What's the noun for fundis? Here's the word you're looking for.
fundoplication
(surgery) An operation in which the gastricfundus (upper part) of the stomach is wrapped, or plicated, around the lower end of the esophagus and stitched in place, reinforcing the closing function of the lower esophageal sphincter. The esophageal hiatus is also narrowed down by sutures to prevent or treat concurrent hiatal hernia, in which the fundus slides up through the enlarged esophageal hiatus of the diaphragm.
“Examples present of paediatric referrals without reference to fundoscopy, red reflex, Bruckner's test, stereopsis or oculomotor balance.”
“Dilated fundoscopy revealed a new large infero-temporal area of haemorrhagic retinitis, with exudates and vasculitis.”
“The authors suggest, however, that fundoscopy might have been the most useful diagnostic test to identify the patient's need for urgent neuroimaging.”