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

A survey method to assess fortifiable condiment use by rural households

Assessment of xerophthalmia and the mass vitamin A prophylaxis program in El Salvador (September 1973--December 1974).

JAMA Comparison of Annual and Biannual Mass Antibiotic Administration for Elimination of Infectious Trachoma Muluken Melese, MD, MPH; Wondu Alemayehu, MD, MPH; Takele Lakew, MD, MPH; Elizabeth Yi, MPH; Jenafir House, MPH, MSW; Jaya D. Chidambaram, MBBS; Zhaoxia Zhou, BA; Vicky Cevallos, MT; Kathryn Ray, MA; Kevin Cyrus Hong, BA; Travis C. Porco, PhD, MPH; Isabella Phan, MD; Ali Zaidi, MD; Bruce D. Gaynor, MD; John P. Whitcher, MD, MPH; Thomas M. Lietman, MD Context: Treatment recommendations assume that repeated mass antibiotic distributions can control, but not eradicate or even locally eliminate, the ocular strains of chlamydia that cause trachoma. Elimination may be an important end point because of concern that infection will return to communities that have lost immunity to chlamydia after antibiotics are discontinued. Objective: To determine whether biannual treatment can eliminate ocular chlamydial infection from preschool children and to compare results with the World Health Organization–recommended annual treatment. Design, Setting, and Participants: A cluster-randomized clinical trial of biannual vs annual mass azithromycin administrations to all residents of 16 rural villages in the Gurage Zone, Ethiopia, from March 2003 to April 2005. Interventions: At scheduled treatments, all individuals aged 1 year or older were offered a single dose of oral azithromycin either annually or biannually. Main Outcome Measure:  Village prevalence of ocular chlamydial infection and presence of elimination at 24 months in preschool children determined by polymerase chain reaction, correcting for baseline prevalence. Antibiotic treatments were performed after sample collections. Results: Overall, 14 897 of 16 403 eligible individuals (90.8%) received their scheduled treatment. In the villages in which residents were treated annually, the prevalence of infection in preschool children was reduced from a mean of 42.6% (range, 14.7%-56.4%) to 6.8% (range, 0.0%-22.0%) at 24 months. In the villages in which residents were treated biannually, infection was reduced from 31.6% pretreatment (range, 6.1%-48.6%) to 0.9% (range, 0.0%-4.8%) at 24 months. Biannual treatment was associated with a lower prevalence at 24 months ( P  = .03, adjusting for baseline prevalence). At 24 months, no infection could be identified in 6 of 8 of those treated biannually and in 1 of 8 of those treated annually ( P  = .049, adjusting for baseline prevalence). Conclusion: Local elimination of ocular chlamydial infection appears feasible even in the most severely affected areas, although it may require biannual mass antibiotic distributions at a high coverage level. Trial Registration: clinicaltrials.gov Identifier:NCT00221364 JAMA. 2008;299(7):778-784.

Frequency of Antibiotic Coverage and Elimination of Blinding Trachoma

Quantifying the efficacy of influenza vaccines: Authors' reply

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=OPHTH&articleId=425138&pdfFileName=eed90029_363_364.pdf

Alfred Sommer

Papers

A survey method to assess fortifiable condiment use by rural households

Assessment of xerophthalmia and the mass vitamin A prophylaxis program in El Salvador (September 1973--December 1974).

Frequency of Antibiotic Coverage and Elimination of Blinding Trachoma

Quantifying the efficacy of influenza vaccines: Authors' reply

Treatment of ocular hypertension: Hamlet's Lament revisited.