▁he aling . ▁ ▁In ▁the ▁most ▁severe ▁forms ▁( stage ▁III ), ▁it ▁is ▁necessary ▁to ▁stop ▁the ▁pro gression ▁towards ▁cor ne al ▁per for ation : ▁in ▁these ▁cases , ▁a ▁possible ▁surg ical ▁treatment ▁option ▁is ▁t ars or rh ap hy , ▁i . e . ▁the ▁temporary ▁or ▁permanent ▁closure ▁of ▁the ▁e y el ids ▁by ▁means ▁of ▁s ut ures ▁or ▁bot ul in um ▁to x in ▁injection . ▁This ▁protect s ▁the ▁cor nea , ▁although ▁the ▁a est h etic ▁result ▁of ▁these ▁procedures ▁may ▁be ▁difficult ▁to ▁accept ▁for ▁patients . ▁Similarly , ▁a ▁procedure ▁that ▁ent ails ▁the ▁creation ▁of ▁a ▁conj unct ival ▁f lap ▁has ▁been ▁shown ▁to ▁be ▁effective ▁in ▁the ▁treatment ▁of ▁chron ic ▁cor ne al ▁ul cers ▁with ▁or ▁without ▁cor ne al ▁per for ation . ▁ ▁In ▁addition , ▁another ▁vi able ▁th era pe ut ic ▁option ▁is ▁am ni otic ▁memb rane ▁gra ft , ▁which ▁has ▁recently ▁been ▁shown ▁to ▁play ▁a ▁role ▁in ▁stim ulating ▁cor ne al ▁ep ith el ium ▁he aling ▁and ▁in ▁reducing ▁v asc ular isation ▁and ▁infl amm ation ▁of ▁the ▁oc ular ▁surface . ▁Other ▁approaches ▁used ▁in ▁severe ▁forms ▁include ▁the ▁administration ▁of ▁aut olog ous ▁ser um ▁eye ▁dro ps . ▁ ▁Research ▁studies ▁have ▁focused ▁on ▁developing ▁novel ▁treat ments ▁for ▁ne uro t roph ic ▁ker at itis , ▁and ▁several ▁ ▁pol ype pt ides ,