Associate Professor Mark Roth
BSc(Pharmacology) BAppSc(Optom) PGCertOcTher NEWENCO FAAO OAM
Just a week of oral NSAIDs use linked to increased heart attack risk
Use of oral non-steroidal anti-inflammatory drugs (NSAIDs) for even one week is associated with increased risk for myocardial infarction, a study in The BMJ finds.
Researchers conducted a data meta-analysis drawn from Canadian and European data bases. A cohort of 446,763 individuals including 61,460 with acute myocardial infarction was acquired.
Compared with NSAIDs non-use, current use of each NSAID studied (including diclofenac, ibuprofen, naproxen, and celecoxib) was associated with increased myocardial infarction risk. Greater risk of myocardial infarction was documented for higher doses of NSAIDs. With use for longer than one month, risks did not appear to exceed those associated with shorter durations.
The authors concluded that all oral NSAIDs were found to be associated with an increased risk of acute myocardial infarction. Risk was greatest during the first month of NSAIDs use and with higher doses.
BMJ 2017; May. doi: 10.1136/bmj.j1909.
OCT to monitor multiple sclerosis
A potential utility for OCT could be to help investigate the neuroprotective benefits of disease-modifying therapies in multiple sclerosis (MS).
There is increasing evidence suggesting that retinal changes and in particular, neurodegeneration, mirror global central nervous system alterations in MS. Several studies have demonstrated that changes within the inner retina (primarily as a reflection of optic neuropathy) as assessed by OCT correlate with reduced quality of life, visual dysfunction and global disability in MS.
Longitudinal studies suggest that inner retinal thinning is an early phenomenon in MS and that retinal thinning may occur independently of previous symptomatic episodes of optic neuritis, significantly correlating with inflammatory disease.
Spectral-domain optical coherence tomography (SD-OCT) offers an inexpensive, rapid, non-invasive and reproducible way to attain high-resolution images of tissues such as the retina. The main advantage of SD-OCT over magnetic resonance imaging techniques in the assessment of neurodegeneration may be its ability to capture changes at the individual patient level.
Curr Treat Options Neurol 2017; 19: 4: 15.
How does topiramate impair thinking?
A new study that associates the antiepileptic drugs topiramate and to a lesser extent, zonisamide with impaired cognition demonstrates the physiologic changes underlying patients’ complaints that they ‘can’t think’ when on the drugs.
Researchers conducted a retrospective analysis of cross-sectional data on 145 patients who were treated with topiramate (TPM), zonisamide (ZNS) and levetiracetam (LEV).
Patients were treated with LEV (median dose 2000 mg), ZNS (median dose 224 mg), or TPM (median dose 312.5 mg). In a presurgical evaluation, patients had functional magnetic resonance imaging while performing a verbal-fluency task. Other cognitive domains were tested separately.
TPM was associated with worse performance on verbal-fluency task than ZNS and LEV. ZNS and TPM were associated with worse performance on digit span than LEV. On the verbal-fluency task, there was a decrease in activation in areas of the frontal and parietal lobe with ZNS and TPM; only TPM was associated with an impaired deactivation of the default mode network.
The researchers conclude that the study provides Class III evidence that in patients with focal epilepsy, TPM and ZNS, compared to LEV, lead to disruption of language and working memory networks.
Neurology 2017; Feb 17 (Epub ahead of print).
Multifocal vs monofocal intraocular lenses post cataract surgery
Multifocal IOLs are effective at improving near vision relative to monofocal IOLs, but there is uncertainty about the size of the effect.
To assess the visual effects of multifocal IOLs in comparison with the current standard treatment of monofocal lens implantation, researchers searched nine electronic databases (CENTRAL, Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid Embase, the ISRCTN registry, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform) for all randomised controlled trials comparing a multifocal IOL of any type with a monofocal IOL as control.
The study authors found 20 eligible trials that enrolled 2,230 people with data available on 2,061 people (3,194 eyes). Most of these trials compared multifocal with monofocal lenses; two trials compared multifocal lenses with monovision.
It was found that there was moderate-certainty evidence that the distance acuity achieved with multifocal lenses was not different from that achieved with monofocal lenses. However, people receiving multifocal lenses may achieve better near vision.
The authors concluded that improvement outweighs the adverse effects of multifocal IOLs, such as glare and haloes, and will vary between people. Motivation to achieve spectacle independence is likely to be the deciding factor.
Cochrane Database of Systematic Reviews 2016; Dec 12. doi: 10.1002/14651858.CD003169.pub4.
Phacoemulsification lowers IOP in patients with POAG
Phacoemulsification as a solo procedure lowers IOP in patients with primary open angle glaucoma (POAG), and reduces dependency on topical glaucoma medications. The effects appear to last at least 36 months with gradual loss of the initial effect noted after two years.
Investigators conducted a systematic review and meta-analysis to synthesise evidence quantifying the effect of phacoemulsification on IOP and the required number of topical glaucoma medications in patients with cataract and POAG.
The search strategy identified 1,613 records. Thirty-two studies (1,826 subjects) were included in quantitative synthesis. A 12 per cent, 14 per cent, 15 per cent and nine per cent reduction in IOP from baseline occurred six, 12, 24 and 36 months, respectively, after phacoemulsification. A mean reduction of 0.57, 0.47, 0.38 and 0.16 medications per patient of glaucoma medication occurred six, 12, 24 and 36 months, respectively, after phacoemulsification.
‘Certain populations appear to experience much greater reductions in IOP than others, and future work to identify these high-responding patients is needed,’ the researchers wrote.
J Glaucoma 2017; Mar 22 (Epub ahead of print).
IOP in POAG patients highest in the morning
In a comparison of the diurnal IOP profiles of primary angle closure glaucoma (PACG) and POAG eyes, researchers found that IOP in primary glaucoma patients peaks in the morning and decreases over the course of the day in a non-clinical environment.
Fifty-three medically-treated eyes of 31 PACG and 22 POAG patients with no previous eye surgery were recruited. Diurnal IOP was measured five times per day at four-hourly intervals from 8:00 am to midnight for one week using rebound tonometry in a non-clinical environment. The diurnal IOP profiles were compared between PACG and POAG eyes.
The authors concluded that mean patient-measured IOP in the home environment was highest at 8:00 am, tended to drop over the course of a day, and was lowest by midnight in both PACG and POAG eyes in this study. The PACG eyes had lower diurnal IOP fluctuation than POAG eyes, and higher midnight IOP.
‘This study demonstrates the feasibility of diurnal IOP documentation by patients themselves using rebound tonometry in their ambient environments,’ the researchers wrote. ‘Such measurements may potentially be of clinical relevance in patient management.’
PLoS One 2017; 12: 3: e0173905.
Complications more common for young adults with type 2 diabetes
According to research published in the JAMA, almost three quarters of teenagers and young adults with type 2 diabetes have a complication, compared with about one in three with type 1 diabetes.
In a prospective observational study at five US sites, researchers examined the prevalence of complications at least five years after diagnosis in 1,746 patients with type 1 diabetes and 272 with type 2 diabetes diagnosed before the age of 20 years.
Overall, 72 per cent of patients with type 2 diabetes, compared with 32 per cent of those with type 1 diabetes, had at least one diabetes-related complication. After adjustment for other risk factors, patients with type 2 diabetes had significantly higher odds of diabetic kidney disease, retinopathy and peripheral neuropathy.
The researchers said that complications and comorbidities were frequent in both groups, although type 2 diabetes is particularly dangerous. They called for greater monitoring of young people with diabetes as well as careful surveillance for early signs of diabetic complications in order to initiate early interventions.
JAMA 2017; 317: 8: 825-835. doi:10.1001/jama.2017.0686.
Modest links between systemic medication use, IOP in glaucoma
Use of systemic medications may modestly affect intraocular pressure (IOP), according to a post-hoc analysis of data from a large, multi-ethnic Asian cohort, JAMA Ophthalmology reports.
The post-hoc analysis was conducted of the Singapore Epidemiology of Eye Diseases study, a population-based study of 10,033 participants from three racial/ethnic groups (Chinese, Malays and Indians). Intraocular pressure was measured using Goldmann applanation tonometry.
Although systemic b-blocker use was associated with lower IOP and systemic angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statin and sulfonylurea use was associated with higher IOP in this study, the associations were modest at best.
Only the associations with systemic hypoglycaemic agents were greater than 1 mmHg, a threshold that has translated to a 14 per cent greater risk of incident glaucoma across five years in other studies.
The study authors wrote: ‘At this point, the effect of systemic medication on IOP in eyes with glaucoma is not well elucidated but important. Our findings indicate that patients with glaucoma may potentially be at risk of higher or lower IOP, depending on medication class, and this would in turn affect management of IOP control.’
JAMA Ophthalmol 2017; 135: 3: 196-202. doi:10.1001/jamaophthalmol.2016.5318.