Objective To observe the change of diffusion upper limit of macromol ecules through pathological retina and the difference between the layers of retina. Methods Retinal edema was emulated by establishing branch retinal vein occlusion (RVO) model in miniature pig eyes under photodynamic method. Two days later, the retinas of both eyeballs were peeled off. The diffusion test apparatus was designed by ourselves. FITC-dextrans of various molecular weights (4.4, 9.3, 19.6, 38.9, 71.2 and 150 kDa) and Carboxyfluorescein (376 Da) were dissolved in RPMI1640 solutions and diffused through inner or outer surface of retina. The rate of transretinal diffusion was determined with a spectrophotometer. Theoretical maximum size of molecule (MSM) was calculated by extrapolating the trend-linear relationship with the diffusion rate. In separate experiments to determine the sites of barrier to diffusion, FITC-dextrans were applied to either the inner or outer retinal surface, processed as frozen sections, and viewed with a fluores cence microscope. Results FITC-dextrans applying to inner retinal surface, 4.4 kDa dextrans were largely blocked by inner nuclear layer (INL); 19.6,71.2 kDa dextrans were blocked by the nerve fiber layer (NFL) and inner plexiform layer; 15.0 kDa dextrans were blocked by NFL. FITC-dextrans applying to outer retinal surface, most dextrans with various molecular weights were blocked before outer nuclear layer (ONL). No matter applying to the inner or outer surface, Carboxyfluore scein can diffuse through the whole retina and aggregate at INL and ONL. After RVO, the inner part of retina became edema and cystoid, loosing the barrier function. Compared with the normal retina, the MSM in RVO tissues increased (6.5plusmn;0 39nm Vs 6.18plusmn;0.54nm, t=4.143, P=0.0001). Conclusions A fter RVO, the barrier function of inner part of retinal is destroyed and the upper limit of diffusion macromolecule size increased, which is nevertheless limited. ONL acts as bottle-neck barriers to diffusion, if the outer part of retina is damaged, the change of the diffusion upper limit will be prominent. （Chin J Ocul Fundus Dis，2008，24：197-201）
Objective To investigate the relationship among central retinal vein occlusion (CRVO), major systemic diseases, ocular local diseases and related risk factors in Chinese population. Methods Seventeen-six patients with CRVO diagnosed by fundus fluorescein angiography (FFA) without any medical treatment were in CRVO group. Another 76 patients without CRVO or any vascular diseases of ocular fundus were in the control group who were matched with the ones in CRVO group to a one-to-one partnership according to the age and gender. The 2 groups were subdivided into le;45 years old (25 patients, 32.9%) and gt;45 years old (51 patients, 67.1%) subgroups according to the age, and 2 ischemia and non-ischema subgroups according to the results of FFA, respectively. The blood lipid, blood pressure, and fasting blood glucose were measured. The systematic diseases, ocular local diseases and the related risk factors were statistically analyzed and compared. Results The incidence of hypertension and hyperlipemia in CRVO group were significantly higher than that in the control group (Plt;0.001,P=0.001). There was no significant difference of cardiovascular diseases, cerebrovascular diseases, open-angle glaucoma, and smoking and drinking between the two groups(Pgt;0.05). In le;45 years old subgroups, there was no significant difference of each examination target between CRVO and control group(Pgt;0.05). In ischemia subgroups, except for the hypertension and hyperlipemia, the incidence of diabetes mellitus was obviously higher in CRVO group than that in the control group (hyperlipidemia:P=0.031; diabetes mellitus:P=0.024; diabetes mellitus: Plt;0.001). Conclusion Hypertension and hyperlipidemia are the systematic factors in Chinese population with occurrence of CRVO. In addition, diabetes mellitus is associated with ischemic CRVO. Timely diagnosis and treatment of the systematic diseases is important to the prevention and treatment for CRVO. (Chin J Ocul Fundus Dis, 2007, 23:159-162)
Objective To observe the effectiveness of combined therapy of intravitreal injections of ranibizumab and macular grid laser photocoagulation for branch retinal vein occlusion (BRVO) with macular edema (ME).Methods Forty-six patients of BRVO with ME were enrolled in this study. All the patients were examined for corrected visual acuity of Early Treatment Diabetic Retinopathy Study (ETDRS), slit lamp microscope, direct ophthalmoscope, intraocular pressure, fundus color photography, fundus fluorescein angiography and optical coherence tomography. The patients were divided into three groups by different treatments: injection group (18 eyes) received intravitreal injections of ranibizumab only, joint group (17 eyes) received intravitreal injections of ranibizumab combined with grid laser photocoagulation, and laser group (11 eyes) received laser photocoagulation only. The follow-up ranged from three to 15 months, with a mean of (8.0plusmn;3.2) months. The same equipment and methods were used to return visit in follow-up period. Repeated injections were adopted in injection group and joint group according to the results of subsequent visits. Then the repeated times of injection in two groups were compared. The visual acuity, macular retinal thickness (CRT) and ocular and systemic adverse reactions about drugs and treatments were followed up. The last follow-up time was considered as the judgment time for the therapeutic effects. Results The mean repeat times of injection in the injection group was 5.4plusmn;0.4, which more than that in the joint group 3.2plusmn;0.6 (t=12.17,P＜0.05). No ocular or systemic adverse events were observed in follow-up period. ETDRS visual acuity of injection group, joint group and laser group increased by 7.30plusmn;8.68,8.50plusmn;6.04,1.55plusmn;6.85 letters respectively after treatment. The differences were statistically significant before and after treatment in injection group and joint group (t=3.58, 5.78;P＜0.05), but there was no significant difference in laser group (t=0.75,P＞0.05). The difference was not statistically significant between injection group and joint group (t=0.45,P＞0.05). The difference was statistically significant between injection group and laser group, but also between joint group and laser group (t=2.13, 2.81;P＜0.05). CRT of injection group, joint group and laser group decreased by (110.56plusmn;43.08), (125.47plusmn;35.19), (50.73plusmn;19.68) mu;m respectively after treatment, with statistically significant differences (t=-10.89,-14.70, -8.55;P＜0.05). Conclusion In the treatment of BRVO with ME, intravitreal injection of ranibizumab combined with macular grid laser photocoagulation can reduce repeat times of injection, improve visual function and relieve ME.
Objective To probe the possibility of electroretinogram(ERG)maximum combined response for typing branch retinal vein occlusion(BRVO). Methods BRVO were divided into ischemic or nonischemic type according to the appearance of fundus fluorescein angiography.The ERG data were used to define the retinl function:a，b-wave amplitude and impact time,b/a-wave ratio,oscillatory potential OP1，OP2，OP3，OP4 amplitude implicit time and Ops amplitude. Results The ERG b-wave and OPs amplitude were significantly lower in ischemic group than those in nonischemic group. Conclusion With the REG test,the decline of b-wave and OPs amplitude of the maximum combined response might be as a reference of ischemic type BRVO. (Chin J Ocul Fundus Dis,1998,14:10-11)
Objective To determine the effect of posterior vitreous detachment on the prognosis of branch retinal vein occlusion (BRVO). Methods One hundred and sixteen patients (116 eyes) with BRVO who underwent vitreous examination were retrospectively studied.The relati onship of vitreous conditions to posterior segment neovascularization and macular edema was statistically investigated. Results In 40 ischemic cases,12 of 25 eyes (48.0%) with no posterior vitreous detachme nt (PVD) or partial PVD developed retinal or optic disc neovascularization ,or both,but only one of the 15 eyes (6.7%) with complete PVD developed neovasculariz ation during a mean follow-up period of 10.7plusmn;2.2 months (Plt;0.05) . Diffuse macular edema was found in 45 eyes (38.8%).The incidence o f macular edema was significantly higher in eyes with vitreomacular attachment (51.5%) than in those with vitreomacular separation (22.0%) (Plt;0.01). Conclusion It was suggest ed that compl ete PVD may play a role in protecting eyes with BRVO from posterior segment neov ascularization and macular edema. (Chin J Ocul Fundus Dis, 2001,17:2-4)
Objective lt;brgt;To evaluate the efficacy of arteriovenous sheathotomy on treatment of branch retinal vein occlusion (BRVO). lt;brgt; lt;brgt;Methods lt;brgt;Six consecutive patients (6 eyes) with BRVO underwent par plana vitrectomy, po lt;brgt;sterios vitreous cortex separation, arteriovenous sheathotomy for BRVO. The foll lt;brgt;owup period was within 3～12 months. Postoperative examinations included color fundus photography, fundus fluorescein angiography(FFA), optical coherence tomography(OCT) and multifocal electroretinography (mERG). lt;brgt; lt;brgt;Results lt;brgt;Increasing downstream blood flow in proximal past of compressed venule was promptly observed during the procedures of incision of the advential sheath of blood vessel, and separating and elevating the ateriole from the venule in all the operations in this series. Visual acuities improved postoperatively in 5 patients, and the best corrected visual acuity was 1.5. The examination of FFA showed obvious absorption of retinal hemorrhage, and leakage of dye was reduced, while large areas of capillary closure in retinas distal to the sheathotomy site were found 3 months after operation in 3 patients. OCT revealed disappearance or lightening of macular edema. mERG showed that the response amplitude of retina including the macular area was obviously higher after the operation. There was recurrent vitreous hemorrhage necessitating further surgery in one patient. lt;brgt; lt;brgt;Conclusion lt;brgt;The operation of arteriovenous sheathotomy for the treatment of BRVO is much beneficial to improve patient′s visual acuity, downstream blood flow and macular affections, although the improvement of retinal reperfusion of the retina is not obvious. lt;brgt; lt;brgt;(Chin J Ocul Fundus Dis,2002,18:6-9)