Rachel L. McIntosh

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.

Systemic associations of retinal microvascular signs: a review of recent population‐based studies

Retinal microvascular signs, such as generalized retinal arteriolar narrowing, focal arteriolar narrowing, arteriovenous nicking and retinal haemorrhages, microaneurysms and cotton wool spots, are common fundus findings in the general population, even in individuals without hypertension or diabetes. Recent population‐based studies have provided new insights into the systemic associations and clinical significance of these retinal signs. Studies show that these retinal microvascular signs are strongly associated with elevated blood pressure (BP). Generalized retinal arteriolar narrowing may be associated with markers of inflammation and risk of diabetes and hypertension. Retinal haemorrhages, microaneurysms and cotton wool spots are associated with risk of subclinical and clinical stroke, cognitive impairment, renal dysfunction and cardiovascular mortality, independent of BP and cardiovascular risk factors. A consistent pattern of association between retinal microvascular signs and ischaemic heart disease has not been demonstrated. This suggests that patients with some retinopathy signs (retinal haemorrhages, microaneurysms and cotton wool spots) may benefit from a careful systemic evaluation and, if supported by further research, appropriate risk reduction therapy.

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. Cohens 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.

Comparing the effectiveness of selective laser trabeculoplasty with topical medication as initial treatment (the Glaucoma Initial Treatment Study): study protocol for a randomised controlled trial

BackgroundGlaucoma is the leading cause of irreversible blindness in the world. Estimated to affect 60 million people worldwide, this figure is expected to rise to 80 million by 2020. Untreated, glaucoma leads to visual decay and eventually to blindness, and can significantly reduce quality of life. First-line treatment in patients with primary open-angle glaucoma and exfoliative glaucoma is topical medical therapy with ocular hypotensives as eye drops. However, eye drops have several disadvantages including cost, possible local and systemic side effects, and adherence and perseverance issues. Randomised controlled trials have demonstrated that selective laser trabeculoplasty is equally as effective in lowering intraocular pressure as eye drops. However, the impact of these two treatment modalities from the patient and economic perspectives has not been adequately determined. Thus, it remains unclear whether topical medical therapy or selective laser trabeculoplasty should be recommended as first-line treatment for glaucoma.Methods/DesignThis protocol describes an international, multi-centre, randomised controlled trial to determine the optimum first-line therapy for people with primary open-angle glaucoma and exfoliative glaucoma. This study will compare the effect of selective laser trabeculoplasty and topical medication with respect to patients’ generic and glaucoma-specific quality of life. The trial will also provide a detailed cost-effectiveness analysis and compare the clinical effectiveness with respect to the degree of intraocular pressure lowering and rates of treatment failure. Research coordinators in each centre will identify and recruit previously untreated patients with primary open-angle glaucoma and exfoliative glaucoma. Those who meet the eligibility criteria will be invited to enter a randomised controlled trial with either selective laser trabeculoplasty or topical ocular hypotensive therapy, according to a stepped regimen. Outcome assessment will be measured at 6 weeks and at 6, 12, and 24 months post-treatment. Regular clinic follow-ups will continue as clinically indicated between study outcome visits.DiscussionThe Glaucoma Initial Treatment Study is the first multi-centred RCT to determine the optimum first-line therapy for people with glaucoma. Our trial will have an unprecedented capacity to meaningfully transform the treatment and management of glaucoma in Australia and overseas.Trial registrationACTRN12611000720910; Date registered: 11 July 2011

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.