Preterm postnatal complications and risk of attention-deficit/hyperactivity disorder

AIM

To investigate the association between the risk of attention-deficit/hyperactivity disorder (ADHD) and preterm birth and determine how postnatal complications in children born preterm is associated with the risk of ADHD.

METHOD

This population-based cohort study used data from the Hong Kong electronic medical records. We followed 359 614 children (48% female; 6-17 years old, mean 11 years 7 months, SD 3 years 2 months) born in public hospitals in Hong Kong from 1st January 2004 to 31st December 2014 and collected medical records and demographic details for mothers and children until 11th November 2020.

RESULTS

The risk of ADHD was 4.0% in children born at term and 5.1% in children born preterm. The odds ratio for ADHD was 2.08 (95% confidence interval [CI] 1.64-2.64) for children born extremely preterm, 1.64 (95% CI 1.46-1.85) for children born very preterm, and 1.15 (95% CI 1.08-1.23) for children born late preterm. Among preterm postnatal complications, only early respiratory disease, retinopathy of prematurity (ROP), and intraventricular haemorrhage were significant predictors of ADHD after controlling for preterm birth, other risk factors, and sociodemographic variables. The excess risk of ADHD among children born very preterm or late preterm could be partly explained by respiratory disease. ROP partially mediated the risk of ADHD in children born very preterm.

INTERPRETATION

Children born preterm in all subcategories, from extremely preterm to late preterm, have increased risk of ADHD. Early respiratory infection partially mediates the risk of ADHD in children born preterm.

Botulinum toxin as an initial therapy for management of sixth nerve palsies caused by nasopharyngeal carcinomas

PurposeThe purpose of this study is to evaluate the efficacy and safety of botulinum toxin injection as a primary treatment for strabismus in a cohort of patients with nasopharyngeal carcinoma (NPC)-related chronic sixth nerve palsy.Patients and methodsWe retrospectively reviewed all cases of NPC-related sixth nerve palsy receiving botulinum toxin injection in the Hong Kong Eye Hospital between January 2009 and January 2016. Only cases with diplopia for at least 6 months; and failed a trial of Fresnel prism therapy were recruited. We excluded cases with prior strabismus surgery and multiple cranial nerve palsies. Patients were offered botulinum toxin injection as primary treatment for their strabismus and were given further injections or offered surgery if diplopia persisted. Success with botulinum toxin was defined as a final distant orthophoria of <15 PD in primary gaze, no diplopia in primary position, and no head turn, as measured 6 months after the last injection, without requiring a second treatment.ResultsA total of 25 patients were included in the study. All patients received concurrent chemo-radiotherapy for NPC. There was a statistically significant reduction in the mean deviation at distant after the last injection compared to that at presentation (P<0.001, Wilcoxin signed rank test). Overall, 7 patients (28%) achieved clinical success and 15 patients (64%) remained diplopia-free by repeated botulinum toxin injections alone. Nine patients went on to receive definitive surgery and all achieved good ocular alignment after surgery. Transient ptosis or vertical deviation was seen in 7 patients, which resolved within 3 months and no serious complications arose from the treatment in our series.ConclusionsBotulinum toxin injection is a relatively less-invasive alternative to surgery that can be done under a topical anesthesia setting, which improves patient's quality of life via reduction in diplopia. It is a recommendable initial option in patients with chronic nerve palsies who may have higher risks associated with strabismus surgery.

Antagonists of growth hormone-releasing hormone receptor induce apoptosis specifically in retinoblastoma cells

Retinoblastoma (RB) is the most common intraocular cancer in children worldwide. Current treatments mainly involve combinations of chemotherapies, cryotherapies, and laser-based therapies. Severe or late-stage disease may require enucleation or lead to fatality. Recently, RB has been shown to arise from cone precursor cells, which have high MDM2 levels to suppress p53-mediated apoptosis. This finding leads to the hypothesis that restoring apoptosis mechanisms in RBs could specifically kill the cancer cells without affecting other retinal cells. We have previously reported involvement of an extrapituitary signaling pathway of the growth hormone-releasing hormone (GHRH) in the retina. Here we show that the GHRH receptor (GHRH-R) is highly expressed in RB cells but not in other retinal cells. We induced specific apoptosis with two different GHRH-R antagonists, MIA-602 and MIA-690. Importantly, these GHRH-R antagonists do not trigger apoptosis in other retinal cells such as retinal pigmented epithelial cells. We delineated the gene expression profiles regulated by GHRH-R antagonists and found that cell proliferation genes and apoptotic genes are down- and up-regulated, respectively. Our results reveal the involvement of GHRH-R in survival and proliferation of RB and demonstrate that GHRH-R antagonists can specifically kill the RB cells.

Advances of optical coherence tomography in myopia and pathologic myopia

The natural course of high-axial myopia is variable and the development of pathologic myopia is not fully understood. Advancements in optical coherence tomography (OCT) technology have revealed peculiar intraocular structures in highly myopic eyes and unprecedented pathologies that cause visual impairment. New OCT findings include posterior precortical vitreous pocket and precursor stages of posterior vitreous detachment; peripapillary intrachoroidal cavitation; morphological patterns of scleral inner curvature and dome-shaped macula. Swept source OCT is capable of imaging deeper layers in the posterior pole for investigation of optic nerve pits, stretched and thinned lamina cribrosa, elongated dural attachment at posterior scleral canal, and enlargement of retrobulbar subarachnoid spaces. This has therefore enabled further evaluation of various visual field defects in high myopia and the pathogenesis of glaucomatous optic neuropathy. OCT has many potential clinical uses in managing visual impairing conditions in pathologic myopia. Understanding how retinal nerve fibers are redistributed in axial elongation will allow the development of auto-segmentation software for diagnosis and monitoring progression of glaucoma. OCT is indispensable in the diagnosis of various conditions associated with myopic traction maculopathy and monitoring of post-surgical outcomes. In addition, OCT is commonly used in the multimodal imaging assessment of myopic choroidal neovascularization. Biometry and topography of the retinal layers and choroid will soon be validated for the classification of myopic maculopathy for utilization in epidemiological studies as well as clinical trials.

Ocular toxicity of hydroxychloroquine

OBJECTIVES

To review the types, incidence, pathogenesis, risk factors, and clinical characteristics of hydroxychloroquine ocular toxicity and current views about its screening and management.

DATA SOURCES

Literature search of Medline up to May 2005.

STUDY SELECTION

Key words for the literature search were 'hydroxychloroquine', 'chloroquine', 'ocular', 'toxicity', 'retinopathy', and 'screening'.

DATA EXTRACTION

Original articles and review papers were examined.

DATA SYNTHESIS

Hydroxychloroquine ocular toxicity includes keratopathy, ciliary body involvement, lens opacities, and retinopathy. Retinopathy is the major concern: others are more common but benign. The incidence of true hydroxychloroquine retinopathy is exceedingly low; less than 50 cases have been reported. Although its pathogenesis is unclear, risk factors include: daily dosage of hydroxychloroquine, cumulative dosage, duration of treatment, coexisting renal or liver disease, patient age, and concomitant retinal disease. Patients usually complain of difficulty in reading, decreased vision, missing central vision, glare, blurred vision, light flashes, and metamorphopsia. They can also be asymptomatic. Most patients have a bull's eye fundoscopic appearance. All patients have field defects including paracentral, pericentral, central, and peripheral field loss. Colour vision is usually undisturbed in early retinopathy, but is impaired in the advanced stage. Most patients have visual loss. Some patients with advanced retinopathy may experience deteriorating visual acuity even after cessation of treatment. There is no consensus on the definition of retinopathy, most-effective ophthalmological assessment, or frequency of screening. Regular screening may be necessary to detect reversible premaculopathy. Cessation of the drug is the only effective management of the toxicity.

CONCLUSION

Consensus with regard to various important aspects of hydroxychloroquine ocular toxicity is limited, especially the definition of true hydroxychloroquine retinopathy, the most effective ophthalmological assessment, and frequency of screening. Decisions to stop medication must be made in conjunction with the rheumatologist or physician managing the patient. Management of hydroxychloroquine retinopathy remains a clinical challenge.

Update of the management of postoperative endophthalmitis

Postoperative endophthalmitis is a rare but potentially devastating complication of intra-ocular surgery. Most cases are caused by bacterial infection. The clinical presentation of endophthalmitis can be classified as acute postoperative endophthalmitis, chronic postoperative endophthalmitis, and bleb-associated endophthalmitis. They each have a different aetiology, treatment, and prognosis. This review discusses these features, as well as the microbiology, diagnosis, and treatment outcomes of these three types of inflammation, with particular emphasis on recent advances in their management. The role of steroids, systemic fluoroquinolones, and the choice of antibiotic against gram-negative bacteria are still controversial and need further study. Moreover, the management of chronic postoperative and bleb-associated endophthalmitis has not been standardised, and no conclusive findings on the efficacy of the various prophylactic measures are available. Thus, the treatment and prevention of postoperative endophthalmitis remain a clinical challenge.