Department of Biosciences, The New England College of Optometry, Boston, MA 02115, United States.
Exp Eye Res. 2012 Sep;102:93-103. doi: 10.1016/j.exer.2012.07.002. Epub 2012 Jul 22.
Ciliary ganglionectomy inhibits the development of myopia in chicks (Schmid et al., 1999), but has no effect on the compensatory responses to spectacle lenses (Schmid and Wildsoet, 1996). This study was done to assess the potential influence of the other parasympathetic input to the choroid, the pterygopalatine ganglia, on the choroidal and axial responses to retinal defocus, and to form deprivation. 4-5 week-old chicks had one of the following surgeries to one eye: (1) Section (X) of the autonomic part of cranial N VII (input to the pterygopalatine ganglia) (PPGX, n = 16), (2) PPGX plus ciliary ganglionectomy (PPG/CGX, n = 23) or (3) PPGX plus superior cervical ganglionectomy (PPG/SCGX, n = 10). Experimental eyes were fitted with positive or negative lenses, or diffusers, several days after surgery. In one group of PPG/CGX, eyes did not wear any devices (n = 8). Intact (no surgery) controls were done for all visual manipulations (lenses or diffusers). Sham surgeries were done for the PPG/CGX condition (n = 4). Ocular dimensions were measured using A-scan ultrasonography prior to the surgery, 5 days later when visual devices were placed on the eyes, at the end of lens- or diffuser-wear, and in the case of diffusers, 4 days after diffuser removal to look at "recovery". Refractive errors were measured using a Hartinger's refractometer. IOP was measured in 7 PPG/CGX birds 7d after surgery. PPGX/CGX resulted in choroidal thickening (125 μm) and a decrease in IOP over one week post-surgery. It also prevented the development of myopia in response to form deprivation (X vs intact: 0.2 D vs -4.1 D; p < 0.005), by preventing the increase in axial elongation (250 μm vs 670 μm/5d; p < 0.005). In fact, growth rate slowed below normal (X vs fellow eyes: 250 μm vs 489 μm/5d; p = 0.002). By contrast, there were no effects of this lesion on the development of myopia in response to negative lenses (X vs intact: -5.4 D vs -5.3 D). All three lesions inhibited the compensatory choroidal thickening in response to myopic defocus (ANOVA, p = 0.0008), but had no effect on the thinning response to hyperopic defocus. These results argue for different underlying mechanisms for the growth responses to form deprivation vs negative lens wear. They also imply that choroidal thickening and thinning are not opposing elements of a single mechanism.
睫状神经节切除术抑制小鸡的近视发展（Schmid 等人，1999 年），但对眼镜的代偿反应没有影响（Schmid 和 Wildsoet，1996 年）。本研究旨在评估脉络膜的其他副交感神经输入——翼腭神经节对视网膜离焦和剥夺性远视的脉络膜和轴向反应的潜在影响。4-5 周大的小鸡接受了以下一种手术之一：（1）颅神经 VII 的自主部分（输入到翼腭神经节）（PPGX，n=16）的 X 节段（X），（2）PPGX 加睫状神经节切除术（PPG/CGX，n=23）或（3）PPGX 加颈上神经节切除术（PPG/SCGX，n=10）。手术后几天，实验眼戴上正或负透镜或散光镜。在一组 PPG/CGX 中，眼睛不戴任何设备（n=8）。对所有视觉操作（镜片或散光镜）进行完整（无手术）对照。对 PPG/CGX 条件进行假手术（n=4）。在散光镜去除后的 4 天，通过测量眼内压来观察“恢复”。在手术前、放置视觉设备后 5 天、镜片或散光镜佩戴结束时以及在散光镜佩戴期间，使用 A 扫描超声测量眼轴长度。使用 Hartinger 折射计测量屈光度。在手术后 7 天，对 7 只 PPG/CGX 鸟类进行了眼内压测量。PPG/CGX 导致脉络膜增厚（125μm）和手术后一周内眼内压降低。它还通过防止轴向伸长（250μm 与 670μm/5d；p<0.005）来防止形觉剥夺引起的近视发展（X 与完整：0.2D 与-4.1D；p<0.005）。事实上，生长速度低于正常水平（X 与对侧眼：250μm 与 489μm/5d；p=0.002）。相比之下，这种病变对负透镜引起的近视发展没有影响（X 与完整：-5.4D 与-5.3D）。所有三种病变都抑制了近视离焦引起的代偿性脉络膜增厚（ANOVA，p=0.0008），但对远视离焦引起的脉络膜变薄没有影响。这些结果表明，形觉剥夺和负透镜佩戴引起的生长反应有不同的潜在机制。它们还意味着脉络膜增厚和变薄不是单一机制的对立因素。
