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 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.

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.

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.

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 investigate the effect of hypericin on the activity of protein kinase C (PKC) in cultured human retinal pigment epithelium (RPE) cells in vitro. Methods RPE cells were cultured in standard medium with 10% serum concentrations containing 0.5 to 5.0 ?mol/L hypericin with or without preincubation of phorbol 12 myristate 13 acetate (PMA). The activities of cytosolic PKC (c PKC) and membranous PKC (m PKC) were assayed by PKC kit. Results The original activities of c PKC and m PKC of RPE cells were (35.34?4.10) pmol?min 1 ?mg 1 and (62.52?8.80) pmol?min 1 ?mg 1 . The activity of c PKC in RPE cells with PMA preincubation decreased rapidly in 5 minutes, with a subsequent slow decrease after 20 minutes and a decrease to 18% of the activity of c PKC in RPE cells without PMA preinubation after 60 minutes. While the activity of m PKC in RPE cells with PMA preincubation increased gradually after 5 minutes and reduced after reached the peak at 40 minutes, and then returned to baseline after 60 minutes, eventually decreased below 30% of the control group. When RPE cells were cultured with PMA for 48 hours, the activities of c PKC and m PKC were hardly detectable, while RPE cells were cultured with both PMA and hypericin, hypericin could counteract most of down regulation by PMA. Conclusion Hypericin may inhibit the translocation of PKC in RPE cells,change the activity of PKC, promote the apoptosis of RPE cells likely,and then prevent proliferative vitreoretinopathy.

Objective To investigate the activation and role of signal transduction pathway of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR)-mitogen activated protein kinase (MAPK) in proliferation of human retinal pigment epithelial (RPE) cells. Methods Human RPE cells were stimulated with 0.1%,10% foetal calfserum (FCS) and EGF(0.1, 1, 10, 50 and 100 ng/ml)in 0.1% FCS Dulbeco′s modified Eagle′s medium (DMEM) and in 10% FCS DMEM for 3 days, respectively. Immunohistochemical staining and in situ hybridization were used to observe the expressions of EGFR protein and EGFR mRNA,respectively. Activation of MAPK was detected by immunohistochemical method with specific anti-phosphorylated ERK 1/2 antibody. Results The optimal concentrations of EGF were 10 ng/ml in 0.1% FCS DMEM and 1 ng/ml in 10% FCS DMEM. After 3 days of stimulation with EGF, phosphorylated ERK 1/2 staining was detectable in nucleus of RPE cells, whereas cells presented immunostaining for phosphorylated ERK 1/2 in the cytoplasm before stimulation. Conclusions EGF may improve the expression of EGFR protein and EGFR mRNA of RPE cells, and induced MAPK nuclear translocation in a concentration-dependent manner. EGF-EGFR-MAPK signal transduction pathway may play a key role in RPE cells proliferation, and serum exerts an important acceclerating function in the process.