A technique called optical coherence tomography (OCT) has been developed for noninvasive cross-sectional imaging in biological systems. OCT uses low-coherence interferometry to produce a two-dimensional image of optical scattering from internal tissue microstructures in a way that is analogous to ultrasonic pulse-echo imaging. OCT has longitudinal and lateral spatial resolutions of a few micrometers and can detect reflected signals as small as approximately 10(-10) of the incident optical power. Tomographic imaging is demonstrated in vitro in the peripapillary area of the retina and in the coronary artery, two clinically relevant examples that are representative of transparent and turbid media, respectively.

/pdf/optical-coherence-tomography-3zqbp7mpwb.pdf

Optical coherence tomography

Aim: To estimate the number of people with open angle (OAG) and angle closure glaucoma (ACG) in 2010 and 2020. Methods: A review of published data with use of prevalence models. Data from population based studies of age specific prevalence of OAG and ACG that satisfied standard definitions were used to construct prevalence models for OAG and ACG by age, sex, and ethnicity, weighting data proportional to sample size of each study. Models were combined with UN world population projections for 2010 and 2020 to derive the estimated number with glaucoma. Results: There will be 60.5 million people with OAG and ACG in 2010, increasing to 79.6 million by 2020, and of these, 74% will have OAG. Women will comprise 55% of OAG, 70% of ACG, and 59% of all glaucoma in 2010. Asians will represent 47% of those with glaucoma and 87% of those with ACG. Bilateral blindness will be present in 4.5 million people with OAG and 3.9 million people with ACG in 2010, rising to 5.9 and 5.3 million people in 2020, respectively. Conclusions: Glaucoma is the second leading cause of blindness worldwide, disproportionately affecting women and Asians.

The number of people with glaucoma worldwide in 2010 and 2020

Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described as the optical analogue to ultrasound. The inherent safety of the technology allows for in vivo use of OCT in patients. The main strength of OCT is the depth resolution. In dermatology, most OCT research has turned on non-melanoma skin cancer (NMSC) and non-invasive monitoring of morphological changes in a number of skin diseases based on pattern recognition, and studies have found good agreement between OCT images and histopathological architecture. OCT has shown high accuracy in distinguishing lesions from normal skin, which is of great importance in identifying tumour borders or residual neoplastic tissue after therapy. The OCT images provide an advantageous combination of resolution and penetration depth, but specific studies of diagnostic sensitivity and specificity in dermatology are sparse. In order to improve OCT image quality and expand the potential of OCT, technical developments are necessary. It is suggested that the technology will be of particular interest to the routine follow-up of patients undergoing non-invasive therapy of malignant or premalignant keratinocyte tumours. It is speculated that the continued technological development can propel the method to a greater level of dermatological use.

https://link.springer.com/content/pdf/bfm%3A978-3-319-06419-2%2F1.pdf

Optical Coherence Tomography

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(07)61690-0.pdf

Maternal and child undernutrition: global and regional exposures and health consequences

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(13)60937-X.pdf

Maternal and child undernutrition and overweight in low-income and middle-income countries

Organizing to prevent Third World blindness.

Methods We searched Medline for randomised controlled trials assessing a relative reduction in infl uenza risk of all circulating infl uenza viruses during individual seasons after vaccination (effi cacy) and observational studies meeting inclusion criteria (eff ectiveness). Eligible articles were published between Jan 1, 1967, and Feb 15, 2011, and used RT-PCR or culture for confi rmation of infl uenza. We excluded some studies on the basis of study design and vaccine characteristics. We estimated random-eff ects pooled effi cacy for trivalent inactivated vaccine (TIV) and live attenuated infl uenza vaccine (LAIV) when data were available for statistical analysis (eg, at least three studies that assessed comparable age groups). Findings We screened 5707 articles and identifi ed 31 eligible studies (17 randomised controlled trials and 14 observational studies). Effi cacy of TIV was shown in eight (67%) of the 12 seasons analysed in ten randomised controlled trials (pooled effi cacy 59% [95% CI 51–67] in adults aged 18–65 years). No such trials met inclusion criteria for children aged 2–17 years or adults aged 65 years or older. Effi cacy of LAIV was shown in nine (75%) of the 12 seasons analysed in ten randomised controlled trials (pooled effi cacy 83% [69–91]) in children aged 6 months to 7 years. No such trials met inclusion criteria for children aged 8–17 years. Vaccine eff ectiveness was variable for seasonal infl uenza: six (35%) of 17 analyses in nine studies showed signifi cant protection against medically attended infl uenza in the outpatient or inpatient setting. Median monovalent pandemic H1N1 vaccine eff ectiveness in fi ve observational studies was 69% (range 60–93). Interpretation Infl uenza vaccines can provide moderate protection against virologically confi rmed infl uenza, but such protection is greatly reduced or absent in some seasons. Evidence for protection in adults aged 65 years or older is lacking. LAIVs consistently show highest effi cacy in young children (aged 6 months to 7 years). New vaccines with improved clinical effi cacy and eff ectiveness are needed to further reduce infl uenza-related morbidity and mortality.

/pdf/effi-cacy-and-eff-ectiveness-of-infl-uenza-vaccines-a-5cdb914h5q.pdf

Effi cacy and eff ectiveness of infl uenza vaccines: a systematic review and meta-analysis

Up to $500m a year could be put to better use by stopping ineffective and potentially harmful supplementation programmes in poorer countries, say JB Mason, CS Benn, and HPS Sachdev; but Keith P West Jr, Amanda C Palmer, and Alfred Sommer disagree, saying that such programmes have been proved to save millions of lives and should be withdrawn only when robust evidence permits

https://www.bmj.com/content/bmj/360/bmj.k927.full.pdf

Should universal distribution of high dose vitamin A to children cease

• Lissamine green staining of the conjunctiva, a new and widely heralded aid for diagnosing early xerophthalmia, was found to be a reasonably specific but inadequately sensitive test for practical use. While 82% of clinically normal children failed to show staining, so did 57% with night blindness, 29% with vitamin A responsive Bitot's spots, and, most significantly, 26% with severe, vitamin A related corneal involvement. The test also failed to distinguish vitamin A responsive "Bitot's spots" from nonresponsive ones.

Lissamine Green Staining in the Clinical Diagnosis of Xerophthalmia

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(13)61735-3.pdf

Alfred Sommer

Papers

Organizing to prevent Third World blindness.

Effi cacy and eff ectiveness of infl uenza vaccines: a systematic review and meta-analysis

Should universal distribution of high dose vitamin A to children cease

Lissamine Green Staining in the Clinical Diagnosis of Xerophthalmia

Vitamin A supplementation in Indian children