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 changes of ocular hemodynamics in patients with retinal vein occlussion(RVO)． Methods The hemodynamic parameters(PSV,EDV,PI,Vmax)of central retinal artery(CRA)and central retinal vein(CRV)were measured in the involved eyes(n=48) with RVO and the contralateral clinically healthy eyes(n=39) and in the control eyes(n=40) by color Doppler imaging (CDI)(ATLHDI3000). Results Peak systolic velocity (PSV) and end diastolic velocity (EDV) were significantly lower in the CRA of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes,and pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with control eyes．PSV were significantly lower in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes．Pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes．Maximun vein velocity (Vmax) was significantly lower in the CRV of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes． Conclusion The changes of hemodynamics in CRA,CRV of involved eyes of patients with RVO may invade their clinically healthy eyes．CDI may be helpful to early diagnosis for RVO． (Chin J Ocul Fundus Dis,1998,14:111-113)
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 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)
Objective To investigate the effects and complications of the vitrectomy for Eales′ disease with vitreous hemorrhage or traction retinal detachment. Methods Seventy-seven eyes of 69 cases undergoing vitrectomy for Eales′ disease with vitreous hemorrhage or traction retinal detachment were analyzed retrospectively. Results (1) The postoperative visual acuity was enhanced significantly. (2) Complications during the operation in 11 eyes (14.3%): iatrogenic retinal break in 7 eyes, bleeding in 3 eyes and lens damage in 1 eye. (3) Postoperative complications in 20 eyes (26.0%): rebleeding in 14 eyes, elevated IOP in 6 eyes, retinal detachment in 5 eyes, hyphema in 2 eyes, and exudative membrane in anterior chamber in 1 eye. (4) The main long-term complication was cataract formation (9 eyes) and macular disorder (6 eyes). Conclusion Vitrectomy is an effective method to treat Eales′ disease with vitreous hemorrhage or traction retinal detachment. (Chin J Ocul Fundus Dis, 2002, 18: 215-217)
Objective To investigate the efficacy and the safety of external therapy of ultrasound (ETUS) enhancing thrombolysis on the experimental retinal vein occlusion. Methods The effect of ETUS enhanced thrombolysis and the impact of ultrasound energy and exposure were investigated respectively after both eyes of 51 rabbits with retinal branch vein occlusion created by photodynamic initiated thrombosis were divided into 4 groups. The first 2 groups are the ETUS groups, including one group (15 rabbits) underwent intravenous injection with urokinase (UK) (1700-2200 UK dissolved into 20 ml normal saline), and other group (12 rabbits) underwent intravenous injection with normal saline. In these 2 groups, each rabbit received ETUS treatment (1.0 W/cm2, 20 min) in one eye and the fellow eye did not which was as the control. The latter 2 groups are the energy and duration of ultrasound groups, and 12 rabbits in each group underwent ETUS with the energy of 0.7 and 1.0 W/cm2 respectively. Each of the 2 groups was divided into 3 subgroups (8 rabbits in each) according to the radiated durations (8, 14, and 20 minutes). All of the eyes except the control ones underwent ETUS with 1 MHz ultrasound and 100 Hz pulsed ultrasound once a day for 3 days. Fundus fluorescein angiography (FFA) was used to detect the vascular condition 4 days after ETUS, and at the 15th day, retinal light microscopy and electron microscopy were performed. Results The vascular recanalization rate in ETUS+UK treatment group was 66.7%, which is obviously higher than which in single UK group (20.0%, P=0.025), normal saline group (8.3%, P=0.005), and ETUS+ normal saline group (8.3%, P=0.005). The vascular recanalization rates in groups with different energy of ultrasound increased obviously as the radiated durations increased (P=0.006, 0.001), while no apparent effect of energy of ultrasound on the vascular recanalization rate was found in the groups with different radiated duration (Pgt;0.05). The eyes which had undergone ETUS treatment had retinal tissue damage and ultrastructure changes of the retinal ganglion cells (RGC), and deteriorated as the radiated duration increased. Conclusion ETUS may enhance the thrombolysis induced by urokinase in experimental retinal vein occlusion. Simultaneously, ETUS can lead to the damage of retinal tissue and changes of the ultrastructure of RGC. (Chin J Ocul Fundus Dis, 2007, 23: 166-169)
Objective To explore the clinical application value of multifocal oscillatory potentials (MOPs) in retinal vein occlusion (RVO). Methods MOPs were tested using VERIS 4.0 visual evoked response imaging system for 19 cases (19 eyes) of RVO，among them 8 cases of central retinal vein occlusion (CRVO) and 11 cases of branch retinal vein occlusion (BRVO). Twenty normal subjects were as normal control group. The stimulative visual angles subtended ±26.6°horizontally and ±22.1°vertically. The filter setting was bandpass 100～1000 Hz. The retinal responses from 103 hexagons were recorded in 4 min (8 segments). Results In normal control group, OP-1, OP-2 and OP-3 were recorded during 37 ms for first order and 47 ms for second order first slice in whole test field and 5 ring retinal regions, the oscillatory wave shapes of second order were clearer than those of first order. In RVO groups, 91.6% latencies of OP-1, OP-2 and OP-3 were delayed, and 70.8% amplitudes of OP-1, OP-2 and OP-3 were reduced. The delay of the latencies and the decrease of the amplitude in CRVO were more markedly than those in BRVO. Conclusion MOPs can be effectively and quantitatively used to evaluate the retinal function of the different location in RVO. (Chin J Ocul Fundus Dis,2002,18:20-22)
Objective To observe the morphologic characters of macular lesions in patients with central retinal vein occlusion(CRVO) in optical coherence tomography(OCT). Methods Thirty-eight patients with the clinical diagnosis of CRVO were examined by OCT.Four scan lines traversing the fovea with the same length and the same angle gap were performed as the basic scan in every eye.Additional scan were selected according to individuals including changing the length or angle of the scan lines and selecting different diameter circle pattern scan. Results Cystoid macular edema (CME) was found in 15 eyes,detachment of the neurosensory retina in 6 eyes，thickened neurosesory retina in 11 eyes,slight intraretinal fluid in 4 eyes,and markedly thichened neurosensory retina in 2 eyes with secondary premacular membrane and intraretinal fluid. Conclusions The major OCT morphologic characters of macular lesions in patinets with CRVO may include:cystoid macular edema,detachment of neurosensory retina,and secondary premacular membrane and pigmentary epithelial changes.These would be helpful for diagnosing and evaluating macular lesion in CRVO. (Chin J Ocul Fundus Dis, 1999, 15: 201-204)
PURPOSE:To investigate the content of vascular endothelial growth factor (VEGF)in vitreous of patients with retinal vascula'r proliferative diseases. METHODS:The concentration of VEGF in undiluted vitreous samples from patients with retina vein occlusion (RVO) (n=7),Eales disease (n=7)and controls (n=7) was measured by enzyme linked immunosorbent assay (EL1SA). RESULTS:The levels of vitreous VEGF were significantly higher 13 folds in patients with RVO(4.67plusmn;3.38)ng/ml and 5 folds in patients with Eales disease(1.79plusmn;0.44)ng/ml than in controls (0.35plusmn;0.15)ng/ml separately(P＜0. 01). CONCLUSIONS:VEGF might play a part in mediating the neovascularization of retinal vascular diseases. （Chin J Ocul Fundus Dis,1997,13:171-173）
Pharmaceutical therapy, including anti-vascular endothelial growth factor treatment and intravitreal corticosteroids, is the most common treatment for branch retinal vein occlusion (BRVO) and its complications, however there are confusing ideas about the protocol, patient selection, timing and endpoint of this treatment. The disease is easy to relapse with these drugs therapy. Collateral vessel formation was found in patients receiving intravitreal injection of ranibizumab or triamcinolone for BRVO and secondary macular edema. The mechanism of collateral vessel formation has not been carefully investigated. In the past thrombolysis, arteriovenous fasciostomy and laser choroidal retinal vascular anastomosis were used to reconstruct the retinal circulation, but their rationality, effectiveness and safety need to be further were studied. In recent years, because of the key technology is still immature, the artificial vascular bypass surgery experiment is not yet practical, but provides us a new idea worth looking forward to for the treatment of BRVO.