P 117 Optic nerve invasion in retinoblastoma A classification proposal

f’mpose Eagonists and tWockers are widely used grstemttcaUy for a variety of dtwases, pmductng tear productton alterattons. The effect of vatious either selective 0r tixed abkcken and sagoni~ts 0” ta productton of the rabbit lacrimal gland was investtgated Method Tear Row was determined by of a direct cannulatton of the excretory duct of the rabbit lacrimal gkmd. for up to 90 tin, under pentobarbttal anesthesia Tear volume secreted was calculated knowing the tube disxneter and length of tear cOk”“n Selectbe 61. & agonists and Mockers, were injected I.M. either in a bob dose one how prior to duct cannubtton or as a single daily treatment for up to five days Rests/b &-ago”& but not 81. given as a single I.M. injectton, significantIy increase tea productton (px 0.001). Increasl ‘ng the 81. a&mists dose an equal effect was deserved too, due to selectivity disappearance. Repeated daily administration of the t&agonists diminished significantly, (p< 0.01). , their inaeasing effect 0” tear prod&ton, within 4-5 days, due to subemtttzat~~n of the laaimal gls~~I &-recepton. An the 5Mockers administemd either acutely or chronicauy. reduced the tear pmductton and aboMwd the &aaontsts increastng effect. Although t-i apparent diffemnms were obsaved ustng eithe? sekctiw (6, or &) hkckers or those with ISA, among them the 6-2 s&dive hkxker was found to be the most potent tear production inhibitor (p< 0.06). conduslolr The rabbit lacrimal gkmd (pmbauy actnar cells) ca”ies &mceptors which are involved in tear -production &cmase by & aaonists and inhibition tu Ehbcka). These meutms dewkw shsemitisation due to ch&ic E-ago”& adnMstrati&, within 4-3 days Our mndusions might expkdi the ine‘rjstance of any dintcally sianificant tears incrsstm effst amona the chronic Eraaontsts users a&l the dry-eye sympt&s o&wed-in pattents under Ebkskers treatit