4132 Analysis of the human lamina cribrosa by laser scanning confocal microscopy

~~Tocompanthemearu~ementroftheshapeof~neuroraioalrimbehraenthe HeidelbergRetlnaTmnographand pho@raphicevahmtm Metho& The optic discs of45 eyes of23 nnmal subjects and 51 aye? of29 patients with open-angle &umnm mre exarmned using the Heidelberg Retiam Tomograph (HRT) Wtware nrsmn I.1 1) and sta”dawJized I5 +w color 6terea qtic disc photographs. FM the BRT mearunments, the contour line dthe optic disc was drawn with the help of an cptic disc photograph simultaeeously projected The optic cup was regarded za all the area beneath a referace line 50 micrometers t&w the maximal reflwtia” line at the &SC border between -4 and -10 ds8mes For the evaluation of the photqtapb, the ocular and camera magnification was mrrected xcordiog to Littmann’s method The qnic disc was all the area inside the peripapillary s&ml ring. The optic cup was defined by contour and not hy pallor. Reaults The nemoretinal rim shape a6 determined by the ratl~~ of the rim width meanrrements obtained every 30 degrees dilibed si@ticanily b&wee” the HRT evaluatm” and the photographic examination. I” the IiRT waleatien as compared to the photc8raphx examination, the largest pan ofthe rim was eften spatially c-x&ted with the remal vessel trunk Conclusions: The detemtinahon of the shape of the nwmreunal rim vanes sl@tficanUy between the HRT walticm and the photographic examination. Reason may he that in the BRT measurement, the blond vweis in the optic cup are partially cunsidemd to belong to the neuroret”ml rim. Th,s discrqaney betww” the HRT meahllreme”ta and the photcgrapluc evaluation is clinically “nportant sl”ce the shape ofthe neumretinal rim is a valuable parameter for the diagnosis and differential diagnosis of glaucoma