Topical medical therapy and ocular perfusion pressure in open angle glaucoma: a systematic review and meta-analysis.

Objective: We compared the benefits and harms of topical interventions for ocular perfusion pressure in open angle glaucoma. Methods: We searched the databases MEDLINE, EMBASE and CENTRAL for randomized controlled trials comparing topical hypotensive agents in glaucoma. Of the 9433 citations identified, 10 randomized controlled trials were included. We summarized data using random effects meta-analysis for post-treatment mean ocular perfusion pressure and using relative risk for adverse events. Results: Ten trials (416 patients) were included. The quality of included trials was low to moderate. There was a higher post-treatment ocular perfusion pressure with bimatoprost compared to timolol (1 trial, 32 patients, mean difference - 4.00 mmHg, 95% confidence interval -7.01 to -0.99, p = .009); heterogeneity was not significant (I2 = 41%, χ2 = 13.55, p = .09). Prostaglandins as a class had higher post-treatment mean ocular perfusion pressure compared to alternative interventions (5 trials, 147 patients, mean difference 2.19 mmHg, 95% confidence interval 0.67-3.70, p = .005); heterogeneity in the subgroup analysis was not significant (I2 = 10%, χ2 = 4.47, p = .35). Adverse events were found to be significant in only one of the studies comparing latanoprost to brimonidine, relative risk 3.67 (standard error 0.59, p = .03). Conclusions: We identified low to moderate quality evidence describing post-intervention mean ocular perfusion pressure in open angle glaucoma. Bimatoprost increases mean ocular perfusion pressure when compared to timolol. As a class, prostaglandins increase mean ocular perfusion pressure. Prostaglandins may provide beneficial ocular perfusion pressure profiles compared to alternative agents.

The impact of optic nerve and related characteristics on disc area measurements derived from different imaging techniques.

PURPOSE: Optic nerve head (ONH) assessment and its interpretation in healthy patients and those with glaucoma remains a pivotal topic specifically considering rapid advancements in imaging technologies. We undertook a large-scale, mixed cohort, comparative study to assess the correlation of optic disc measurements between different imaging modalities and investigated the impact of patient and disc associated parameters. METHODS: ONH sizes were obtained from one randomly selected eye of each of 209 patients using stereophotography, confocal scanning laser ophthalmoscopy and two different optical coherence tomographers (OCT). Patient related data, glaucoma status and optic disc variables, specifically oblique insertion, torsion, presence of beta PPA and spherical equivalent were recorded. Measurements between imaging modalities were analysed using Pearson correlation, linear regression analysis and Blend-Altman plots. Individual variables were compared applying multivariate regression analysis, ANOVA and chi square statistics was used to determine correlations between patient and clinical characteristics. RESULTS: Absolute measurements significantly differed between imaging modalities generally producing smaller measurements for OCT derived measurements of Bruch's membrane opening (BMO). Pairwise correlations between imaging modalities were between 0.83 and 0.93 for discs without myopia, oblique insertion, or beta PPA. These features impacted on measurements for individual modalities and consequently contributed to inconsistencies and variability. CONCLUSION: In comparison to planimetry, OCT derived BMO measurements are more variable in the presence of oblique insertion, beta PPA or magnification errors due to myopia. Impact of these factors, however, differs between instruments and needs to be considered to accurately interpret optic disc features in particular within the context of glaucoma diagnosis.

Nicotinamide and neurocognitive function.

Nicotinamide, or vitamin B3, is a precursor of nicotinamide adenine dinucleotide (NAD(+)) and is involved in a multitude of intra- and inter-cellular processes, which regulate some of the cell's metabolic, stress, and immune responses to physiological or pathological signals. As a precursor of NAD(+), which is a key coenzyme in the production of adenosine triphosphate or cellular energy, nicotinamide has been investigated for potential neuroprotective effects in cellular, animal, and human studies. Objectives We aimed to summarize the current evidence on the effect of dietary and supplemental nicotinamide on cognitive function. Methods A literature review was conducted on the effects of nicotinamide and its derivatives as a preventive and therapeutic agent for disorders of neurocognitive function. Specific conditions examined include age-related cognitive decline, Alzheimer's disease, Parkinson's disease, and ischaemic and traumatic brain injury. Results Data from animal and human interventional studies and epidemiological research suggests that nicotinamide may be beneficial in preserving and enhancing neurocognitive function. Discussion Nicotinamide is non-toxic, inexpensive and widely available, and interventional studies in humans, using supplemental doses of nicotinamide, are now warranted.

Postnatal development of periodic breathing cycle duration in term and preterm infants.

Previous studies of the maturation of periodic breathing cycle duration (PCD) with postnatal age in infants have yielded conflicting results. PCD is reported to fall in term infants over the first 6 mo postnatally, whereas in preterm infants PCD is reported either not to change or to fall. Contrary to measured values, use of a theoretical respiratory control model predicts PCD should increase with postnatal age. We re-examined this issue in a longitudinal study of 17 term and 22 preterm infants. PCD decreased exponentially from birth in both groups, reaching a plateau between 4 and 6 mo of age. In preterm infants, PCD fell from a mean of 18.3 s to 9.8 s [95% confidence interval (CI) is +/- 3.2 s]. In term infants, PCD fell from 15.4 s to 10.1 s (95% CI is +/- 3.1 s). The higher PCD at birth in preterm infants, and the similar PCD value at 6 mo in the two groups, suggest a more rapid maturation of PCD in preterm infants. This study confirms that PCD declines after birth. The disagreement between our data and theoretical predictions of PCD may point to important differences between the respiratory controller of the infant and adult.