Consejo Alejandra, Radhakrishnan Hema, Iskander D Robert
Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland.
Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
Ophthalmic Physiol Opt. 2017 May;37(3):263-274. doi: 10.1111/opo.12377.
To assess whether the sclera changes its shape during accommodation, quantify those changes and ascertain whether they depend on age and refractive power.
Twenty-two subjects, aged between 19 and 84 years old were recruited for the study. Young subjects were grouped according to their refractive power as emmetropes (seven subjects) and myopes (seven subjects). Data were obtained with a height corneo-scleral topographer (Eye Surface Profiler) with coverage area far beyond the limbus. Lenses of different power were used to stimulate accommodative demand of 0.0 D, 2.5 D and 4.0 D. Elevation differences between measurements acquired while at the intermediate or close target and infinity where calculated for each participant for the horizontal meridian for a 16 mm chord.
We found that sclera undergoes significant changes in its shape with accommodation in young subjects able to accommodate but not for those with limited accommodation. For a 4.0 D stimulus at the nasal side the scleral change amounted on average to 390 ± 330 μm (mean ± S.D.) for the young group. This phenomenon was more pronounced in myopes (for a 4.0 D target; nasal part: 560 ± 350 μm (mean ± S.D.)) than emmetropes (for a 4.0 D target; nasal part: 220 ± 120 μm (mean ± S.D.)). Differences were also found between different meridians.
Scleral shape undergoes changes with accommodation and this phenomenon is more pronounced in myopes than emmetropes.
评估在调节过程中巩膜是否改变其形状，量化这些变化并确定它们是否取决于年龄和屈光力。
招募了22名年龄在19至84岁之间的受试者进行该研究。年轻受试者根据其屈光力分为正视眼（7名受试者）和近视眼（7名受试者）。使用具有远超出角膜缘覆盖区域的高分辨率角膜巩膜地形图仪（眼表面轮廓仪）获取数据。使用不同屈光度的镜片来刺激0.0D、2.5D和4.0D的调节需求。为每个参与者计算水平子午线16mm弦长在中间或近距离目标与无穷远时所获取测量值之间的高度差。
我们发现，能够调节的年轻受试者的巩膜在调节时其形状会发生显著变化，而调节能力有限的受试者则不会。对于年轻组，在鼻侧给予4.0D刺激时，巩膜变化平均为390±330μm（平均值±标准差）。这种现象在近视眼中比正视眼中更明显（对于4.0D目标；鼻侧部分：560±350μm（平均值±标准差））（对于4.0D目标；鼻侧部分：220±120μm（平均值±标准差））。在不同子午线之间也发现了差异。
巩膜形状在调节时会发生变化，并且这种现象在近视眼中比正视眼中更明显。
