Objective To analyze the protective effects of heat-shock response on the retinae of the rats after retinal ischemic reperfusion injury.Method Twenty Wistar rats (20 eyes) were divided into 4 groups: intracameral perfusion group (group P), intracameral perfusion after quercetin injection group (group P+Q), intracameral perfusion after heat shock group (group P+H), and in tracameral perfusion after quercetin injection and heat shock group (group P+Q+H ). According to the standard program established by International Society for Clinical Visual Electrophysiology, we recorded the results of the dark-adapted electroretinogram (D-ERG ),oscillatory potentials (OPs),and light-adapted ERG (L-ERG) of the rats with intraocular hypertension after induced by heat shock response. The expressions of HSP 70 of the rats in all groups were observed by Western blotting.Results The expression of HSP 70 of the rats in group P+H was the highest in all groups, but the expressions of HSP70 in group P+Q and P+Q+H were inhibited significantly. The amplitudes of a and b wave of ERG and O2 wave of OPs decreased, and the delitescence of them were delayed significantly in rats after intracameral perfusion. The amplitude of b wave of D-ERG and O2 wave of OPs in group P+H were higher than which in group P. Zero hour after perfusion, the amplitudes of all waves in group P+H increased significantly (Plt;0.05). Twenty-four hours after perfusion, the retinal functional resumption of the rats in group P+H was better than which in group P. In group P+Q and P+Q+H, the delitescences of all waves of ERG and O2 wave of OPs were the longest and the amplitudes were the lowest, and some waves even disappeared.Conclusions The heat-shock response may improve the recovery ability of the retinal cells after injury of ischemic reperfusion.(Chin J Ocul Fundus Dis，2003，19：117-120)
In this paper,the changes of activities of enzymes relating toenergy metabolism in rabbit's retina during acute ocular hypertension were observed.The activities of succinate dehydrogenase and adenosine triphosphatase were foud to be reduced,while the activities of the lactatic dehydrognease and glucose-6-phosphatase increased.The results reveal the disturbance of metabolism of energy in retina undergone acute ocular hypertension,and suggest that this might be the underlying factors relating to the defects of the functions and structures of the retina. （Chin J Ocul Fundus Dis,1993,9:141-144）
Objective To observe the incidence of ciliary detachment and its relationship with intraocular hypotension soon after vitrectomy. Methods A total of 46 eyes of 46 patients who underwent vitrectomy were examined by ultrasound biomicroscope (UBM). The patients were divided into three groups according to different tamponade: gas group (11 eyes), silicone oil group (8 eyes) and balanced saline solution (BSS) group (27 eyes). Basing on the postoperative intraocular pressure (IOP), the patients were divided into two groups: IOPlt; 10 mm Hg (25 eyes) and IOPge;10 mm Hg (21 eyes). UBM was applied to determine the tomographic features of the ciliary body 3 days after the surgery. IOP were monitored by noncontact tonometer daily after the surgery. The eyes with ciliary detachment were then examined once a week till the ciliary detachment reattached. The followup period was from 14 to 35 days. Results After vitrectomy, ciliary detachment was observed in 20 eyes of 46 eyes (43.5%), The incidence of ciliary detachment was 27.3％ in gas group, 25.0％ in silicone oil group, and 55.6％in BSS group. The average IOP in eyes with ciliary detachment ［(6.47plusmn;4.49) mm Hg （1 mm Hg=0.133 kPa）］ was significantly lower than that in the eyes without ciliary detachmen ［(15.61plusmn;7.72) mm Hg］ (t=8.031,Plt;0.001). The incidence of ciliary detachment was higher in eyes with postoperative IOP lt;10 mm Hg (68.0％) than that in the eyes with postoperative IOP ge;10 mm Hg (14.3%) (chi;2＝15.60, Plt;0.001). All eyes with postoperative ciliary detachment got spontaneous reattachment within 30 days after the surgery except that one eye had optic disc edema due to severe intraocular hypotension. Conclusions Early postoperative ciliary detachment is a common complication after vitrectomy. Eyes filled with BSS have the highest incidence of postoperative ciliary detachment. Most of the patients with ciliary detachment may get spontaneous reattahment within 30 days after the surgery.
Objective:To observe the changes of the thickness of reti nal nerve fiber layer (RNFL) of optic disc in rats with chronic glaucoma continuously dete cted by optic coherence tomography (OCT). Methods:A total of 48 Wist ar rats (24 males and 24 females) were randomly divided into 3 groups with 16 ra ts (32 eyes) in each group. The right eyes were the photocoagulation eyes and the left ones were as the control. Laser photocoagulation with the wavelength of 532 nm was perfo rmed on the trabecular network of the right eyes to induce the chronic middlelevel oc u lar hypertension. The changes of the intraocular pressure (IOP) were observed. O pticdisc linear scanning of OCT was performed 3, 6, and 9 weeks after IOP incr e ased, and the thickness of RNFL of optic disc was detected by the computer. Eight rats in each group were killed and retinal histology slic es were used to detect the thickness of RNFL. The flatmount s of retina from the right eyes of the other 8 rats in each group were stai ned by 1% toluidine blue. The density of retinal ganglion cells (RGC) was calcul ated and the results were compared and analyzed. Results:IOP o f the rats increas ed chronically and moderately after photocoagulation. IOP of the experimental ey e 3,6, and 9 weeks after photocoagulation was obviously higher than which of the control eyes, respectively （P＜0.001）. The results of OCT showed that the thickness of the RNFL of the experimental eyes was (67.39plusmn;5.91) mu;m, (53.4 2plusmn;5.64) mu;m，and (44.35plusmn;5.76) mu;m 3, 6, and 9 weeks after photocoagulation, and the corresponding thickness in the control eyes was（80.32plusmn;5.87）, （79.69plusmn;5.69）, and （80.78plusmn;5.84）mu;m, respectively. The thickness of the retinal fiber layer detecte d by histological method was （64.38plusmn;6.54）, （51.47plusmn;6.4）, and （42.10 plusmn;6.10）mu;m in the experimental eyes 3, 6, and 9 weeks after photocoagulation, and (76.23plusmn;6.78), (78.64plusmn;6.15), and (77.64plusmn;6.63) mu;m in the control eyes. Regression analysis of the thickness detected by the two methods was made, and the regression coefficients was 0.932（P＜0.001）.The differ ence of the ave rage density of RGC between the two groups was significant (P＜0.05）. Conclusi on:Glaucoma model in Wistar rats may successfully set up b y photocoagulating the trabecular meshwork. The thickness of retinal nerve fiber layer of the optic disc in rats with chronic glaucoma detected by OCT and obser ved by the light m icroscope is accordant. The changes of the thickness of RNFL in rats with chroni c glaucoma could be continuously detected by OCT to investigate the progress of the glaucomatic retinopathy in rat model.
Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.
Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100.7 μV/μm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 μV/mm Hg under the ideal condition.
Objective To observe the changes of electroretino gram(ERG) in temporary traumatic ocular hypotension and to detect the possiblem echanism. Method The rabbit model with ocular hypotenstion was made. At the 2nd, 4th, 8th, 16th week after trauma, the ocular tension and ERG was examined. Result Amplitude of b wave in treated group was 2.5 times as high as that in the control at the 2nd week after trauma, and then decrease to 1.5 times as high as that in the control at the 16th week. Conclution Higher amplitude of b-wave of ERG in rabbit with ocular hypotension may be related to blood circulation congestion, which might lead to accumulation of the metabolic toxin. (Chin J Ocul Fundus Dis，2004，20：189-191)
Objective To observe the relationship between the suturing patterns to close the scleral incision and postoperative intraocular pressure (IOP) in 23G minimally invasive vitrectomy. Methods Eighty eyes of 80 patients with vitreoretinal diseases, who were treated with primary 23G minimally invasive vitrectomy, were enrolled in this prospective clinical study. Patients with poor closed scleral incision which need suturing were excluded from this study. The corrected visual acuity ranged from hand movement to 0.2. The IOP ranged from 7.9 to 19.8 mm Hg (1 mm Hg=0.133 kPa), with the mean of (13.9plusmn;1.8) mm Hg. The eyes were randomly divided into three groups: group A (20 eyes), suturing all three scleral puncture after vitrectomy; group B (20 eyes), suturing only two upper scleral puncture, but not the lower infusion puncture after vitrectomy; group C (40 eyes), no suturing for all 3 scleral puncture after vitrectomy. All patients underwent 23G vitrectomy only. The corrected visual acuity and IOP were observed after surgery. Results The corrected visual acuity were 0.1 -0.3, 0.2- 0.5, 0.3 -0.8 in one, seven and 14 days after surgery, respectively. No one in group A, B experienced hypotony in one, three, seven and 14 days after surgery. Thirteen (32.5%), five (12.5 %), two eyes (5.0%) in group C experienced hypotony in one, three and seven days after surgery. Seven eyes (17.5%) experienced severe hypotony (＜5 mm Hg) in 14 day after surgery in group C. The difference was statistically significant compared the incidence of hypotony in group C with group A, B respectively at different time points after surgery (chi;2= 16.82,P=0.007). The difference was statistically significant compared the incidence of hypotony in group C at different time points after surgery (chi;2=11.64,P=0.003). The difference was no significant compared the IOP between group A and B at different time points after surgery (F=1.618,P=0.205). Compared the IOP of group C to group A and B, the difference was statistically significant in one and three days after vitrectomy (F=9.351,P=0.000); but not statistically significant in seven and 14 days after vitrectomy(F=0.460,P=0.633). Conclusions Whether or not suturing the scleral punctures is closely related to postoperative hypotony in 23G vitrectomy. Suturing only the two upper scleral punctures can reduce the occurrence of postoperative hypotony.
Objective To investigate the effect of proanthocyanidins (PC) on retina of rats with acute ocular hypertension. Methods The SpraqueDawley (SD) rats were randomly divided into the normal group, the model group and PC high or lowdosage group. The PC high or low dose group received 300mg/kg.d or 100mg/kg.d of PC in suspension solution for 5 days respectively. The normal group and the model group fed with distilled water for 5 days. Then acute ocular hypertension was induced in the model group and all PC groups, and after 48h of ocular hypertension the eyeballs were analyzed by electron microscope and UV spectrophotometer to measure the levels of superoxide dismutase(SOD), malonaldehyde (MDA), nitrogen monoxidum (NO), glutamic acid (Glu) and calcium ion(Ca2+). Results PC could raise the activity of SOD and reduced the levels of MDA,NO,Glu and Ca2+ in retina tissue. Electron microscope examination revealed that PC reduced retinal edema and ganglion cell apoptosis. PC also enhanced the SOD activity and suppressed the levels of MDA, NO, Glu and Ca2+. Conclusions PC can protect retina from acute ocular hypertension. The main mechanism might relate to anti-free radical oxidation, antagonizing calcium overloading, reducing toxicity of NO and Glu on the retina.