EC Ophthalmology

Background: Diabetes mellitus has been postulated to alter the morphology of the cornea. The cornea consists of 5 layers. The Endothelium being the most important layer, consists of a monolayer of polygonal cells and that maintains corneal deturgescence throughout life by pumping excess fluid out of the stroma.

Aim of the Study: To compare the morphological characteristics of corneal endothelial cells in type 2 diabetic patients with agematched healthy subjects in terms of the general characteristics, gender, and laboratory data of diabetic patients, including disease duration, HbA1c, type of medication.

Materials and Methods: A case-control study in tertiary health care centre, with a total of 50 diabetic patients and 50 healthy subjects were enrolled. Selected participants who qualified the inclusion criteria and were enrolled for the study after taking a written informed consent underwent complete ophthalmological examination. Corneal endothelial morphology and central corneal thickness were measured using a noncontact specular microscopy and compared 50 diabetic patients with 50 healthy controls. Laboratory data including serum fasting glucose, HbA1c levels were also recorded. Statistical analysis was undertaken with P < 0.05 significance.

Results: In this study, we identified significantly decreased Endothelial Cell Density and percentage of hexagonal cells, elevated average cell size and coefficient of variation in diabetic patients compared with the same parameters in healthy controls (p = 0.000). When correlation analysis was performed between corneal morphological features and laboratory data of diabetic patients, Endothelial Cell Density showed a significant negative correlation with diabetes duration.

Conclusion: As compared with healthy controls, Diabetic patients have definite more endothelial cell loss. Endothelial keratopathy is an important complication of type 2 diabetes. In that respect, we can suggest that endothelial keratopathy and endothelial cells should be evaluated more cautiously in diabetic patients.

Keywords: Specular Microscopy; Corneal Endothelial Cells; Diabetes Mellitus

1. Islam QU., et al. “Comparison of corneal morphological characteristics between diabetic and nondiabetic population”. Pakistan Journal of Medical Sciences6 (2017): 1307-1311.
2. Shih KC., et al. “A systematic review on the impact of diabetes mellitus on the ocular surface”. Nutrition and Diabetes3 (2017): e251.
3. El-Agamy A and Alsubaie S. “Corneal endothelium and central corneal thickness changes in type 2 diabetes mellitus”. Clinical Ophthalmology 11 (2017): 481-486.
4. Storr-Paulsen A., et al. “Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus”. Acta Ophthalmologica2 (2014): 158-160.
5. Lutty GA. “Effects of diabetes on the eye”. Investigative Ophthalmology and Visual Science 14 (2013): ORSF81-7.
6. Bikbova G., et al. “Corneal changes in diabetes mellitus”. Current Diabetes Reviews4 (2012): 294-302.
7. Sudhir RR., et al. “Changes in the corneal endothelial cell density and morphology in patients with type 2 diabetes mellitus: a population-based study, Sankara Nethralaya Diabetic Retinopathy and Molecular Genetics Study (SN-DREAMS, Report 23)”. Cornea10 (2012): 1119-1122.
8. Benetz B., et al. “Specular microscopy”. In: Krachmer J, Mannis M, Holland E. Cornea, 3rd edition. Philadelphia: Elsevier Mosby (2011): 178-198.
9. American Diabetes Association. “Diagnosis and classification of diabetes mellitus”. Diabetes Care1 (2010): S62-S69.
10. Choo M., et al. “Corneal changes in type II diabetes mellitus in Malaysia”. International Journal of Ophthalmology3 (2010): 234-236.
11. Shenoy R., et al. “Corneal endothelium in patients with diabetes mellitus: a historical cohort study”. European Journal of Ophthalmology3 (2009): 369-375.
12. Su DW., et al. “Diabetes, hyperglycemia, and central corneal thickness: the Singapore Malay Eye Study”. Ophthalmology6 (2008): 964-968.
13. Mohan V., et al. “Epidemiology of type 2 diabetes: Indian scenario”. Indian Journal of Medical Research3 (2007): 217-230.
14. Lee JS., et al. “Differences in corneal thickness and corneal endothelium related to duration in diabetes”. Eye3 (2006): 315-318.
15. Wild S., et al. “Global prevalence of diabetes estimates for the year 2000 and projections for 2030”. Diabetes Care5 (2004): 1047-1053.
16. Inoue K., et al. “The corneal endothelium and thickness in type II diabetes mellitus”. Japanese Journal of Ophthalmology1 (2002): 65-69.
17. Rao SK., et al. “Corneal endothelial cell density and morphology in normal Indian eyes”. Cornea6 (2000): 820-823.
18. Ohno K., et al. “Comparison of Recording Systems and Analysis Methods in Specular Microscopy”. Cornea4 (1999): 416-423.
19. Yee R., et al. “Changes in the Normal Corneal Endothelial Cellular pattern as a Function of Age”. Current Eye Research6 (1985): 671-678.
20. Tanimura K. “A Quantitative Analysis of Corneal Endothelial Cells”. Japanese Journal of Ophthalmology 32 (1981): 1835-1839.
21. Busted N., et al. “Clinical observations on the corneal thickness and the corneal endothelium in diabetes mellitus”. British Journal of Ophthalmology10 (1981): 687-690.
22. Maurice DM. “Cellular membrane activity in the corneal endothelium of the intact eye”. Experientia11 (1968): 1094-1095.