P 385 Experimental evaluation of a IOTA-carrageenan/polyvinylpyrrolidon gel as vitreous substitute

EXPERIMENTAL EVALUATION OF A IOTA-CARRAGEENANIPOLYVINYLPYRROLIDON GEL AS VITREOUS SUBSTITUTE KOBUCH K. SCHLODERER M. LE-RUPPERT K. UEDA N. GABEL V.P. Deportment of Ophthalmology , Uniwrsttv clinic Regenrburg (G) Pm: A new hydrogel composed ofiota-carrageenan/polyvinylpyrrolidon (icgn/pvp) was tested in rabbit eyes to dctennine its intraocular tolerance and to evaluate its suitability as a vitreous substitute. MefhodF: Aver pars-plana lensectomy and pars-plana vitrectomy 1,Sml of icgn/pvp were injected into 4 eyes of 4 rabbitsThe untreated contralateral eyd served as controlAl eyes were examined clinically by slit-lamp and indirect ophfhalmoscopy.The eyes were enucleated after an observation period of 16/l? days and 8/9 weeks and prepared for lightmicroscopic examination. RA: Injected intraocularly, i-cgn/pvp mixed with the intraocular fluid immediately and moved to the anterior chamber. All eyes showed moderate signs of acute inflammation of the ant. segment and neovascularisation of the cornea, which almost cleared after 2 weeks.Increasing turbidity of the vitreous was observed from the 2.day on.IOP was lesr. than 4mmHg from the 2nd week postoperatively. After enucleation the vitrc:ous content was homogenous and solid after 16117 d; after S/9 weeks consistency was imhomogenous,partialy liquid and showed hemorrhagic infiltration.P.etinal detachement had developed in 1 eye.Lightmicroscopic examination showed infiltration by macrophages and foam-cells in the iris,the vitreous,and the retina after 16/17d,in addition granulomatous reactions after S/9 weeks. Stmctural disarrangement of the retina and increased vacuolisation of the nerve tiber layer were observed,more distinct after S/9 weeks. ConclusionxDue to insufficient gel stability i-cgn/pvp seems to us in this composition unsuitable as vitreous substitute.The acute and chronic inflanunatorq reactions can possibly be influenced pharmacologically,but this needs furthe investigation.