Effect of Atropine Eye Drops on Choroidal Thinning Induced by Hyperopic Retinal Defocus

Chiang, Samuel; Phillips, J. R.

doi:10.1155/2018/8528315

Cited by 43 publications

(36 citation statements)

References 28 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…administered 0.5 per cent atropine 22 hours prior to exposing subjects to −2.00 D hyperopic blur and found that prior atropine use negated the thinning effect of the hyperopic blur. Sander et al used two per cent homatropine in combination with ±3.00 D of blur and found that after 60 minutes, the homatropine had eliminated the thinning effect of minus blur, similar to the longer‐term findings of Chiang and Phillips . These findings suggest that a muscarinic pathway may be involved in the eye’s response to minus blur.…”

Section: Changes In the Choroid Associated With Environmental Factorsmentioning

confidence: 79%

See 1 more Smart Citation

Choroidal changes in human myopia: insights from optical coherence tomography imaging

Read

Fuss

Vincent

et al. 2019

Clinical and Experimental Optometry

114

View full text Add to dashboard Cite

The choroid is a vascular tissue which plays a range of critical roles in the normal physiology of the eye, such as supplying the outer retina with oxygen and nutrients and the regulation of intraocular pressure. There is also substantial evidence, particularly from animal studies, that the choroid plays an important role in the regulation of eye growth and the development of common refractive errors like myopia. In recent years, advances in optical coherence tomography technology have improved our ability to image and measure the choroid in the human eye. Research using this technology over the past decade has dramatically improved our knowledge of the normal choroid, and its potential role in the regulation of eye growth and refractive error development. This review aims to provide an overview of recent work examining the normal human choroid, its changes with myopia and the possible role of the choroid in the mechanism regulating eye growth. Studies have demonstrated that choroidal thinning accompanies the development and progression of myopia, and have established a close link between eye growth and choroidal thickness changes. Dramatic thinning of the choroid is seen with high myopia, and associations are also observed between choroidal thinning and reduced vision, and the development of retinal pathology associated with high myopia. In the short-term, environmental factors known to be associated with myopia development and more rapid eye growth typically lead to a thinning of the choroid, whereas factors linked to a slowing of eye growth are typically associated with short-term choroidal thickening. Collectively, these findings suggest that the choroid is an important biomarker of eye growth in the human eye, and additional research to better understand the human choroid is likely to further our knowledge of the signals and pathways regulating eye growth, myopia development and progression.

show abstract

Section: Changes In the Choroid Associated With Environmental Factorsmentioning

confidence: 79%

“…Combinations of anti‐muscarinics and optical blur have been studied. Chiang and Phillips . administered 0.5 per cent atropine 22 hours prior to exposing subjects to −2.00 D hyperopic blur and found that prior atropine use negated the thinning effect of the hyperopic blur.…”

Section: Changes In the Choroid Associated With Environmental Factorsmentioning

confidence: 99%

Choroidal changes in human myopia: insights from optical coherence tomography imaging

Read

Fuss

Vincent

et al. 2019

Clinical and Experimental Optometry

114

View full text Add to dashboard Cite

show abstract

“…Studies in a range of species show that a thinning or thickening of the choroid in response to hyperopic or myopic defocus results in a rapid movement of the retina towards the defocused image plane, followed by alterations in scleral growth that eventuates in the development of experimental myopia or hyperopia, respectively . In humans, short‐term exposure to full‐field myopic and hyperopic defocus in both children and adults has also elicited a transient increase or decrease in choroidal thickness respectively, implying that the choroid may contribute to the mechanisms involved in the longer‐term development of refractive errors in humans …”

Section: Introductionmentioning

confidence: 99%

“…To date, human studies have only examined foveal or nasal and temporal parafoveal choroidal thickness changes in response to full‐field defocus and suggest that the defocus mediated changes in choroidal thickness occur uniformly across the central macular area. However, studies in chicks have revealed that greater changes in choroidal thickness occur centrally, rather than peripherally, in response to full‐field optical defocus .…”

Section: Introductionmentioning

confidence: 99%

Regional alterations in human choroidal thickness in response to short‐term monocular hemifield myopic defocus

Hoseini-Yazdi

Vincent

Collins

et al. 2019

Ophthalmic Physiologic Optic

View full text Add to dashboard Cite

Purpose To examine the regional changes in human choroidal thickness following short‐term exposure to hemifield myopic defocus using optical coherence tomography (OCT). Methods The central 26˚ visual field of the left eye of 25 healthy young adults (mean age 26 ± 5 years) was exposed to 60 min of clear vision (control session), +3 D full‐field, +3 D superior retinal and +3 D inferior retinal myopic defocus, with the right eye occluded. Choroidal thickness across the central 5 mm (17°) macular region was examined before and after 60 min of defocus using a high‐resolution, foveal centred vertical OCT line scan, with optical defocus simultaneously imposed using a Badal optometer and cold mirror system mounted on a Spectralis OCT device. Results Averaged across the central 5 mm macular area, choroidal thickness decreased by −4 ± 7 μm during the control session (p = 0.01), most likely due to the unique stimulus conditions of this study. The mean macular choroidal thickness increased during full‐field (+2 ± 8 μm), inferior retinal (+3 ± 7 μm) and superior retinal myopic defocus (+5 ± 9 μm), representing a significant thickening of the choroid compared to the control session (all p < 0.05). The defocus induced changes in macular choroidal thickness differed between the superior and inferior hemiretinal regions (F2.26, 54.27 = 29.75, p < 0.001). When only the superior retina was exposed to myopic defocus, the choroid thickened in the superior region (+7 ± 8 μm, p < 0.001), but did not change significantly in the inferior region (+3 ± 9 μm, p = 0.12). When only the inferior retina was exposed to myopic defocus, the choroid thickened inferiorly (+4 ± 8 μm, p = 0.005), with no significant change observed in the superior region (+1 ± 8 μm, p = 0.46). Conclusions These findings provide evidence supporting a local regional choroidal response to myopic defocus in the human eye, with hemifield myopic defocus leading to significant thickening of the choroid localised to the retinal region exposed to defocus. The novel finding of a localised response of the human choroid to hemifield myopic defocus, particularly in the superior hemiretina, may have important implications in optimising the optical design of myopia control interventions.

show abstract

“…8 Evidence from animal studies indicates that atropine acts via a non-accommodative mechanism, 9 and in humans atropine eye drops cause thickening of the choroid 10 and also abolish the choroidal thinning normally associated with exposing the retina to hyperopic defocus. 11 Atropine also reduces the refractive error changes associated with myopia progression in concentrations as low as 0.01% (which produce negligible mydriasis and cycloplegia). 6 Support for a retinal site of action comes from the finding that retinal dopamine levels, which are reduced in experimentally induced myopia in chicks, are increased with intravitreal injection of atropine that subsequently triggers spreading depression effects in the retina.…”

mentioning

confidence: 99%

The Effect of Atropine on Human Global Flash mfERG Responses to Retinal Defocus

Khanal

Turnbull

Lee

et al. 2019

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

PURPOSE. To investigate the action of atropine on global flash multifocal electroretinogram (gmfERG) responses to retinal defocus. METHOD. gmfERG recordings were made monocularly in 19 healthy adults under three lensimposed defocus conditions (2 diopters myopic, 2 diopters hyperopic, and no defocus) before and 24 hours after instillation of 1 drop of 0.1% atropine. Signals reflecting activity from the outer and inner retina (direct [DC] and induced [IC] components respectively) were analyzed. Responses were grouped into either a central (08-68) or peripheral (68-248) retinal zone. The gmfERG responses were compared relative to the no defocus, no atropine condition. RESULTS. Within the central zone, atropine had no effect on the amplitudes and peak times of DC or IC responses to defocus. For IC responses in the peripheral zone, there was a significant interaction effect of atropine and defocus (F 2,36 ¼ 6.050, P ¼ 0.011) with greater post-atropine amplitudes under myopic defocus (mean increase ¼ 15.5%, 95% confidence interval [CI] ¼ 5.6%-25.4%, P ¼ 0.004). Atropine also had a significant main effect of increasing IC peak times (F 1,18 ¼ 9.722, P ¼ 0.006). For DC responses, atropine had a significant main effect of increasing DC amplitudes (F 1,18 ¼ 7.821, P ¼ 0.012) and peak times (F 1,18 ¼ 15.406, P ¼ 0.001) regardless of sign of defocus. CONCLUSIONS. Our results imply that atropine acts in the inner layers of the peripheral retina to affect neuronal responses to myopic defocus, raising the possibility that atropine may potentiate the effects of myopic defocus in inhibiting eye growth.

show abstract

Effect of Atropine Eye Drops on Choroidal Thinning Induced by Hyperopic Retinal Defocus

Cited by 43 publications

References 28 publications

Choroidal changes in human myopia: insights from optical coherence tomography imaging

Choroidal changes in human myopia: insights from optical coherence tomography imaging

Regional alterations in human choroidal thickness in response to short‐term monocular hemifield myopic defocus

The Effect of Atropine on Human Global Flash mfERG Responses to Retinal Defocus

Contact Info

Product

Resources

About