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Background The neovascular form of the disease usually causes severe vision loss in a number of eye diseases.Special-domain optical coherence tomography (SD-OCT) provides high-quality in retinal imaging and the possibility of the measurement in vivo.Objective This study aimed to investigate the feasibility of SD-OCT dynamically measuring choroidal neovascularization (CNV).Methods CNV was induced in 30 left eyes of 30 clean Brown Norway(BN)rats by retinal photocoagulation with the laser parameter as follows: wavelength 532 nm,exciting power 200 mW,spot diameter 100 μm and irradiating time 50 ms.Bubble or less retinal bleeding was thought as Brunch membrane breakage and CNV model establishment.Fundus fluorescein angiography(FFA) was performed to determine the establishment of CNV model and scored based on the fluorescein leakage on 3,7,14,21 days after photocoagulation.Meanwhile,CNV memberane thickness (CMT) was dynamically measured in vivo as the maxiume value from retinal inner limiting membrane through choroidal vessel layer in various time points.Histopathologic examination was used in the 14th day to evaluate and verify the result of SD-OCT.The right eyes were as controls.Results FFA examination showed that disc-like leakage of fluorescein appeared in 7 days and extended in 14 days after photocoagulation with the scores of 1.6±0.4,2.5±0.6 and 2.4±0.5 in 7,14 and 21 days,showing a significant difference among them(F=13.11,P＜0.01).The fluorescein leakage score was significantly higher in 14 and 21 days than that of 7 days(both P＜0.05).CMT measured by SD-OCT was(76.33±10.09),(102.03±14.21)and(98.03±13.76) μm in 7,14 and 21 days after photocoagulation respectively,with a significant difference among 3 time points (F=23.25,P＜0.01),and that in 14 and 21 days was significantly declined in comparison with 7 days(both P＜0.05).The results of SD-OCT showed a consistent tendency with that of FFA.Histopathological examination showed CNV formation in 14 days after photocoagulation.Conclusions Experimental CNV model was successfully induced by laser photography.SD-OCT technology allows excellent visualization of CNV in vivo.
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Wet age-related macular degeneration (AMD) is one of major causes of blindness in elder people.Intraocular injection of anti-vascular endothelial growth factor (VEGF) -A regimen has made big breakthrough for the treatment on choroidal neovascularization of wet AM D,while long-term follow-up and necessary retreatments are the key issues to remain obtained visual acuity.Multiple strategies of wet AMD have been used in following-up and retreating based on the visual acuity,optical coherence tomography (OCT),ophthalmoscope and fluorescein fundus angiography (FFA) in abroad.However,there also are major differences in the patient' s composition,treatment habits and distribution of medical sources in China from Western.So we suggest to standardize the follow-up and retreatment strategies about intravitreal injection of VEGF-A for wet AMD as to achieve a better effectiveness.OCT-guided individual follow-up and retreatment strategies should be very helpful for maintaining a long-term efficacy,minimizing the treatment time and reducing medical cost.
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<p><b>BACKGROUND</b>It was well known that tangential vitreoretinal traction and epiretinal membrane play important roles during the formation of macular hole (MH) associated with retinal detachment (RD) in highly myopic eyes. But it was not clear about the correlations between anteroposterior traction, posterior vitreous cortex (PVC) and MH-RD. The vitreous status in highly myopic eyes were analyzed to explore the effect of PVC in the role of MH-RD formation.</p><p><b>METHODS</b>Sixteen consecutive highly myopic eyes with RD due to MH were retrospectively analyzed from January 2009 to April 2009. The preoperative examinations for detecting posterior vitreous detachment (PVD) and vitreoretinal traction included B-mode ultrasonography and optical coherence tomography (OCT). The residual PVC and PVD were confirmed intraoperatively during triamcinolone acetonide (TA) assisted vitrectomy.</p><p><b>RESULTS</b>Under ultrasonography, the preoperative PVD patterns were stratified as: complete PVD in three (19%) eyes, partial PVD in eight (50%) eyes, and no PVD in five (31%) eyes. OCT confirmed vitreoretinal traction and no complete PVD in 10 (63%) eyes, including anteroposterior traction in four eyes and tangential traction in six eyes. During TA-assisted vitrectomy, it was confirmed that no complete PVD existed in 16 eyes, including six eyes (38%) finally diagnosed of partial PVD, and five (31%) eyes with vitreoschisis. Anteroposterior vitreoretinal traction around MH is always in conjunction with partial PVD (67%), and high proportion (80%) of vitreoschisis is associated with tangential vitreoretinal traction. Comparing with the precision of TA staining of PVD diagnosis, the coincidence rate of ultrasonography was 69% (P = 0.02), and that of OCT was 63% (P < 0.01).</p><p><b>CONCLUSIONS</b>The residual PVC due to partial PVD or vitreoschisis may cause the anteroposterior or tangential traction of macular area, which contributes to the formation of MH and subsequent RD in highly myopic eyes. And it is necessary to realize the vitreoretinal relationship and assess the status of PVC synthetically for surgery by combined ultrasonography and OCT preoperatively and TA staining intraoperatively.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Myopia , Retinal Detachment , Retinal Perforations , Retrospective Studies , Vitreous DetachmentABSTRACT
Objective To evaluate the toxicity of intravitreal injection of triamcinolone acetonide on the cornea,lens,ciliary body and retina in rabbit eyes. Methods Thirty-two gray rabbits were divided into four groups(n=8).The rabbits were intravitreally injected with buffered saline solution(control group),4 mg triamcinolone acetonide(group B),1.3 mg triamcinolone acetonide(group C) and vehicle(group D).Intraocular pressure,scotopic and photopic electroretinogram examinations were performed before injection and at different time points after injection.Histologic and ultrastructural changes were observed 1 week,1 month and 3 months after injection. Results Compared with the other groups,the intraocular pressure of group B was significantly increased on day 1,week 1 and week 2 after injection(P
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Objective To investigate the healing mechanism of the rabbit's selerotomy sites undergoing the transconjunctival su- tureless vitrectomy(TSV),and to compare the wound healing effect of the different surgery procedures.Design Experimental study. Participants New Zealand white rabbits.Methods Thirty-two New Zealand white rabbits were divided into four groups:the core vitrec- tomy and fluid-air exchange (Group A),the core vitrectomy (Group B),the non-core vitrectomy and fluid-fir exchange (Group C) and the non-core vitrectomy(Group D).Intraocular pressure(IOP)was measured on the day preoperatively and the day 1,3,5,7,14 postopera- tively with Tonopen tonometers.Sclerotomy sites were investigated with the ultrasound biomicroscope(UBM)on the day 1,5 and 9 postoperatively,and the internal and the external diameter of the wound was estimated on the day 1 postoperatively.The pathological sections of the sclerotomy sites on the day 3,5 and 9 postoperatively were observed under the light microscope.Main Outcome Mea- sures IOP,the internal and external diameter of the wound.Results The IOP of Group A was obviously higher than the other groups on the day 1 postoperatively (P