Objective To study the effect of cyclosporine A drug delivery system (CsA-DDS) on the prevention of posterior capsule opacification (PCO) after experimental intraocular lens implantation in rabbit eyes. Methods Twenty healthy New Zealand white rabbits, whose left eyes and right eyes were used respectively as experiment eyes and controls, were subjected to extracapsular lens extraction and artificial lens implantation. During the operation, CsA-DDS with poly (lactideco-glycolide) as carriers or empty DDS was implanted in the capsular bag for the experimental eyes and controls respectively. After the operation, anterior chamber reaction, intraocular pressure (IOP) and CsA concentration were monitored and twelve weeks after the operation, the eyes were extracted for histopathological and morphological examinations. Results There were no differences between the two groups in conjunctival congestion,IOP change and anterior chamber reaction. PCO was less severe in the experimental eyes than in the controls. Light microscopy revealed that posterior capsular membrane in the experimental eyes was slick, with no obvious proliferation,whereas in the controls, there were lens epithelial cell proliferation and cortex regeneration of different degrees.Morphological examination with electron microscope showed that in the experimental eyes, lens epithelial cells did not function actively and apoptosis occurred, whereas in the controls, epithelial cells presented active function. No marked ultrastructural changes were found in either group. Conclusion Cs-DDS can inhibit PCO after intraocular lens implantation in rabbit eyes and does not have toxic effects on the surrounding ocular tissues. Therefore, it has a good potential for clinical use in prevention of PCO.

ObjectiveAfter performed the silicone-rubber membrane implantation in rabbits, we investigated the efficacy and security of the silicone-rubber membrane implant through observed intraocular pressure, bleb and morphologic result. MethodsForty rabbits were divided into 4 groups by randomized fashiones. Each group consisted of 10 rabbits. Subscleroflapectomy and the silicone membrane implantation were operated in one eye of each rabbit. And the other eye was only performed subscleroflapectomy, which be controlled eye. The change of intraocular pressure, bleb were observed postoperatively. And every eye for histopathologic examination. ResultsThe lasted time of lower intraocular pressure and filtration bleb in implanted eyes were longer than controlled eyes in two groups. Light microscope revealed that patent drainage tract and bite site could be seen in cilicone membrafe implant eyes. The activity and regularity of fibroblast proliferation in implanted eyes and controlled eyes were similarly. The excessive expression of fibroblast proliferation was not excit ed by silicone membrane. ConclusionIt is characterized by safely, effectively and operate simply that silicone membrane implant drainage surgery act as a new drainage surgery.

Objective To study the pharmacokinetic characters of cyclosporin A(CsA) in aqueous humor in rabbit after implanting different dosages of CsA in eyes and to provide a theoretical basis for the treatment of after cataract. Methods ECCE was performed in all rabbit eyes. CsA-MS was injected into the anterior chamber and the capsular bag in left eyes as expression group and MS was given in the same way in right eyes as control group. The concentration of CsA in the aqueous humor was monitored with high-performance liquid chromatogram. The follow-up period was 4 weeks. The samples were separated on a C18 column at 60℃ and detected at 210nm. The mobile phase was acetonitrile-water (67∶33). Results The correlation analysis showed a positive correlation within the range of 0.13-1.25mg/L (r=0.9951) and the detection limit was 0.13mg/L. The accuracy was 95.91% and the inter-day and intro-day precision was less than 5%. CsA in aqueous humor sustained a high concentration within 2 weeks. There were no significant differences in t1/2Ka and CL between the two dosage groups. AUC and Cmax increased in a dose-dependent manner. Conclusion The sustain-released CsA ophthalmic gels provided significant ocular bioavailability in rabbit eyes and they can reach the therapeutic dose in order to inhibit after cataract.

ObjectiveTo observe the morphology of the uveoscleral pathway following topical Prazosin（PZ） in rabbit free-sympathetic eyes．MethodsThe one lateral superior cervical ganglionectomy（SCG） were preformed on each rabbit．PZ drops were installed only on the SCG eyes on 14 days Postoperationly．Microamounts of fluorescein isothiocyanate-bovine serum albumin（FITC-BSA） was infused into anterior chamber of rabbit eyes as the teacer，two rabbits in each group were killed at 2，4，6，8，10，and 12h after PZ instillation．Degress of fluorescent intensity of ciliary body，suprachoroidal space，anterior and posterior sclera，and choroid were observed under fluorescence microscopy．ResultsThe IOP of the SCG eyes was lower after installation of PZ．But the reduced extent is below that of normal rabbit eyes；After installation of PZ，the fluorescent intensity of the ciliary body，suprachoroidal space，anterior and posterior sclera，and choroid was less stronger than the control eyes，but fader than at the same area of the normal eyes obviously．ConclusionThe outflow effects of PZ drops on increasing uveoscleral pathway were obviously decreased in the SCG eyes．It depends on the activity of sympathetic nerve system partially．Besides，there are other mechanisms．

Objective The neuroprotection provided by recombinant human erythropoietin(rhEPO)on the retina from ischemia-reperfusion injury has been confirmed but its mechanism is not fully understood.The present study aimed to investigate the effect of systemic administration of recombinant human erythropoietin(rhEPO)on the expression of glutamate in the retina after acute high intraocular pressure in vitro.MethodsThe acute high intraocular pressure models were established by the perfusion of physiological saline into anterior chamber of the lateral eye in forty-eight Japanese white rabbits.Other 6 Japanese white rabbits were as normal control group.The experimental rabbits were then equally divided into the model group and EPO group,and hypodermic injection of rhEPO was only performed in the EPO group.Glutamate expression in the retina in both groups was observed by immunohistochemistry on days 1,3,7,and 14 after retinal ischemia-reperfusion.Glutamate expression in another 6 rabbit retina without any treatment was determined as normal by the same method.The use of animal followed the Standard of Association for Research in Vision and Ophthalmology.ResultsNo positive expression of glutamate was observed in normal rabbit retina,but positive expression response of glutamate occurred in the rabbit retina of the model group.The number of positive expression cells in the EPO group was more than that in the model group at each time point(P＜0.01).On day 14 after ischemia-reperfusion,the number of positive expression cells was 3.3±1.1 per high visual field in the retina of the model group but 0.3±0.2 in the retina of the EPO group,showing a significant decrease of positive expression cells in EPO group(P＜0.01).ConclusionSystemic administration of rhEPO can down-regulate the expression of glutamate in the retina with acute high intraocular pressure.This process may be one of the mechanisms that rhEPO protects the retina from ischemia reperfusion injury.

Objective To investigate inhibitory effects of Oridonin on the proliferation of cultured rabbit conjunctival fibroblast (RCF). Design Experimental study. Participants Cultured RCF obtained from filtering area after trabeculectomy. Methods Trabeculectomy was performed in rabbits. On day 7 after surgery, subconjunctival tissue from filtering area was obtained for culturing RCF in vitro. Cultured RCFs were exposed to different concentration Oridonin (5, 10, 20, 30, 40, and 50 ?mol?L-1) for 48h, respectively. The proliferation of RCF was investigated by MTT assay at different time points. Main Outcome Measures Optical density (OD) value of RCF and inhibitory rate of cell growth. Results OD values of each concentration Oridonin group (5, 10, 20, 30, 40, and 50 ?mol?L-1) were (0.402?0.013), (0.347?0.011), (0.293?0.015), (0.236?0.022), (0.184?0.023), and (0.125?0.014), respectively. These data showed a significant difference compared with the OD value (0.453?0.015) of control group without Oridonin (P=0.021-0.000). The inhibitory effects showed a significant difference in a dose-dependent manner (F=5.48, P=0.003). Oridonin (5, 10, 20, 30, 40 and 50 ?mol?L-1) sup-pressed the proliferation of RCF in vitro at rates of 11.26%, 23.40%, 35.32%, 47.90%, 59.38% and 72.41%, respectively. Conclusion Oridonin can inhibit the proliferation of cultured RCF obtained from filtering area. The effect is in a dose-dependent manner. This indicates that Oridonin is most likely to be a novel agent to prevent excessive scarring following glaucoma surgery.

Objective To appraise therapeutic effects of tubeimoside on herpes simplex keratitis of rabbits. Methods HSV-1 (SM_(44) strain) is recovered on monolayers of BHK-21 cell cultures, then rabbit model of HSK was established after inoculation. After 0.2g/L Tu topically given, all eyes are examined by using slit-lamp-microscopy, and corneal samples were observed for ocular changes under transmission and scanning electromicroscope. (Results )Differences were significant in the three groups of corneal involvement scores. 0.2g/L Tu can obviously reduce corneal involvement area, and can also help to rehabilitate affected corneal epithelial cells. Conclusion Tu agent is able to cure experimental HSK to a certain degree, however, is less effective on HSK than acyclovir.

It is to discuss the method for studying uveoscleral pathway and the influence of uveoscleral outflow on aqueous humor drainage. Seventeen rabbits were randomly divided into the flow group that included 5 rabbits and the morphological group that included 12. Fluorescein-isothiocyanate bovine serum albumin (FITC-BSA) was perfused into anterior chambers of flow group rabbit eyes as the tracer for measuring uveoscleral outflow. This tracer was infused into anterior chambers of morphological group rabbit eyes for observing fluorescent intensity of all tissue of the uveoscleral pathway with fluorescence microscopy. Fluorescence was seen in all sites of uveoscleral pathway. The fluorescent intensity of ciliary body and suprachoroidal space was significantly stronger than that of anterior sclera (P＜0.05). The intensity of choroid and posterior sclera was significantly weaker than that of other tissues (P＜0.05). The average value of uveoscleral outflow was (0.18±0.031) μl/min. This study demonstrates that uveoscleral pathway plays an important role in aqueous humor drainage. Anterior sclera is the main site where aqueous humor flows out. FITC-BSA is an effective tracer for studying uveoscleral pathway from both morphological and functional aspects.

Oblective To evaluate the corneal healing of non-epuality diopter response histopathologically,immunohistochemically and ultrastructurally after excimer laser photorefractive keratectomy(PRK) with SVS APEX PLUS(Summit Technology Inc. USA) excimer laser, and the effects of corticosteroid on the healing. Methods PRK on 6 white rabbits(12 eyes) was performed on right eye of the rabbit for an attampted correction of -4.00 diopter and on left eye for an attempted correction of -8.00 diopter. The rabbits were divided into 2 groups randomly and each group included 6 eyes: Group FLM (3 rabbits, 6 eyes) and group CM (3 rabbits, 6 eyes). Fluoromethalone was given to group FLM,and chloromycetin to group CM. On 10d, 30d and 100d ,the eyes of one rabbit in each group were enucleated randomly. Half of each cornea was prepared for electron microscope observation (SEM and TEM)and the rest embedded in OCT compound for immunohistochemical study to examine Ⅲ -C and FN. Results All eyes were reepithelialized within 3d after PRK. Subepithelial corneal haze was observed on 15d,which was dominant on 30 or 60d. On 100d postoperatively,corneal hazes of 11 eyes were grades 0 or 0. 5,only 1 eye(the left eye of group CM) was denser haze (grade 1). On 3d postoperatively, one or two layers of corneal epithelial cell covered the ablation zone. On 30d after PRK,the epithelial cells showed hyperplastic changes. The cells were larger and increased from normal 5 or 6 layers to 7 or 8 layers of cells on 100d after PRK,epithelium was clear with more bright epithelium. Microplicae and microvilli were less than before. The expression of Ⅲ -C and FN in group CM was significantly more evident than that in group FLM. Conclusion The study show that despite recovery of a continuous and smooth epithelial layer and nearly normal corneal tissues on 100d after PRK,abnormalities of both epithelium and superficial stroma can be detected in the area of ablation. The ablation depth of stroma can influence the appearance of corneal haze after PRK. The microplicae and microvilli of rabbit cornea epithelium become less after PRK,which can be one of cause leading to ocular dry sensation in some patients.

To evaluate the efficacy and accuracy of photorefractive keratectomy (PRK) for myopia and myopic astigmatism .SVS APEX excimer laser with a wave length of 193 nm(Sumit Technology Inc. Waltham, Mass, USA) was applied. 316 myopic eyes of 168 patients were treated with PRK between September, 1996 and October, 1997, and 260 eyes (84%) of 150 patients were followed for more than three months, including male 68(116 eyes, 40.1%) and female 82(144 eyes, 59.9%). The preoperative spherical equivalent refractive errors ranged from -1.25D to -10.00 (mean -4.67±1.63D), and astigmatism ranged from 0 to -2.00D (means -0.33±0.45D). We divided the patients into two groups according to the referaction: group A (from -1.25D to -5.90D) and group B(from -6.00 to -10.00D). The number of eyes in the two groups were 220 and 40 respectively. In group A, on the 10th day, 68.9% has the uncorrected visual acuity (UCVA) equal to or one line better or lower than the preoperative best corrected visual acuity (BCVA). In 1,3,6 and 12 months, 90%, 96%, 95% and 94% had the UCVA equal to or one line better or lower than the preoperative BCVA respectively. In group B, on the 10 th day, in 1,3,6 and 12 months, UCVA equal to or one line better or lower than the preoperative BCVA occurred in 35.9%, 83%, 87%, 86%, and 84% of the cases respectively. Most of the haze showed 0.5～1 grades except 3 eyes with the haze of 2 grade in 3 or 6 months and it changed to 1 and 0.5 grade respectively within one year. In 10 days and 1,3,6,12 months postoperatively, the corneal haze was noted in 32.9%, 84.8%, 62.8%,9.0% and 2.8% of the treated eyes respectively. We found that 193 nm excimer laser PRK was a predictable, safe, stable, and effective refractive surgery for correcting myopia up to -10.00D in Chinese patients, and the effect was better in myopia lower than -6.00D.