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 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 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)
【Abstract】 ObjectiveTo review the advances in techniques of hepatic blood occlusion in hepatectomy. Methods The related literatures were reviewed and analysed. ResultsThere were many techniques of hepatic blood occlusion. The most frequently used and studied techniques were hemihepatic vascular occlusion and intermittent hepatic inflow occlusion. Hepatic vascular exclusion was employed when hepatic veins and/or vena cava would be damaged. Total vascular exclusion and other techniques were rarely used. Conclusion To reduce blood loss in hepatectomy and make patient safe, based on the situation of the patient, the technique should be ingeniously selected.
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)
Two-hundred and forty-five eyes of 240 cases of branch retinal vein occlusion (BRVO) were analysed to determine the risk factors influencing the development of retinal neovascularization (NV).There were 208 eyes with major BRVO, 37 eyes with macular BRVO, 79 eyes with major BRVO developed NV, and the incidence of NV in this series was 37.9%.The incidence of vitreous hemorrhage in these eyes was 15.9%(39 eyes). The risk factors influencing the development of retinal NV in BRVO seem as follows: (]) the extent of retinal capillary nonperfusion area, (2)inefficiency of arterial infusion, (3) the extent of venous block at the arteriovenous crossing, (4) the duration of follow-up since onset of BRVO, and (5) the lack of collateral formation, Because BRVO has a long natural history, it is recommended that the patients should be followed-up for a long time If the vessels at peripheral retina closed, fluorescein angiography should be performed without hesitation and if the nonperfusion area is greater than 20-30 disc area, one should follow the patient carefully.As soon as the new vessels appear, laser photocoagulation should be applied without delay. （Chin J Ocul Fundus Dis,1994,10:67-70）
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 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 refine the technique of portal inflow occlusion and parenchymal transection for laparoscopic hepatectomy in the porcine model. Methods Ten pigs were used. The portal inflow complete or selective occlusion was carried out with portal triad clamping or dissection and division of the left portal pedicle. The sequential laparoscopic local hepatectomy, left lateral lobectomy, and left medial lobectomy were performed without portal inflow occlusion. Parenchymal transection was performed with harmonic scalpel, LigaSure, microwave dissector, bipolar electrocautery, surgical clips, and endoscopic stapler. The efficacy and safety of different techniques in laparoscopic parenchymal transection of the liver were compared. Results The ischemic liver was darken with complete or selective portal triad clamping. The ischemic demarcation line between left and right lobe was obvious with the dissection and division of the left portal pedicle. There was an applicable scope of each hepatic parenchymal transection apparatus. The optimal combination of different techniques could increase efficacy and reduce hemorrhage in laparoscopic parenchymal transection of the liver. Conclusion Technical refinements of portal inflow occlusion and parenchymal transection in porcine models could provide evidences to clinical appliance of laparoscopic anatomic major hepatectomy.