The outcome of visual functions in a number of retinal diseases after treatment still remains limited, although significant advances in techniques of surgery and laser treatments have been made for these diseases, such as retinal degeneration and retinal detachment. Under anoxic conditions, death of photoreceptor cell occurs after retinal damage. Apoptosis, survival and rescue of retinal neurons depend on various biochemical changes, mediators and neurotrophic factors, and are also influenced by responses of glial cells. It is, therefore, of critical importance to pay more attention to further understanding of the neuropathology, and study and clinical application of neuroprotective strategies in order to promote functional recovery of the retina.

Study of new or previously known drugs for new applications in the treatments of eye diseases hasbeen one of the ma ior subjects in the ophthalmic field.However,we had found several caveats in the recently publishedpapers on experimental ophthalmic drug studies,such as new-drug trials lack of systemic designing,experimentalstudies without following the standard guidelines,in-vivo animal tests bypassed the necessary in-vitro cell screenings,and studies lack known-drug controls,etc.In order to improve the quality of such kind of studies,researchers should befamiliar with the standard procedures of new drug testing,and with the basic rules for drug screenings and efficacyassessments by in-vitro cell culture systems and in-vivo animal models.

Retinal break is the cause of primary retinal detachment,which remains a main cause for visual loss,and closure of the breaks is the principle of treatment.Currently surgical treatment can successfully reattach the retina in most cases.However,some basic questions still beset treatment of the disease,such as the cause responsible for development of retinal breaks and how to prevent it,and how the visual recovery can be satisfactory after reattachment surgery.Recent research indicates that the development of retinal breaks is associated with the process of vitreous liquefaction,posterior vitreous detachment (PVD) and abnormal vitreoretinal adhesion and traction.The retinal breaks can occur in the posterior margin of the vitreous base in the eye with complete PVD.Partial PVD may cause posterior breaks especially in cases of myopic traction maculopathy associated with schisis-like thickening in the outer retina (foveoschisis) and vitreomacular traction.It is known that microstructural changes and atrophy of the macula,and epiretinal membrane formation are the reasons for poor vision after the retina is reattached.Therefore,more attention should be paid to further understand the vitreous pathology and traction mechanism,to research for methods of its clinical evaluation and strategy of prevention and treatment,and to accelerate visual recovery after reattachment surgery,in order to raise the standard of the disease treatment.

The prevalence of diabetes mellitus in adults of China has reached 12.8%. Diabetic retinopathy (DR) accounts for approximately 1/4-1/3 of the diabetic population. Several millions of people are estimated suffering the advanced stage of DR, including severe non-proliferative DR (NPDR), proliferative DR (PDR) and diabetic macular edema (DME), which seriously threat to the patients' vision. On the basis of systematic prevention and control of diabetes and its complications, prevention of the moderate and high-risk NPDR from progressing to the advanced stage is the final efforts to avoid diabetic blindness. The implementation of the DR severity scale is helpful to assess the severity, risk factors for its progression, treatment efficacy and prognosis. In the eyes with vision-threatening DR, early application of biotherapy of anti-vascular endothelial growth factor can improve DR with regression of retinal neovascularization, but whether it is possible to induce capillary re-canalization in the non-perfusion area needs more investigation. Laser photocoagulation remains the mainstay treatment for non-center-involved DME and PDR.

Vitrectomy is helpful in the management of ocular trauma,but prolonged inflammation following vitrec tomy may be associated with a high incidence of traction retinal detachment. To test this hypothesis! ma-crophages.the main cellular component of vitreous inflammation,were injected into the vitreous cavity of rabbit eyes following vitrectorny. Fibrovascular proliferation over the medullary rays and optic disc and traction retinal detachment occurred in 13 of 15 vitrectomized eyes injected with macrophages,while in only three of 15 vitrectomized eyes injected with culture medium (controls). These results demonstrate that macrophages are capable of stimulating intraocular cellular proliferation. It is therefore suggested that anti-inflammation drugs and minimization of surgical intervention may improve the prognosis following vitrectomy.

Purpose To study the refractive state of silicone oil tamponade eyes. Methods To calculate the theoretical refractive state of eyes with silicone oil based on clinical visual optics and to perform retinoscopy on 48 silicone oil filled eyes with pars plana vitrectomy (PPV) and 45 ones with PPV plus lensectomy with retinal reposition, and then study theoretical and experimental differences of diopter in silicone oil filled eyes. Results Postoperative diopter of the former increases (+6.26?1.20) D than preoperative diopter, while that of the latter is (+11.40?2.22) D. Conclusion Hyperopic changes are found in silicone oil tamponade eyes, and the experimental values are lower than the theoretical ones. This may be helpful in predicting the change of diopter of silicone oil tamponade eyes.

Based on the histopathological observation of the perforated eyes in 74 cases, it is suggested that, according to the severity of the trauma, perforating eye injuries may be classified into 3 degrees. Those having enucleation done within 1 week after injury were all severe cases; none of them developed sympathetic ophthalmia. The eyes with less and moderate degree of injuries were enucleated mainly duo to secondary complications. Among the eyeballs examinedlater than 2 weeks after injury, intraocular fibropla-sia was found in 49 cases (92%), ciliary membranes in 34 cases (64%), epiretinal membranes in 23 cases (43%), and retinal detachment in 47 cases (89%). Contractive tissues were found in 19 cases with retinal detachment. Cellular proliferation was originated from the wound as well as the intraocular cell elements such as the ciliary epithelium.The following factors might stimulate the proliferation, e.g. incarceration of tissue in the wound, failing of the epithelium to cover the inner surface of the wound, inflammation and intraocular hemorrhage. Therefore, it is important to close the wound as early as possible and to remove blood and inflamed tissue with vitrectomy within 2 weeks after injury.

Objective To establish a method for primary culture of iris pigment epithelial cells (IPE). Methods Enzyme Assisted microdissection was used to isolate and cultivate the IPE cells. An identification was made with microscopic and immunohistochemical observations. Results IPE were successfully cultured and showed on differences with RPE in primary culture and subculture. Conclusion Enzyme Assisted microdissection is a reliable and quick method for the isolation of IPE.

Purpose To investigate bax expression and induction of apoptosis in normal cultured retinal pigment epithelium (RPE) cells . [WT5”HZ]Methods [WT5”BZ]Cultured human RPE cells were transfected by P MDNA3 hbax ,which incoded the whole bax gene and may be induced by Zn 2+ under the MTII promoter, through lepofectin mediated protocol.The tested RPE cells were divided into three groups of A, P MDNA3 hbax transfected ;B,P MDNA3 (nude vector) transfected and C,normal RPE cells.After transfection, DNA gel electrophoreses were performed ,the tested RPE cell cycles were analyzed with flow cytometry (FCM). Results The gel electrophoretogram showed DNA ladder phenomenon,FCM confirmed the apoptosis of RPE cells P MDNA3 bax transfected , consisting of significant apoptotic peak sited before the G 1 phase and the apoptotic rate was 36%. Conclusion The foreign bax gene can be effectively conducted into the RPE cell through lepofectin mediated protocol and induced expression . The foreign bax overexpression may induce the cultured human RPE cell susceptibility to apoptosis.

Objective To evaluate the visual results,surgical technique and safety of secondary intraocular lens (IOL) implantation in aphakic eyes following vitrectomy and lensectomy for complicated ocular trauma or retinal detachment. [WT5”HZ]Methods The clinical records of 32 cases (32 eyes),received these surgeries during November 1996 and December 1999,were reviewed retrospectively.During the secondary operation,intraocular infusion through the pars plana was performend and the type of IOL was chosen based on the integrity of lens capsule. [WT5”HZ]Results The study included 30 eyes suffering from trauma (foreign bodies in 15 eyes,penetrating injury with traumatic endophthalmitis and with vitreous hemorrhage in 6 eyes respectively,blunt trauma with lens dislocation in 3 eyes),and 2 eyes with primary retinal detachment.Those eyes all received vitrectomy,lensectomy,and/or removal of foreign bodies and corneal suture.The interval of two operations ranged from 1 to 16 months with an average of 6.8?3.7 months.Posterior chamber IOL was implanted in the ciliary sulcus in 25 eyes with a whole or 2/3 of lens capsule,trans scleral suture fixation of IOL in 5 eyes,anterior chamber IOL and IOL with artificial iris in one eye respectively.Silicone oil was removed in 5 eyes during the secondary operation.Post operative visual improvement was achieved in 29 eyes.Main complications were corneal edema and low intraocular pressure after operation. [WT5”HZ]Conclusion Intraocular infusion and proper IOL implantation during the secondary operation following vitrectomy can provide selected aphakic eyes with better visual recovery.