ResearchPad - Optometry https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Novel Technique for Quantifying Retinal Nerve Fiber Bundle Abnormality in the Temporal Raphe]]> https://www.researchpad.co/product?articleinfo=5bfde5e2d5eed0c4846e2185

SIGNIFICANCE

Glaucomatous nasal visual field abnormalities correspond to damage in the temporal raphe—where individual nerve bundles can be visualized. The ability to quantify structural abnormality in the raphe, with a clinically applicable protocol, sets the stage for investigating the raphe as a potential site for assessing early glaucoma.

PURPOSE

To develop a clinically applicable imaging and analysis technique for identifying retinal nerve fiber bundle abnormalities in the temporal raphe.

METHODS

Spectralis optical coherence tomography scans customized for the temporal raphe were gathered from 30 younger controls, 30 older controls, and 29 patients with glaucoma. An analysis technique was developed based on the reflectance of the nerve fiber bundles. The technique was first developed in the younger controls, and then applied to the older controls to generate normative data for quantifying nerve fiber bundle reflectance abnormalities in the patients with glaucoma. Matrix perimetric data were gathered in the patients with glaucoma to evaluate the reflectance technique’s findings. Reflectance abnormality in the patients was defined when the fraction of enface area showing reflectance abnormality was greater than the 95th percentile estimated from controls. Spearman’s rho was used to quantify the relation between the total deviation at the perimetric testing locations and the fraction of corresponding enface area showing reflectance abnormality.

RESULTS

Twenty-five of the 29 patients had reflectance abnormalities. Eight of these had mild to no perimetric mean deviation abnormality. Similar results were found when perimetric total deviations were compared to reflectance abnormalities in the corresponding enface locations. Spearman’s rho comparing the total deviations to reflectance abnormalities found rs(174) = −0.72, P < .001.

CONCLUSIONS

The technique typically identified reflectance abnormality when perimetric abnormality was present. It also identified reflectance abnormalities even when perimetric abnormality was mild or absent. The findings support the potential of raphe imaging in detecting early glaucomatous damage.

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<![CDATA[Brimonidine Ophthalmic Solution 0.025% for Reduction of Ocular Redness: A Randomized Clinical Trial]]> https://www.researchpad.co/product?articleinfo=5bfaa65bd5eed0c48473a785

SIGNIFICANCE

The α2-adrenergic receptor agonist brimonidine has been reported to induce conjunctival blanching in cataract, strabismus, laser refractive, and filtration procedures. Clinicians are often faced with red eyes with no apparent underlying pathology. Low-dose brimonidine reduced ocular redness in such subjects with efficacy maintained over 1 month and negligible rebound redness.

PURPOSE

The aim of this study was to evaluate the safety and efficacy of brimonidine tartrate ophthalmic solution 0.025% for the treatment of ocular redness.

METHODS

In this single-center, double-masked, phase 3 clinical trial, adult subjects with baseline redness of more than 1 unit in both eyes (0- to 4-unit scale) were randomized 2:1 to brimonidine 0.025% or vehicle. A single dose was administered in-office (day 1); thereafter subjects instilled treatment four times a day for 4 weeks, with clinic visits on days 15, 29, and 36 (7 days post-treatment). Efficacy end points included investigator-evaluated redness 5 to 240 minutes post-instillation on day 1 (primary); investigator-evaluated change from baseline 1, 360, and 480 minutes post-instillation on day 1, and 1 and 5 minutes post-instillation on days 15 and 29; total clearance of redness, and subject-assessed redness. Safety/tolerability measures included adverse events, rebound redness, and drop comfort.

RESULTS

Sixty subjects were randomized (n = 40 brimonidine, n = 20 vehicle). Investigator-assessed redness was lower with brimonidine versus vehicle over the 5- to 240-minute post-instillation period (mean [SE], 0.62 [0.076] vs. 1.49 [0.108]; P < .0001) and at each time point within that period (P < .0001). At 1, 360, and 480 minutes post-instillation, respectively, the mean differences (95% confidence interval) between treatments were −0.73 (−1.05 to −0.41), −0.57 (−0.84 to −0.29), and −0.39 (−0.67 to −0.10), respectively. No tachyphylaxis was evident with brimonidine on days 15 and 29, and minimal rebound redness was observed following discontinuation. Adverse events were infrequent, and brimonidine was rated as very comfortable.

CONCLUSIONS

Brimonidine 0.025% appeared safe and effective for reduction of ocular redness, with an 8-hour duration of action, no evidence of tachyphylaxis, and negligible rebound redness.

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