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Nickolai Godtfred Nilsen, Stuart J. Gilson, Rigmor C Baraas; Evening crystalline lens thickening remains after administration of atropine 1%.. Invest. Ophthalmol. Vis. Sci. 2020;61(7):1922.
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© ARVO (1962-2015); The Authors (2016-present)
Crystalline lens thickening has been reported to occur in the evening and night when participants have been in dim illumination and measurements have been carried out after a 10 to 15 minutes “wash-out period’’ to relax their accommodation. It is not known if this thickening may be related to lens metabolism changes or accommodation. Here we measured crystalline lens thickening throughout the day and evening after administration of atropine 1%.
Six healthy adults (all females), aged 19–25yrs. Three myopic (≤-0.50D), one emmetropic and two hyperopic (≥0.50D) as measured with cycloplegic autorefraction (Huvitz HRK-8000A) participated in the study. Measurements of ocular biometry including crystalline lens thickness (LT: IOLMaster 700) were taken in the morning 2 hours post habitual wake-up time (HWT), 9 hours prior to habitual sleep time (HST) and every hour from 5 hours pre HST until 2 hour post HST. Atropine sulphate 1% (Minims single dose; Bausch Health Ireland Ltd, Ireland) were administered in OD only at HWT+2 (min. 5 hours prior to HST-9) with OS as a control eye. Objective measures of accommodation was performed with Nvision-K 5001 open-view autorefractor (Shin-Nippon, Tokyo, Japan) at distance and near. HWT and HST was confirmed wearing Actigraph GT3X for a week prior to measurements. Participants remained in the lab with light levels below 20 lux from HST-9 and did not engage in any near work. They viewed a movie at 5 m for 15 minutes prior to each set of measurements to relax their accommodation. The 12-hour diurnal LT [mm] profiles were modelled using R software.
Accommodation remained below 0.18D (0.08–0.27) all evening in the atropine treated eye. Crystalline lens thickness remained stable throughout the day with increasing thickening from about HST-2. This thickening was observed both in the control and atropine eye, but to a lesser extent in the latter (38.6± 12.2 μm and 17.8± 4.5, respectively when using HST-9 as a baseline). The mean change for all participants was larger than the instrument’s reported LT repeatability errors.
The results show that the crystalline lens undergoes thickening during the night, even after administration of atropine 1%. Thus, diurnal thickening appears to be partially related to diurnal changes in lens metabolism although possible changes in the ciliary muscle tonus cannot be excluded.
This is a 2020 ARVO Annual Meeting abstract.
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