P 313 The trabecular meshwork in diabetic neovascular glaucoma. Histopathologic study with scanning microscopy

Pur~osg: Nsovascular glaucoma is a severe complication of diabetic retinopathy but its natural evolution is not sufficiently known. In this paper we study the trabecular meshwork of patients who have been operated because of nsovascular glaucoma with the aim to stablish the distribution of neovessels and to understand the mechanism of formation of goniosinechiae and the possible obstruction of the trabecular meshwork. Methods: We have studied the trabscular meshwork of-diabetic patients who were operated because of neovascular glaucoma secondary to diabetic retinopathy.-Surgical technique was trabsculectomy + iridsctomy + panretinal cryocoagulation. The samples were fixed in Karnovsky solution and studied using scanning microscopy. Result+: The main signs were:. 1) the existence on a inflamatory fibrovascular membrane or pseudo-membrane with neovessels, fibroblast, inflamatory cells, 2) Goniosinechiae in the anterior face of the iris and cornea1 endothelium, 3) neovessels in the anterior and internal zone of the esclerocorneal trabecula. Conclusions: We could observe the fibrovascular membrane that covers the trabecula, the goniosinechiae and the distribution of neovessels in the angle. These observations allow us to improve our knowledge about the mechanisms of goniosinechiae in nsovascular glaucoma. Purpose: Glycan expression in glaucomatow trabecular meshwork (TM) was compared with normal TM in order to obtain data which may reflect pathological changes due to primary open angle glaucoma (POAG). Method: I5 specimens 6om patients with POAG (14 trabeculectomies, I post mortem globe) and 12 normal cases (all resin embedded) were probed with a panel of biotinylated lectins and an avidin-peroxidase revealing system Results: ConA and ePHA showed strong staining in all areas ofthe TM, with STA biding to a lesser extent. With all of these l&ins, staining was decreased in POAG material. PSA LCA and SNA bound most strongly to Schlemm's canal (SC) endothetium, with a decrease in labelling in glaucomatous TM In part, this was doe to diicontimdties in the staining of SC endothelium WGA, DSA, ECA, AHA and MPA hound more. weakly throughout the TM in both groups. Jac showed strong staining in both series whilst IPHA SBA, DBA. CTA UEA-I and LTA did not bind to TM in either group Conclusion: There are no major differences in the types of glycans expressed in POAG and normal TM. However, glaucomatow TM shows a reduction m some N-linked and sialylated structures, particularly associated with the SC endothelium, but no apparent change in O-linked glycans. This may reflect alterations in glycoprotein expression or differences in the …