Objective To investigate the early influences of laser photocoagulation on retinal function in diabetic retinopathy(DR)． Methods The multifocal electroretinograms (MERG) of 30 eyes with DR (phase Ⅲ～Ⅳ) were tested with visual evoked response image system IV b efore,and the 3rd day and the 7th day after laser photocoagulation． Results Three days after photocoagulation, the latency of N1 prolonged in the central macula 5deg; area and superionasal quadrant．Th e response densities of N1,P1 and N2 markedly reduced, and most significant changes occurred in the central macula 5deg; area and then in the central 10deg;area． There were also differences in the changes of the amplitude of N1 and P1 in diff erent quadrants ．The changes of visual acuity were positively related to the de crease of amplitudes of N1,P1 and N2 in the macula． Conclusion The reduction of response densities in MERG reveals functional damage in diabetic retina occurring early after photocoagulation．The functional damage in macula induced indirectly by photocoagulation may explain the reduction of visual acuity after panretinal photocoagulation in some degree． (Chin J Ocul Fundus Dis, 2001,17:181-183)
PURPOSE:To investigate the effect of the retinal ganglion cell on the origin of the scotopic threshold response(STR)of the cat and human electroretinogram. METHODS:An optic atrophy model was established in cats with retinal photocoagulation around the optic disc. The STR and flash visual evoked potentials(FVEP)were recorded from 18 cases(24 eyes)of normal human,6 cases of the optic atrophy patients,6 cases of normal cats and 4 cases of retinal photocoagulating cats in 4, 8 and 16 weeks after retinal photocoagulation. In addition,ganglion cells were observated in 8 and 16 weeks after retinal photocoagulation using light and electron microscopes. RESULTS :The pathologic changes after retinal photocoagulation verify secondary atrophy of ganglion cells. STR was normal and FVEP was not recorded in cats of retinal photocoagulation and patients with optic atrophy. CONCLUSION :Retinal ganglion cell loss does not abolish the cat and human STR.There is no effect of ganglion cell on the origin of STR. （Chin J Ocul Fundus Dis,1997,13: 215-218 ）
Purpose To evaluate the safety and efficacy of draining subretinal fluid with transchoroidal probing by using the traditional needling and diode endolaser probing. Methods The investigation included 70 consecutive patients(74 eyes) with rhegmatogenous retinal detachment undergoing scleral buckling surgery.Seventy cases were randomly divided into 2 groups,group A 34 cases(36 eyes)with the needle drainage procedure and group B 36 cases(38 eyes) with the diode probe respectively.The safety and efficacy were compared in between the 2 groups. Results No operative failure was found in these 2 groups.In group A,subretinal hemorrhage occurred in 3 eyes,and retinal incarceration,retinal preforation in one eye. No significant complication occurred in group B. Conclusion Diode laser drainage has the advantage in that it may reduce the incidence of operative complication with drainage.This technique might be used in any case requiring drainage of subretinal fluid especially of rhegmat ogenous retinal detachment in cases of shallow retinal detachment. (Chin J Ocul Fundus Dis,1998,14:202-203)
Objective To study and compare the clinical efficacy between intravitreal conbercept injection and (or) macular grid pattern photocoagulation in treating macular edema secondary to non-ischemic branch retinal vein occlusion (BRVO). Methods Ninety eyes of 90 patients diagnosed as macular edema secondary to non-ischemic BRVO were enrolled in this study. Forty-eight patients (48 eyes) were male and 42 patients (42 eyes) were female. The average age was (51.25±12.24) years and the course was 5–17 days. All patients were given best corrected visual acuity (BCVA), intraocular pressure, slit lamp with preset lens, fluorescence fundus angiography (FFA) and optic coherent tomography (OCT) examination. The patients were divided into conbercept and laser group (group Ⅰ), laser group (group Ⅱ) and conbercept group (group Ⅲ), with 30 eyes in each group. The BCVA and central macular thickness (CMT) in the three groups at baseline were statistically no difference (F=0.072, 0.286;P=0.930, 0.752). Patients in group Ⅰ received intravitreal injection of 0.05 ml of 10.00 mg/ml conbercept solution (conbercept 0.5 mg), and macular grid pattern photocoagulation 3 days later. Group Ⅱ patients were given macular grid pattern photocoagulation. Times of injection between group Ⅰ and Ⅲ, laser energy between group Ⅰ and Ⅱ, changes of BCVA and CMT among 3 groups at 1 week, 1 month, 3 months and 6 months after treatment were compared. Results Patients in group Ⅰ and Ⅲ had received conbercept injections (1.20±0.41) and (2.23±1.04) times respectively, and 6 eyes (group Ⅰ) and 22 eyes (group Ⅲ) received 2-4 times re-injections. The difference of injection times between two groups was significant (P＜0.001). Patients in group Ⅱ had received photocoagulation (1.43±0.63) times, 9 eyes had received twice photocoagulation and 2 eyes had received 3 times of photocoagulation. The average laser energy was (96.05±2.34) μV in group Ⅰ and (117.41±6.85) μV in group Ⅱ, the difference was statistical significant (P=0.003). BCVA improved in all three groups at last follow-up. However, the final visual acuity in group Ⅰ and group Ⅲ were better than in group Ⅱ (t=4.607, –4.603;P＜0.001) and there is no statistical significant difference between group Ⅲ and group Ⅰ (t=–0.802,P=0.429). The mean CMT reduced in all three groups after treating for 1 week and 1 month, comparing that before treatment (t=–11.855, –10.620, –10.254;P＜0.001). There was no statistical difference of CMT between group Ⅰand Ⅲ at each follow up (t=0.404, 1.723, –1.819, –1.755;P=0.689, 0.096, 0.079, 0.900). CMT reduction in group Ⅰ was more than that in group Ⅱ at 1 week and 1 month after treatments (t=–4.621, –3.230;P＜0.001, 0.003). The CMT in group Ⅲ at 3 month after treatment had increased slightly comparing that at 1 month, but the difference was not statistically significant (t=1.995,P=0.056). All patients had no treatment-related complications, such as endophthalmitis, rubeosis iridis and retinal detachment. Conclusions Intravitreal conbercept injection combined with macular grid pattern photocoagulation is better than macular grid pattern photocoagulation alone in treating macular edema secondary to non-ischemic BRVO. Combined therapy also reduced injection times comparing to treatment using conbercept injection without laser photocoagulation.
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)
Objective To investigate the early influences of laser photocoagulation on macular retinal thickness in diabetic retinopathy(DR). Methods Optic coherence tomography examination was performed in 30 eyes with DR(phase Ⅲ~Ⅳ) before, and on the 3rd day and the 7th day after photocoagulation respectively. The thickness of neuroretina and pigment epithelium were measured in the areas of fovea macula and 750 μm from fovea macula. Results Three days after photocoagulation, significant thickening of neuroretina was observed in the fovea macula, which is positively related with age, fasting blood sugar and duration of DR. There was no significant changes in the thickness of pigment epithelium in macula and in the thickness of neuroretina 750 μm from fovea macula. Conclusion Significant thickening of neuroretina in fovea macula in DR early after photocoagulation reveals progressed macular edema induced by photocoagulation which is positively related with age, fasting blood sugar and duration of DR. (Chin J Ocul Fundus Dis, 2002, 18: 31-33)
Objective To evaluate the effect of the treatment of diode laser for retinopathy of prematuriy (ROP).Methods Six-eight premature infants, with the gestation lt;32 weeks and birth weight lt;1500 g,were examined 6-7 weeks after birth. The infants suffering from threshold ROP were treated by diode laser through a binocular indirect ophthalmoscope within 48 hours after the confirmation of diagnosis, and with the follow-up of 4～6 moths. Retinal detachment was found in 1 eye 1 month after laser treatment, and scleral encircling operation was performed on the eye which was followed up for 3 months after the operation. Cycloplegic refractive examination was performed on the eyes with threshold ROP 4 months postnatally to determine the presence of refractive errors.Results Six infants (1) eyes were diagnosed as with threshold ROP. The average age of the occurrence of threshold ROP were (10±2.89) (ranging from 6 to 14 weeks) weeks postnatally. The successful rate of diode laser treatment was 91.67%. Retina was flat in one eye treated by scleral encircling operation. Refractive errors of the eye treated by scleral encircling operation was -14.5 D, and the median spherical equivalent errors in other 11 eyes was ( -2.89±-1.86) D. Conclusion The treatment of diode laser is effective for threshhold ROP. (Chin J Ocul Fundus Dis，2003，19：96-98)
Objective To evaluate the single-use of laser photocoagulation (LP) and the combined-use of laser photocoagulation plus intravitreal triamcinolone (LP+IVTA) for diabetic macular edema (DME) in terms of clinical therapeutic effect and safety. Methods Such databases as The Cochrane Library, Medline, Embase, CBM, CNKI and Wanfang Data were searched from the date of their establishment to September 2011, and the references of all included studies were also traced, so as to identify the randomized controlled trials (RCTs) on LP vs. LP+IVTA for DME. The quality assessment and data extraction were conducted in accordance with the Cochrane Handbook 5.0 by two reviewers independently, and then Meta-analyses were conducted using RevMan 5.0 software. Results Ten RCTs involving 525 ill eyes were included, and all of them were classified as Grade B in methodological quality. Results of meta-analysis showed that: at the end of follow-up, there were significant differences between the LP+IVTA group and the LP group in the best corrected visual acuity (BCVA) (RR=–0.14, 95%CI –0.20 to –0.08, Plt;0.000 01), and the central macular thickness (CMT) (RR=–56.78, 95%CI –84.03 to –29.54, Plt;0.000 1). In comparison with the LP group, there were more people in the LP+IVTA group who needed to be treated for their elevated intraocular pressure and to have surgery for the progression of cataract. But no significant difference was found between the two groups in vitreous hemorrhage, retinal detachment, retinal vein occlusion and macular epiretinal membrane. Conclusion Current evidence of clinical research shows that the LP+IVTA is superior to LP in reducing macular edema and improving vision in the treatment of diabetic macular edema, but it may also result in a high incidence of elevated intraocular pressure and cataract. Because the methodological quality limitation of included studies may affect the authenticity of outcomes, this conclusion has to be further proved by more high-quality and large-scale clinical trials.
Objective To investigate the clinical characteristics of retinal degeneration (RD) with retinal holes and the therapeutic effect of argon laser therapy. Methods The data of argon laser therapy in 210 RD patients (224 eyes) with retinal holes who underwent the treatment in our department were retrospectively analyzed, which was compared with the data of argon laser therapy in 173 RD patients (198 eyes) without retinal holes. Results In RD patients with retinal holes, 89.7% of the patients were less than 60 years old (53.3% males and 46.7% females). Grid-like degeneration was found in 65.6% of the patients in whom 87.5% had the range of degeneration less than 1 quardrant. There were oval-shaped holes in 60.7% of the patients and accompanied with limited rhegmatogenous retinal detachment (LRRD) in 23.7%. Compared with RD patients without retinal holes, the ratio of patients with the age ofge;35 years, cystic degeneration, retinal lengthways small plica, and subjective symptoms was higher in RD patients with retinal holes; while the therapeutic effect of argon laser therapy on patients with LRRD was obviously less than whom without retinal holes (Plt;0.01 ). Conclusions RD with retinal holes often occurs in youth, most of whom have grid-like degeneration with the range of le;1 qua drant. The major types of retinal holes are oval-shaped degeneration without retinal detachment. There was no sex difference in RD patients with retinal holes and most of the patients have no subjective symptoms. The therapeutic effect of prophylactic argon laser therapy on RD patients with retinal holes but no retinal detachment is satisfying. (Chin J Ocul Fundus Dis, 2006, 22: 39-41)
Objective To observe the effect of the treatment of neodymium-yttrium aluminum garne (Nd:YAG) vitreolysis for the anterior vitreous opacity after implantation of intraocular lens.Methods Forty-nine eyes of 47 patients with the anterior vitreous opacity after implantation of intraocular lens received the slitlamp examination, optical coherence tomography (OCT), and B-scan. The anterior vitreolysis and posterior capsulotomy were performed simultaneously with Nd :YAG laser. The outcomes of visual acuitiy changes and complications were studied.Results In 49 eyes, 46 had anterior vitreous opacity associated with posterior capsule opacification, and the other 3 without obvious posterior capsule opacification. In all patients, the visual acuity improved significantly without any complications after the laser procedure (t=32.50, P=0.007). After Nd:YAG laser treatmen, transparent area was found in anterior opaque vitreous in 21 eyes (42.86%) within 15 minutes, and in 47 eyes (95.92%) within 24 hours. No complication occured in or after the operation.Conclusions In the patients with visual deterioration after implantation of intraocular lens, the prescence of anterior vitreous opacity should be concerned. Opening the opaque anterior vitreous with Nd:YAG vitreolysis is effective for the patients with the anterior vitreous opacity after implantation of intraocular lens.(Chin J Ocul Fundus Dis，2003，19：106-108)