玻璃体切除治疗视网膜分支静脉阻塞引起玻璃体积血的临床效果

目的:探讨玻璃体切除手术治疗视网膜分支静脉阻塞引起的玻璃体积血的临床效果。方法:回顾分析28例28眼视网膜分支静脉阻塞引起的玻璃体积血患者进行闭合式玻璃体切除,联合增殖膜剥离、眼内激光光凝及玻璃体腔长效气体、硅油或灌注液填充手术的临床疗效。结果:该28例患者术中均可见视网膜分支静脉阻塞闭锁呈白线状。视网膜静脉阻塞颞上方20例,颞下方8例。合并视盘新生血管2例,18例阻塞区可见视网膜新生血管及交通支。并发视网膜脱离7例,患者术前及术后视力比较有统计学差异(P<0.05)。结论:玻璃体切除是视网膜分支阻塞的有效手术方法,术中应谨慎去除阻塞区增殖病灶,光凝视网膜无灌注区,术后注意观察阻塞部位的视网膜复位及增殖情况。     

Intraocular pressure after intravitreal injection of triamcinolone acetonide following vitrectomy for macular edema

PURPOSE: To evaluate long-term intraocular pressure (IOP) response after intravitreal injections of different doses of triamcinolone acetonide (TA) upon completion of pars plana vitrectomy (PPV) for macular edema secondary to diabetic retinopathy or retinal vein occlusion. PATIENTS AND METHODS: Retrospective, consecutive, comparative, interventional case series. Twenty-seven eyes of 25 consecutive patients with macular edema associated with diabetic retinopathy (n=18) or retinal vein occlusion (n=9), who underwent PPV for the treatment of macular edema between January 2003 and December 2003, were included. Upon completion of vitrectomy, different doses of TA were injected into the vitreous cavity: 14 eyes with 5 mg of TA (group 1) and 13 eyes with 10 mg of TA (group 2). The main outcome measure was IOP. RESULTS: All patients were followed up for at least 12 months. Preoperative IOP was 12.6+/-2.6 mm Hg (mean+/-standard deviation) in group 1 and 13.2+/-2.1 mm Hg in group 2. Postoperatively, IOP increased to a mean maximum of 20.6+/-5.5 mm Hg in group 1 and 31.5+/-3.5 mm Hg in group 2 (P<0.01 for both groups). The difference between groups was also significant (P<0.05). Five of 14 eyes (36%) in group 1 and 10 of 13 eyes (77%) in group 2 had an elevation of IOP exceeding 21 mm Hg (P=0.03). The median interval from surgery to reach maximal IOP was 7 days in both groups. The significant IOP elevation lasted for 3 months in group 1 and 6 months in group 2. CONCLUSIONS: After injecting of TA into the vitreous cavity upon completion of PPV for macular edema, a dose-dependent IOP elevation was observed, starting from early postoperative days and returning to normal values after several months. These results show that intravitreal TA injection in the vitrectomized eyes might have different IOP changes from in the nonvitrectomized eyes.     

Management of retinal vein occlusion

Recent research into the relationship between retinal venous occlusion and general vascular disorders has shown that retinal venous occlusion seems to be related only to systemic hypertension. The role of systemic hemorrheologic parameters in the pathophysiology of venous occlusion is a controversial one. Of the various treatment modalities, isovolemic hemodilution has been found to improve retinal perfusion, but the treatment must be repeated about once a week for at least 2 months. The presence of tissue hypoxia in areas of ischemic venous occlusion has been confirmed by measurements of preretinal oxygen pressure in experimental venous occlusion. Reduced preretinal oxygen pressure in these experimental cases normalized after retinal scatter photocoagulation. The inhibiting role of posterior vitreous detachment on posterior segment neovascularization and the fact that panretinal photocoagulation has a better effect on anterior than on posterior segment neovascularization have been evaluated in clinical studies.     

The role of the vitreous in retinal detachment surgery with external buckling

PURPOSE: To prove the role of the vitreous in retinal detachment surgery with scleral buckling procedures, we retrospectively investigated the charts of patients who were operated on for retinal detachment by scleral buckling between January 1995 and June 1997. METHODS: Out of a total of 718 cases, 41 retinal detachments occurred in previously vitrectomized eyes. The buckling procedure consisted of silicone sponge explants in 513 cases (254 radial, 259 circumferential) and of encircling elements in 202 cases. Three eyes received a temporary balloon. The minimal follow-up was 3 months. RESULTS: After primary surgery in the 677 nonvitrectomized eyes, the retina was attached in 482 eyes (71.2%), after reoperation in 627 eyes (92.6%). With up to 3 reoperations (including vitrectomy with gas or silicone oil tamponade in 79 eyes), the final success rate was 98.7%. The corresponding reattachment rates in the 41 vitrectomized eyes were 82.9% after primary surgery and 97.6% after reoperation. Repeated surgery in 6 eyes consisted of successful internal tamponade by silicone oil. The reattachment rates after primary buckle procedure are of most interest to the role of the vitreous: the highest success rate (82.9%) was achieved in the vitrectomized eyes versus 71.2% in the nonvitrectomized eyes. The difference is statistically not significant. CONCLUSIONS: We therefore conclude that the absence of the vitreous has no adverse effect on the results of buckling procedures for retinal detachment. The choice of the surgical technique in treating retinal detachments in vitrectomized eyes should only determined by retinal findings such as the number and extent of breaks or the presence and stage of proliferative vitreoretinopathy.     

Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

PURPOSE: To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs. METHODS: Experimental BRVO was induced by diathermy close to the optic disc. RPO(2) was measured with an oxygen-sensitive electrode 0.5 mm above the BRVO-affected area, which was compared to the retinal areas not affected by BRVO. In one group of five pigs, RPO(2) was measured at baseline, 1 and 3 hours after BRVO, and after intravenous injection of 500 mg dorzolamide. In a second group of five pigs, RPO(2) was measured 1 week after the BRVO, both before and after intravenous injection of 500 mg dorzolamide. RESULTS: The average baseline RPO(2) was 2.64 +/- 0.09 kPa (mean +/- SD). In the BRVO-affected areas, RPO(2) decreased significantly (by 0.67 +/- 0.29 and 0.94 +/- 0.13 kPa) at 1 hour and 3 hours after BRVO induction. In the non-BRVO areas RPO(2) increased significantly (by 0.51 +/- 0.14 kPa) 1 hour after BRVO induction, but subsequently decreased and reached baseline 3 hours after BRVO induction. One week after BRVO induction, RPO(2) was 0.67 +/- 0.29 kPa lower in affected areas when compared with the non-BRVO areas. In the BRVO-affected areas, dorzolamide increased RPO(2) significantly (by 0.36 +/- 0.21 kPa at 3 to 4 hours and by 0.67 +/- 0.40 kPa) 1 week after BRVO induction. CONCLUSIONS: Retinal hypoxia induced by experimental BRVO remained significant 1 week after BRVO. Dorzolamide increased retinal oxygen tension in the BRVO-affected areas both at 4 hours and 1 week after experimental BRVO in pigs.     

Late complications in branch retinal vein occlusion

Neovascularization in branch retinal vein occlusion usually develops 6–12 months after the onset of the disease, although some cases have been reported in which neovascularization and subsequent vitreous haemorrhage developed 2–3 years later.This is a report of nine cases of late appearance of vitreous haemorrhage due to branch retinal vein occlusion, which occurred 3–6 years after the initial onset of the disease. In two of these nine cases the vitreous haemorrhage was very profound and had to be managed by vitrectomy. We have studied the remaining seven cases, which had retinal ischaemia and optic disc or retinal neovascularization documented by fluorescein angiographic examination. Laser coagulation was applied in these seven cases, which resulted in considerable regression of the neovascularization and absorption of the vitreous haemorrhage. In one out of the seven cases recurrent vitreous haemorrhages appeared and it was finally treated by vitrectomy. Visual acuity improved in six of the seven cases. The follow-up period ranged from 12 to 48 months.The late appearance of the ischaemic type of branch retinal vein occlusion with neovascularization can be attributed to the change in character of the initially mild oedematous form of the disease. Partial posterior vitreous detachment and traction exerted at some later stage upon the neovascularization could be additional factors of the late appearance of vitreous haemorrhage.Patients with branch retinal vein occlusion should be followed up regularly over a long period of time in order to avoid late complications of the disease, such as vitreous haemorrhage following optic disc or retinal neovascularization.     

Scatter photocoagulation restores tissue hypoxia in experimental vasoproliferative microangiopathy in miniature pigs

Experimental retinal branch vein occlusion using argon laser photocoagulation in miniature pigs induced the development of ischemic retinal territories associated with preretinal neovascularization. Preretinal partial pressure of oxygen (PO2) measurements on the ischemic territories, using O2-sensitive microelectrodes, established that the ischemic retinal areas were hypoxic. Scatter photocoagulation of these ischemic hypoxic territories restores the local PO2 to the normal values within 2 weeks. Hence, the reported inhibitory effect of photocoagulation on the development of retinal neovascularization could be due to a reversal effect on tissue hypoxia.     

Difference in clearance of intravitreal triamcinolone acetonide between vitrectomized and nonvitrectomized eyes

PURPOSE: To study the difference in clearance of intravitreal triamcinolone acetonide quantitatively between vitrectomized and nonvitrectomized eyes. METHODS: Eighty-four eyes of 42 rabbits were divided in 2 groups: 42 right eyes underwent standard pars plana vitrectomy (vitrectomized group), and 42 left eyes were not operated on (nonvitrectomized group). All eyes received intravitreal injections with 0.1 mL (0.3 mg) of triamcinolone acetonide. Every 12 eyes were obtained by killing 6 rabbits 1, 2, 4, 7, 12, 20, or 30 days after intravitreal injection. Each eye was enucleated and immediately frozen at -70 degrees C. The frozen vitreous was prepared for measuring the concentration of triamcinolone acetonide. Triamcinolone acetonide was quantified by high-performance liquid chromatography and ultraviolet absorbance detection. RESULTS: After 30 days, triamcinolone acetonide was detected only in 1 eye (0.22 microg/mL) in the vitrectomized group compared with 4 of 6 eyes (0.92 +/- 1.25 microg/mL) in the nonvitrectomized group. The coefficient of logarithmic regression was -0.12 in the vitrectomized group and -0.08 in the nonvitrectomized group. Triamcinolone acetonide decreased 1.5 times more rapidly in the vitrectomized group than in the nonvitrectomized group. The half-life of triamcinolone acetonide was 1.57 days in the vitrectomized group and 2.89 days in the nonvitrectomized group. CONCLUSION: Intravitreal triamcinolone acetonide decreases more rapidly in the vitrectomized eye than in the nonvitrectomized eye. Therefore, the faster clearance of intravitreal triamcinolone acetonide must be considered when planning intravitreal injection of triamcinolone acetonide in the vitrectomized eye.     

Branch retinal vein occlusion: clinical findings, natural history, and management

Branch retinal vein occlusion is a common retinal vascular condition characterized by sectoral intraretinal hemorrhages, retinal ischemia, retinal exudates, and macular edema. The site of occlusion usually occurs in the vicinity of arteriovenous crossing sites, and is predisposed by various systemic and local factors. Complications of branch retinal vein occlusion include macular edema, capillary nonperfusion, retinal neovascularization, vitreous hemorrhage, and tractional retinal detachments that often result in loss of vision. Until recently, laser photocoagulation was the only therapy recommended for eyes with branch retinal vein occlusion. New medical and surgical treatment options aimed at reducing macular edema have been evaluated in recent years, and include intraocular injections of steroids and anti-vascular endothelial growth factor agents, sustained drug release devices, vitrectomy, and sheathotomy.     

Diabetes as a risk factor for retinal neovascularization in retinal vein occlusion

We evaluated a series of patients with retinal vein occlusive disease to determine whether diabetic patients with vein occlusions developed retinal neovascularization more frequently than did nondiabetics. Retinal neovascularization occurred in 68.8% of diabetics after central retinal vein occlusion compared with 27.8% of nondiabetics. Diabetics with branch retinal vein occlusions showed no greater likelihood for subsequent retinal neovascularization than did nondiabetics.     

Effect of the vitreous on retinal wound-healing

The healing process of experimental retinal wounds in nonvitrectomized and vitrectomized rabbit eyes was compared. Using light, transmission and scanning electron microscopy, a significant difference was observed at the late stages of the healing process. The retinal wounds in the nonvitrectomized eyes healed properly, forming regular and smooth scars, while the scars that developed in the vitrectomized eyes were irregular and hypertrophic. Our observations suggest that the vitreous plays a role in normal healing of retinal wounds.     

视网膜静脉阻塞玻璃体积血的手术治疗

目的 分析2型糖尿病患者（T2DM）玻璃体积血合并视网膜分支静脉阻塞（BRVO）玻璃体切除手术的效果.方法 回顾分析因玻璃体积血在我院接受玻璃体切除手术治疗的T2DM 228例（289只眼）的临床资料.根据术中观察,其中16例（17只眼）的玻璃体积血由BRVO引起.玻璃体切除手术前视力手动～0.04.随访时间9～60个月,平均（32.80±16.70）月.结果 T2DM玻璃体积血合并BRVO的发生率为5.9％;玻璃体切除手术后视力0.01～1.0,颞上分支静脉阻塞者术后视力较差;手术时机≥6个月者易发生牵引性视网膜脱离,且术后视力较差.结论 颞上分支静脉阻塞、手术迟于6个月者术后视力较差.     

Vitrectomy for nondiabetic vitreous hemorrhage. Retinal and choroidal vascular disorders

The results and complications of pars plana vitrectomy for nondiabetic vitreous hemorrhage due to retinal and choroidal vascular disorders were studied in 68 eyes of 66 patients. Diagnoses included: retinal branch vein obstruction (34 eyes), choroidal neovascularization (15 eyes), central retinal vein occlusion (5 eyes), Eales' disease (10 eyes), pars planitis (3 eyes), and hemoglobin S-C retinopathy (1 eye). The duration of the vitreous hemorrhage was 6 months or more in 48 eyes (71%), and averaged 17.8 months. Preoperative visual acuity was less than 5/200 in 57 eyes (84%). Best postoperative visual acuity was 5/200 or better in 55 patients (81%), and vision improved two or more lines after vitrectomy in 54 eyes (80%). Patients with retinal branch vein obstruction, Eales' disease, or pars planitis had the best prognosis. Those with central retinal vein obstruction or choroidal neovascularization had the worst prognosis.     

Ophthalmodynamometric assessment of the central retinal vein collapse pressure in eyes with retinal vein stasis or occlusion

PURPOSE: Using a new Goldmann contact lens associated ophthalmodynamometric device, it was the purpose of the present study to determine the central retinal vein collapse pressure in eyes with retinal vein occlusions or retinal venous stasis. METHODS: The prospective clinical non-interventional comparative study included 19 patients with central retinal vein occlusion ( n=8), branch retinal vein occlusion (n=4), or retinal venous stasis (n=7) and 42 subjects of a control group. With topical anesthesia, a Goldmann contact lens fitted with a pressure sensor was put onto the cornea. Pressure was exerted on the globe by pressing the contact lens, and the pressure value at the time when the central retinal vein started pulsating was noted. RESULTS: Central retinal vein collapse pressure measured 103.6+/-25.4 arbitrary units (AU) in eyes with central retinal vein occlusion what was significantly higher than in the eyes with retinal venous stasis (58.1+/-37.5 AU; p=0.02) and the eyes with branch retinal vein occlusion (43.8+/-25.5 AU; p=0.004). In the latter two groups, the measurements of the central retinal vein collapse pressure were significantly (p<0.001) higher than the measurements in the eyes of the control group (4.2+/-7.8 AU). CONCLUSION: As measured by a new ophthalmodynamometer with direct biomicroscopic visualization of the central retinal vessels during examination, central retinal vein collapse pressure is significantly higher in eyes with central retinal vein occlusion, followed by eyes with branch retinal vein occlusion, eyes with retinal venous stasis and, finally, normal eyes. These findings may have diagnostic and therapeutic implications.     

Vitrectomy for macular edema combined with retinal vein occlusion

This study was performed in order to evaluate the effect of vitrectomy in eyes with retinal vein occlusion associated with macular edema. Twenty-nine years eyes (27 patients) with branch retinal vein occlusion (BRVO), and 14 eyes (13 patients) with central retinal vein occlusion (CRVO) both associated with macular edema underwent phacoemulsification, intraocular lens implantation, pars plana vitrectomy and peeling of the posterior hyaloid membrane. Follow-up ranged from 12 to 32 months. Macular edema was reduced, and visual improvement was observed (p < 0.0001 in BRVO, p = 0.0257 in CRVO, paired t-test). Visual outcome was better in eyes with better visual acuity before surgery. Early vitrectomy may be recommended for retinal vein occlusion associated with macular edema. This revised version was published online in July 2006 with corrections to the Cover Date.     

Initial clinical experience using a diode red laser (670 nm) in the treatment of retinal disease

AIM: To investigate the clinical use of a 670-nm diode red laser in the treatment of a number of retinal conditions. METHODS: In all, 17 eyes of 17 patients were treated for conditions such as proliferative diabetic retinopathy, retinal neovascularization in central retinal vein occlusion, rhegmatogenous retinal lesions and retinal breaks, and prophylactic peripheral retinopexy prior to silicone oil removal after three port pars plana vitrectomy. RESULTS: Regression of neovascularization was observed in all the eyes treated for vascular proliferation at the 3-month follow-up visit. Adhesive pigmented scars were observed in the remaining eyes 1 month after treatment. No major complications were recorded. CONCLUSIONS: In this pilot study, the 670-nm diode laser appears to be a promising modality for laser photocoagulation of the retina.     

视网膜分支静脉阻塞伴视网膜脱离21例手术疗效分析

目的 分析视网膜分支静脉阻塞伴视网膜脱离的手术治疗效果.方法 回顾性分析视网膜分支静脉阻塞伴视网膜脱离21例（21眼）的手术治疗效果,随访6～18个月,观察视力、眼底及视网膜复位情况.结果 视网膜分支静脉阻塞以颞侧分支尤其是颞上支静脉为主;视网膜裂孔为圆形及马蹄形,均位于牵引点附近,沿血管分布.进行玻璃体切除视网膜脱离复位手术及眼内激光光凝.随访6～18个月,所有患者视网膜均复位,19眼（90.5％）视力改善明显,3眼（9.5％）保持不变.无严重并发症发生.结论 及时进行视网膜脱离复位及激光光凝术是治疗视网膜分支静脉阻塞伴视网膜脱离的有效方法.     

Arteriovenous sheathotomy for persistent macular edema in branch retinal vein occlusion

PURPOSE: To evaluate the efficacy of arteriovenous (AV) sheathotomy with internal limiting membrane peeling for persistent or recurrent macular edema after intravitreal triamcinolone injection and/or laser photocoagulation in branch retinal vein occlusion. METHODS: Twenty-two eyes with branch retinal vein occlusion (BRVO) with recurrent macular edema underwent vitrectomy with AV sheathotomy and internal limiting membrane peeling. All eyes had previous intravitreal triamcinolone injection and/or laser photocoagulation for macular edema. The best corrected visual acuity (BCVA), fluorescein angiography and optical coherence tomography (OCT) before and after surgery were compared. RESULTS: The mean preoperative BCVA (log MAR) were 0.79 +/- 0.29 and postoperative BCVA (log MAR) at 3 months was 0.57 +/- 0.33. And improvement of visual acuity > or = 2 lines was observed in 10 eyes (45%). The mean preoperative fovea thickness measured by OCT was 595.22 +/- 76.83 microm (510-737 microm) and postoperative fovea thickness was 217.60 +/- 47.33 microm (164-285 microm). CONCLUSIONS: Vitrectomy with AV sheathotomy can be one treatment option for the patients with recurrent macular edema in BRVO.     

Intravitreal injection of triamcinolone acetonide for cystoid macular edema resistant to vitreous surgery

PURPOSE: To report the efficacy of intravitreal injection of triamcinolone acetonide(TA) for cystoid macular edema remaining after vitreous surgery. METHODS: Eight eyes of 7 patients aged from 32 to 84 years old were studied. The original diseases that caused macular edema were central retinal vein occlusion in 2 eyes, branch retinal vein occlusion in one eye, Irvine-Gass syndrome in 2 eyes, and diabetic retinopathy in 3 eyes. 4 mg of TA was injected intravitreally and visual acuity and foveal thickness measured by optical coherence tomography(OCT) were evaluated in before and after the surgery. RESULTS: Macular edema resolved rapidly after injection of TA in all cases and cysts were extinguished or diminished. The foveal thickness in OCT was reduced significantly from preoperative 495 +/- 116 (mean +/- standard deviation) microns to 267 +/- 117 microns after one week, and 246 +/- 81 microns after one month. The effect persisted for three months. Visual improvement of more than two Snellen lines was seen in 4 eyes. No side effects were observed except a temporary increase of intraocular pressure in one eye. CONCLUSION: Intravitreal injection of TA is effective in a short-term for cystoid macular edema remaining after vitrectomy.     

Bevacizumab联合视网膜光凝治疗虹膜和视网膜新生血管

目的:观察Bevacizumab玻璃体腔注射联合视网膜光凝治疗虹膜和视网膜新生血管的疗效和安全性。方法:回顾分析虹膜和视网膜新生血管患者13例13眼玻璃体腔注射Bevacizumab联合视网膜光凝治疗的临床随访资料。13眼中视网膜新生血管9眼(其中继发于视网膜分支静脉阻塞的2眼,增生型糖尿病视网膜病变的6眼,Eales病的1眼),虹膜新生血管4眼(均继发于视网膜中央静脉阻塞)。13眼全部行玻璃体腔注射1.25mg/0.05mL的Bevacizumab,术前或术后分次补充完成视网膜光凝。随诊3～18mo,随访期间发现新生血管复发者,再行同样方法的注射和光凝治疗。观察治疗前后最佳矫正视力、眼压、眼底荧光血管造影。结果:经治疗后,13眼中8眼(61.5%)视力提高,4眼(30.8%)视力保持不变,1眼(7.7%)视力下降;6例合并玻璃体积血,术后均明显吸收;13眼视网膜及虹膜新生血管均消退,随诊期间复发2眼,行第二次注射和光凝治疗后新生血管无复发。虹膜新生血管(新生血管性青光眼)4眼中2眼治疗后眼压下降,随访期间均控制正常,另2眼联合青光眼阀植入后眼压控制正常。随诊期中,其余9眼眼压无升高。1例患者注药后结膜下出血,其余患者未出现其他并发症。结论:Bevacizumab玻璃体腔注射联合视网膜光凝治疗虹膜和视网膜新生血管在短期内能促进玻璃体积血吸收和新生血管萎缩,副作用少;但尚需进一步大样本、多中心的临床随机对照研究。