[A prospective cohort study on refractive status of schoolchildren in Huangzhong District, Xining City, Qinghai Province].

Objective: To determine the characteristics and progress of the visual acuity and refractive state of schoolchildren in Huangzhong District, Xining City, Qinghai Province in China. Methods: Cohort study. Department of Ophthalmology, Beijing Children's Hospital carried out a cohort study by collecting the visual acuity and refractive state of Grade 1-5 schoolchildren among 16 primary schools in Huangzhong District, Xining City, Qinghai Province in September 2020 and July 2021. Cycloplegic retinoscopy with eye drop which contained tropicamide (0.5%) and phenylephrine hydrochloride (0.5%) was performed in children with low vision(<1.0). Myopia was defined as the spherical equivalent (SE) ≤-0.5 D after cycloplegic retinoscopy. Measurement data was analyzed by t-test and enumeration data was analyzed by χ2 test. Multiple linear regression was used to analyze the influencing factors. Results: The 2 489 individuals with repeated tests in two years were included in the follow-up study, among whom the prevalence of myopia was 26.24%(653/2 489) in 2020, while 32.94% (820/2 489)respectively in 2021. The incidence of myopia in one school year from grades 1 to 5 was 11.19%(47/420), 5.44%(21/386), 6.39%(25/391), 11.52%(44/382) and 11.67%(30/257). The average SE of children in all grades in 2021 increased negatively from the previous year (Grade 1 to Grade 5 increased respectively: 0.40 D, 0.69 D, 0.62 D, 0.52 D and 0.37 D). Conclusions: The prevalence of myopia among schoolchildren in Huangzhong District, Xining City, Qinghai Province was relatively high. There were two peaks of myopia incidence in the first, fourth and fifth grades. Female, age, and the baseline of SE were the related influencing factors for myopia progression.

Tuberculosis of the nasopharynx following radiotherapy.

We report the case history of a patient who was treated with radiotherapy for nasopharyngeal carcinoma. During follow-up, she showed signs, symptoms and radiological evidence of disease recurrence and progression. However, repeated biopsies of the posterior nasal space (PNS) failed to demonstrate malignancy. A diagnosis of nasopharyngeal tuberculosis was finally made when tissue from a PNS biopsy stained positive for acid-fast bacillus. The patient responded to antituberculous chemotherapy.

HDR intraluminal brachytherapy for lung tumours--a case report.

The lung is a common site for cancer to occur, for both primary as well as metastases. The presence of such tumours can give rise to symptoms such as haemoptysis, cough, breathlessness and pneumonia. In most cases, treatment is strictly for palliation. We present a case report of a patient with an endobronchial metastasis from a primary hypernephroma which recurred following external beam radiotherapy. He was treated with a single fraction of intraluminal brachytherapy to a dose of 10Gy at 1 cm from the axis on a High Dose Rate Ir192 Remote Afterloading Machine. There were no adverse effects following treatment. On follow-up 7 months later, the patient did not have any further recurrence of breathlessness although his disease had progressed at other sites.