Clinical Research On The Effects Of Emulsified Silicone Oil On The Retina And Optic Nerve

Objective: To observe the effects of emulsified silicone oil droplets onthe structure of the retina and optic nerve, whether emulsified silicone oildroplets can invade into the retinal layers, retinal blood vessels and the opticnerve, and further migrate to the other places(brain),to explore its mechanism.Methods:There were730patients(730eyes) were taken silicone oilremoval from september2011to december2013in the second hospital, hebeimedical university,27cases (27eyes) with emulsification of silicone oilinvolved,the incidence of silicone oil emulsification was4.3%. male caseswere19(70.4%),8cases (29.6%) of women, aged from28to68years, anaverage age of46.33±15.3years old. They were hospitalized and treated withsilicone oil removal.Using slit lamp microscope,optical coherence tomography(OCT) and fundus fluorescein angiography (FFA) to observe emulsifiedsilicone oil droplets at day3, day30, best corrected visual acuity, intraocularpressure and anterior segment photographic were recorded.Examingemulsified silicone oil and the location of the retina and optic nerve structurerelationship is important,record the time when emulsification happened.General chek-up under way in patients with emulsified silicone oil deopletsinto retina vessels, clear whether there are migrate to the other places(brain).Results:Silicone oil emulsification happened to0.5-84months, average siliconeoil emulsification time was13.02±19.19months.Best corrected visual acuity, intraocular pressure, slit lamp microscopeand anterior segment photographic:27silicone oil emulsification patients hadan averages preoperative BCVA1.29±0.37, after silicone oil removal1month27eyes average BCVA was1.14±0.38,compared with the preoperativedifference was statistically significant (P <0.05).One month postoperatively, visual acutity tending towards stability. Emulsified silicone oil droplets canresult in increasing intraocular pressure,secondary glaucoma in5cases(18.5%), whose intraocular pressure ranged from28to36mmHg, averageintraocular pressure was31.4±3.07mmHg, the mean pressure after surgerywas14.2±4.42mmHg. Slit lamp microscope showed that band-shapeddegeneration of cornea in2cases (7.4%), characterized by the cornea exposedparts of palpebral fissure area, uneven gray opacity of bowman’s membranewere observed,without big bubble keratitis. Nine cases arised emulsifiedsilicone oil droplets into anterior chamber (33.3%, among them7cases areaphakia, pseudophakia in2cases), Keratic precipitates was observed in3cases, characterized by platelet brown fine dot behind corneal,most of whichwas in the pupil area.Above the anterior chamber silicone oil liquid flat in2cases, the presented as multiple milky white opaque water sample dropletsgathered on the top of anterior chamber.Four cases,silicone oil emulsiondroplets was found in crypts iris and artificial crystal surface, clusters oftransparent beads sample.Caused concurrency cataract patients is6cases(27.3%, intraocular lens in16cases,3cases for aphakia),5cases in16whowith artificial lens accompanied by posterior capsular opacification.Indirect ophthalmoscope fundus examination：all patient were examinedfundus carefully under the condition of big pupil,we didn’t found anyhemorrhage or leakage，retina reattached，without retina traction or subretinaproliferation. Eleven patients with the shortage of silicone oil tamponade，inthe below1/4-1/3of vitreous cavity we could see the silicone oil-waterinterface, a large number of emulsified silicone oil clusters as belt near theinterface, on both sides along the superior and inferior retinal vessels couldfound clusters of emulsified silicone oil,around optic disc emulsified siliconeoil droplets gathered.OCT: Emulsification silicone oil droplets on OCT presented as thehyperreflective signal,epiretinal lamellar hyperreflective signal find in11cases (40.7%), characterized by single layer or multi-layer hyperreflectivedroplets or small clumps hyperreflective signal in the retina surface. In the lumen above retinal,there are hyperreflective, tiny droplets, whose locationcorresponded to the fundus photographs. Emulsified silicone oil dropletsinvade into the retina layer in9cases (33.3%),intraretinal hyperreflectivesignal can be observed in nerve fiber layer, outer plexiform layer,rod cell layer,pigment epithelium layer, retinal structure is normal. After silicone oil removal,retinal surface and intraretinally signals disappeared.One case (3.7%) wasfound that emulsified silicone oil droplets into the optic nerve in27patients,characterized by visible hyperreflective signals exist in optic nervesection.Fundus photographs and FFA: Fundus photographs of27cases wereobserved clusters of more or less emulsified silicone oil droplets near retinalblood vessels or in the surface of the inferior(liquid silicone oil-waterinterface) retina. Emulsified silicone oil droplets invaded in the retinal bloodvessels in6cases (27.3%),4of them were found emulsified droplets wasmoving in retinal blood vessels along with the blood flow (14.8%). In FFA,emulsified silicone oil droplets show high fluorescence dots emerged in retinalblood vessels(veins or arteries)at early stage when imaging, high fluoresce-nce sustained during the whole process,In FFA process,the emulsified dropletsemulsified droplets was moving in retinal blood vessels along with the bloodflow, high fluorescence dots location corresponding to the emulsified siliconeoil droplets in fundus photographs. There are no patient with emulsifiedsilicone oil droplets infiltrating into the optic nerve in fundus photographs andFFA.General physical examination: Three patients who were observed withemulsified silicone oil droplets in retinal blood vessels underwent magneticresonance imaging enhanced scan,no positive finding was noticedin intracranial (include lateral ventricle, saddle pool, subarachnoid).Conclusion:1Emulsified silicone oil droplets into the anterior chamber, can causesecondary glaucoma.2Emulsified silicone oil droplets can invade into the retina layers and subretinal.3Emulsified silicone oil droplets invade into the retinal blood vessels andmoving with the circulation of blood.4OCT examination can intuitively reflect the position of emulsified siliconeoil droplets,and provide reliable evidence to investigate the function ofemulsified silicone oil droplets in retina and optic nerve.5Using fundus photographs and FFA examine make dynamic images thatemulsified silicone oil in the retina vessles can be obtained,combining FFAwith OCT, we can further understanding the effects of emulsified siliconeoil on the retina and optic nerve.