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 investigate the relationship between exposure intensity and illumination time of blue light and replicative senescence of rat retinal pigment epithelial （RPE） cells.Methods Thirtysix 12-14 weeks Wistar rats were kept in the cage with a bluelight bulb ［(450plusmn;10) nm］, and were randomly divided into four groups (no light，nature light，500 lx light and 1000 lx light illumination), each has nine rats. The rats in each group were further divided into three subgroups according to illumination time (one month，two months or three months). Eyeballs were collected after intraperitoneal injection of 10% chloral hydrate. The right eye of each rat was embedded in paraffin and sectioned for hematoxylineosin (HE) staining, while frozen sections of the left eye were stained for the senescence-associated beta;-galactosidase (SA-beta;-Gal). The data were analyzed by SPSS11.5 statistical software.Results The amounts of SA-beta;-Gal positive RPE cells were significantly different between all groups under the same illumination time 17 (P＝0.000）, and between all subgroups of different illumination time with same exposure intensity （P＜0.01）except for the control group (no light). Conclusion Bluelight can induce replicative senescence in rat RPE cells in an intensity and timedependent manner.
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 investigate the effect of micropulse di ode laser treatment on the retina in Brown-Norway rats (BN Rats).
Methods
130 eyes of BN rats received irradiance of different powers of micr opulse diode laser with 810nm wavelength through a contact lens. Fundus color photography and fundus fluorescein angiography (FFA) were performed on day 1, 3, 7, 14 and 28 days after treatment. Animals were sacrificed on 1, 3, 7, 14 and 28 days separately for historical study. The expression of heat shock protein-70 (HSP-70) in the retina was observed with immunohistochemistry. Cell apoptosis of retina tissue was examined by TdT mediated dUTP nick end labeling (TUNEL).
Results
(1) No change was found in no visible reaction laser spots by light microscope. High duty cycles with threshold and suprathreshold en ergies can produce severe damage even to the inner nuclear layer. (2) HSP-70 ex pression was markedly increased in the inner nuclear layer at 1d after micropulse diode laser. This increase in HSP-70 expression peaked at day 3 whereafter a decline near to normal at 2 weeks was detected. (3) Apoptosis was detected mainl y in retinal pigment epithelium, outer nuclear layer, inner nuclear layer and ev en choroid by TUNEL after micropulse diode laser treatment. The TUNEL-positive cells increased with the laser power. Maximum TUNEL-positive cells could be seen at day 3 after treatment.
Conclusions
The retinal injury has positive relationship with laser energy. The thermal damage is confined to the RPE and spare the neurosensory retina when using threshold power (50mW) with 50% duty-cycle and supra-threshold power with high duty-cycle (100mW，5%～15%). The hyper expression of HSP-70 and apoptosis mechanism may play an important role in the tissue repair process.
(Chin J Ocul Fundus Dis,2008,24:122-126)
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 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 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)
ObjectiveTo evaluate the safety to perform 23G vitrectomy with scleral incisions at 5.0 mm behind the limbus.MethodsThis is a prospective uncontrolled case study. The data of 140 consecutive primary 23G vitrectomy patients (145 eyes) were enrolled in this study. There were 56 males (59 eyes) and 84 females (86 eyes), with the mean age of (56.34±9.98) years and axial length of (23.99±2.57) mm. There were 139 phakic eye and 6 aphakic eyes. All the eyes received 23G pars plana vitrectomy with scleral incisions at 5.0 mm behind the limbus. To measure the normal Chinese adult parameters of anteroposterior axis of the eyeball, lens thickness and scleral distances from the limbus to the plane passing through the lens posterior apex, the head CT scans of 105 patients without eye diseases in our hospital were studied during the same period of time for these vitrectomy surgeries. Pearson correlation analysis was used to analyze the relationship between age, anteroposterior axis of eyeball, lens thickness and scleral distances from the limbus to the plane passing through the lens posterior apex.ResultsSurgical related complications included retinal tears close to the scleral incision sites (3/145 eyes, 2.1%) and lens injury (3/121 eyes, 2.5%). No other surgical complications occurred, such as retinal hemorrhage, supra-choroidal expulsive hemorrhage and iatrogenic retinal detachment. Based on CT images, the average scleral distance from limbus to the plane passing through the lens posterior apex, anteroposterior axis of eyeball and lens thickness was (6.72±0.81), (24.39±0.97), (4.22±0.47) mm, respectively. The results of Pearson correlation analysis showed that age and lens thickness had statistically significant correlation (r=0.328 9, P=0.000 6).ConclusionPrimary 23G pars plana vitrectomy with incisions at 5.0 mm posterior to the limbus is safe.
ObjectiveTo investigate the medium and long-term influence of silicon oil versus heavy silicone oil on rabbit retinas.
Methods28 health standard rabbits were randomly divided into A, B and C groups, with 12, 12 and 4 rabbits respectively. All rabbits received routine vitrectomy and tamponade with silicone oil (group A), or heavy silicone oil (group B) or balanced salt solution (group C). After 4, 8, 12 and 24 weeks, the retinal b-wave amplitude was measured by ERG, posterior retinal thickness was measured by optical coherence tomography (OCT). Retinal ultrastructure and tissue morphology were observed by transmission electron microscopy and optical microscopy.
ResultsCompare to group C, the b-wave amplitude decreased at 4 weeks after surgery, and decreased at 8 weeks after surgery for group B, and decreased at 8 weeks after surgery, and decreased at 24 weeks after surgery for group A. The decreases were greater in group B than group A at 8, 12, 24 weeks after surgery, the difference was statistically significant (P < 0.05). The posterior retinal thickness of group A and B was thinner than group C at 24 weeks after surgery (P < 0.05). The decreases were greater in group B than group A, the difference was statistically significant (P < 0.05). Transmission electron microscopy and optical microscopy revealed severe pathological changes of retinal ultrastructure and morphology in group A and B rabbit eyes, at 12 weeks and 8 weeks after surgery respectively. The changes were more severe in group B and group A, including edema and necrosis in cone/rod cells, in disk membranes, mitochondria, cytoplasm, nucleus and other organelles. The morphological changes were also more severe in group B and group A, including degenerations of ganglion cell layer, inner nuclear layer changes. Those changes became more severe when the tamponade time extended.
ConclusionThe heavy silicone influence on visual function, ultrastructures, histomorphology of rabbit retinas is much worse than the silicon oil, and the effect is more significant with its time prolong.
