Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, China; School of Nursing, Chengde Medical University, Chengde, Hebei, 067000, China.
Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, China; Shenyang Mental Health Center, Shenyang, 110168, China.
J Psychiatr Res. 2022 Aug;152:278-288. doi: 10.1016/j.jpsychires.2022.06.012. Epub 2022 Jun 13.
A large body of recent research has demonstrated that patients with schizophrenia exhibit significant changes in visual function and ocular tissue structure in the early stages of onset. It is therefore possible to explore a novel scientific breakthrough in the etiology of schizophrenia by transforming the traditional study of brain structure and function with a view to examining the potential field of eye tissue and function. However, few studies have investigated the correlation between iris characteristics and schizophrenia, and evidence is lacking in this regard. Thus, further exploration is needed.
This study was designed to analyze the characteristics of iris structure, color vision function and cognitive function, as well as the changes therein in patients with the first-episode drug-free schizophrenia before and after antipsychotic treatment. It aimed to preliminarily identify easily-measurable biomarkers for early clinical screening and diagnosis of schizophrenia.
This study recruited 61 patients (22 males) with first-episode schizophrenia. Prior to the commencement of treatment with antipsychotic drugs, the Montreal Cognitive Assessment (MoCA) and Farnsworth-Munsell Dichotomous (D-15 Hue Test) were used as assessment tools to evaluate cognitive function and color vision function, respectively. Over a 6-week period, patients received a second-generation antipsychotic treatment (all converted to olanzapine equivalent dose) as prescribed by the doctor, and the Positive and Negative Syndrome Scale (PANSS) was applied to evaluate the clinical treatment effects before treatment (baseline), as well as at the 2nd, 4th, and 6th weeks after drug treatment. On the basis of iris characteristics, the patients were divided into groups. The observed differences in drug treatment effects between the groups were then compared and analyzed to further clarify the relationship between treatment efficacy and iris characteristics. Finally, changes in the cognitive function and color vision function of patients at baseline and at the 6th week after drug treatment were compared, and the effects of antipsychotic drug treatment on the above-mentioned functions were analyzed.
On the basis of structural iris characteristics, 61 patients were classified as follows: 28 patients without iris crypts and 33 with iris crypts; 35 without iris pigment dots and 26 with iris pigment dots; 42 without iris wrinkles and 19 with iris wrinkles. No significant difference was observed in the PANSS scores of all of the patients at baseline; however, significant differences were found in patients with iris crypts and iris pigment dots at each follow-up timepoint (i.e., at the 2nd, 4th, and 6th week). Moreover, it is noteworthy that, compared with other patients, the PANSS scores of patients without specific iris structure characteristics (iris crypts and pigment dots) decreased significantly (P<0.05), which indicated that the drug therapy was highly effective. Excluding the interference of drug factors, a significant correlation was found between the results of the D-15 (color vision function) and MoCA (cognitive function) in first-episode untreated patients (r = -0.401, P < 0.05). In addition, the MoCA scores (mean difference = 2.36, t = 10.05, P ˂ 0.01) were significantly higher after 6 weeks of antipsychotic drug treatment compared to conditions at baseline.
The findings of this study demonstrated that color vision function of patients with schizophrenia improved with the improvement of cognitive function. The structural characteristics of the iris with crypts and pigment dots could have a significant impact on the drug treatment effect of schizophrenia and could be considered as a potential biomarker for detecting and recognizing schizophrenia.
大量近期研究表明，精神分裂症患者在发病早期表现出明显的视觉功能和眼部组织结构变化。因此，通过将传统的大脑结构和功能研究转化为研究潜在的眼部组织和功能，有可能探索精神分裂症病因学的新科学突破。然而，很少有研究探讨虹膜特征与精神分裂症之间的关系，而且这方面的证据也不足。因此，需要进一步探索。
本研究旨在分析首发未经药物治疗的精神分裂症患者在抗精神病治疗前后的虹膜结构、色觉功能和认知功能特征及其变化，旨在初步确定易于测量的生物标志物，用于早期临床筛查和诊断精神分裂症。
本研究纳入了 61 名首发精神分裂症患者（男 22 名）。在开始使用抗精神病药物治疗之前，使用蒙特利尔认知评估（MoCA）和 Farnsworth-Munsell 二值（D-15 色调测试）分别作为评估认知功能和色觉功能的工具。在 6 周的时间内，患者按照医生的建议接受第二代抗精神病药物（全部转换为奥氮平等效剂量）治疗，并应用阳性和阴性症状量表（PANSS）在治疗前（基线）以及治疗后第 2、4 和 6 周评估临床治疗效果。根据虹膜特征，将患者分为两组。然后比较和分析两组之间药物治疗效果的差异，以进一步阐明治疗效果与虹膜特征之间的关系。最后，比较患者在基线和药物治疗后第 6 周的认知功能和色觉功能变化，并分析抗精神病药物治疗对上述功能的影响。
根据结构虹膜特征，将 61 名患者分为以下两组：28 名无虹膜隐窝患者和 33 名有虹膜隐窝患者；35 名无虹膜色素点患者和 26 名有虹膜色素点患者；42 名无虹膜皱纹患者和 19 名有虹膜皱纹患者。所有患者在基线时的 PANSS 评分均无显著差异；然而，在每个随访时间点（即第 2、4 和 6 周），有虹膜隐窝和虹膜色素点的患者的 PANSS 评分均有显著差异。此外，值得注意的是，与其他患者相比，没有特定虹膜结构特征（虹膜隐窝和色素点）的患者的 PANSS 评分显著降低（P<0.05），这表明药物治疗非常有效。排除药物因素的干扰后，首次未经治疗的患者的 D-15（色觉功能）和 MoCA（认知功能）结果之间存在显著相关性（r=−0.401，P<0.05）。此外，与基线相比，抗精神病药物治疗 6 周后 MoCA 评分（平均差值=2.36，t=10.05，P<0.01）显著提高。
本研究结果表明，精神分裂症患者的色觉功能随着认知功能的改善而改善。具有隐窝和色素点的虹膜结构特征可能对精神分裂症的药物治疗效果有显著影响，可以作为检测和识别精神分裂症的潜在生物标志物。
