RCSV and School of Optometry 45th Anniversary Joint Research Seminar - "From Hyperopic Reserve to Myopia: A Different View of Refractive Development"
Conference / Seminar
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Date
23 Aug 2023
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Organiser
Research Centre for SHARP Vision (RCSV) and School of Optometry (SO)
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Time
01:00 - 02:00
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Venue
Room FJ302, PolyU
Speaker
Prof. Ian Morgan
Enquiry
Ms Shirley NG (852) 3400 2312 info.rcsv@polyu.edu.hk
Summary
Emmetropisation generally regards emmetropia as the normal endpoint for refractive development, with a mechanism for maintaining emmetropia once it is achieved. In contrast, the endpoint for normal refractive development appears to be mild hyperopia, and there is no evidence for a mechanism for maintaining emmetropia. However, there does appear to be a mechanism aimed at maintaining a hyperopic reserve around 1.0 to 1.5D, based on modulation of rate of loss of lens power. Once refractions drop below +0.75D into the premyopic range, rates of myopic shifts in refraction accelerate towards those typical of myopia progression, and there is no natural mechanism to prevent the development of myopia except declining plasticity with age. we therefore need to focus on how to maintain a hyperopic reserve in children to prevent the development of myopia and high myopia.
Keynote Speaker
Prof. Ian Morgan
Visiting Fellow
Australian National University, Australia
Professor Ian Morgan is a Visiting Fellow at the Australian National University in Canberra and at the Zhongshan Ophthalmic Center in Guangzhou. His work has overturned the long-standing belief that myopia is under tight genetic control in favour of a major role for environmental factors in generating the East Asian epidemic of myopia and high myopia. It has also identified the protective effects of increased time outdoors, which is increasingly being used to prevent myopia in preschools and primary schools in Taiwan and mainland China. He also argues that the high-pressure educational systems common in East Asia, and in Singapore, are a major factor in the emergence of the myopia epidemic, and suggests that the recent changes to the education system in mainland China provide excellent opportunities for myopia prevention.
