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Toronto Notes 2019 Vitreous Vitreous
• cleargel(99%waterpluscollagenfibrils,glycosaminoglycans,andhyaluronicacid)thatfillsthe posterior segment of eye
• normallyadherenttoopticdisc,parsplana,andalongmajorretinalbloodvessels
Posterior Vitreous Detachment
Etiology
• centralvitreouscommonlyshrinksandliquefieswithage(syneresis)
• duringsyneresis,moleculesthatholdwatercondensecausingvitreousfloaters
• liquidvitreousmovesbetweenposteriorvitreousgelandretina
• vitreousispeeledawayandseparatesfromtheinternallimitingmembraneoftheneurosensoryretina
posterior to the vitreous base
Clinical Features
• floaters,flashesoflight
Complications
• tractionatsitesoffirmadhesionmayresultinaretinaltearwithorwithoutsubsequent rhegmatogenous retinal detachment
• retinal tears/detachment may cause vitreous hemorrhage if bridging retinal blood vessel is torn
• complications more common in high myopes and following ocular trauma (blunt or perforating)
Treatment
• acuteonsetofPVDrequiresadilatedfundusexamtoruleoutretinaltears/detachment • nospecifictreatmentavailableforfloaters/flashesoflight
Vitreous Hemorrhage
• bleedingintothevitreouscavity
Etiology
• PDR
• retinaltear/detachment • PVD
• retinalveinocclusion
• trauma
Clinical Features
• suddenlossofVA
• maybeprecededby“shower”ofmanyfloatersand/orflashesoflight
• ophthalmoscopy:noredreflexiflargehemorrhage,retinanotvisibleduetobloodinvitreous
Treatment
• ultrasound(B-scan)toruleoutRD
• expectant:innon-urgentcases(e.g.noRD),bloodusuallyresorbsin3-6mo
• surgical:vitrectomy±RDrepair±retinalendolasertopossiblebleedingsites/vessels
Endophthalmitis and Vitritis
• intraocularinfection:acute,subacute,orchronic
Etiology
• mostcommonlyapost-operativecomplication;riskfollowingcataractsurgeryis<0.1%
• alsoduetopenetratinginjurytoeye(riskis3-7%),endogenousspread,andintravitrealinjections • etiologyusuallybacterial,maybefungal
Clinical Features
• painful,redeye,photophobia,discharge
• severelyreducedVA,lidedema,proptosis,cornealedema,anteriorchambercells/flare,hypopyon,
reduced red reflex
• mayhavesignsofarupturedglobe(severesubconjunctivalhemorrhage,hyphema,decreasedIOP,etc.)
Treatment (see Ocular Trauma, OP40)
• OCULAREMERGENCY:presentingvisionbestindicatesprognosis
• LPorworse:admission,immediatevitrectomy,andintravitrealantibioticstopreventlossofvision • HMorbetter:vitreoustapforcultureandintravitrealantibiotics
• topicalfortifiedantibiotics
Ophthalmology OP21
WeissRing:formedbyglialtissuearound the optic disc that remains attached to the detached posterior vitreous
Floaters: “bugs”, “cobwebs”, or “spots” of vitreous condensation that move with eye position
Although most floaters are benign, new or markedly increased floaters or flashes of light require a dilated fundus exam to rule out retinal tears/detachment
Any time a vitreous or retinal hemorrhage is seen in a child, must rule out child abuse
Remember to inquire about tetanus status in post-traumatic endophthalmitis