Temporal relationship of choroidal blood flow and thickness changes during recovery from form deprivation myopia in chicks
Temporal relationship of choroidal blood flow and thickness changes during recovery from form deprivation myopia in chicks
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DOI：
10.1006/exer.2002.1142
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发表时间：
2002-05-01
影响因子：
3.4
通讯作者：
Reiner, A
中科院分区：
文献类型：
--
作者：
Fitzgerald, MEC;Wildsoet, CF;Reiner, A
当形态被剥夺时，雏鸡迅速发展为轴向近视，如果在足够早的年龄停止治疗，它们就会恢复。眼球轴向生长增加伴随着脉络膜变薄和脉络膜血流减少（ChBF）。相反，在恢复过程的早期阶段。脉络膜变厚，使视网膜向新的聚焦平面移动。关于近视恢复期间ChBF的信息很少。由于近视恢复期间脉络膜增厚可能是由ChBF的增加驱动的，因此我们研究了近视恢复期间ChBF与脉络膜厚度变化的时间关系。从3日龄开始，用可拆卸的塑料扩散器进行2-3周的饲养。在扩散器移除240小时后，在不同时间用高频a超扫描测量眼轴向尺寸，包括脉络膜厚度。采用激光多普勒血流法，在a超扫描后立即经眼测量ChBF。在去除扩散器后立即测量的雏鸡中，处理组的玻璃体腔长29.9%，脉络膜薄6.4%，ChBF为13.7%，低于未处理组的对照组。这些变化是小鸡近视的特征，在年轻的眼睛中是可逆的。因此，在去除扩散器7小时后检查的雏鸡，恢复眼的ChBF现在大于对照眼。ChBF增加在移除了扩散器后约19小时达到峰值。在7-30小时的监测期间，与对照组相比，治疗眼的ChBF平均增加187%。治疗后眼ChBF逐渐恢复到对照水平。与早期短暂的ChBF增加相反，治疗眼的脉络膜增厚直到弥散器移除后30小时才观察到，并且在剩余的监测期间相对于对照眼继续增加，最终达到平均值182%。本研究表明，在从形式剥夺性近视恢复的雏眼中，ChBF的大幅增加先于脉络膜厚度的增加，并且比后者更短暂。这些结果提高了ChBF增加可能触发甚至驱动脉络膜扩张的可能性，这可能是通过促进鸟类眼睛中发育良好的脉络膜淋巴腔的填充。(C) 2002 Elsevier Science Ltd.
When form deprived, young chicks rapidly develop axial myopia, from which they recover if the treatment is ceased at a sufficiently early age. The increased axial growth of the eye is accompanied by choroidal thinning and decreased choroidal blood flow (ChBF). In contrast, during the early part of the recovery process. the choroid thickens, shifting the retina towards the new plane of focus. Little information is available about ChBF during recovery from myopia. Because of the possibility that choroidal thickening during recovery from myopia might be driven by an increase in ChBF, the temporal relationship of ChBF and choroidal thickness changes was examined during such recovery.White Leghorn chicks were form deprived from 3 days of age for 2-3 weeks using detachable plastic diffusers. Axial ocular dimensions, including choroidal thickness, were then measured by high frequency A-scan ultrasonography at various times after the diffusers were removed up to 240 hr. ChBF was measured transclerally immediately following the A-scan ultrasonography, using laser Doppler flowmetry.In the chicks measured immediately after diffuser removal, the vitreous chamber was 29.9%, longer, the choroid was 6.4% thinner and ChBF was 13.7%, less in the treated than in the non-treated control eyes. These changes are characteristic of myopic chick eyes and are reversible in young eyes. Thus, in chicks examined 7 hr after diffuser removal, the ChBF in recovering eyes was now greater than that in control eyes. This ChBF increase peaked about 19 hr after the diffusers were removed. The mean increase in ChBF in treated eyes for the 7-30 hr monitoring period was 187%, relative to control eyes. ChBF in the treated eyes gradually returned to the control level after this time. By contrast to the early, transient increase in ChBF, significant choroidal thickening was not observed in treated eyes until 30 hr after diffuser removal, and continued to increase relative to control eyes over the remainder of the monitoring period, reaching a final mean value of 182%.This study demonstrates, in chick eyes recovering from form deprivation myopia, large increases in ChBF that preceded increases in choroidal thickness and were also more transient than the latter. These results raise the possibility that the increase in ChBF may trigger or even drive the subsequent onset of choroidal expansion, perhaps by facilitating the filling of the choroidal lymphatic lacunae that are well developed in the avian eye. (C) 2002 Elsevier Science Ltd.