Associate Professor Mark Roth
BSc(Pharmacology) BAppSc(Optom) PGCertOcTher NEWENCO FAAO OAM
FDA approves new herpes zoster vaccine
GlaxoSmithKline’s recombinant zoster vaccine Shingrix has been approved in the United States for the prevention of herpes zoster in adults aged 50 years and older.
The approval follows a unanimous vote by the Vaccines and Related Biological Products Advisory Committee of the US Food and Drug Administration that the vaccine is effective and safe for adults aged 50 years and older.
Shingrix combines an antigen, glycoprotein E, and an adjuvant system, AS01B, intended to generate a strong and long-lasting immune response that can help overcome the decline in immunity as people age, the company explained in a media release. Shingrix is given in two doses, with a two- to six-month interval between doses.
Shingrix was approved in Canada in October 2017 for the prevention of herpes zoster in people aged 50 years or older. Regulatory filings in the European Union, Australia and Japan are underway.
Nerf guns pose potential risks to the eyes of those who use them.
Researchers from the Accident & Emergency Department, Moorfields Eye Hospital NHS Foundation Trust, London, UK reported three unrelated patients presenting with pain and blurred vision following an injury caused by a Nerf gun.
Two of the patients were adults and one was a child, all of whom presented within a three-month period. All three cases were found to have less than or equal to 1 mm of traumatic hyphaema, indicating significant ocular trauma. The two adult patients had formed hyphaema and uveitis. The 11-year-old child had formed hyphaema, corneal oedema, anterior uveitis, localised angle recession and commotio retinae, which further highlight the severity of the ocular trauma.
Although all three patients recovered their full vision, the study authors warned of potentially serious consequences from using the toy, noting: ‘although Nerf guns are generally believed to be less harmful than pellet guns, this case series calls into consideration the need for protective eyewear with their use ... [and] calls for reconsideration of the safe age limits for Nerf gun use in children.’
BMJ Case Report. Sep 2017. doi: 10.1136/bcr-2017-220967.
OCT-A for corneal neovascularisation
Researchers demonstrated that optical coherence tomography angiography (OCT-A) can visualise corneal neovascularisation in patients with corneal diseases more clearly than slitlamp photography.
Five patients with five eyes showing partial or total limbal stem cell deficiency were involved in the evaluations. Three eyes had severe corneal scarring. Five 6 mm × 6 mm images (frontal, upper, lower, nasal and temporal) were obtained by OCT-A. Slitlamp photography was performed for all patients on the same day.
The results showed that OCT-A has two advantages over slitlamp photography for clear demonstration of corneal neovascularisation. OCT-A can show neovascularisation in cases with severe corneal opacification, and can detect not only large vessels but also small vessels that cannot be seen by slitlamp.
‘OCT-A is a powerful tool for objective evaluation of vascularisation in the anterior and posterior segments of the eye,’ the authors concluded.
Cornea. Sept 2017. 14. doi: 10.1097/ICO.0000000000001382.
Minor salivary gland transplantation for severe dry eyes
To evaluate the use of salivary glands as a source of lubrication to treat severe cases of dry eye, researchers at the Federal University of Sao Paulo, Brazil distributed symptoms questionnaires to patients who had undergone a specific procedure: minor salivary gland autotransplantation together with labial mucosa, used as a complex graft to the conjunctival fornix in severe dry eye.
The patients’ responses revealed improvements in foreign body sensation, photophobia and pain. They also demonstrated significant improvements in best corrected visual acuity, Schirmer’s test score, corneal transparency and neovascularisation after using this technique.
The authors wrote that their study demonstrated the viability of minor salivary glands transplanted into the fornix of patients with dry eye by performing immunohistochemistry on graft biopsies with antibodies against lactoferrin, lysozyme, MUC1 and MUC16.
Cornea. Nov 2017. doi: 10.1097/ICO.0000000000001358.
Delay between eye-drop instillations increases efficacy
Patients with chronic conditions requiring multiple, different eye-drops should wait five minutes between administration, according to a study in Optometry and Vision Science.
The authors designed their study to address a ‘puzzling observation’: patients are usually advised to wait five minutes between eye-drops to allow the first drop not to be washed out by the second one. However, in the only experimental study conducted in humans on the concurrent administration of two different eye-drops, the authors concluded that a 10-minute time interval between eye-drops did not increase their combined effect.
Using digital photographs shot in photopic conditions in 40 eyes of 20 healthy volunteers, researchers compared relative pupil surface before and after the administration of one drop of 10% phenylephrine and one drop of 0.5% tropicamide either immediately or after a five-minute time interval.
One hundred and sixty pupil and iris surface images were anonymised and randomly arranged before being presented to two independent observers. The researchers found that waiting five minutes between two different eye-drops significantly increased their combined effect, contrary to previous conclusions made by other studies.
They propose that if two drops of different drugs are administered separately, with too small an interval between them, dilution limits the extent of absorption of both drugs compared with a combined drug solution.
Optom Vis Sci. Aug 2017. doi: 10.1097/OPX.0000000000001104.
Is aspirin safe for AMD patients?
The answer, according to a review published in Retina, is a qualified yes.
Researchers reviewed the current literature of the benefits that aspirin provides for patients’ cardiovascular health compared to the risk of AMD worsening. Six cardiovascular and four ophthalmological trials on the risks and benefits of aspirin use were analysed.
The reviewed meta-analysis literature demonstrated a statistically significant 32 per cent reduction in the risk of nonfatal stroke with regular aspirin users. The study also documented that aspirin users decreased the risk of fatal vascular deaths by 15 per cent. Of the three ophthalmological studies highlighting the adverse affects of aspirin association with AMD, all suggested an exacerbation of AMD without statistical significance and broad confidence bands.
The authors concluded that the number, size and quality of the cardiovascular studies recommending aspirin use were far superior to the fewer, smaller and conflicting studies suggesting a possible adverse effect of aspirin use in relation to AMD.
‘The benefits of aspirin usage include preserving the duration and quality of life by decreasing stroke and heart attack risk,’ the authors wrote. ‘These benefits seem to far outweigh the theoretical risks of possibly exacerbating wet AMD, which can be reasonably controlled with anti-VEGF therapy.’
Retina. Sept 2017. doi: 10.1097/IAE.0000000000001475.
CoQ10 in retinal diseases
In a review published in Current Medicinal Chemistry, authors proposed that coenzyme Q10 (CoQ10) could have therapeutic potential for various retinal diseases.
CoQ10 plays a critical role in mitochondrial oxidative phosphorylation by serving as an electron carrier in the respiratory electron transport chain. CoQ10 also functions as a lipid-soluble antioxidant by protecting lipids, proteins and DNA damaged by oxidative stress.
The authors explained that CoQ10 deficiency had been associated with a number of human diseases including mitochondrial diseases, neurodegenerative disorders, cardiovascular diseases, diabetes and cancer, along with the ageing process. In many of these conditions CoQ10 supplementation therapy had been effective in slowing or reversing pathological changes, the authors noted. Oxidative stress is also a major contributory factor in the process of retinal degeneration.
The authors also discussed the use of CoQ10 in the treatment of age-related macular degeneration and glaucoma, and suggested that CoQ10 could have therapeutic potential for other retinal diseases in light of current data.
Curr Med Chem. Aug 2017. doi: 10.2174/0929867324666170801100516. [Epub ahead of print]
Topical tacrolimus for SEIs
Topical tacrolimus, compounded in the pharmacy, appears to be an effective and safe alternative for the treatment of corneal subepithelial infiltrates (SEIs) secondary to adenovirus keratoconjunctivitis.
To determine the efficacy and safety of topical tacrolimus for the treatment of SEIs secondary to adenoviral keratoconjunctivitis, researchers conducted a retrospective study of patients who had been dispensed topical tacrolimus for the condition during the previous year.
Fifty-five patients (85 eyes) were included, 54.5 per cent with bilateral involvement. A total of 31 (36.5 per cent) eyes were treated with tacrolimus ointment and 54 eyes (63.5 per cent) with tacrolimus eye-drops. The median length of treatment was 185 days and the mean follow-up duration was 363 days.
In 62.35 per cent of the eyes, the SEIs were reduced in number and size, and in 31.76 per cent, they were eliminated. The patients had better visual acuity after treatment with highly statistically- significant differences. Tolerance was good overall, being better in the eye-drops group.
Cornea. Sept 2017. doi: 10.1097/ICO.0000000000001279.
Low-dose atropine safer
A meta-analysis of published studies has found that low-dose atropine is equally effective in slowing myopia progression in children and has fewer side-effects than higher doses.
Researchers conducted a meta-analysis of published studies in PubMed, EMBASE and the Cochrane Central Register for Controlled Trials.
The data showed significantly less progression of myopia with all doses of atropine compared with control groups, but no correlation was found between dose and treatment effect. Ethnicity also had no impact on the effect of treatment.
A total of 308 adverse effect events occurred in 2,425 patients in the atropine groups (12.7 per cent). The difference with control groups was statistically significant. The most common effects were photophobia, poor vision at near and allergy, and their incidence significantly increased with dose escalation.
The authors recommended the use of the lowest dose of atropine (0.01%) for therapy, but cautioned that more clinical trials with this dose were needed.
JAMA Ophthalmol. Jun 2017. doi: 10.1001/jamaophthalmol.2017.1091