SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
scrapings for cytology . In order to ensure a good sample one may physically need to perform a scraping of the lesion . Topical ophthalmic anaesthetic drops can be applied and using the back of a scalpel blade / cytobrush the lesion can be scraped . This ideally should be performed at the edge and base of the lesion . These cases should be managed with topical antibiotics [ qid ], atropine drops [ oid ], and systemic NSAIDs if uveitis is suspected . Topical corticosteroids are contraindicated and topical NSAID should be used with great care or not at all . Mechanical debriding could also be performed .
Complicated corneal ulcers are those that do not heal within 72hrs , have a melting stromal component and are infected or unable to heal for some reason . There may be a mechanical obstruction to healing as a result of a foreign body , abrading neoplasia , an indolent ulcer or infection with bacteria or fungi All these also could lead to imminent perforation .
Indolent corneal ulcer : This ulcer classically is a superficial ulcer that shows no healing over at least a two week period . The underlying cause is usually unknown but a previous history of trauma is however common . These ulcers are very similar to those in small animals – Spontaneous Chronic Corneal Epithelial Degeneration [ SCCED ]. The lesion is also usually unilateral , centrally or paracentrally located and a halo of loose epithelium is visible around the lesion . The affected eye usually has little neovascularisation present , some oedema is usually seen around the lesion and the eye is painful . There may be bouts of intermittent healing . The non-adherent epithelial edges can be identified by infiltration of fluorescein underneath the epithelium surrounding the erosion . This occurs due to the decreased adhesion sites between migrating epithelial cells as well as lack of adhesions to the basement membrane [ decreased density of hemidesmosomes ]. Recently the presence of a hyalinised membrane has been shown to further hinder adhesion of the epithelial layer . A thorough clinical investigation looking for foreign bodies , ectopic cilia or any eyelid abnormalities is essential .
The treatment approach for these cases is to ensure there is no mechanical cause present [ foreign body , cilia etc ]. The options include :
1 . Mechanically debriding the sloughing edge with a cotton bud or more abrasive instrumentation .
2 . Diamond head burr [ Algerbrush ] debridement which removes redundant epithelium in a controlled and uniform manner as well as the hyaline zone lining the base of the lesion . This is a newer treatment modality that has great potential as it can be performed under standing sedation , is relatively safe to perform and success rates are good . An equine contact lens and topical medication with Tobrex or Vigamox , Atropine drops and morphine drops can be added as an adjuvant preparation to assist in reducing discomfort in the first 1-2 days .
3 . Grid keratotomy - A grid keratotomy is performed by initially debriding the epithelium off the cornea with a blade and then creating a hatched , grid pattern across the entire erosion [ using the bevel edge of a needle ] through the basement membrane , which exposes epithelial cells to stromal collagen type I , which is believed to promote more effective basal cell attachment . A potential negative complication could be the extension or entrapment of
78