Program list

SCIENTIFIC POSTER SESSION

ULTRASTRUCTURAL APPROACH OF VITREOUS AND EPIRETINAL MEMBRANES
IN DIFFERENT PVR STAGES.
Maria Gemeneji
Department of the Aristotelio University, Thessaloniki, Greece.

Purpose: Our intention was to look for the existence of possible differences at an ultrastructural level in tissues coming from PVR patients with different clinical characteristics. The observations at the moment concern tissues from early and late stages of PVR, probably showing another aspect of future therapeutic directions.
Methods and Material: During our study five vitreous samples and three epiretinal membranes were obtained from eight patients who underwent PVR surgery by the following surgeons:
S.Dimitrakos, P.Brazitikos, Department of Ophthalmology , University Hospital of Thessaloniki, Greece and A.Vakalis, Clinic of Ophthalmology, Kianus Stavros Hospital,Thessaloniki.
The procedure used to take ultrathin sections of Epon-embedded specimens and the ultrastructural examination under TEM took place in the laboratory of the Histology- Embryology Department, Aristotelio University of Thessaloniki, Greece, under the supervision of Professor A. Manthos.
Among clinical factors we took under consideration, we focused our attention mostly on the stage of PVR according to the Retina Society classification. Two of the patients had PVR stage B, four of them had PVR C and two had PVR D.
Results: We found that there is a correlation between the amount of cells and the appearance of connective tissue on one side and the grade of PVR on the other. Vitreous samples of PVR grade B patients had no apparent cellular components but there was a strong presence of connective tissue unlike vitreous samples of PVR grade C or D patients where the presence of cellular components mainly in the fibroblastic form is evident.
In the vitreous samples and epiretinal membranes obtained from patients of both early and late PVR stages we found that there is apparent lateral aggregation of collagen fibrils. Their heterotypic nature remains to be shown by immunostaining with specific antibodies against collagen types V/XI and IX.