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

Hoseini-Yazdi, Seyed Hosein; Vincent, Stephen J.; Collins, Michael J.; Read, Scott A.

doi:10.1111/opo.12609

Cited by 30 publications

(33 citation statements)

References 74 publications

(156 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This study investigated the independent and combined effects of atropine eye drops and short-term retinal defocus on the thickness of the choroid in children. With regard to defocus, our results are in line with previous human studies showing that imposition of myopic and hyperopic retinal defocus leads to choroidal thickening and thinning respectively within 60 min of applying defocus in adults 11 , 31 , 34 , 35 and children 33 . With regard to atropine, our results also corroborate previous findings that atropine eye drops themselves increase the thickness of the choroid in young adults 25 and children 26 .…”

Section: Discussionsupporting

confidence: 91%

Additive effect of atropine eye drops and short-term retinal defocus on choroidal thickness in children with myopia

Chiang

Turnbull

Phillips

2020

Sci Rep

View full text Add to dashboard Cite

Atropine eye drops and myopic retinal defocus each slow progression of myopia (short-sight). They also cause thickening of the choroid, and it has been suggested that the thickening is a precursor for reduced eye growth and slowed myopia progression. We investigated whether choroidal thickening due to optical defocus would add to thickening due to atropine when both were applied simultaneously. Addition would suggest that combining the two clinical treatments may improve efficacy of myopia control. We studied 20 children receiving 0.3% atropine daily for myopia control, over a period of 6 months. We imposed short periods of retinal defocus (1 h of myopic or hyperopic defocus (± 2.00D)) both before, and after 1 week and 3 and 6 months of atropine treatment. Prior to atropine, myopic or hyperopic defocus caused significantly thicker or thinner choroids respectively (± 12 µm, p < 0.001). After one week of atropine alone, thickness had increased (+ 21 µm; SD 17 µm; p < 0.001), and it increased further (by + 13 µm; SD 6 µm; p < 0.001) when exposed to myopic defocus. Atropine abolished choroidal thinning in response to hyperopic defocus. These effects remained the same after 3 and 6 months of atropine treatment. Our results show that additive effects of atropine and optical defocus are present at the level of the choroid, and suggest that combining optical and pharmaceutical treatments is likely to enhance efficacy of clinical myopia control.

show abstract

Section: Discussionsupporting

confidence: 91%

Additive effect of atropine eye drops and short-term retinal defocus on choroidal thickness in children with myopia

Chiang

Turnbull

Phillips

2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Choroidal thickness changes bidirectionally after short-term exposure to imposed spherical defocus, with myopic defocus eliciting a thickening 30 , 38 − 42 and hyperopic defocus a thinning of the choroid. 38 − 40 , 42 , 43 These spherical defocus-mediated changes in ChT occur within 20 minutes in the subfoveal location 39 , 40 and contribute to alterations in the diurnal variations of axial length 41 , 43 and longer term changes in the axial growth of the eye.…”

Section: Discussionmentioning

confidence: 99%

“…During the OCT imaging, the left eye viewed a small fixation arrow on an LCD screen, presented externally through the Badal optometer and the bright blue internal fixation light of the Spectralis was switched off. 30 The instrument's follow-up mode allowed all the B-scan images, acquired across all measurement times over the four experimental sessions, to be registered to the first baseline scan of the first visit.…”

Section: Methodsmentioning

confidence: 99%

“…The OCT B-scans collected at each measurement time point were exported and segmented using a semi-automatic procedure. 30,31 The anterior boundary of the choroid, defined as the outer border of the hyperreflective line corresponding to the retinal pigment epithelium/Bruch's membrane complex, and the posterior boundary of the choroid, defined as the inner border of the hyper-reflective line corresponding to the chorioscleral junction, were segmented automatically using a custom-written algorithm, 32 with any errors in segmentation manually corrected by one experienced masked observer. The mean macular ChT, averaged across the central 5-mm region centered on the fovea, was then estimated across the vertical and horizontal meridian ( Fig.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Astigmatic Defocus Leads to Short-Term Changes in Human Choroidal Thickness

Hoseini-Yazdi

Vincent

Read

et al. 2020

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

To examine the choroidal thickness (ChT) response to short-term with-the-rule (WTR) and against-the-rule (ATR) simple myopic astigmatic defocus, with the response to spherical myopic defocus and clear vision used as control conditions. METHODS. The left eye of 18 healthy adults aged 28 ± 6 years was exposed to clear vision, +3 D spherical myopic defocus, +3 D × 180 WTR, or +3 D × 90 ATR astigmatic defocus for 60 minutes, over four randomly ordered visits, while their right eye was optimally corrected. The macular ChT was measured with optical coherence tomography along the vertical and horizontal meridians before and after 20, 40, and 60 minutes of defocus. RESULTS. After 60 minutes of defocus, ChT increased by +8 ± 5 μm (P < 0.001) with spherical myopic defocus, but varied with simple myopic astigmatic defocus, depending on the axis of astigmatism (P < 0.001), increasing by +5 ± 6 μm (P = 0.037) with WTR and decreasing by −4 ± 5 μm (P = 0.011) with ATR astigmatic defocus. These changes were similar across the vertical and horizontal meridians (P = 0.22). The ChT changes were greater than the change during the clear vision control condition (−1 ± 4 μm) for WTR (+5 ± 5 μm, P = 0.002) but not ATR (−4 ± 6 μm, P = 0.09) astigmatic defocus. CONCLUSIONS. These results provide insights into the human ChT response to short-term astigmatic defocus and highlight a potential difference in the myopiagenic signal associated with the orientation of astigmatic blur.

show abstract

“…To cite examples, Marzani and Wallman have provided compelling evidence showing how the choroid influences the proteoglycan synthesis of the sclera in chick eyes undergoing and recovering from form-deprivation [23]. There is also evidence from humans suggesting an active contribution of the choroid in the process of emmetropization [24,25]. Not focusing on the choroid and sclera in this review does not mean at all, that they may not be involved in the process of myopization.…”

Section: Bruch's Membrane and Process Of Elongationmentioning

confidence: 99%

Advances in myopia research anatomical findings in highly myopic eyes

et al. 2020

View full text Add to dashboard Cite

Background: The goal of this review is to summarize structural and anatomical changes associated with high myopia. Main text: Axial elongation in myopic eyes is associated with retinal thinning and a reduced density of retinal pigment epithelium (RPE) cells in the equatorial region. Thickness of the retina and choriocapillaris and RPE cell density in the macula are independent of axial length. Choroidal and scleral thickness decrease with longer axial length in the posterior hemisphere of the eye, most marked at the posterior pole. In any eye region, thickness of Bruch's membrane (BM) is independent of axial length. BM opening, as the inner layer of the optic nerve head layers, is shifted in temporal direction in moderately elongated eyes (axial length <26.5 mm). It leads to an overhanging of BM into the intrapapillary compartment at the nasal optic disc side, and to an absence of BM at the temporal disc border. The lack of BM at the temporal disc side is the histological equivalent of parapapillary gamma zone. Gamma zone is defined as the parapapillary region without BM. In highly myopic eyes (axial length >26.5 mm), BM opening enlarges with longer axial length. It leads to a circular gamma zone. In a parallel manner, the peripapillary scleral flange and the lamina cribrosa get longer and thinner with longer axial length in highly myopic eyes. The elongated peripapillary scleral flange forms the equivalent of parapapillary delta zone, and the elongated lamina cribrosa is the equivalent of the myopic secondary macrodisc. The prevalence of BM defects in the macular region increases with longer axial length in highly myopic eyes. Scleral staphylomas are characterized by marked scleral thinning and spatially correlated BM defects, while thickness and density of the choriocapillaris, RPE and BM do not differ markedly between staphylomatous versus non-staphylomatous eyes in the respective regions. Conclusions: High axial myopia is associated with a thinning of the sclera and choroid posteriorly and thinning of the retina and RPE density in the equatorial region, while BM thickness is independent of axial length. The histological changes may point towards BM having a role in the process of axial elongation.

show abstract

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

Cited by 30 publications

References 74 publications

Additive effect of atropine eye drops and short-term retinal defocus on choroidal thickness in children with myopia

Additive effect of atropine eye drops and short-term retinal defocus on choroidal thickness in children with myopia

Astigmatic Defocus Leads to Short-Term Changes in Human Choroidal Thickness

Advances in myopia research anatomical findings in highly myopic eyes

Contact Info

Product

Resources

About