILM) in diabetic eyes was performed. The thickness of the ILM was correlated with the level of glycosylated hemoglobin (HbA(1C)) and other clinical factors. METHODS: The prospective study involved 56 eyes of 52 diabetic patients with a mean age of 63 +/- 7.6 years. Vitrectomy with trypan blue-assisted ILM peeling was performed in the standard way. The mean follow-up period was 8.7 months (range 3-19 months). The ILM was fixed immediately after peeling in 2.5% glutaraldehyde and submitted for electron microscopic evaluation. The ILM was photographed at standard magnification (x5,000) with the scale of 1 microm in the shot. RESULTS: Morphometric analysis demonstrated a significant thickening of the ILM in all eyes, with a mean thickness of the ILM of 3.61 +/- 1.22 microm. It was found that a higher thickness of the ILM is related to elevated HbA(1C) in both types of diabetes mellitus (DM) (p = 0.040). We also found significant dependence of ILM thickness in relation to duration of DM by comparison of men and women (p = 0.026), and a significant correlation between ILM thickness and the age of diabetic patients related to their gender (p = 0.029). CONCLUSIONS: We confirmed increased thickness of the surgically peeled ILM and statistically significant correlations to elevated HbA(1C) in both types of DM, and to further clinical characteristics of case series. Morphometric and histopathologic analyses of the ILM contribute to more objective evaluation of the ultrastructure of the vitreomacular interface.