Neuro-Ophthalmology Unit, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland.
Invest Ophthalmol Vis Sci. 2012 Aug 15;53(9):5562-9. doi: 10.1167/iovs.12-10230.
We characterized the pupil responses that reflect rod, cone, and melanopsin function in a genetically homogeneous cohort of patients with autosomal dominant retinitis pigmentosa (adRP).
Nine patients with Gly56Arg mutation of the NR2E3 gene and 12 control subjects were studied. Pupil and subjective visual responses to red and blue light flashes over a 7 log-unit range of intensities were recorded under dark and light adaptation. The pupil responses were plotted against stimulus intensity to obtain red-light and blue-light response curves.
In the dark-adapted blue-light stimulus condition, patients showed significantly higher threshold intensities for visual perception and for a pupil response compared to controls (P = 0.02 and P = 0.006, respectively). The rod-dependent, blue-light pupil responses decreased with disease progression. In contrast, the cone-dependent pupil responses (light-adapted red-light stimulus condition) did not differ between patients and controls. The difference in the retinal sensitivity to blue and red stimuli was the most sensitive parameter to detect photoreceptor dysfunction. Unexpectedly, the melanopsin-mediated pupil response was decreased in patients (P = 0.02).
Pupil responses of patients with NR2E3-associated adRP demonstrated reduced retinal sensitivity to dim blue light under dark adaptation, presumably reflecting decreased rod function. Rod-dependent pupil responses were quantifiable in all patients, including those with non-recordable scotopic electroretinogram, and correlated with the extent of clinical disease. Thus, the chromatic pupil light reflex can be used to monitor photoreceptor degeneration over a larger range of disease progression compared to standard electrophysiology.
我们对一组具有常染色体显性遗传性视网膜色素变性（adRP）的遗传同质患者进行了研究，以确定反映视杆细胞、视锥细胞和黑视素功能的瞳孔反应。
研究了 9 名携带 NR2E3 基因 Gly56Arg 突变的患者和 12 名对照者。在暗适应和明适应条件下，记录了瞳孔对红光和蓝光闪烁的主观视觉反应和瞳孔反应，光强度范围为 7 个对数单位。将瞳孔反应绘制为刺激强度图，以获得红光和蓝光的响应曲线。
在暗适应蓝光刺激条件下，与对照组相比，患者的视觉感知和瞳孔反应的阈值强度明显更高（分别为 P = 0.02 和 P = 0.006）。随着疾病的进展，视杆细胞依赖的蓝光瞳孔反应逐渐下降。相比之下，视锥细胞依赖的瞳孔反应（明适应红光刺激条件）在患者和对照组之间没有差异。对蓝光和红光刺激的视网膜敏感性差异是检测光感受器功能障碍的最敏感参数。出乎意料的是，患者的黑视素介导的瞳孔反应下降（P = 0.02）。
NR2E3 相关的 adRP 患者的瞳孔反应显示在暗适应下对弱蓝光的视网膜敏感性降低，这可能反映了视杆细胞功能的降低。所有患者都可定量测量视杆细胞依赖性的瞳孔反应，包括那些无法记录暗视电图的患者，并且与临床疾病的严重程度相关。因此，与标准电生理学相比，色觉瞳孔光反射可以在更大的疾病进展范围内监测光感受器的退化。
