IMMUNOHISTOCHEMICAL STRUCTURE OF TENONS CAPSULE IN DIABETIC EYES
IMMUNOHISTOCHEMICAL STRUCTURE OF TENON’S CAPSULE IN DIABETIC EYES Y. Ozdamar 1 , P. Atilla 2, G. Acaroglu 3, O. Aslan 1, S. Muftuoglu 2, S. Ozalp 1, J. Karakaya 4, O. Zilelioglu 1 1 Ankara Ulucanlar Eye Research Hospital, Department of Retinal Diseases, Ankara, TURKEY. 2 Hacettepe University Faculty of Medicine, Department of Histology and Embriyology, Ankara, TURKEY. 3 Ankara Ulucanlar Eye Research Hospital, Department of Neuro-ophthalmology, Ankara, TURKEY. 4 Hacettepe University Faculty of Medicine, Department of Biostatistics, Ankara, TURKEY.
Introduction • Diabetes-related reactions have lead to structural and functional alterations in the connective tissue of skin, kidneys, peripheral nerves, cardiovascular system and other body structures, and these alterations are probably responsible of the development of diabetic long-term complications. • In this study, we investigated the immunohistochemical features of Tenon’s capsule on biopsy specimens from patients with diabetic retinopathy and non-diabetic controls, and compared the results.
Material-Methods: • This study included 43 eyes; 26 eyes had diabetic macular oedema (study group) 17 eyes were healthy controls (control group). • Tenon’s capsule biopsy specimens from the type II diabetic and nondiabetic patients were examined. • In the study group, biopsy specimens were obtained from the eyes with diabetic macular edema, right before undergoing posterior subtenon triamcinolone acetonide injection. • Diabetic patients diagnosed with clinically significant macular edema according to the Early Treatment Diabetic Retinopathy Study criteria were scheduled for injections. • In the control group, biopsy specimens were obtained during elective cataract surgery.
Material-Methods: • The specimens were processed according to routine electron microscopic analysis technique. • Semithin sections were stained with Methylene blue-Azur II and examined. • Type I and type III collagen fibers were labelled immunohistochemically to understand the amount of the predominating collagen fibers. • Amount of the collagen fibers type I and type III were calculated by Leica Q-Win program. • The results were compared between the groups and statistical significance was set as p<0. 05.
Results: • Demographic characteristics of both groups were similar (p>0. 05). • The light microscopic examination results; In non-diabetic patients’ tenon capsule biopsies (Figure 1 A-B) . *irregular dense connective tissue with abundant randomly scattered collagen fibers were present. *many blood vessels and fibroblasts were seen in between the collagen fibers In diabetic patients’ biopsies (Figure 1 C-D) *connective tissue was denser and more irregular than the connective tissue of non-diabetics’. *collagen fibers forming short and thick fibrils were thought to be newly synthesized and immature in the polymerization period. *subintimal thickening was obvious under the endothelium of the blood vessels.
Figure 1: Sections of control (A-B) and diabetic group (C-D) A-C: Methylen blue-Azur II X 400, B-D: Methylen blue-Azur II X 400
• Collagen type I and type III immunoreactivity was observed both in control (Figure 2 A-B) and diabetic groups (Figure 2 C -D). Figure 2: Distribution of type I & type III collagen fibers in control (A: Type I collagen, B: Type III collagen Indirect immunoperoxidase, Hematoxylen X 200) and diabetic group (C: Type I collagen, D: Type III collagen Indirect immunoperoxidase, Hematoxylen X 200)
• Amount of the collagen fibers type I and type III were significantly higher in diabetic group than control group. * mean collagen type I area: 13. 410± 0. 99 and mean collagen type III area: 23. 692± 0. 17 for control group * mean collagen type I area: 25. 270± 6. 48 and mean collagen type III area: 28. 192± 0. 82 for study group (p=0, 0037 for type I and p=0, 0000 for type III)
Conclusion: • Tenon's capsule is composed of groups of type I and III collagen fibrils arranged irregularly in different orientations and fibroblasts. • Tenon’s capsule fibroblasts and collagen fibres play a major role in subconjunctival wound healing after glaucoma filtration surgery.
Conclusion: • Diabetes mellitus may produce increased amount of collagen in Tenon’s capsule and under the endothelium of the blood vessels. • These results suggest that diabetes mellitus may affect connective tissue components of all ocular segments and this alteration affecting the success of filtration surgery should be kept in mind especially in diabetic eyes with glaucoma. Correspondence: yaseminozdamar@gmail. com
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