Objective: To analyze the characteristics of full-field stimulus thresholds (FST) in patients with middle-and late-stage inherited retinal dystrophy (IRD), and to explore the feasibility of the FST test in evaluating the retinal function for IRD patients. Methods: It was a retrospective case series study. Twenty-eight patients with IRD whose full-field electroretinogram (ERG) results showed no electrical activity (20 patients) or a serious decrease in electrical activity (8 patients) were enrolled, including 17 males and 11 females, with a median age of 32 years. Ten normal controls were also enrolled. All eyes had a measurement of best corrected visual acuity (BCVA) and an ERG test. FST stimulated by red, blue and white lights were examined with an electrophysiological instrument. The decimal value of BCVA was converted to logarithm of the minimum angle of resolution. Data of the better eye of each participant were used for statistical analysis. Independent sample t-test was used to analyze the difference in FST among patients. Linear regression was used to analyze the correlation between FST, visual acuity and ERG amplitudes. Results: The BCVA of all eyes was 0.7±0.6. Under the stimulation of red, blue and white lights, the FST were(-27.0±7.1), (-47.4±12.2) and(-41.7±11.5) dB in the 8 eyes with decreased electrical activity, (-16.3±7.0), (-27.2±13.7) and(-23.5±12.5) dB in the 20 eyes with no electrical activity, and(-39.9±4.0), (-65.8±4.0) and(-58.5±3.4) dB in the 10 control eyes, respectively. The FST of IRD patients were higher than the normal controls. The FST with red, blue and white lasers in eyes with no electrical activity were higher than those with severely reduced electrical activity (t=-3.472, -3.506, -3.433; all P=0.002). The BCVA was not correlated with the FST under the red, blue and white light stimulation in eyes with a serious reduction in electrical activity (r=0.134, 0.011, 0.010; P=0.055, 0.601, 0.611). There was a linear correlation between the red light stimulus FST and the b-wave amplitude of flicker ERG response (r=-0.591, P=0.026), but there was no significant correlation between other amplitudes and FST. Conclusions: The FST test is a supplementary method to evaluate the retinal function of patients with middle-and late-stage IRD. It can quantitatively reflect the function of rod and cone cell system. As the retinal function of IRD patients decreases, the FST gradually increase.
目的： 探讨中晚期遗传性视网膜营养不良（IRD）患者全视野刺激阈值（FST）的特点及临床上用FST检查结果评估IRD患者视网膜功能的可行性。 方法： 回顾性病例系列研究。纳入2019年10月至2021年10月在北京协和医院眼科确诊中晚期IRD并且全视野视网膜电图（ERG）结果为熄灭型或重度降低型的28例患者资料，其中男性17例，女性11例；年龄中位数为32岁。包括中重度降低型8例，熄灭型20例。另募集矫正视力正常的志愿者10名作为对照。所有受检者均行最佳矫正视力（BCVA）及ERG检查，并使用电生理仪检查红、蓝、白光刺激下的FST。采用独立样本t检验分析不同类型患者间各刺激光下的FST差异；采用线性回归分析各刺激光FST与视力、ERG各项振幅之间的相关性。 结果： 所有患眼BCVA为0.7±0.6（最小分辨角的对数）。红、蓝、白光刺激下，8只重度降低型患眼的FST分别为（-27.0±7.1）、（-47.4±12.2）、（-41.7±11.5）dB；20只熄灭型患眼分别为（-16.3±7.0）、（-27.2±13.7）、（-23.5±12.5）dB；10只对照眼分别为（-39.9±4.0）、（-65.8±4.0）、（-58.5±3.4）dB。IRD患眼不同刺激光下的FST均较对照眼升高；熄灭型患眼红、蓝、白色光刺激下的FST均高于重度降低型患眼（t=-3.472，-3.506，-3.433；均P=0.002）。重度降低型患眼BCVA与红、蓝、白光刺激下的FST阈值均无相关（r=0.134，0.011，0.010；P=0.055，0.601，0.611）；明适应30 Hz闪烁ERG的b波振幅与红光刺激下的FST呈负相关（r=-0.591，P=0.026），其他各项ERG振幅与FST之间均无相关性。 结论： FST是一种评估中晚期IRD患者视功能的可行的补充检测方法，可定量反映IRD患者的视杆和视锥细胞系统功能。随着IRD患者视网膜功能降低，其FST阈值逐渐升高。.