Effect of retinal image defocus on the thickness of the human choroid

PURPOSE: To describe the time-course and amplitude of changes to sub-foveal choroidal thickness (SFCT) induced by imposed hyperopic and myopic retinal defocus and to compare the responses in emmetropic and myopic subjects. METHODS: Twelve East Asian subjects (age: 18-34 years; six were emmetropic and six had myopia between -2.00 and -5.00 dioptres (D)) viewed a distant target (video movie at 6 m) for 60 min on two separate occasions while optical coherence tomography (OCT) images of the choroid were taken in both eyes every 5 min to monitor SFCT. On each occasion, one eye was optimally corrected for distance with a contact lens while the other eye wore a contact lens imposing either 2.00 D hyperopic or 2.00 D myopic retinal defocus. RESULTS: Baseline SFCT in myopic eyes (mean ± S.D.): 256 ± 42 μm was significantly less than in emmetropic eyes (423 ± 62 μm; p < 0.01) and was correlated with magnitude of myopia (-39 μm per dioptre of myopia, R(2) = 0.67: p < 0.01). Repeated measures anova (General Linear Model) analysis revealed that in both subject groups, 2.00 D of myopic defocus caused a rapid increase in SFCT in the defocussed eye (significant by 10 min, increasing to approximately 20 μm within 60 min: p < 0.01), with little change in the control eye. In contrast, 2.00 D of hyperopic defocus caused a decrease in SFCT in the experimental eye (significant by 20-35 min. SFCT decreased by approximately 20 μm within 60 min: p < 0.01) with little change in the control eye. CONCLUSIONS: Small but significant changes in SFCT (5-8%) were caused by retinal defocus. SFCT increased within 10 min of exposure to 2.00 D of monocular myopic defocus, but decreased more slowly in response to 2.00 D of monocular hyperopic defocus. In our relatively small sample we could detect no difference in the magnitude of changes to SFCT caused by defocus in myopic eyes compared to emmetropic eyes.

Clinical performance of three silicone hydrogel daily disposable lenses

Purpose: To determine the clinical performance of DAILIES TOTAL1 (DT1), Clariti 1Day (C1D), and 1-DAY ACUVUE TruEye (AVTE) silicone hydrogel daily disposable contact lenses (SiHy DDCLs).

Methods: Eligible participants, subdivided into asymptomatic and symptomatic groups, wore each SiHy DDCLs for three consecutive days. Each participant attended three visits (on day 1 at 0 hours; on days 1 and 3 after 8 hours of wear) per lens type. The order of lens wear was randomized, with at least 1 day washout between lenses. Lens-related performance was evaluated by assessing lens surface deposits, wettability, pre-lens noninvasive tear breakup time, lens movement, and centration; ocular response assessments included conjunctival redness, corneal staining, and conjunctival staining and indentation.

Results: Fifty-one asymptomatic and 53 symptomatic participants completed the study. For all visits, the mean noninvasive tear breakup time was about 1 second longer with DT1 than with C1D and AVTE (p < 0.01). Overall, the wettability of all three lenses was good; however, DT1 was graded marginally better than the other lenses (both p < 0.01). On day 3, eyes wearing AVTE had significantly more dehydration-induced corneal staining compared with DT1 (AVTE, 24%; DT1, 11%; p < 0.01). After 8 hours, conjunctival staining was different between lenses (greatest with C1D and least with DT1; all p < 0.01). Conjunctival indentation was more prevalent with the C1D lenses (n = 70) compared with DT1 (n = 1; p < 0.01) and AVTE (n = 11; p < 0.01). There were no differences between asymptomatic and symptomatic lens wearers for any of the clinical parameters (all p > 0.05).

Conclusions: Each of the three SiHy DDCLs performed well. Noninvasive tear breakup time was longest and wettability was greater with DT1. C1D had the most conjunctival staining conjunctival indentation. There was no difference between asymptomatic and symptomatic wearers with regard to ocular response and contact lens–related parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient

Minahasan indigenous perspectives on place planning and management : tracing the indigenous culture through the lens of local wisdom

Indigenous cultures draw upon many thousands of years of residency and environmental adaptation offering unique knowledge resources to better understand our landscapes and environment. The Minahasan society, on the island of Sulawesi in the Indonesian archipelago, is one such Indigenous community. The Minahasan are the Indigenous community of northern Sulawesi, before the Portuguese and Dutch 1500-1900 colonization of this island, and the later nationalist cultural assimilation following post Indonesian independence. Thus, some 500 years of post-European contact and management can be contrasted against over I 00,000 years of Minahasan society. Further, the majority of this colonisation has been focused upon the coastal fringes resulting in a relatively intact Minahasan cultural landscape within the interior of northern Sulawesi focused upon the Tondano Lake catchment. This paper considers the importance of the Minahasan-formed cultural landscape, its importance to this culture, and the role and influence it continues to have in settlement formation and planning in northern Sulawesi despite conventional Indonesian and Western-informed sustainable urban and regional planning traditions and knowledge. It draws upon intensive qualitative research using 14 different villages, to analyse and compare local knowledge and land-relationships developed by the respective communities to manage and curate their unique characteristics as well as ensuring adaption without compromising their cultural, social and economic values. The research embodies this ethnoecological information in seeking to analyse historical and contemporary land use planning systems, and to offer a future planning perspective that will respect and endure this relationship and environmental management regime.

Marginalisation of dental students in a shared medical and dental education programme

OBJECTIVES: Internationally, there are a number of universities at which medical and dental education programmes share common elements. There are no studies about the experiences of medical and dental students enrolled in different programmes who share significant amounts of learning and teaching. METHODS: Semi-structured interviews and focus groups were conducted with 36 students and staff in a learning programme shared between separate medical and dental faculties. They were transcribed and an iterative process of interpretation and analysis within the theoretical framework of the contact hypothesis and social identity theory was used to group data into themes and sub-themes. RESULTS: Dental students felt 'marginalised' and felt they were treated as 'second-class citizens' by medical students and medical staff in the shared aspects of their programmes. Contextual factors such as the geographical location of the two schools, a medical : dental student ratio of almost 3 : 1, along with organisational factors such as curriculum overload, propagated negative attitudes towards and professional stereotyping of the dental students. Lack of understanding by medical students and faculty of dental professional roles contributed further. CONCLUSIONS: Recommendations for reducing the marginalisation of dental students in this setting include improving communication between faculties and facilitating experiential contact. This might be achieved through initiating a common orientation session, stronger social networks and integrated learning activities, such as interprofessional problem-based learning and shared clinical experiences.