Objective：To observe the protective effect of ginkgo bilo ba extrac t (EGb 761), a free radical scavenger, on the photoreceptor cells after lighti nduced retinal damage. Methods：Seventytwo female SpragueDa wley (SD) rats we re randomly divided into 4 groups: normal control group, lightinduced retinal da m age model group, model+physiological saline group, and model+EGb 761 group, with 18 rats in each group. All of the rats except the ones in the control group were exposed to white light at (2740plusmn;120) lx for 6 hours after the dark adap tation for 24 hours to set up the lightinduced retinal damage model. Rats in m o del + physiological saline group and model+EGb 761 group were intraperitoneall y injected daily with physiological saline and 0.35% EGb 761 (100 mg/kg), respec tively 7 days before and 14 days after the light exposure. Apoptosis of photorec eptor cells was detected 4 days after light exposure; 7 and 14 days after light exposure, histopathological examination was performed and the layer number of ou ter nuclear layers (ONL) on the superior and inferior retina was counted. Results：Four days after light exposure, the apoptosis of photorecep tor cells was fou nd on ONL in model, model+ physiological saline and model+EGb 761 group, and w as obviously less in model + EGb 761 group than in model and model+physiologic al saline group. Seven days after light exposure, the layers of ONL on the super ior retina were 3 to 4 in model and model+physiological saline group, and 7 to 8 in model+EGb 761 group; the mean of the layer number of ONL in model+EGb 761 group (6.92plusmn;0.82) was less than that in normal control group (8.40plusmn;0.95) (t=-1.416, P＜0.05), but significantly more than that in model (5.96 plusmn;1.36 ) and model+physiological saline group (5.90plusmn;1.40）（t=1.024, 1.084; P＜0.05). Fourteen days after light exposure, the layers of ONL on the superior retina were 0 to 1 in model and model+physiological saline group, and 3 to 4 i n model+EGb 761 group. The mean of the layer number of ONL in model+EGb 761 group (5.5 2plusmn;1.06) was significantly more than that in model (3.44plusmn;2.15) and model + physiological saline group (3.37plusmn;1.91) (t=2.082, 2.146, P＜0.05). Conclusion：EGb 761 can partially inhibit the apoptosis of pho toreceptor cells, thus exert protective effect on photoreceptor cells.
Objective To observe the changes of intraocular pressure (IOP) after intravitreous injection wih triamcinolone acetonide (TA) and their affected factors. Methods The clinical data of 125 patients (125eyes) who had undergone intravitreous injection with TA were retrospectively analyzed. The patients (52 males and 73 females) aged from 17 to 83 years with the average age of 56.5. There were 49 patient (39.2%) with diabetic retinopathy (DR), 56 (44.8%) with retinal vein occlusion (RVO), and 20 (16.0%) with exudative age-related macular degeneration (AMD). One day before the treatment, IOP was measured by Goldmann applanation tonometry, and the basic IOP was 7~31 mm Hg (1 mm Hg=0.133 kPa) and the average IOP was (14.69plusmn;3.72) mm Hg. The patients were divided into two groups according to the basic IOP:below 15 mm Hg group (n=64) and 15 mm Hg or above group (n=61). All of the patients underwent intravitreous injection with 4mg TA. IOP was measured 1 day, 3 days, 1 week, 2 weeks, and 1 month after the treatment in the same way, respectively, and later was measured once every 1 month. The follow-up period was 3~21 months with the mean of 5 months. The elevation of IOP would be defined as the pressure of 21mmHg or higher. The changes of IOP in patients before and after the treatment, and with different diseases and ages were analyzed. Results Thirty-six patients (28.8%) had elevation of IOP after the treatment, out of whom 97.2% had the elevation within 3 months after the injection and decreased to the basic level 7 months after the injection. In these patients, there were 11 (17.19%) in the below 15 mm Hg group and 25 (40.98%) in 15 mm Hg or above group, and the difference between the two groups was statistically significant (P＜0.01）. During the followup period, the mean maximum IOP was (20.09plusmn;7.58) mmHg, which was 5.43 mmHg higher than that before the treatment（P＜0.001）. The mean maximum IOP of 53 patients (42.4%) after the treatment was 5 mm Hg higher than that before the treatment. The mean maximum IOP during the followup period was （18.19plusmn;4.73）mmHg in DR group，（22.50plusmn;9.30）mmHg in RVO group, and（18.12plusmn;6.09）mmHg in AMD group. The occurrence of the elevation of IOP in RVO group was obviously higher than that in the other 2 groups (P＜0.01）. The result of regression analysis showed that age was correlative with the elevation of IOP after the treatment: more risks of occurrence of high IOP were found in younger patients (P=0.000). Conclusion Elevation of IOP after intravitreous injection with TA is common, which is correlative with the basic IOP, age, and pathogeny. After the intravitreous injection with TA, the elevation of IOP often occurs in patients with high basic IOP before treatment, younger age, and RVO. (Chin J Ocul Fundus Dis, 2007, 23: 115-117)
Objective To assess the effects of 670nm LED (lightemitting diode) to protect the photoreceptor from the lightinduced damage in a rat model. Methods 32 SD rats were randomly assigned to one of eight groups: untreated control group, the LEDtreated control group, three groups of lightinduced damage，and three groups of lightinduced damage treated with LED. Lightinduced damage result from exposing to constant light for 3 hours of different illuminations of 900，1800 and 2700 lx, respectively. The LED treatment (50 mW) was delivered for 30 minutes at 3 hours before the light damage and 0，24 and 48 hours after the light damage. Retinal function and morphology were measured by electroretinogram (ERG) and histopathology assay. Results The illumination of 900 lx for 3 hours did not damage the rat retina. The illumination of 1800 lx for 3 hours resulted in thinner ONL and no OS and IS. The ratio of damaged area/total retinal area was 048plusmn;012， the damaged thickness of ONL/normal ONL (L5 ) was 039plusmn;007，and the amplitude of ERG b wave was (431plusmn;120) mu;V. With the LED treatment the ratio of damaged area decreased (M6=017plusmn;0.12, P5/6=0.002), and the ratio of the damaged thickness of ONL also decreased (L6=0.22plusmn;0.09, P5/6lt;0.01), and the amplitude of ERG b wave increased to (1011plusmn;83) mu;V（P5/6lt;0.001）. The illumination of 2700 lx for 3 hours caused severed damage to the rat retina and the LED could not protect them significantly. Conclusions 670 nm LED treatment has an evident protective effect on retinal cells against light-induced damage, which may be a simple and effective therapy to prevent or to delay agerelated macular degeneration.
Objective To investigate the refractive changes of ocular measurable factors due to scleral buckling surgery. Methods A total of 86 eyes of successful rhegmatogenous retinal detachment with a higher encircling scleral buckle underwent A-scan and keratometer examination before surgery as well as l week,4 and 12 weeks after surgery.The refractive factors included the depth of anterior chamber,thickness of lens,axial length of eye,corneal curvature and refraction of eye were detected pre- and post-operatively. Results Compared with preoperation,the depth of anterior chamber was decreased significantly at the lst,4th and 12th postoperative week(P＜0.05),while no significant change of the axial length of eye was observed.The thickness of lens was increased significantly and the refractive error was myopic shifted at the lst and 4th week after operation(P＜0.05),but no significant change was observed at the 12th postoperative week.Statistically significant difference was also observed in corneal curvature of central axis in the local bucklele;1 quadrant with encircling group between preoperation and the lst and 4th postoperative week. Conclusions With higher encircling scleral buckle,the refractive change after buckling surgery may be caused primarily by the shallowing of anterior chamber and thickening of lens. (Chin J Ocul Fundus Dis, 1999, 15: 227-229)
Radiotherapy is the prior treatment for uveal melanoma, but a major problem confronted most of the patients is radiation retinopathy, which accompanied with severe visual loss and secondary enucleation potential. There is no optium choice and normative strategy so far, the intraocular melanoma society has focused on application of anti-vascular endothelial growth factor drugs injection and glucocorticoids. This article reviews a series of potential managements for radiation retinopathy and its further stage .
Objective To observe the visual field loss after 577 nm krypton pan-retinal photocoagulation (PRP) in the treatment of diabetic retinopathy (DR). Methods A prospective clinical studies. Forty-six eyes of 26 patients with proliferative DR (PDR) and severe non-proliferative DR (NPDR) diagnosed by clinical examination from No. 306 Hospital of PLA during January 2014 and December 2015 were included in this study. Among them, 21 eyes of NPDR and 20 eyes of PDR; 13 eyes with diabetic macular edema (DME) (DME group) and 28 eyes without DME (non-DME group). All eyes underwent best corrected visual acuity (BCVA), fundus color photography, fundus fluorescein angiography (FFA) and optical coherence tomography (SD-OCT) examinations. The visual field index (VFI) and visual field mean defect (MD) values were recorded by Humphrey-7401 automatic visual field examination (center 30° visual field). The BCVA of DR eyes was 0.81±0.28; the VFI and MD values were (89.8±8.4)% and −7.5±3.85 dB, respectively. The BCVA of the eyes in the without DME group and DME group were 0.92±0.20 and 0.57±0.27, the VFI were (90.86±7.86)% and (87.46±9.41)%, the MD values were −6.86±3.43 and 8.87±4.48 dB. PRP was performed on eyes using 577 nm krypton laser. The changes of VFI, MD and BCVA were observed at 1, 3, and 6 months after treatment. Results Compared with before treatment, the VFI of DR eyes decreased by 12.0%, 12.3% and 14.8% (t=7.423, 4.549, 4.79; P＜0.001); the MD values were increased by −4.55, −4.75, 6.07 dB (t=−8.221, −5.313, −5.383; P＜0.001) at 1, 3 and 6 months after treatment, the differences were statistically significant. There was no difference on VFI (t=1.090, −0.486; P＞0.05) and MD value (t=−0.560, −0.337; P＞0.05) at different time points after treatment. Compared with before treatment, the BCVA was significantly decreased in DR eyes at 1 month after treatment, the difference was statistically significant (t=2.871, P＜0.05). Before and after treatment, the BCVA of the DME group was lower than that of the non-DME group, the difference were statistically significant (t=4.560, 2.848, 3.608, 5.694; P＜0.001); but there was no differences on the VFI (t=1.209, 0.449, 0.922, 0.271; P＞0.05) and MD values (t=1.582, 0.776, 0.927, 1.098; P＞0.05) between the two groups. Conclusion The range of 30° visual field loss is about 12%-14.8% after 577 nm krypton laser PRP for DR. VFI and MD can quantitatively analyze the and extent of visual field loss after PRP treatment.
Objective To observe the survival of human umbilical cord derived mesenchymal stem cells (hUC-MSCs) after injection into the vitreous of rabbits,and the animal safety under those procedures.Methods Twentyseven pigmented rabbits were randomly divided into 3 groups (intravitreal injection 1 week group，2 weeks group and 4 weeks group)， each with 9 rabbits.For each animal the right eye was the experimental eye receiving hUCMSCs injection,while the left eye was the control eye receiving culture medium. The rabbit eyes were examined by slitlamp microscope, indirect ophthalmoscopy, fundus photography, fundus fluorescence angiography（FFA）and Tonopen tonometer before and after injection. hUCMSCs were labeled by CMDil in vitro, and their survival status was measured by confocal fluorescence microscopy, light microscope and transmission electron microscope at 4 weeks after injection. Results Four weeks after injection, a large number of the hUCMSCs were still alive in the vitreous cavity. The overall condition of those rabbits was good. The anterior segment and retina of experimental eyes were normal, without hyperfluorescence, hypofluorescence and leakage in the retina at 1,2 and 4 weeks after injection. There was no significant difference on IOP before and after injection at different time points (P＞0.05), and no obvious changes at cornea, anterior chamber angle,lens,retinal structure by.light microscope and transmission electron microscope examination.Conclusion hUC-MSCs can survive in the rabbit vitreous for four weeks；intravitreal injection of hUCMSCs was safe and feasible.
Objective To observe the effect of panretinal photocoagulation (PRP) on the expression of cyclooxygenase-2 (COX-2), vascular endothelial cell growth factor (VEGF) in epiretinal membrane of proliferative diabetic retinopathy (PDR). Methods Atotal of 35 patients (35 eyes) with PDR and underwent plana vitrectomy were enrolled in this study. The patients were divided into non-PRP group (19 patients, 19 eyes) and PRP group (16 patients, 16 eyes) depends on if they had received PRP before surgery. The epiretinal membranes stripped during operation were collected for pathological examination. The histopathological features was observed by haematoxylin and eosin stain. The expression of CD34, COX-2 and VEGF, and microvessel density (MVD) were measured by immunohistochemistry method. Results Many new dispersed capillary blood vessels were found in the thick epiretinal membranes of non-PRP group, while scattered small blood vessels were found in the relatively thin epiretinal membranes of PRP group. MVD value was (7.42±1.39) in the non-PRP group and (4.56±1.22) in the PRP group, which was lower than the non-PRP group (t=6.41, P<0.01). The expression of CD34, COX-2 and VEGF in the tissues of epiretinal membrane in PRP group were obviously lower than the non-PRP group (t=6.147, 5.944, 7.445; P<0.01). Conclusion PRP can effectively inhibit the expression of COX-2 and VEGF in epiretinal membrane of PRP patients.
The introduction of anti-vascular endothelial growth factor (VEGF) therapy represents a landmark in the management of wet age-related macular degeneration (AMD). However, as a new therapy, several problems such as durability of the therapeutic effects, medication side effects, and medication selection have emerged. We should make appoint of improving the therapeutic effect and safety by realizing the limitation of the therapy, monitoring the clinical potential adverse reactions of anti-VEGF agents, and recommending individualized treatment.
Objective To observe the effect of persistent flickering stimulus on the structure and function of retina in guinea pigs during a developmentally sensitive period.Methods Twenty-four two- week-old guinea pigs were randomly divided into flicker light (FL) group and control group, with 12 guinea pigs in each group. Animals in FL group were raised under 500 Lux illumination with a duty diurnal cycle of 50% at a flash rate of 0.5 Hz. Animals in control group were reared under steady 500 Lux illumination. Light emitting diode (LED) lamps were used for lighting under a 12-hour light/12-hour dark cycle. After the collection of fundus photographs and electroretinograms recorded at week 12, eyeballs were taken out, three dimensions were measured, and histopathological changes were examined.Results Compared to control group, tessellated fundus in FL group appeared more prevalent; implicit time of ldquo;ardquo; waves were prolonged in electroretinogram; the eyeballs were increased in horizontal, vertical, axial dimensions by (0.89plusmn;0.30), (0.69plusmn;0.20) and (0.96plusmn;0.30) mm respectively, the differences between two groups were statistically significant (t=12.7,11.9,15.8;P＜0.05). The gap of sclera collagen fiber was slightly widened.The photoreceptor layer was more likely to develop a disordered outer segment, which contained deciduous disc membranes.Conclusion Persistent flickering stimulus is attended by development of excessive ocular enlargement,which could affect the retinal structure and function of photoreceptors.