Complications of proliferative diabetic retinopathy have become the major indications of vitrectomy. The surgery, however, is not basically a causative therapy. The visual function after operation depends on the degree of retinal ischemia and damage induced. The surgery itself has a potential for severe complications. Therefore it is important to better understand the pathology and to master surgical strategy and techniques in order to improve surgical outcomes and reduce the surgical complications. (Chin J Ocul Fundus Dis,2007,23:234-237)
Complications of proliferative diabetic retinopathy have become the major indications of vitrectomy. The surgery, however, is not basically a causative therapy. The visual function after operation depends on the degree of retinal ischemia and damage induced. The surgery itself has a potential for severe complications. Therefore it is important to better understand the pathology and to master surgical strategy and techniques in order to improve surgical outcomes and reduce the surgical complications. (Chin J Ocul Fundus Dis,2007,231-233)
Objective To analyze the reasons, methods of treatment, and effects on prognosis of vitreous hemorrhage after vitrectomy in patients with diabetic retinopathy. Methods The clinical data of 98 patients (122 eyes) with diabetic retinopathy (VI stage) who had undergone vitrectomy were retrospectively analyzed. Results Post-vitrectomy vitreous hemorrhage (gt;grade 2) was found in 25 eyes with the occurrence of 20.5%, in which the hemorrhage occurred 1 week after the surgery in 8 eyes, 1 week to 1 month in 6 eyes, and more than 1 month in 11 eyes. In the 25 eyes, C3F8 tamponade eyes occupied 31.1%, silicone oil tamponade eyes occupied 6.1%, air tamponade eyes occupied 33.3%, and infusion solution tamponade eyes occupied 26.3%. Peripheral fibrovascular proliferation was found in 9 eyes. In the 3 eyes with silicone oil tamponade, the hemorrhage was absorbed in 2, and epiretinal membrane was found in 1 which was moved when the silicon oil was taken out. In the 22 eyes without silicone oil tamponade, the hemorrhage was absorbed in 6 and aggravated in 2 without any timely treatment, neovascular glaucoma occurred in 1, and wide vitreo-retinal proliferation and retinal detachment was observed in 1 with the visual acuity of no light perception. Operations such as fluid-air exchange, vitrectomy were performed on 14 eyes 2 weeks after the hemorrhage absorption stopped. Recurrent vitreous hemorrhage was not found in 12 eyes after single operation. At the end of the follow up period, the visual acuity was no light perception in 3 eyes, hand moving in 2 eyes, counting finger-0.1 in 10 eyes, under 0.3 in 4 eyes, and over 0.3 in 6 eyes. Conclusion Most of the patients with vitreous hemorrhage after vitrectomy due to DR had peripheral fibrovascular proliferation. The visual prognosis after re-operation is good. (Chin J Ocul Fundus Dis,2007,23:241-243)
Objective To analyze the pathogeny of vitreous re-hemorrhage in proliferative diabetic retinopathy (PDR) after vitrectomy, and to evaluate the treatment effects. Methods The clinical data of 315 eyes of 302 patients with PDR who had undergone vitrectomy were retrospectively analyzed. Thirty-two eyes with vitreous re-hemorrhage after the treatment had undergone vitrectomy again. The follow-up duration was 3-48 months (average 12 months). Results The occurrence of vitreous hemorrhage after vitrectomy was 10%. The reasons included fibrovascular ingrowth at the sclera incision (28%), residual neovascularization membrane or inappropriately treated vascular stump on the surface of optic nerve (19%), insufficient photocoagulation on retina (22%), residual epiretinal neovascularization membrane (9%), retinal vein occlusion (6%), and ocular trauma (16%). Re-hemorrhage occurred 1-210 days (average 51 days) after vitrectomy. The patients with re-hemorrhage underwent cryotherapy for fibrovascular at the incision site, removal of residual neovascularization membrane on the optic nerve and retina, electrocoagulation of the vascular stump, complementary retinal photocoagulation and binding up of two eyes. After the re-treatment, the visual acuity increased in 91% and decreased in 9%. The postoperative complications mainly included vitreous re-hemorrhage, posterior synechia of the iris, lens sclerosis, and delayed healing of corneal epithelium. Conclusion The main reasons of vitreous re-hemorrhage after vitrectomy in patients with PDR include fibrovascular ingrowth at sclera incision, residual neovascularization membrane or inappropriately treated vascular stump on the surface of optic nerve, insufficient photocoagulation on retina, residual epiretinal neovascularization membrane, retinal vein occlusion, and ocular trauma. The efficient methods in preventing and treating re-hemorrhage after vitrectomy are appropriate management of insection sites, completely removal of residual neovascularization membrane on the optic nerve and retina, electrocoagulation of the vessel stump and sufficient retinal photocoagulation. (Chin J Ocul Fundus Dis,238-240)
Objective To observe the efficacy of vitreoretinal surgery on proliferative diabetic retinopathy (PDR) in patients with type 1 and type 2 diabetes mellitus (DM). Methods Retrospectively analyzed the clinical data of 451 patients with DM (71 with type 1 and 380 with type 2) who underwent PDR from June 1999 to October 2003. The follow-up period was at least 14 months with the average of 29 months. The pre-and post-operative visual acuity, progression and regression of iris neovascular (INV), neovascular glaucoma (NVG), and the reattached and being attached rate of retina were observed and compared between the two groups. The effect of different types of DM on vitreoretinal surgery for PDR were observed. Results The preoperative data showed that the number of type 1 DM patients with severe PDR was more than the type 2 DM patients: the rate of grade VI PDR, the visual acuity lower than 0.1, INV and NVG were all higher that which in type 1 DM patients. The increased ratio of postoperative visual acuity was 64.8% (46/71) in type 1 DM patients and 72.4% (275/380) in type 2 DM patients (P=0.196). There were 75.0% patients with PDR combined with rubeosis iridis in type 1 DM group and 60.0% in type 2 DM group (P＝0.678);the rate of new rubeosis iridis after surgery was 6.3% in type 1 DM group and 5.6% in type 2 DM group (P＝0.822). The intraocular pressure of NVG eyes were all controlled effectively in both type 1 and type 2 DM groups, and INV did not regressed only in one case in type 1 DM group. In the patients with preoperative retinal detachment at the grade VI of PDR, the rate of retinal reattachment after on off operation was 87.2% in type 1 DM group and 89.8% in type 2 DM (P＝0.611); the rate of retina being-attachment after one-off surgery were 90.1% in type 1 DM group and 93.4% in type 2 DM group, respectively (P＝0.323). Conclusion There was no obvious difference of surgical efficacy on the two types of DM in patients with PDR. (Chin J Ocul Fundus Dis,2007,23:248-251)
Objective To analyze the risk factors of no light perception (NLP) after vitreoretinal surgery for proliferative diabetic retinopathy (PDR). Methods Retrospectively analyzed the follow-up data of 882 patients (1000 eyes) with PDR who had undergone vitreoretinal surgery. The standard of NLP was: in a darkroom, one eye was covered, and the other one could not catch the candlelight 30 cm in front of the eye. The number of eyes with NLP was counted and the clinical data of the eyes with or without NLP were analyzed and compared. chi;2 test was used to analyze the risk factors of NLP. Results In these 1000 eyes with PDR,the postoperative visual acuity was NLP in 22 eyes (2.2%) and light perception in 978 eyes (97.8%). Comparing with the patients with light perception, the patients with NLP had severer disease condition, including ante-operative neovascular glaucoma (NVG)(36.4%), tension combined with retinal detachment 50%, and a need for lens excision during the surgery (45.5%) and for silicone oil filling at the end of the operation (63.6%). After the surgery, NVG was found in 14 eyes, un-reattached retina in 5 eyes (before the surgery was VI stage of PDR), and optic nerve atrophy and retinal vessel atresia in 3 eyes, which significantly differed from which in the patients with light perception (Plt;0.001，P=0.004, (Plt;0.001). The differences of sex, diabetes type and PDR stage between the NLP group and non-NLP group were not significant (P=0.136, P=0.681, P=0.955). Conclusions The incidence of NLP after vitreoretinal surgery for proliferative diabetic retinopathy is low. The direct causes were NVG, optic nerve atrophy, retinal vessel atresia and retinal redetachment, while the sex, type of diabetes mellitus and stage of PDR show no statistical relation to the occurrence of NLP after surgery. (Chin J Ocul Fundus Dis,2007,23:244-247)
Objective To observe the effect of laser-Doppler retinal blood flowmeter in diabetic retinopathy. Methods The blood flow volume (VOL), the blood flow velocity (FLW) and the erythrocyte flow velocity (VEL) of peri-papillary retina were measured with the non-invasive Heidelberg Retinal Flowmeter (HRF) in 108 patients (216 eyes) with diabetes and 32 patients (64 eyes) in normal control group. The patients with diabetes were divided into non-diabetic retinopathy (NDR) group (27 patients, 54 eyes) and non-proliferative diabetic retinopathy (NPDR) group (81 patients, 162 eyes). NPDR group were subdivided into 3 groups: 26 patients (52 eyes) in mild group, 24 patients (48 eyes) in moderate group, and 31 patients (62 eyes) in severe group. The foveal avascular zone area (FAZ) was measured by fundus flourescein angiography (FFA) in patients with diabetes and some in the control group. The data in each group were statistically analyzed. Results The parameter of retinal blood flow of temporal and nasal peri-papillary retina in NDR and NPDR group was significantly lower than that in the control group (Plt;0.05). With the degree of retinopathy becoming more severe, the FLW and VEL of temporal and nasal peri-papillary retina in NDR and mild NPDR group presented ascending tendency, reached the peak in moderate NPDR group, and then decreased. The change tendency of the FLW was more obviously. The VOL of temporal and nasal peri-papillary retina in moderate NPDR group was obviously higher than that in the other groups (Plt;0.01).The FLW and the VEL of temporal and nasal peri-papillary retina in moderate NPDR group were significantly higher than that in mild NPDR and NDR group (Plt;0.01). The FLW and the VEL of temporal peri-papillary retina in severe NPDR group were obviously higher than that in NDR group (Plt;0.01). Blood sugar value positively correlated with degree of diabetic retinopathy (r=0.172，P=0.046). The FLW and the VEL of temporal peri-papillary retina positively correlated with FAZ area in patients with diabetes (r=0.268, P=0.000；r=0.275, P=0.000). The FAZ area positively correlated with the degree of macular degeneration in patients with diabetes (r=0.559, P=0.000). Conclusion As a non-invasive method for measurement of retinal blood flow, HRF has important value in revealing the mechanism and degree of pathological changes and choice of treatment for diabetic retinopathy. (Chin J Ocul Fundus Dis,2007,23:256-259)
Objective To investigate the feasibility and clinical significance of monitoring diabetic macular edema by Heidelberg retina tomograph Ⅱ (HRT). Methods The diabetic macular edema (DME) was diagnosed by slit-lamp microscopy combined with three-mirror contact lens examination and fundus fluorescein angiography (FFA). The exponential of macular edema (e value) of healthy people and patients with DME or without DME (NDME) (the total number is 77 individuals and 120 eyes) were detected by HRT Ⅱ. All of the 77 people were divided into three groups. In DME group, there were 23 patients (40 eyes), including 13 males (23 eyes) and 10 females (17 eyes), at the age of 44-68 (average of 55.17plusmn;8.26). In NDME group, there were 32 patients (40 eyes), including 18 males (22 eyes) and 14 females (18 eyes), at the age of 44-68 (average of 55.17plusmn;6.5). In normal control group, there were 22 patients (40 eyes), including 10 males (19 eyes) and 12 females (21 eyes), at the age of 42-65 (average of 53.32plusmn;6.04). According to the results of FFA, the 40 eyes in DME group were divided into: grade 1 of FFA in 9 eyes, with macular suspicious leakage or the area of leakage of lt;25%; grade 2 of FFA in 10 eyes, with the area of leakage between 25% and 66%; grade 3 of FFA in 21 eyes, with the area of leakage of gt;66%. The differences of sex and age among the 3 groups were not significant (Pgt;0.05). The relationship among e value, leakage area, and visual acuity was observed. Results There was a significant difference of e value (the macular diameter was 1, 2, and 3 mm) among the 3 groups(Plt;0.05). The e value in normal control group didnrsquo;t differ much from which in NDME group (Pgt;0.05), but was statistically different from which in DME group (Plt;0.05). Significant difference of e value was also found between NDME group and DME group (Plt;0.05). There was a correlation between visual acuity and e value in DME group (Plt;0.05). In DME group, the difference of e value among FFA grade 1, 2, and 3 groups was found according to the variance analysis; the macular leakage area in FFA grade 3 group differed much from which in grade 1 (Plt;0.05) and grade 2 group (Plt;0.05), while no significant difference was found between grade 1 and grade 2 group. The result was not correlated with the macular diameter. Conclusion E value in the macular module of HRT Ⅱ can detect and evaluate the degree of DME. (Chin J Ocul Fundus Dis,2007,23:252-255)
Objective To observe the effect of celecoxib on the expression vascular endothelial growth factors (VEGF) in diabetic rats. Methods Thirty-six wistar rats were used to establish the diabetic models by intraperitoneal injection with streptozotocin. The diabetic rats were divided into 2 groups: diabetic group (n=18) and celecoxib group (n=18). Celecoxib (50 mg/kg) was administered orally to the rats in celecoxib group and the physiological saline with the same volume was given orally to the rats in diabetic group. Eighteen else rats were in normal control group. All of the rats were executed 3 months later. The expression of VEGF protein was detected by immunohistochemistry method. Reverse transcription-polymerase chain reaction（RT-PCR） analysis was used to examine the expression of retinal VEGF mRNA and cyclooxygenase-2 mRNA. Results Lower positive expression of VEGF mRNA and cyclooxygenase-2 mRNA, weakly positive action of immunohistochemistry of VEGF, and lower expression of VEGF protein were detected in normal control group; in the diabetic group, the expression of VEGF mRNA and cyclooxygenase-2 mRNA increased obviously comparing with which in the control group (Plt;0.05), and the bly positive action of immunohistochemistry of VEGF and increased expression of VEGF protein were detected (Plt;0.01); in celecoxib group, the expression of VEGF mRNA was lower than that in the diabetic group (Plt;0.05), the expression of cyclooxygenase-2 mRNA didnprime;t decrease much (Pgt;0.05), the positive action of immunohistochemistry of VEGF decreased, and the expression of VEGF protein decreased (Plt;0.01). Conclusion By inhibiting the activation of cyclooxygenase-2, celecoxib can inhibit the expression of retinal VEGF mRNA and protein in diabetic rats induced by streptozotocin. (Chin J Ocul Fundus Dis,2007,23:265-268)
Objective To observe the changes of expression of glutamine synthetase (GS) in early diabetic ratsprime; retina and investigate its possible mechanism. Methods Three groups of streptozotocininduced diabetic models of SpragueDawley (SD) rats with different diseased courses, ie, 1 month, 2 months, and 3 months, respectively, with 8 rats in each group, and 8 normal ones as control were examined. The expressions of GS, interleukin-1beta; (IL-1beta;) and c-Jun in retina in the 4 groups were detected by indirect immunofluorescence and western blotting techniques. Meanwhile, different doses of IL-1beta;（0,100,500,and 1000 ng/ml） were injected into the vitreous cavities of 32 normal rats (8 rats in each group), and 24 hours later, the expressions of GS and c-Jun in retina were detected by the same methods. Results The expression of GS in retina did not changed in control group or in 1 month and 2 months group, but decreased obviously in 3 months group comparing with which in the control group (Plt;0.01).The expressions of c-Jun and IL-1beta; in retina in control group were very low, but increased gradually in diabetic rats in 1-3 months group, which significantly differed from which in the control group (Plt;0.01). Vitreous injection with IL-1beta; (500 and 1000 ng/ml) down regulated the expressions of GS, and the expression of c-Jun increased in a dose-dependent way after injection with IL-1beta; at the concentration of 100 ng/ml. Conclusions In early diabetic ratsrsquo; retina, IL-1beta; may down regulate the expression of GS. The possible mechanism may be the activation of c-Jun by IL-1beta;. (Chin J Ocul Fundus Dis,2007,23:260-264)