| ObjectiveThe purpose of this study is to make a safety evaluation of Pars Plana Filtration Technique by both experimental and clinical study. Through a retrospective observational study of the clinical data to investigate the efficiency, safety,complicati-ons and its treatments of Pars Plana Filtration Technique performed on different types of glaucoma.The mechanism of optic neuroprotection by controlling the intraocular pressure of the surgery was disscussed in two aspects.One is to count the retinal ganglial cells(RGCs) by optical microscope,the other is to identify the different protein expressions of the retina by label free liquid chromatography/mass spectrometry(LC-MS/MS).Methods1. The establishment of the hyper intraocular pressure(IOP) rabbit model:The lasting effect hyper IOP rabbit model was established by injecting the carbomer solution into the anterior chamber of the rabbit eyes.2. B-scan ultrasonography examination:To examine the rabbit eyes of the three groups(the surgical treatment group, hyper IOP control group and the normal control group):The rabbit eyes were divided into two groups randomly after the establishment of hyper IOP, for the surgical treatment group, Pars Plana Filtration Technique were performed after the high IOP situation lasted for one week, while the hyper IOP control group was treated by nothing.Along with the normal control group, all the three groups were examined by B-scan ultrasonography at the same time point to observe the histomorphology changes of the vitreous,retina and chorioid.3. Counting the RGCs numbers:Counting the RGCs of the three groups by optical microscope. The retina sections of the three groups were stained with H.E using conventional histopathology technique. The numbers of RGCs were counted under the optical microscope.4. Observation of differentially expressed proteins of the retina from the three groups by label free liquid chromatography/mass spectrometry(LC-MS/MS):The different protein expression of the retina was identified by LC-MS/MS. The functions of the proteins and the relationships between those proteins and the mechanism of glaucoma development, damage and repair were discussed thoroughly. Also, the neuroprotection mechanism through ocular hypotensive effect by the surgery was investigated.5. The clinical study of Pars Plana Filtration Technique:A retrospective analysis of the clinical and surgical data from 78 eyes of 73 patients with different types of glaucoma who underwent Pars Plana Filtration Technique in eye hospital,China Academy of Chinese Medical Sciences,over a period that from January 2005 to April 2011. A long-term follow-up was done to evaluate the efficacy and safety of the surgery, on different types of glaucoma.And then to disscuss the surgery is most suitable for which type of glaucoma.Results1. The establishment of the hyper intraocular pressure(IOP) rabbit model:By injecting the carbomer solution into the anterior chamber of the rabbit eyes,we got a stable hyper IOP rabbit model. It is necessary to reinject in order to keep the high IOP condition persist for a longer time.It is an effective method to establish hyper IOP rabbit model,thus simulate the glaucomatous pathologic process.2. Results of B-scan ultrasonography examing the rabbit eyes of the three groups (the surgical treatment group,hyper IOP model group and normal control group):Retinal detachment(RD):At the 1st postoperative month,1 eye of the 25 eyes in the surgical treatment group got RD.1 eye of the 17 eyes in the surgical treatment group got RD.But those have no significant relevance to the surgery.Vitreous opacity:At the 1st postoperative month,9 eyes of the 25 eyes in the surgical treatment group got vitreous opacity.3 eye of the 17 eyes in hyper IOP 1 month group got vitreous opacity,there is no statistical significance between them (P=0.173, P>0.05).At the 3rd postoperative month,5 eyes of the 9 eyes in the surgical treatment group got vitreous opacity.4 eyes of the 10 eyes in hyper IOP 3 month group got vitreous opacity, there's no statistical significance between them (P=0.414,P>0.05). At the 6th postoperative month,6 eyes of the 17 eyes in the surgical treatment group got vitreous opacity.5 eyes of the 17 eyes in hyper IOP 6month group got vitreous opacity, there's no statistical significance between them (P=0.500, P>0.05). None of the normal control group at any period of time got vitreous opacity.Vitreous organization:At the 1st postoperative month,3 eyes of the 25 eyes in the surgical treatment group got vitreous organization. None of the17 eyes in hyper IOP 1 month group got vitreous organization,there is no statistical significance between them (P=0.260, P> 0.05). At the 3rd postoperative month,2 eyes of the 9 eyes in the surgical treatment group got vitreous organization. None of the 10 eyes in hyper IOP 3 month group got vitreous organization, there's no statistical significance between them(P=0.211, P>0.05). At the 6th postoperative month,2 eyes of the 17 eyes in the surgical treatment group got vitreous organization.1 eye of the 17 eyes in hyper IOP 6 month group got vitreous organization, there's no statistical significance between them (P=0.500, P>0.05). None of the normal control group at any period of time got vitreous organization.Choroidal detachment:None of the eyes in the three groups got choroidal detachment at any period of time.3. Counting the RGCs of the three groups by optical microscope (unit:n/HP)Hyper IOP rabbit model group:The quantity of the RGCs were decreased significantly,the cells were degenerated and some of them became vacuolations,some appeared karyopyknosis.The cells were arranged irregularly. The thickness of all the layers of the retina became thinner,and disorganizationed.And the inner nuclear layer was arranged irregularly. With the duration of the elevated IOP situation get longer the pathologic damage bacame more serious.The surgical treatment group:The quantity of the RGCs were less than the normal control group but more than the hyper IOP group significantly.The cells were arranged more regularly than the hyper IOP group. And the inner nuclear layer was arranged more regularly than the hyper IOP group.Although the thickness of all the layers of the retina is thinner than the normal control,but they were thicker than the hyper IOP group.At the 1st postoperative month, the average quantity of the RGCs was(17.80±8.65), more than (14.40±7.27) of the hyper IOP 1 month group,but there is no statistical significance (P=0.119,P>0.05). The 1st postoperative month group vs normal control group was (17.80±8.65)/(23.53±9.09),the quantity of the RGCs was decreased,and there is statistical significance between them (P=0.009,P<0.05).The hyper IOP 1 month group vs normal control was (14.40±7.27)/(23.53±9.09),while the quantity of the RGCs was decreased significantly, and there is statistical significa-nce between them (P=0.000,P<0.05)At the 3rd postoperative month the average quantity of the RGCs was(19.30±5.32), more than (13.47v3.98) of the hyper IOP 3 month group,and there is statistical significance(P=0.001, P<0.05).The 3rd postoperative month group vs normal control group was (19.30±5.32)/(23.53±9.09),the quantity of the RGCs was decreased,and there is statistical significance between them (P=0.013, P<0.05).The hyper IOP 3 month group vs normal control was (13.47±3.98)/(23.53±9.09),while the quantity of the RGCs was decreased significantly, and there is statistical significance between them (P=0.000,P<0.05)At the 6th postoperative month the average quantity of the RGCs was(18.70±9.61), more than (14.47±6.21) of the hyper IOP 6 month group,but there is no statistical significance (P=0.055, P> 0.05).The 6th postoperative month group vs normal control group was (18.70±9.61)/(23.53±9.09),the quantity of the RGCs was decreased,and there is statistical significance between them (P=0.029, P<0.05).The hyper IOP 6 month group vs normal control was (14.47±6.21)/(23.53±9.09),while the quantity of the RGCs was decreased significantly, and there is statistical significance between them (P=0.000,P<0.05)The average quantity of the RGCs of the surgical treatment group were more than the hyper IOP model group at any period of time,but only at the 3rd month have statistical significance (P<0.05).The average quantity of the RGCs of the surgical treatment group at any period of time were less than the normal control but the results were still better than the hyper IOP model group at the same period of time.4. Identify the different protein expressions of the retina from the three groups by LC-MS/MS:By LC-MS/MS,23 proteins were identified from the retinal protein samples of the three groups,9 (Hemoglobin, Alpha-hemoglobin, ATP synthase subunit beta, Carbonic anhydrase 2, Malate dehydrogenase, Protein S100-B, Alpha-tubulin, Neurofilament medium polypeptide and Annexin A1) of them we have made detailed analysis.The functions and features of those proteins had close relevance to the glaucomatous optic nerve damage and the mechanism of optic neuroprotection by controlling the intraocular pressure of the surgery.5. Clinical study of Pars Plana Filtration Technique:After long period of follow up,while 4 years at most and 2 weeks at least from January 2005 to April 2011. Confirmed that Pars Plana Filtration Technique is an effective and a safe surgery for the treatment of glaucoma,with high success rate(at the 1st postoperative year is 88.13%, the 2nd postoperative year is 78%, the 3rd postoperative year is 79%, the 4th postoperative year is 82%). The best correct vision of preoperative and postoperative are stable and have no severe surgical complications.Comparaed with other anti-glaucoma operative techniques, Pars Plana Filtration Technique is much more effective in treating the intractable glaucoma such as malignum glaucoma and refractory glaucoma,etc.Conclusions1. After B-scan ultrasonography examing the histomorphology changes to the vitreous retina and chorioid of the rabbit eyes in the three groups proved that Pars Plana Filtration Technique surgery is safe.It will not cause severe postoperation complications.2. Pars Plana Filtration Technique is able to control the IOP of the hyper IOP rabbit model successfully,and the treatment effect is stable and permanent.After counting the RGCs of the three groups by optical microscope, we have detected that the RGCs of the surgery group was much more than the hyper IOP group.It is a significant index for the optic neuroprotection.3. The 9 proteins which we analyzed in detail, may have some relevance to the pathogenesis, the damage and recovery,the immunoregulation process,the antioxidation process,the stress reaction process, the anti-inflammation reaction process,the optic nerve repair process,and the cell apoptosis process.Those are important to the damage repairment of the retina and optic nerve,which comfired the control IOP effect of Pars Plana Filtration Technique.It is important to glaucomatous optic neuropathy reparation.And the surgery is safe. 4. After the clinical study we found that the success rate of the surgery to all types of glaucoma is high.Comparaed with other anti-glaucoma operative techniques, Pars Plana Filtration Technique is much more effective in treating the intractable glaucomas such as malignum glaucoma and refractory glaucoma,etc.5. Pars Plana Filtration Technique is an effective and a safe surgery for the treatment of glaucoma.lt is easy to operate, have no sever postoperative complications,and the cost of the surgery is moderate.lt can be wildly practiced. |
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