Prevalence and associations of retinal vein occlusion in Australia. The Blue Mountains Eye Study

Visual acuity and multifocal electroretinographic changes after arteriovenous crossing sheathotomy for macular edema associated with branch retinal vein occlusion

PURPOSE

To evaluate the influence of arteriovenous (AV) sheathotomy on retinal function with central multifocal electroretinography (mfERG) in eyes with macular edema secondary to branch retinal vein occlusion (BRVO).

METHODS

Fifteen patients (15 eyes) who underwent AV sheathotomy for macular edema secondary to BRVO were included in the study. Best-corrected visual acuity and mfERG responses from the most central seven hexagons were analyzed before and 6 months after the operation.

RESULTS

The mean preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score +/- SD was 34.1 +/- 12.7 letters (Snellen equivalent, 20/50) and significantly improved up to 40.5 +/- 10.9 letters (Snellen equivalent, 20/40) at 6 months after AV sheathotomy (P = 0.027, Wilcoxon signed rank test). The mean preoperative P1 amplitude +/- SD of the most central 7 hexagons was 39.30 +/- 10.86 nV/deg(2) for the affected eye versus 47.72 +/- 6.67 nV/deg(2) for the normal fellow (control) eye (P = 0.013, Mann-Whitney U test) and significantly increased up to 50.71 +/- 15.58 nV/deg at 6 months after the operation (P = 0.014, Wilcoxon signed rank test). Significant correlations between preoperative and postoperative ETDRS score and preoperative P1 amplitude were present (r = 0.929, P < 0.001; r = 0.768, P = 0.001; respectively [Spearman correlation]).

CONCLUSIONS

AV sheathotomy improved macular function and anatomical outcome as measured by ETDRS score and mfERG responses in patients with macular edema due to BRVO.

Branch retinal vein occlusion: pathogenesis, visual prognosis, and treatment modalities

In branch retinal vein occlusion (BRVO), abnormal arteriovenous crossing with vein compression, degenerative changes of the vessel wall and abnormal hematological factors constitute the primary mechanism of vessel occlusion. In general, BRVO has a good prognosis: 50-60% of eyes are reported to have a final visual acuity (VA) of 20/40 or better even without treatment. One important prognostic factor for final VA appears to be the initial VA. Grid laser photocoagulation is an established treatment for macular edema in a particular group of patients with BRVO, while promising results for this condition are shown by intravitreal application of steroids or new vascular endothelial growth factor inhibitors. Vitrectomy with or without arteriovenous sheathotomy combined with removal of the internal limiting membrane may improve vision in eyes with macular edema which are unresponsive to or ineligible for laser treatment.

Evaluation of arteriovenous crossing sheathotomy for decompression of branch retinal vein occlusion

PURPOSE

To report the effects of arteriovenous adventitial sheathotomy on anatomical and functional improvements in patients with macular oedema due to branch retinal vein occlusion (BRVO).

METHODS

Pars plana vitrectomy and arteriovenous sheathotomy was performed on 11 patients with BRVO who had vision loss due to macular oedema. Ten patients with macular oedema due to BRVO and who have been treated with grid laser photocoagulation were included in the control group. The measurement of visual acuity with ETDRS chart was taken preoperatively and at 1, 3, 6, and 9 months follow-up in the study group and at 1, 3, 6, and 9 months after grid laser in the control group.

RESULTS

The mean preoperative logMAR visual acuity was 0.84+/-0.3 in the surgical group and 1.06+/-0.4 in the control group. The postoperative mean logMAR visual acuity was 0.41+/-0.2, 0.40+/-0.2, 0.40+/-0.3, and 0.36+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. In the control group the postlaser mean logMAR visual acuity was 0.92+/-0.3, 0.87+/-0.4, 0.85+/-0.3, and 0.82+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. The improvements of visual acuity in both groups were statistically significant when compared to pretreatment (P=0.003 and P=0.007 at 9 months in the study and control group, respectively).

CONCLUSION

Arteriovenous sheathotomy for decompression of BRVO in patients who have vision loss due to macular oedema was safe and effective for anatomical and functional improvement and resulted in significantly better visual outcomes than a matched control group of laser-treated eyes.

Ocular vascular thrombotic events: central retinal vein and central retinal artery occlusions

We prospectively assessed associations of thrombophilia- hypofibrinolysis with central retinal vein occlusion (CRVO) (40 patients) and central retinal artery occlusion (CRAO) (9 patients). We used polymerase chain reaction measures for thrombophilia (factor V Leiden, prothrombin, C677T MTHFR, platelet glycoprotein PlA1/A2) and hypofibrinolysis (plasminogen activator inhibitor-1 4G4G). Serologic thrombophilia measures included protein C, protein S (total and free) and antithrombin III, homocysteine, lupus anticoagulant, anticardiolipin antibodies IgG-IgM, and factors VIII and XI. Serologic hypofibrinolysis measures included Lp(a) and plasminogen activator inhibitor activity. For comparison with 40 CRVO and 9 CRAO patients, 80 and 45 race-gender matched controls were studied. The factor V mutation was more common in CRVO (3/40, 8%) than controls (0/79, 0%), P = .036, as was high (>150%) factor VIII (12/40, 30%) versus (4/77, 5%), P = .0002. Low antithrombin III (<80%) was more common in CRVO (5/39, 13%) than in controls (2/73, 3%), P = .049. Homocysteine was high (> or =13.5 micromol/L) in 5/39 (13%) CRVO patients versus 2/78 controls (3%), P = .04. Three of 9 CRAO patients (33%) had low (<73%) protein C versus 2/37 controls (5%), P = .044. Two of 9 CRAO patients (22%) had high (> or =13.5 micromol/L) homocysteine versus 0/42 controls (0%), P =. 028. Four of 9 CRAO patients had the lupus anticoagulant (44%) versus 4/33 (12%) controls (P = .050). CRVO is associated with familial thrombophilia (factor V Leiden, factor VIII, low antithrombin III, homocysteinemia), and CRAO is associated with familial and acquired thrombophilia (low protein C, homocysteinemia, lupus anticoagulant), providing avenues for thromboprophylaxis, and triggering family screening.

Central retinal vein occlusion case-control study

PURPOSE

To investigate risk factors for central retinal vein occlusion (CRVO).

DESIGN

Retrospective case-control study.

METHODS

Consecutive patients with CRVO examined from July 1, 2005 through July 31, 2006 were compared with an historical gender- and age-matched control group of patients with ocular problems other than vascular occlusive disease from the same referral practice. Risk factors for CRVO were evaluated.

RESULTS

The 144 patients in the CRVO group, 87 males and 57 females, had a mean age of 69.6 years (+/-13.6 years). CRVO was associated with hypertension (P < .001), diabetes mellitus (P = .047), glaucoma (P < .001), atrial fibrillation (P = .036), angiotensin-converting enzyme inhibitor use (P = .022), aspirin use (P < .001), and warfarin use (P = .011) by univariate analyses. Postmenopausal estrogen use was more common among women in the control group (P = .029). Multivariate logistic regression found the independent predictors for CRVO to be: glaucoma (adjusted odds ratio [OR], 4.75; P < .001), aspirin use (adjusted OR, 2.66; P = .001), and warfarin use (adjusted OR, 3.34; P = .005).

CONCLUSIONS

We found many of the same risk factors previously identified for CRVO by other studies, but we identified both aspirin and warfarin use to be independent risk factors for CRVO. Although these findings suggest the vasculopathic and prothrombotic risks in some patients may not be addressed adequately by antithrombotic therapy, they also suggest that the pathogenesis of CRVO may be more complicated than just the development of a primary thrombus within the vein.

Retinal vein occlusions and mortality: the Beijing Eye Study

PURPOSE

To assess the association between retinal vein occlusion (RVO) and mortality in a population-based setting.

DESIGN

Population-based, longitudinal study.

METHODS

At baseline in 2001, the Beijing Eye Study examined 4,335 subjects for RVO with a frequency of detected vein occlusions of 61 (1.4%) in 4,335 subjects. In 2006, all study participants were invited for a follow-up examination.

RESULTS

Of the 4,335 subjects, 3,195 (73.7%) returned for follow-up examination, whereas 132 (3.0%) subjects had died and 1,008 (23.3%) subjects declined to be re-examined or had moved away. For the subjects younger than 70 years or than 65 years, respectively, RVO was associated significantly with an increased mortality rate (P = .05; 95% confidence interval [CI], 0.995 to 8.26; and P = .001; 95% CI, 2.11 to 18.73, respectively).

CONCLUSIONS

RVO in relatively young persons may signal a significant risk of mortality.

High-throughput capillary electrophoresis method for plasma cysteinylglycine measurement: evidences for a clinical application

Increased levels in plasma homocysteine and cysteine, and more recently, decreased levels in cysteinylglycine have been indicated as a risk factor for vascular diseases. Most assays focused their attention only on homocysteine determination and when also other thiols were measured, analytical times drastically increased. By modifying our previous method for thiols detection, we set up a rapid capillary electrophoresis method for the selective quantification of plasma cysteinylglycine, cutting the analysis time of about 50%. Samples were treated with tri-n-butylphosphine as reducing agent, proteins were precipitated with trichloroacetic acid and released thiols were successively derivatized by the selective thiol laser-induced fluorescence-labeling agent 5-iodoacetamidofluorescein and separated by capillary electrophoresis. A baseline separation between peaks was obtained in about 2 min using 3 mmol/L sodium phosphate/2.5 mmol/L boric acid as electrolyte solution with 75 mmol/L N-methyl-D-glucamine at pH 11.25 in a 47 cm long capillary with a cartridge temperature of 45 degrees C. The method application was checked by measuring plasma Cys-Gly levels in a group of patients affected by retinal vein occlusion (RVO), an important cause of visual loss in the elderly. The low levels of Cys-Gly found in the RVO patients suggest that these small thiols may have importance in the disease development.

Active tremor compensation in microsurgery

This work presents the development of an intelligent microsurgical instrument to perform real-time tremor compensation within a handheld tool. The intelligent instrument senses its own motion, distinguishes between voluntary and erroneous motion, and manipulates its tip to cancel the undesired component in real-time. The on-board sensing unit is made up of a magnetometer-aided all-accelerometer inertial measurement unit and sensor fusion is performed via a quaternion-based Kalman filtering. Tremor is modeled and filtered by an adaptive zero-phase notch filter. The intraocular shaft manipulator is a three DOF piezoelectric actuated mechanism driven by a feedforward controller with inverse rate-dependent hysteresis model. Laboratory experimental results of the system are presented.

Interventions for branch retinal vein occlusion: an evidence-based systematic review

TOPIC

To assess the evidence on interventions to improve visual acuity (VA) and to treat macular edema and/or neovascularization secondary to branch retinal vein occlusion (BRVO).

CLINICAL RELEVANCE

Branch retinal vein occlusion is the second most common retinal vascular disease.

METHODS/LITERATURE REVIEWED

English and non-English articles were retrieved using a keyword search of Medline (1966 onwards), Embase, the Cochrane Collaboration, the National Institute of Health Clinical Trials Database, and the Association for Research in Vision and Ophthalmology Annual Meeting Abstract Database (2003-2005). This was supplemented by hand searching references of review articles. Two investigators independently identified all randomized clinical trials (RCTs) with more than 3 months' follow-up.

RESULTS

From 4332 citations retrieved, 12 RCTs were identified. There were 5 RCTs on laser photocoagulation. Grid macular laser photocoagulation was effective in improving VA in 1 large multicenter RCT, the Branch Vein Occlusion Study (BVOS), but 2 smaller RCTs found no significant difference. The BVOS showed that scatter retinal laser photocoagulation was effective in preventing neovascularization and vitreous hemorrhage in patients with neovascularization, but a subsequent RCT found no significant effect. Randomized clinical trials evaluating intravitreal steroids (n = 2), hemodilution (n = 3), ticlopidine (n = 1), and troxerutin (n = 1) showed limited or no benefit.

CONCLUSIONS

There is limited level I evidence for any interventions for BRVO. The BVOS showed that macular grid laser photocoagulation is an effective treatment for macular edema and improves vision in eyes with VA of 20/40 to 20/200, and that scatter laser photocoagulation can effectively treat neovascularization. The effectiveness of many new treatments is unsupported by current evidence.

Retinal Vein Occlusion and Vascular Mortality

PURPOSE

To assess the association of retinal vein occlusion (RVO) with cardiovascular and cerebrovascular mortality.

DESIGN

Pooled data from 2 population-based cohort studies.

PARTICIPANTS

At baseline, the Beaver Dam Eye Study (BDES) examined 4926 persons aged 43 to 86 years (from 1988-1990) and the Blue Mountains Eye Study (BMES) examined 3654 persons aged 49 to 97 years (from 1992 to 1994).

METHODS

Retinal vein occlusion was assessed from retinal photographs. Vascular deaths were determined using either death certificates (BDES) or the Australian National Death Index (BMES). Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

MAIN OUTCOME MEASURE

Vascular (cardiovascular and cerebrovascular) mortality was determined.

RESULTS

Of 8384 baseline participants, 96 (1.14%) had RVO at baseline (BDES, n = 38; BMES, n = 58). Over 12 years, 1312 (15.7%) died of cardiovascular-related conditions and 341 (4.1%) died of cerebrovascular-related conditions. Age-standardized vascular mortality rates were 26.0% and 5.3%, respectively, in persons with RVO and 17.1% and 4.5%, respectively, in those without RVO. After adjusting for age, gender, body mass index, hypertension, diabetes, smoking, glaucoma, and study site, RVO was not associated with cardiovascular-related mortality (HR, 1.2; 95% CI, 0.8-1.8) or cerebrovascular-related mortality (HR, 0.9; 95% CI, 0.4-2.1) among participants of all ages. However, in persons aged less than 70 years, baseline RVO was associated with higher cardiovascular mortality (combined BDES and BMES: HR, 2.5; 95% CI, 1.2-5.2; BDES: HR, 2.5; 95% CI, 0.9-6.9; BMES: HR, 2.1; 95% CI, 0.7-6.8).

CONCLUSIONS

Retinal vein occlusion in persons aged 43 to 69 years may signal a doubling of the risk of cardiovascular mortality.

Interventions for Central Retinal Vein Occlusion

TOPIC

To assess the evidence for the effectiveness of interventions to improve visual acuity (VA) and prevent or treat neovascularization secondary to central retinal vein occlusion (CRVO).

CLINICAL RELEVANCE

Central retinal vein occlusion is a common cause of visual morbidity and blindness. Many different interventions have been advocated, but the evidence justifying their use remains unclear.

METHODS/LITERATURE REVIEWED

English and non-English language articles were retrieved using a keyword search of Medline (1966 onwards), Embase, the Cochrane Collaboration, the National Institutes of Health Clinical Trials database, and the Association for Research in Vision and Ophthalmology (2003-2005). This was supplemented by manually searching references of review articles. Two investigators independently identified all randomized clinical trials (RCTs) on interventions in CRVO with more than 3 months' follow-up.

RESULTS

Of 4133 citations retrieved, 17 RCTs comparing intervention with a control group were identified. There were 4 RCTs on laser photocoagulation. Grid macular laser photocoagulation did not improve VA in CRVO with macular edema. Prophylactic panretinal photocoagulation did not prevent angle and iris neovascularization in ischemic CRVO, but resulted in regression of angle and iris neovascularization and reduced progression to neovascular glaucoma. There were 4 RCTs that reported improvement in VA with inpatient hemodilution, 2 RCTs with no significant improvement, and 1 RCT showing deterioration in VA after outpatient hemodilution. Randomized clinical trials evaluating ticlodipine, troxerutin, and streptokinase showed a limited or no benefit.

CONCLUSIONS

This review found limited level I evidence for any intervention to improve VA in patients with CRVO. Panretinal photocoagulation resulted in regression of neovascularization. Hemodilution may improve vision in some patients, but the data conflict. More robust randomized controlled trials evaluating current treatments for CRVO are needed. The results of ongoing RCTs on intravitreal triamcinolone, anti-vascular endothelial growth factor agents, and chorioretinal anastomosis are awaited with interest.

The eye in hypertension

Hypertension has a range of effects on the eye. Hypertensive retinopathy refers to retinal microvascular signs that develop in response to raised blood pressure. Signs of hypertensive retinopathy are frequently seen in adults 40 years and older, and are predictive of incident stroke, congestive heart failure, and cardiovascular mortality--independently of traditional risk factors. Hypertension is also a major risk factor for the development of other retinal vascular diseases, such as retinal vein and artery occlusion, and ischaemic optic neuropathy. High blood pressure increases the risk of both development of diabetic retinopathy and its progression. Adequate control of blood pressure has been proven in randomised clinical trials to reduce vision loss associated with diabetic retinopathy. Finally, hypertension has been implicated in the pathogenesis of glaucoma and age-related macular degeneration. Recognition of the ocular effects of blood pressure could allow physicians to better manage patients with hypertension, and to monitor its end-organ effects.

Branch retinal vein occlusion and fluoxetine

A case of branch retinal vein occlusion associated with fluoxetine-induced secondary hypertension is described. Although an infrequent complication of selective serotonin reuptake inhibitor therapy, it is important that ophthalmologists are aware that these agents can cause hypertension because this class of drugs is widely prescribed.

Familial central retinal vein occlusion

AIM

To report four cases of central retinal vein occlusion (CRVO) in a French family.

PATIENTS AND METHODS

Ophthalmological examination and medical work-up of seven members of the family.

RESULTS

There were four cases of CRVO in two consecutive generations. Three of them had CRVO in both eyes. Arterial hypertension was present in two, associated to glaucoma in one. Medical work-up did not reveal additional risk factors.

CONCLUSIONS

We report a case of familial clustering of CRVO. Our cases combined to other cases reported in the literature provide arguments for the existence in some subjects of a genetic predisposition of CRVO. Additional case series are however needed to confirm this hypothesis.

Radial optic neurotomy for the management of hemicentral retinal vein occlusion: long-term follow-up study

PURPOSE

To assess the efficacy of radial optic neurotomy (RON) for hemicentral retinal vein occlusion (hemi-CRVO) in patients with follow-up of >12 months.

METHODS

Five consecutive patients with hemi-CRVO were enrolled in the study and underwent vitrectomy with RON. The effects of this treatment were assessed by visual acuity, optical coherence tomography, indocyanine green angiography, and kinetic visual field testing.

RESULTS

The median and mean visual acuities improved from 20/250 to 20/50 and from 20/286 to 20/51, respectively. Four patients (80%) had visual acuity improvement of > or =3 lines; visual acuity in 1 patient (20%) remained the same. Visual acuity in all four eyes with preoperative visual acuity of <20/200 improved to >20/200 12 months after surgery. Foveal thickness was gradually reduced during the follow-up period. Chorioretinal anastomosis was detected by indocyanine green angiography in 3 eyes (60%). A temporal visual field defect was found in two eyes. No neovascularization on the iris, angle, optic disk, or retina was detected postoperatively.

CONCLUSION

Visual acuity may improve more with RON compared with the natural history of the disease, and no neovascular formation may occur after RON, suggesting that this procedure may be an effective treatment for hemi-CRVO.

The management of retinal vein occlusion: is interventional ophthalmology the way forward?

Retinal vein occlusions (RVO) are the second commonest sight threatening vascular disorder. Despite its frequency treatments for RVO are unsatisfactory and include several that have not been tested by large, well designed, prospective, randomised controlled trials. There is also the lack of long term follow up in many of the available small uncontrolled studies, and the timings of interventions are haphazard. This review aims to evaluate the current knowledge relating to the pathogenesis, suggested treatments for the different types of RVO, and their complications. Isovolaemic haemodilution is of limited benefit and should be avoided in patients with concurrent cardiovascular, renal, or pulmonary morbidity. Evidence to date does not support any therapeutic benefit from radial optic neurotomy, optic nerve decompression, or arteriovenous crossing sheathotomy on its own. Vitrectomy combined with intravenous thrombolysis may offer promise for central RVO. Similarly, vitrectomy combined with arteriovenous sheathotomy intravenous tissue plasminogen activator may offer benefits for branch RVO. RVOs occur at significantly high frequency to allow future prospective randomised controlled studies to be conducted to evaluate the role of different therapeutic modalities singly or in combination.

Intravitreal triamcinolone for the treatment of ischemic macular edema associated with branch retinal vein occlusion

PURPOSE

To evaluate the safety and efficacy of intravitreal triamcinolone acetonide (IVTA) for ischemic macular edema associated with branch retinal vein occlusion (BRVO) and foveal ischemia.

DESIGN

Prospective interventional case series.

METHODS

setting: Clinical practice. study population: Eighteen eyes of 18 patients with macular edema associated with BRVO and foveal ischemia. intervention: Four mg IVTA. main outcome measures: Visual acuity (VA), optical coherence tomography, macular thickness measurements, and treatment-related complications.

RESULTS

The mean duration of BRVO before treatment was 14 months. All patients were followed for a minimum of nine months, and 12 patients completed 12 months follow-up. The mean logarithm of the minimum angle of resolution (logMAR) VA improved significantly from 0.81 +/- 0.36 at baseline to 0.65 +/- 0.30 at one month (P = .03) but did not vary significantly from baseline at three, six, nine, and 12 months. Macular thickness improved significantly in all eyes from a mean of 400 +/- 134 mum preinjection, to 228 +/- 58 mum at one month (P < .01) and 256 +/- 121 mum at three months (P < .01) but did not vary significantly from baseline at six, nine, and 12 months. Eight eyes developed posterior subcapsular cataract, intraocular pressure (IOP) exceeded 21 mm Hg in four eyes, and two eyes developed vitreomacular traction during follow-up.

CONCLUSIONS

IVTA is effective in reducing ischemic macular edema associated with BRVO and foveal capillary nonperfusion. This reduction is often associated with a temporary improvement in VA. Raised IOP and development of posterior subcapsular cataract are disadvantages of this treatment.

RETINAL VASCULAR OCCLUSION IN PATIENTS INFECTED WITH HUMAN IMMUNODEFICIENCY VIRUS

PURPOSE

To describe the clinical features of retinal vascular occlusions (macrovasculopathy) and the proportion of affected patients with human immunodeficiency virus (HIV) infection.

METHODS

Retrospective chart review of all HIV-infected individuals with retinal vascular occlusions seen at a single tertiary care clinic between November 1983 and May 1998.

RESULTS

Retinal vascular occlusion was found in 38 eyes of 33 (1.3%) of the 2,484 consecutive patients examined. Of the 33 patients, 16 (48.5%) had central retinal vein occlusion, 9 (27.3%) had branch retinal vein occlusion, 4 (12.1%) had hemiretinal vein occlusion, and 1 each (3.0%) had central retinal arterial occlusion, branch retinal arterial occlusion, and combined hemiretinal vein occlusion and branch retinal artery occlusion. One patient (3.0%) had Purtscher-like retinopathy in one eye. Multiple regression analysis revealed that macrovasculopathy was associated with the presence of noninfectious retinal microvasculopathy (odds ratio, 5.76; 95% confidence interval, 2.59-12.80). Vision at the time of diagnosis ranged between 20/20 and no light perception. Twenty-five (75.8%) of the 33 patients had follow-up examinations for a mean period of 9.1 months. Ocular findings during follow-up included capillary dropout in 3 patients (11.5%), posterior pole neovascularization in 4 (15.4%), vitreous hemorrhage in 4 (15.4%), and optic atrophy in 6 (23.1%). Vision at the last eye examination ranged between 20/20 and no light perception and was 20/200 or worse in 15 (39.5%) of 38 eyes.

CONCLUSIONS

Patients with HIV infection have a small risk of retinal vascular occlusion, but complications and visual loss are common in affected patients. There is a strong association between noninfectious retinal microvasculopathy and retinal vein occlusions.

Surgical induction of chorioretinal venous anastomosis in ischaemic central retinal vein occlusion: a non-randomised controlled clinical trial

AIM

To evaluate the safety and efficacy of surgical induction of chorioretinal venous anastomosis in the management of ischaemic central retinal vein occlusion (CRVO).

METHODS

In a comparative clinical trial, 28 patients with ischaemic CRVO were included, of whom 18 who declined surgery were considered as controls. The 10 surgical cases underwent standard vitrectomy with incisions into the choroids adjacent to the partially cut major retinal veins. Mersilene suture insertion was done to induce chorioretinal venous shunt. Mild endolaser was applied. Patients were followed up for 6-18 (mean 10) months.

RESULTS

Clinical success in shunt development was 90%. Surgical cases had a significantly better visual acuity improvement compared with controls (mean difference: 1.5 logMAR, p = 0.001) with 80% of them showing improvement (compared with 28% of the controls, p = 0.016). Neovascularisation developed in 39% of the control group compared with 0% of the surgical cases (p = 0.03). In multivariate analysis, surgery remained the sole significant predictor of visual improvement. There were three re-operations for vitreous cavity haemorrhage, cataract, and retinal detachment.

CONCLUSIONS

Surgical induction of chorioretinal venous anastomosis may result in visual acuity improvement and prevent neovascularisation in ischaemic CRVO. Randomised studies are needed to compare the current study modality with the natural course of CRVO and emerging procedures, such as optic neurotomy, in the management of ischaemic CRVO.

Les occlusions vasculaires rétiniennes : diagnostic et prise en charge

PURPOSE

The diagnosis of retinal venous and arterial occlusions is usually easily evoked on visual symptoms and ophthalmoscopic features. However, their management (etiologic explorations and treatment) has not been formally established and remains controversial.

CURRENT KNOWLEDGE AND KEY POINTS

Some retinal vascular occlusions may result of loco-regional ocular causes. They more often occur in patients with cardiovascular pathologies or risk factors, or sometimes other systemic diseases that need to be recognized for a proper treatment. Therefore, a comprehensive management of patients with retinal vascular occlusions is necessary to correct associated diseases or predisposing abnormalities that could lead to local recurrences or systemic events.

CONCLUSION

Along with a review of the literature, we suggest a practical approach for the management of retinal vascular occlusions, which requires a collaboration between the ophthalmologist and other physicians: general practitioner, cardiologist, internist... as appropriate according to each case.

Management of branch retinal vein occlusion with vitrectomy and arteriovenous adventitial sheathotomy, the possible role of surgical posterior vitreous detachment

BACKGROUND

To analyze the results of vitrectomy and adventitial sheathotomy in the management of branch retinal vein occlusion (BRVO). This is a nonrandomized interventional case series.

METHODS

Patients with BRVO with progressive decrease in visual acuity underwent surgery and were prospectively evaluated in two centers. Surgical procedure included a 3-port pars plana vitrectomy, removal of the internal limiting membrane and arteriovenous crossing sheathotomy. Clinical evaluation consisted of best-corrected visual acuity, fluorescein angiography and optical coherence tomography.

RESULTS

Thirteen eyes were analyzed consecutively. An improvement in visual acuity of two ETDRS lines or more was observed in nine eyes (69%). The mean gain was 1.9 ETDRS lines. The absence of previous posterior vitreous detachment (PVD), poor initial visual acuity and the presence of retinal ischemia were correlated to the improvement in vision (P=0.014, P=0.002 and P=0.052, respectively). Eyes with initial PVD had a mean loss postoperatively of -5.7 lines, but eyes without PVD experienced a gain of 4.2 lines (P<0.001). Macular edema decreased significantly (preoperative thickness: 714 micro m, postoperative thickness: 353 micro m, P=0.04), whereas the aspect of the vein at the crossing and the non-perfused area remained unchanged.

CONCLUSION

Vitrectomy with sheathotomy seems to be of benefit in the management of BRVO, particularly in eyes with no previous PVD, and the main postoperative feature was the decrease in macular edema. The surgical detachment of posterior hyaloid could be as important (or more) as the sheathotomy itself. Further studies are needed to define the most efficient surgical management of BRVO.

Diabetes mellitus: a risk factor affecting visual outcome in branch retinal vein occlusion

PURPOSE

The prognosis of visual acuity (VA) after branch retinal vein occlusion (BRVO) in patients with diabetes mellitus is unknown compared to the VA in non-diabetic patients with BRVO. The aim of this study was to evaluate the visual outcome of BRVO in diabetic and non-diabetic patients.

METHODS

A retrospective case-control study of diabetic and non-diabetic patients with BRVO was performed. VA and commonly known risk factors and complications of BRVO were compared in a follow-up period of at least 1 year.

RESULTS

A total of 28 eyes of patients with diabetes and 49 eyes of non-diabetic patients with BRVO were included. One year after BRVO, the VA in the patients with diabetes decreased significantly more than that of the non-diabetic patients. During the second year after BRVO, the VA did not change significantly in either group. BRVO in patients with diabetes occurs at an earlier age. Diabetic patients needed more outpatient visits.

CONCLUSIONS

The VA 1 year after BRVO in patients with diabetes is worse compared to the VA in patients without diabetes. The VA stabilizes 1 year after onset in both groups. Diabetic patients tend to need more frequent follow-up in order to treat the sequelae of BRVO.

The platelet glycoprotein Ia/IIa gene polymorphism C807T/G873A: a novel risk factor for retinal vein occlusion

Retinal vein occlusion (RVO) is associated with hyperhomocysteinaemia and the antiphospholipid syndrome-disorders known to contribute to both arterial and venous thrombosis. In both of these conditions and RVO, platelet activation occurs. Aspirin, not warfarin, is the most effective antithrombotic agent in RVO and, taken together, these observations suggest an important role for platelets in this common ocular thrombotic condition. Platelet glycoprotein Ia/IIa (GpIa/IIa) is an adhesion molecule mediating platelet-collagen interactions and is key to the initiation of thrombosis. Recently, the cellular density of this molecule was shown to be determined by two silent, linked polymorphisms (C807T/G873A) within the GpIa/IIa gene. There is evidence that some of the resulting genotypes are associated with thrombo-embolic disease. This study therefore aimed to establish the prevalence of the GpIa/IIa polymorphisms and the three commonest hereditary thrombophilic disorders (prothrombin gene G20210A (PT) mutation, Factor V Leiden (FVL), and the thermolabile methylene tetrahydrofolate reductase C677T (MTHFR) mutation) in patients with RVO and normal controls. The GpIa/IIa polymorphisms and thrombophilic abnormalities were all identified using the polymerase chain reaction.Our results show that the frequency of the GpIa/IIa polymorphisms was similar in our normal control population to previously published series. Patients with RVO, however, had only a 10% (4/40) frequency of the lowest risk subtype (CC/GG) compared to 37.5% (15/40) in the control group-P 0.0039. The incidence of the PT, FVL, and MTHFR thrombophilic mutations was not different between the two groups, but interestingly none of the 7/40 RVO cases with a PT, FVL, or MTHFR mutation had the low-risk GpIa/IIa genotype while all but one of the controls did-P<0.05. Thus, 17.5% of RVO patients harboured more than one prothrombotic abnormality. The principal difference between the RVO and control group was the very high incidence of the intermediate-risk GpIa/IIa subtype (CT/GA)-82.5 vs 50%, P&<0.05. These results suggest a major role for GpIa/IIa polymorphisms in the pathogenesis of RVO.

Central retinal vein occlusion risk profile: a case-control study

PURPOSE

To identify risk factors for central retinal vein occlusion (CRVO).

METHODS

This clinic-based case-control study included 408 patients with CRVO aged 21 years and older and 566 controls who were seen between January 1, 1990, and December 31, 2001. Multivariate logistic regression analysis was used to adjust for various factors and test potential interactions between the different variables.

RESULTS

An increased risk of CRVO was found in persons with systemic hypertension, but odds ratios were greater for older patients. Risk of CRVO increases with age and also in association with hypercoagulability. Diabetes mellitus, kidney disease, and glaucoma were associated with increased risk for CRVO. A significantly greater prevalence of higher erythrocyte sedimentation rate was present in young adults compared with older patients.

CONCLUSIONS

The results suggest a relationship between CRVO and certain risk factors (systemic hypertension, diabetes mellitus, kidney disease, glaucoma, older age) and support the possibility of an association between CRVO and urban location. The findings also support the potential value of medical treatment of underlying medical conditions in preventing occurrence of CRVO.

Vitrectomy with arteriovenous decompression and internal limiting membrane dissection in branch retinal vein occlusion

PURPOSE

The therapeutic armamentarium for functional improvement after branch retinal vein occlusion (BRVO) is limited with uncertain efficacy. Some surgeons have proposed surgical decompression of the vein at the arteriovenous (AV) crossing.

METHODS

Forty-three patients with BRVO were treated in the authors' department from August 1999 to April 2001 with AV decompression. Twenty-five patients with comparable BRVO who refused this surgical intervention served as a control group. All 68 patients received an isovolemic hemodilution therapy for 10 days. The surgical procedure consisted of a standard pars plana vitrectomy and separation of the overlying artery from the vein using microscissors. In 16 cases dissection of the internal limiting membrane (ILM) in the macular area and around the AV crossing was also performed. Assessment of visual acuity, fluorescein angiography, and multifocal electroretinography were performed preoperatively and 6 weeks after surgery in seven patients.

RESULTS

Surgical procedure and postoperative course were uneventful. In most of the treated eyes visual acuity improved and fluorescein angiography revealed capillary reperfusion. Functional results in patients with AV decompression were highly significantly better than in the control group. Furthermore, removal of the ILM seems to have an additional beneficial effect on the functional outcome.

CONCLUSION

These results demonstrate the therapeutic effect of surgical AV decompression in BRVO. Additional removal of the ILM seems to improve the functional results. Further experience may answer some open questions.

Cardiovascular and thrombophilic risk factors for central retinal vein occlusion

Retinal vein occlusion (RVO) is a relatively common disease that is often associated with a variety of systemic disorders including arterial hypertension, diabetes mellitus, dyslipidemia, and systemic vasculitis. There are various types of RVO, categorized on the basis of the site of occlusion and on the type of consequent vascular damage. Central retinal vein occlusion (CRVO) is the most frequently occurring and clinically relevant type of RVO. In addition to the well-known classical risk factors, new hemostasis-related ones have been investigated in patients affected by CRVO. The data concerning a number of parameters remain contradictory; yet, high levels of type 1 plasminogen activator inhibitor (PAI-1) and hyperhomocysteinemia appear to play a significant role in the pathogenesis of this disease. Although based on a limited number of studies, this new knowledge could eventually provide important indications regarding prognosis and therapeutic strategies.

Central retinal vein occlusion and thrombophilia

Central retinal vein occlusion is one of the commonest vascular diseases of the eye. The pathogenesis is multifactorial with both local factors and systemic diseases being aetiologically important. Many thrombophilic conditions have recently been identified and studies looking at their potential role in CRVO have been undertaken. The aim of this review is to critically appraise these studies as to date many have given conflicting results, making it far from clear what role thrombophilic conditions play in CRVO. It appears that hyperhomocysteinaemia and antiphospholipid syndrome are causes of CRVO and there is evidence that disorders causing hypofibrinolysis may also be important. The common hereditary thrombophilic conditions however do not appear to be strong risk factors but larger studies are needed for a definitive answer.

Can the specificity of the FDT for glaucoma be improved by confirming abnormal results?

PURPOSE

To determine whether the specificity of the frequency-doubling technology (FDT) perimeter in the screening mode for glaucoma can be improved by repeating abnormal screening results.

METHODS

The FDT perimeter was used in C-20-5 screening mode, and the right eye was tested first. After both eyes were tested, the screening was repeated in eyes with any abnormal visual field defects on FDT perimetry. The printouts were categorized as possible visual field abnormality (zero or one miss), probable visual field abnormality (two to four misses), and definite visual field abnormality (more than five misses). A clinical ophthalmologic examination was conducted on the day of the FDT perimetry screening.

RESULTS

Complete data were available for 223 people. The participants ranged in age from 23 to 91 years (mean, 68.5 years; standard deviation. 13.7 years), and 119 (53%) were women. The sensitivity of the FDT perimetry screening was 100%; both cases of glaucoma showed an abnormality on FDT perimetry both times. The specificity improved moderately from the first screening to the second screening. The specificity the first time was 62% (95% confidence interval, 53.1-71.2). The specificity the second time was 68.5% (95% confidence interval, 59.8-77.1). Improvement on FDT perimetry rescreening varied by the language spoken at home. Seven of the 19 non-English speakers without glaucoma improved on rescreening, compared with none of the 23 English speakers (P = 0.002). Seven of the 25 right eyes with FDT perimetry abnormalities both times and no glaucoma had no other detectable diseases. Three of 24 left eyes with FDT perimetry abnormalities both times and no glaucoma had no other detectable diseases. Of the 85 patients who did not have glaucoma but had FDT perimetry abnormalities both times, only one did not have some other detectable disease.

DISCUSSION

In summary, the sensitivity for glaucoma of the C-20-5 screening mode is excellent, but a paradigm for screening with the FDT perimeter to improve the overall specificity for glaucoma still must be developed.

Superselective ophthalmic artery fibrinolytic therapy for the treatment of central retinal vein occlusion

AIM

To study the effect of superselective ophthalmic artery fibrinolysis as a treatment for central retinal vein occlusion (CRVO).

METHODS

Retrospective, university based single centre study. The charts of 26 eyes of 26 patients treated were reviewed. Among the 26 patients, there were nine cases of combined artery and vein occlusion, three cases of combined cilioretinal artery and CRVO, and 14 cases of classic CRVO. Complete preoperative and postoperative ophthalmological examination and fluorescein angiography were performed in all cases. The therapeutic procedure comprised the infusion of urokinase through a microcatheter into the ostium of the ophthalmic artery, via a femoral artery approach. The main outcome measure was the improvement in visual acuity 48 hours after the procedure.

RESULTS

Six eyes of six patients exhibited significant improvement in visual acuity immediately after the fibrinolysis procedure. Among them, four had a initial funduscopic appearance suggestive of combined occlusion of the central retinal artery (CRAO) and vein. For these patients, the visual benefit was maintained in the long term. Intravitreal haemorrhage occurred in two patients. There were no extraocular complications linked to the procedure.

CONCLUSIONS

Selective ophthalmic artery infusion of urokinase was followed by improvement in VA in six out of 26 cases of CRVO. Eyes with combined CRAO and CRVO with recent visual loss appeared to be the most responsive. This treatment did not prevent the occurrence of ischaemia in the failure cases. The efficacy of in situ fibrinolysis for treatment of CRVO needs to be further evaluated in a controlled study.

[Extra-ocular etiologic factors in retinal vein occlusion. Retrospective study of 24 patients]

PURPOSE

Retinal vein occlusion has several causes. Cardiovascular risk factors, particularly systemic hypertension; as well as thrombophilia appear to be involved in the development of retinal vein occlusion.

METHODS

In a retrospective study we analyzed these factors in 24 patients, admitted for retinal vein occlusion and isovolaemic hemodilution in an internal medicine unit.

RESULTS

In patients over 50 years of age, cardiovascular risk factors predominate; while in patients under 50, one patient out of two has biological features indicating a risk for thrombosis.

CONCLUSION

Serological abnormalities could be involved in the physiopathology of retinal vein occlusion in young patients.

Visual function tests, eye disease and symptoms of visual disability: a population-based assessment

PURPOSE

To examine associations between eye disease and tests of visual function with self-reported visual disability.

METHODS

The Blue Mountains Eye Study is a cross-sectional census-based survey of eye disease in two postcode areas in the Blue Mountains, west of Sydney, Australia. Of 4433 eligible residents, 3654 (82,4%) participated. Subjects had a detailed eye examination, including tests of visual acuity, contrast sensitivity, disability glare and visual field. Lens and retinal photographs were taken and graded according to standardized protocols for presence of cataract, early and late age-related maculopathy, glaucoma, diabetic retinopathy, retinal vein occlusion and other eye diseases. An interviewer-administered questionnaire included questions about perception of visual disability.

RESULTS

Scores on all tests of visual function significantly decreased with age (P < 0.0001). This decrease persisted for all tests except disability glare after excluding subjects with identifiable eye disease. The presence of one or more eye diseases was significantly associated with all (self-reported) measures of visual disability (trouble driving at night, difficulty recognizing a friend across the street, reading a newspaper or recognizing detail on televsion): mixed cataract (cortical and nuclear, or posterior subcapsular and nuclear) was associated with trouble driving at night and difficulty recognizing a friend across the street. A 10-letter (two-line) decrease in best corrected or presenting visual acuity was significantly associated with all self-reported measures of vsual dsability, as was a two-step decrease in contrast sensitvity. A five-point increase in points missing in the visual field was weakly but significantly associated with all self-reported measures of visual disability except trouble driving at night.

CONCLUSIONS

Visual function declines with age. Impaired visual function was strongly, and eye disease relatively weakly associated with reports of visual disability.

Raised plasma homocysteine as a risk factor for retinal vascular occlusive disease

BACKGROUND/AIMS

A moderately elevated plasma concentration of the sulphur amino acid homocysteine is an independent risk factor for atherosclerotic vascular disease. Many of the risk factors associated with coronary, cerebral, and peripheral atherosclerotic vascular disease are common to retinal vascular occlusive disease but it is unclear whether elevated plasma concentrations of homocysteine are also associated with such disease. This study assessed the relation between retinal vascular occlusive disease and elevated levels of plasma total homocysteine (tHcy).

METHODS

A retrospective case-control study involving hospital based controls and cases with retinal artery, central retinal vein (including hemiretinal vein), and branch retinal vein occlusions was performed. The relation between elevated tHcy, defined as a level greater than or equal to 12 micromol/l and risk of retinal vascular occlusive disease was examined.

RESULTS

87 cases of retinal vascular occlusive disease including 26 cases of retinal artery occlusion, 40 cases with central retinal vein occlusion, and 21 cases of branch retinal vein occlusion were compared with 87 age matched controls. Mean tHcy levels were higher in all disease groups and this difference was significant in patients with retinal artery occlusions (p= 0.032) and patients with central retinal vein occlusion (p=0.0001). When adjusted for known cardiovascular risk factors, tHcy was an independent risk factor for retinal vascular occlusive disease (OR 2.85 (95% CI 1.43-5.68)).

CONCLUSIONS

Elevated tHcy is an independent risk factor for retinal vascular occlusive disease. Assessment of tHcy may be important in the investigation and management of patients with retinal vascular occlusive disease.

Laser-induced chorioretinal venous anastomosis for non-ischaemic hemi-central vein occlusion

PURPOSE

To assess the effectiveness and complications of laser-induced chorioretinal venous anastomosis performed on eyes with non-ischaemic hemi-central retinal vein occlusions (hemi-CRVO).

METHODS

Fourteen eyes with a hemi-CRVO which reduced the visual acuity to 6/24 or less were treated with argon laser photocoagulation in an attempt to create a chorioretinal venous anastomosis between a retinal vein and the choroidal circulation.

RESULTS

Laser anastomoses were successfully created in six eyes (43%) and required a mean of 1.8 attempts in each eye. Of the eyes that developed an anastomosis, four had significant visual improvement. The distal retinal venous segment closed off in five eyes and these had prophylactic segmental argon pan-retinal photocoagulation performed. Two eyes had localized fibrovascular proliferation. No permanent vision-threatening complications were observed in any of the 14 eyes over the follow-up period.

CONCLUSIONS

Successful anastomosis between the retinal and choroidal circulation in eyes with hemi-vein occlusions may reduce macular oedema and improve vision. Complications of the technique are significant and a randomized clinical trial is due to commence which may clarify the suitability of this treatment.

Retinal vein occlusion in Armenia

PURPOSE

To determine the demographic characteristics, associated ophthalmic and systemic conditions of retinal vein occlusion (RVO) and associations of central retinal vein occlusion among Armenian patients.

METHODS

A retrospective study of 460 patients aged 30 years and older with a clinical diagnosis of RVO who were seen in the five-year period between January 1, 1993, and December 31, 1997 at the Eye Hospital.

RESULTS

Signs of central RVO were found in 297 eyes (64.5%), branch RVO in 163 eyes (35.5%). Among the 460 patients occlusion was hemispheric in 4 eyes (2.4%), hemicentral in 5 eyes (3%). CRVO was more common among the younger patients (odds ratio [OR] = 2.42, 95% confidence interval [CI]: 1.06-5.65). Hypercoagulability was noted in the majority of RVO cases. Glaucoma was an associated condition (12.6%). Systemic hypertension was the most frequent association. In CRVO a significant association was found with hypertension (OR = 1.89, 95% CI: 1.23-2.70).

CONCLUSIONS

Our results suggest RVO is associated with glaucoma and hypertension. RVO was more closely associated with hypertension than BRVO. There were no differences in the distribution for the site of occlusion with regard to sex in patients with CRVO and BRVO. No seasonal pattern was found in the onset of any type of RVO. Hypercoagulability may be a contributing factor in the pathogenesis. The findings reinforce recommendations to carefully evaluate patients with RVO for open-angle glaucoma, and to diagnose and treat systemic hypertension.

Central retinal vein occlusion: review of management

Central retinal vein occlusion is usually a disease of the elderly and is often associated with systemic vascular disease, e.g., hypertension, diabetes mellitus, arteriosclerotic vascular disease. Younger patients, especially those less than 45 years of age, with retinal vein occlusion should be evaluated carefully for the possibility of an underlying thrombotic tendency. The authors describe the ocular manifestations, pathogenesis, associated conditions, patient evaluation, and treatment of patients with central retinal vein occlusion.

Thrombin-antithrombin III complex in acute retinal vein occlusion

PURPOSE

To determine whether quantitative differences in systemic hypercoagulable state could be identified among patients with retinal vein occlusion at various sites of occlusion.

METHODS

The value of thrombin-antithrombin III complex was determined in 57 patients with retinal vein occlusion within 1 month after the subjective onset of retinal vein occlusion and in 15 age-matched normal controls.

RESULTS

Levels of log thrombin-antithrombin III complex were significantly higher in the patients with proximal retinal vein occlusion in which the occlusion site is at the optic disc (mean +/- SD, 0.493 +/- 0.389) than in those with distal retinal vein occlusion in which the occlusion site is away from the optic disc (0.312 +/- 0.150, P = .025) and in the normal controls (0.294 +/- 0.151, P = .020). There was no significant difference between the distal retinal vein occlusion and the normal controls (P = .720). More patients with proximal retinal vein occlusion showed elevated thrombin-antithrombin III complex values more than 3.9 ng/ml than those with distal retinal vein occlusion (8/29 vs 1/28, P = .025). Of nine patients showing an initial value of thrombin-antithrombin III complex of more than 3.9 ng/ml, repeated measurements were obtained in eight patients, who showed reduced value of thrombin-antithrombin III complex in the normal range in several months.

CONCLUSIONS

A systemic hypercoagulable state, which could be demonstrated with the elevation of thrombin-antithrombin III complex value, may contribute more to the development of retinal vein occlusion with thrombus at or near the trunk of the central retinal vein than those with thrombus at branch veins away from the optic disc in the retina.