Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia.
Ophthalmic Physiol Opt. 2019 May;39(3):172-182. doi: 10.1111/opo.12609. Epub 2019 Apr 4.
To examine the regional changes in human choroidal thickness following short-term exposure to hemifield myopic defocus using optical coherence tomography (OCT).
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.
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 (F = 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).
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.
使用光学相干断层扫描（OCT）检查人眼脉络膜厚度在短期暴露于偏中心性近视离焦后的区域变化。
25 名健康年轻成年人（平均年龄 26 ± 5 岁）的左眼中央 26°视野暴露于 60 分钟清晰视力（对照期）、+3 D 全视野、+3 D 上视网膜和+3 D 下视网膜近视离焦，右眼被遮盖。使用高分辨率、中心凹垂直 OCT 线扫描，同时使用 Badal 验光仪和安装在 Spectralis OCT 设备上的冷反射镜系统在中央 5mm（17°）黄斑区域检查 60 分钟离焦前后的脉络膜厚度。
在中央 5mm 黄斑区域内，对照期脉络膜厚度平均减少-4 ± 7μm（p=0.01），这可能是由于该研究独特的刺激条件所致。全视野（+2 ± 8μm）、下视网膜（+3 ± 7μm）和上视网膜近视离焦（+5 ± 9μm）期间平均黄斑脉络膜厚度增加，与对照期相比表现出脉络膜明显增厚（均 p<0.05）。上、下半视网膜近视离焦引起的黄斑脉络膜厚度变化存在差异（F=29.75，p<0.001）。仅上视网膜暴露于近视离焦时，上区脉络膜增厚（+7 ± 8μm，p<0.001），但下区无明显变化（+3 ± 9μm，p=0.12）。仅下视网膜暴露于近视离焦时，下区脉络膜增厚（+4 ± 8μm，p=0.005），上区无明显变化（+1 ± 8μm，p=0.46）。
这些发现为人类眼球对近视离焦的局部区域性脉络膜反应提供了证据，偏中心性近视离焦导致与离焦视网膜区域相对应的脉络膜显著增厚。人类脉络膜对偏中心性近视离焦的局部反应的新发现，特别是在上半视网膜，可能对优化近视控制干预的光学设计具有重要意义。
