Clinica And Trialstudy Of New Technique In The Diagnosis And Therapy Of Submacular Choroidal Neovascularization

Background Submacular choroidal neovascularization (SCNV) can cause subretinal hemorrhage, exudation, serous nerve epithelium detachment, pigment epithelium detachment and the formation of scar .It is the major cause of visual loss. How to find the choroidal neovascularization (CNV) early and make the CNV atrophy is the key to save the visual acuity. Fundus fluorescein angiography (FFA) can find the CNV, but many CNV couldn't be detected accurately and in time because of the RPE of macular, phylloxanthine, fast fluorescein leakage or the block of local hemorrhage and muddy exudation. Indocyanine green choroidal angiography (ICGA) can not only find the CNV accurately but also detect the feeder vessel (FV). Indocyanine green didn't leak from the choroid vessel because 98% indocyanine green combine with the serous protein, and also indocyanine green can absorb and radiate the infrared ray, which can penetrate the macular hemorrhage and the muddy exudation. Optical coherence tomography (OCT) can measure the retina accurately in quantitative and show the form, situation, border, and range of CNV in high resolutioa Many methods can treat the CNV, such as submacular membranectomy, macular inversion, photodynamic therapy (PDT), photocoagulation and transpupillary thermotherapy (TTT). Surgery can cause many complications and is very dangerous. PDT can make the CNV disappear, but CNV can reoccur and need management again. The medicine Visudyen is expensive, so it can't b populated in now days. Now the photocoagulation is the most effective and safe method. This means depends on the CNV situation, size, and range. So the discovery ratio of CNV is the key to therapy. Because different length wave laser has different injury and effect on the retina. It is useful to choosing suitable laser to increase the effect and decrease the complication.The objective of this research is to detect the CNV early, increase the discovery ratioand divide the type of the CNV. Different length wave laser and TTT are chosen to treat the CNV depending on the type of CNV. The result is assessed through the changing of macular hemorrhage, edema and exudation by the checking of visual acuity, center visual field, FFA, ICGA and OCT. The technique parameters and depending of how to diagnosis and treat the CNV are concluded scenically accurately and practically. The discovery ratio of CNV can be verified through the zooperal mode of laser inducing CNV by using FFA, ICGA, OCT and tissue checking. And the foundation of the CNV's mechanism and therapy method is set up.Objective To Probe into the effectiveness of FFA> ICGAand OCT for various laser-photocoagulation and TTT in CNV. To explore the occurrence of induction of experimental CNV bydifferentparameter of Fd-Nd:YAG laser( k ,532nm ) photocoagulation and the significance of comprehensive evaluation on the occurrence rate by FFA , ICGA and OCT.Methods FFA, ICGA and OCT combined were used in 120 patients(125eyes) with CNV. A comparing analysis between the FFA , ICGA and OCT photographs was carried out. The location , arrangement ,size, and quantity of CNV were observed and the feeder vessels (FVs) of CNV was noted. According to the appearance and forms of CNV, the types of CNV are classified: classic type and occult type , the later subdivided into subtype I, subtype II, and hemorrhage-shaded type .Under the guiding of the FFA , ICGA and OCT photography ,based on the disparity of the given typings, a different laser-photocoagulation of semiconductor-infra red laser (810nm) and Fd-Nd: YAG laser(532nm) and TTT was carried on separately .Posttreatment, based upon the improvement in visual acuity, perimetry and fundus feature and in changes of FFA, ICGA and OCT re-detections, the effectiveness was evaluated comprehensively .Twelve rabbits were randomly divided into 3 groups: group A,groupBand group C ,there were four rabbits(eight eyes)in each group. The three groups were photocoagulated by different parameter of laser respectively: group A:1000mv,50 u m,0.1s; group B:1200mw.,50 U m ,.0.1s; group C:1200mw,200 u m,0.1s .FFAJCGA and OCT was performed on the rabbits after seven days,fourteen days,twenty-one days. We observedthe formation of CNV and evaluate the rate of occurrence of CNV. The rabbits were killed in one month after photocoagulation by laser, then examination was performed with histology. To investigate the change of histology in fundus of rabbits and the formation of CNV.Results Of the 125 eyes undergone FFA, 50 eyes were typical (40%), 75 eyes(60%) occult type, among them were 28 eyes (37.3%) of type I, 32 eyes (42.7%) of type II and 15 eyes (20%) of hemorrhage-shaded type. Of the 125 eyes detected by ICGA, 90 eyes (72%) were typical type, 18 eyes with FV were noted. Hot spot were in 25eyes(20%), Placoid hyperfluorescence were 10 eyes(8%). The incidence of typical CNV founded by ICGA was remarkably more than that of FFA, PO.01. OCT images revealed 5 kinds of morphological features of CNV: well-defined CNV(63.3%), poorly defined CNV(11.6%),CNV companied with serous(15%) or hemorrhagic neurosensory retina detachment(1.6%), hemorrhagic pigment epithelium detachment(PED)(8.3%). OCT images revealed CNV on the surface of RPE in 28 eyes (46.8%), sub-RPE in 32 eyes (53.8%). The outcomes of laser-photocoagulation in 60 eyes were satisfied, among them were 21 eyes (35.0%) with excellent effect , 16 eyes (26.7%) with better efficacy. The effectiveness by lasering was more significant than that of control cases, PO.01. The result of TTT for exudative AMD in 40 eyes were satisfied, among them were 14 eyes (35.0%) with excellent effect, 16 eyes (40%) with better efficacy. The effectiveness by TTT was more significant than that of control cases, PO.01. Twenty eyes of central exudative chorioretinopathy were treated with TTT. Five or more lines improvement measured by Snellen chart in visual acuity was found after the treatment in 4 eyes(16%), three to five lines in 10 eyes(40%) and one to two lines in 8eyes (32%). TTT shows no complication.After photocoagulation by Fd-Nd: YAG laser(532nm), the occurrence rate of CNV showed by FFA: group A was 70%;group B was 73%.There was no statistical difference between the two groups(p>0.05),group C was 30%,the occurrence of group C was lower than group A and B. There was significant differences between group C and group A (p<0.01). The occurrence rate of CNV by ICGA: group A is 65%, group B is 68%, group C...