The effect of topical atropine on the choroidal thickness of healthy children

Abstract

The purpose of the current study was to investigate the effect of topical atropine on choroidal thickness using spectral-domain optical coherence tomography. A total of 30 healthy eyes from 30 children were analyzed in this study. A single drop of 1% atropine gel was administered twice daily for a week. Choroidal thickness (CT) was measured using SD-OCT, and changes in CT before and after administration of the eye drops were analyzed at the subfovea and at 1.0-mm intervals (up to 3.0 mm) from the fovea at superior, inferior, nasal, and temporal locations. Pre- and post-cycloplegic axial length (AL) was also measured using the IOLMaster. We observed that administration of 1% atropine gel led to a significant increase in the choroidal thickness under the fovea and at all intervals from the fovea. The greatest change in CT was observed in the inferior meridian, while the nasal meridian exhibited the least change. AL did not significantly differ before and after cycloplegia, and there was no significant correlation between the changes in AL and subfoveal CT. It was concluded that administration of 1% atropine gel can significantly increase CT in the eyes of young Chinese children, albeit with different magnitude at different locations.

The Influence of the Autonomic Nervous System on the Human Choroid

“…The current study has also confirmed previous findings that the topical administration of antimuscarinic agents with no optical blur causes an increase in choroidal thickness (Chapter two, Öner et al, 2016;Zhang et al, 2016), and support Nickla and Schrödl (2012) hypothesis that the non-visual choroidal thickening reflects the loss of an excitatory cholinergic input to the choroid.…”

“…Choroidal thickness has been shown to be sensitive to a range of antimuscarinics (atropine, homatropine, and cyclopentolate) that significantly increase subfoveal choroidal thickness in humans (Oner et al, 2016;Zhang et al, 2016). In Chapter two we also showed that the muscarinic antagonist (homatropine) can increase choroidal thickness in the human eye.…”

“…Some studies have found that application of the non-selective muscarinic antagonist 1% tropicamide does not have any influence on choroidal thickness (Mwanza et al, 2013;Öner et al, 2016), while other authors have observed a decrease in choroidal thickness after administration of 1% tropicamide or 1% cyclopentolate (Kara et al, 2014;Yuvaci et al, 2015). Contrary to these findings, three recent studies have reported that 2% homatropine, 1% atropine and 1% cyclopentolate significantly increased subfoveal choroidal thickness Öner et al, 2016;Zhang et al, 2016 selective antagonist pirenzepine (Shih et al, 1999, Siatkowski et al, 2004Chua et al, 2006;Chia et al, 2012, Chia et al, 2016. Fan and colleagues (2007), who investigated the effect of 1% atropine ointment on myopia progression in children over a one year period, demonstrated that the rate of myopia progression was lower in children receiving atropine than in those using the placebo.…”

“…An increase in choroidal thickness following administration of anticholinergic drugs (Arumugam andMcBrien, 2012, Nickla et al, 2013a) or surgical modification of parasympathetic input to the eye Wildsoet, 1996, Nickla andSchrodel, 2012) have been demonstrated in a number of different species. However, there is limited evidence regarding choroidal thickness changes after administration of anticholinergic agents in human subjects (Mwanza et al, 2013;Kara et al, 2014;Yuvaci et al, 2015;Öner et al, 2016;Zhang et al, 2016). Human clinical studies also indirectly support the notion that cholinergic transmission can influence choroidal thickness and refractive error development.…”

“…Imposed defocus produces rapid changes in the choroid; this was first documented in the chick model and subsequently confirmed in mammals including humans. The magnitude of choroidal thickness variations found in humans and mammals is much smaller than in avian species (10-20 µm vs. ≈100 µm respectively), Wildsoet and Wallman, 1995;Hung et al, 2000;McBrien et al, 2000;Hewlett and McFadden, 2009;Nickla and Wallman, 2010a;Read et al, 2010b, Chakraborty et al, 2012Chiang et al, 2015;Öner et al, 2016;Zhang et al, 2016). Choroidal thickness changes observed during emmetropization represent a physiological response to external stimulation (optical defocus), which aims to adjust the retinal position to provide clear vision and drive growth of the eye.…”