Hypertensive retinopathy: comparing the Keith-Wagener-Barker to a simplified classification.

PURPOSE: This study assessed the interobserver and intraobserver grading reliability of the Keith-Wagener-Barker (KWB) system to the proposed Mitchell-Wong 'simplified' three-grade classification for hypertensive retinopathy. METHODS: Digital retinal images of normal and hypertensive human fundii (n = 50 per group) were randomly graded by an optometrist and an ophthalmologist using the two systems. Interobserver agreement was compared to a 'gold standard' research grader. Intraobserver agreement was assessed through a repeat grading after 6 months. Cohen's kappa coefficients were used to assess the degree of agreement. RESULTS: Both clinicians demonstrated a good level of agreement with the KWB and simplified classification compared with a 'gold standard' grader; there was no significant difference in the level of agreement for either of the two classification methods for either observer. The simplified classification was found to be equally as efficacious as the KWB system with respect to interobserver and intraobserver agreement for both practitioners. CONCLUSION: These findings indicate that the simplified classification of hypertensive retinopathy is both reliable and repeatable. The advantage of the simplified method over the KWB system in correlating retinal microvascular signs to incident cardiovascular risk supports its adoption in clinical practice.

Association of retinal vessel calibre with diabetic retinopathy in an urban Australian indigenous population.

PURPOSE: To assess the relationship of retinal vessel diameter and diabetic retinopathy (DR) in a subgroup of participants recruited through the Darwin Region Urban Indigenous Diabetes study. METHODS: Participants were examined as part of the Darwin Region Urban Indigenous Diabetes study. All participants with gradable fundus photographs were included in the current analysis. Assessment of retinal vascular diameter, including arteriolar diameter (central retinal arteriolar equivalent) and venular diameter (central retinal venular equivalent), was undertaken using a semi-automated retinal vascular imaging program. DR was graded according to the modified Early Treatment DR Study scale. RESULTS: A total of 110 participants, 25 men and 85 women, with a mean age of 50.8 years were included in the analysis. The odds ratio for having DR for each standard deviation increase in central retinal venular equivalent was as high as 1.62 (95% confidence intervals 0.94, 2.80); however, this did not reach statistical significance (P = 0.08). Moreover, individuals with severe non-proliferative DR and proliferative DR were found to have narrower arteriolar diameters compared with those with no DR, but this was not statistically significant (-8.1 microm, 95% confidence intervals, -39.3 microm, 23.1 microm; P = 0.612). CONCLUSION: Our data indicate a trend for narrower arteriole diameter and wider venular diameter with DR in this high-risk ethnic group, which concurs with overall trends seen in non-indigenous populations.

Natural history of central retinal vein occlusion: an evidence-based systematic review.

OBJECTIVE: To describe the natural history of central retinal vein occlusion (CRVO) based on the best available evidence from the literature. CLINICAL RELEVANCE: Central retinal vein occlusion is a common sight-threatening retinal vascular disease. Despite the introduction of new interventions, the natural history of CRVO is unclear. METHODS: Systemic review of all English language articles retrieved using a keyword search of MEDLINE, EMBASE, Current Contents, and the Cochrane Library to November 13, 2008. This was supplemented by hand-searching references of review articles published within the last 5 years. Two investigators independently identified all relevant observational studies evaluating the natural history of RVO and all clinical trials evaluating interventions for CRVO; an untreated control arm was included. RESULTS: Of 5966 citations retrieved, 53 studies were reviewed, providing 3271 eyes with CRVO for analysis of its natural history. Visual acuity (VA) was generally poor at baseline (<20/40) and decreased further over time. Although 6 studies reported an improvement in VA, none of these improvements resulted in VA better than 20/40. Up to 34% of eyes with nonischemic CRVO converted to ischemic CRVO over a 3-year period. In ischemic CRVO cases, neovascular glaucoma developed in at least 23% of eyes within 15 months. In nonischemic CRVO cases, macular edema resolved in approximately 30% of eyes over time, and subsequent neovascular glaucoma was rare. CONCLUSIONS: Untreated eyes with CRVO generally had poor VA, which declined further over time. One quarter of eyes with nonischemic CRVO converted to ischemic CRVO.

Natural history of branch retinal vein occlusion: an evidence-based systematic review.

OBJECTIVE: To describe the natural history of branch retinal vein occlusion (BRVO) based on the best available evidence from the literature. CLINICAL RELEVANCE: Branch retinal vein occlusion is the second most frequent major retinal vascular disease. Although several new treatments for BRVO are currently being introduced, data on its natural history are sparse. METHODS: English language articles were retrieved using a keyword search of MEDLINE, EMBASE, Current Contents, and the Cochrane Library to November 13, 2008, supplemented by manually searching the references of review articles published within the last 5 years. All relevant observational studies evaluating the natural history of BRVO and all clinical trials evaluating BRVO interventions with an untreated control arm were independently identified by 2 investigators. RESULTS: Of a total of 5965 citations retrieved, 24 eligible studies were identified and reviewed, providing 1608 eyes with BRVO with data on natural history. Visual acuity (VA) was moderately poor at baseline (<20/40). Although VA generally improved, with mean improvement ranging from 1 letter at 6 weeks to 28 letters up to 24 months, few studies reported improvement beyond 20/40. Over a 1-year period, 5% to 15% of eyes developed macular edema (ME), but of those with ME at baseline, 18% to 41% resolved. At baseline, 5% to 6% of eyes had bilateral BRVO, with 10% developing fellow eye involvement over time. There were few high-quality studies on other outcomes, including development of new vessels. CONCLUSIONS: Visual acuity generally improved in eyes with BRVO without intervention, although clinically significant improvement beyond 20/40 was uncommon.

The prevalence of retinal vein occlusion: pooled data from population studies from the United States, Europe, Asia, and Australia.

OBJECTIVE: To summarize the prevalence of retinal vein occlusion (RVO) from studies in the United States, Europe, Asia, and Australia. DESIGN: Pooled analysis using individual population-based data. PARTICIPANTS: Individual participant data from population-based studies around the world that had ascertained RVO from fundus photographs. METHODS: Each study provided data on branch RVO and central RVO by age, sex, and ethnicity. Prevalence rates were directly age and sex standardized to the 2008 world population aged 30 years and older. Estimates were calculated by study and, after pooling, by ethnicity. Summary estimates included studies in which RVO was assessed from fundus photographs on >or=2 fields of both eyes. MAIN OUTCOME MEASURES: Any RVO, CRVO, or BRVO. RESULTS: The combined pooled data contained 68,751 individuals from 15 studies, with participants' ages ranging from 30 to 101 years. In analyses of 11 studies that assessed >or=2 fundus fields of both eyes (n=49,869), the age- and sex-standardized prevalence was 5.20 per 1000 (confidence interval [CI], 4.40-5.99) for any RVO, 4.42 per 1000 (CI, 3.65-5.19) for BRVO, and 0.80 per 1000 (CI, 0.61-0.99) for CRVO. Prevalence varied by race/ethnicity and increased with age, but did not differ by gender. The age- and sex-standardized prevalence of any RVO was 3.7 per 1000 (CI, 2.8-4.6) in whites (5 studies), 3.9 per 1000 (CI, 1.8-6.0) in blacks (1 study), 5.7 per 1000 (CI, 4.5-6.8) in Asians (6 studies), and 6.9 per 1000 (CI, 5.7-8.3) in Hispanics (3 studies). Prevalence for CRVO was lower than BRVO in all ethnic populations. On the basis of these data, an estimated 16.4 million (CI, 13.9-18.9) adults are affected by RVO, with 2.5 million (CI, 1.9-3.1) affected by CRVO and 13.9 million (CI, 11.5-16.4) affected by BRVO. Study limitations include non-uniform sampling frames in identifying study participants and in acquisition and grading of RVO data. CONCLUSIONS: Our study provides summary data on the prevalence of RVO and suggests that approximately 16 million people may have this condition. Research on preventive and treatment strategies for this sight-threatening eye disease is needed.

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.

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

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.