Diagnostic assessment of glaucoma and non-glaucomatous optic neuropathies via optical texture analysis of the retinal nerve fibre layer.

The clinical diagnostic evaluation of optic neuropathies relies on the analysis of the thickness of the retinal nerve fibre layer (RNFL) by optical coherence tomography (OCT). However, false positives and false negatives in the detection of RNFL abnormalities are common. Here we show that an algorithm integrating measurements of RNFL thickness and reflectance from standard wide-field OCT scans can be used to uncover the trajectories and optical texture of individual axonal fibre bundles in the retina and to discern distinctive patterns of loss of axonal fibre bundles in glaucoma, compressive optic neuropathy, optic neuritis and non-arteritic anterior ischaemic optic neuropathy. Such optical texture analysis can detect focal RNFL defects in early optic neuropathy, as well as residual axonal fibre bundles in end-stage optic neuropathy that were indiscernible by conventional OCT analysis and by red-free RNFL photography. In a diagnostic-performance study, optical texture analysis of the RNFL outperformed conventional OCT in the detection of glaucoma, as defined by visual-field testing or red-free photography. Our findings show that optical texture analysis of the RNFL for the detection of optic neuropathies is highly sensitive and specific.

Nicotinamide riboside as a neuroprotective therapy for glaucoma: study protocol for a randomized, double-blind, placebo-control trial.

BACKGROUND: Whereas lowering the intraocular pressure (IOP) can slow optic nerve degeneration in glaucoma, many patients with glaucoma continue to develop progressive loss in vision despite a significant reduction in IOP. No treatment has been shown to be effective for neuroprotection in glaucoma. We set out to conduct a randomized controlled trial to investigate whether nicotinamide riboside (NR), a nicotinamide adenine dinucleotide precursor, is effective to slow optic nerve degeneration in patients with primary open-angle glaucoma (POAG). We hypothesize that patients treated with NR have a slower rate of progressive retinal nerve fiber layer (RNFL) thinning compared with those treated with placebo. METHODS: This is a randomized, double-blind, placebo-controlled, parallel-group, multi-center study including 125 patients with POAG. Patients will be randomized to receive 300 mg NR or placebo for 24 months. Clinical examination, optical coherence tomography imaging of the RNFL, and visual field (VF) test will be performed at the baseline, 1 month, 4 months, and then at 2-month intervals until 24 months. The primary outcome measure is the rate of RNFL thinning measured over 24 months. The secondary outcome measures include (1) time to VF progression, (2) time to progressive RNFL/ganglion cell inner plexiform layer (GCIPL) thinning, and (3) the rate of change of VF sensitivity over 24 months (to investigate neuroprotection) and 1 month (to investigate neuroenhancement). The rates of RNFL thinning and VF sensitivity decline between treatment groups will be compared with linear mixed modeling. Survival analysis will be performed to compare the differences in time from baseline to VF progression and time from baseline to progressive RNFL/GCIPL thinning between treatment groups using Cox proportional hazards models. DISCUSSION: Outcome measures in glaucoma neuroprotection trials have been centered on the detection of VF progression, which may take years to develop and confirm. In addition to addressing whether NR has a neuroprotective/neuroenhancement effect in glaucoma patients, this study will demonstrate the feasibility of studying neuroprotection in a relatively short trial period (24 months) by comparing the rates of progressive RNFL thinning, a more reproducible and objective outcome measure compared with VF endpoints, between treatment groups. TRIAL REGISTRATION: Chinese Clinical Trial Registry 1900021998.

Topical cyclosporine in the treatment of allergic conjunctivitis: a meta-analysis.

PURPOSE: To assess the efficacy and safety of topical cyclosporine versus placebo in the treatment of allergic conjunctivitis. DESIGN: Systematic review and meta-analysis. PARTICIPANTS: Seven qualified studies incorporating 306 eyes of 153 patients were analyzed. METHODS: Searches of randomized controlled trials were conducted in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. MAIN OUTCOME MEASURES: We assessed the methodologic quality of individual included trials and performed meta-analyses using the random effects model if P<0.1 in the test for heterogeneity, or otherwise used the fixed effects model. We assessed scores of composite signs and symptoms, reduction in steroid eye drop use in steroid-dependent patients, and safety outcomes (i.e., stinging or burning sensation). RESULTS: At 2 weeks of follow-up or longer, evidence suggests a statistically significant improvement in the composite signs (standardized mean difference [SMD], -1.21; 95% confidence interval [CI], -1.80 to -0.62; I(2) = 71%) and symptoms (SMD, -0.84; 95% CI, -1.51 to -0.16; I(2) = 80%) after topical cyclosporine treatment for allergic conjunctivitis regardless of the dosage of treatment. There was a significant reduction (mean difference, -61.16; 95% CI, -101.61 to -20.72; I(2) = 58%) in the use of steroid eye drops in patients with steroid-dependent allergic conjunctivitis. Stinging or burning sensation (odds ratio, 2.56; 95% CI, 0.19-35.06; I(2) = 73%) was common in both the cyclosporine and placebo groups. CONCLUSIONS: This systematic review and meta-analysis suggests topical cyclosporine could be an effective and safe treatment method for allergic conjunctivitis. Further randomized controlled trials with larger sample sizes and standardized outcome measurements, follow-up periods, and cyclosporine concentrations are warranted to determine the short- and long-term efficacy and safety and the minimal effective dosage of topical cyclosporine for allergic conjunctivitis.

Screening and Referral of Diabetic Retinopathy: A Comparative Review of the Practice Guidelines.

Diabetic retinopathy (DR) is a leading cause of preventable visual impairment in the working age group. The major risk factors for development and progression are duration of disease and the severity of hyperglycemia. The Global Diabetic Retinopathy Project developed a new classification system for DR and macular edema to enhance communication and coordination among the multidisciplinary team of physicians taking care of diabetic patients. Diabetic retinopathy progresses from nonproliferative DR to proliferative DR through a series of stages. Early detection and timely referral are critical for timely interventions to prevent further deterioration. Primary care physicians have an integral role in the community as they are the first point of contact for patients. Guidelines from various associations provide recommendations to physicians taking care of diabetic patients on how to screen and situations where referral to an ophthalmologist is needed. Dilated direct ophthalmoscopy is a convenient method to assess the fundus, but it does not replace retinal photography in the screening of DR. All patients with proliferative DR and diabetic macular edema should be referred to an ophthalmologist, whereas the situation for nonproliferative DR remains unclear as no consensus was drawn from the various guidelines.