糖尿病併視網膜病變患者視覺功能之研究

Measurement of Visual Function in People with Diabetic Retinopathy

蔡麗婷(Li-Ting Tsai)

指導教授 ： 張 彧

國立臺灣大學/醫學院/職能治療研究所/博士(2014年)

https://doi.org/10.6342/NTU.2014.03189

摘要

背景與目的: 隨著罹患糖尿病的人口數不斷增加，糖尿病容易造成大、小血管之併發症，因此對於個人健康或國家的照護體制而言都是沉重負擔。其中糖尿病視網膜病變是造成工作年齡成人視覺障礙和失明的主要原因。除了視網膜血管病變之外，糖尿病也會造成視網膜神經細胞退化，且可能發生於視網膜血管病變之前。過去研究指出，糖尿病視網膜病變會減退患者的視覺功能，進而影響患者的生活品質，但早期視網膜神經細胞退化同樣會影響患者的視覺功能。本研究之目的是以第二型糖尿病患者為研究對象，探討糖尿病患者在沒有視網膜病變和不同階段視網膜病變下的視覺功能表現，以及患者的視覺功能與其生活品質之相關性。
方法: 糖尿病患者的收案來源是台北市聯合醫院忠孝院區新陳代謝科，且有加入糖尿病照護網之病患。依糖尿病患者最近一次眼科檢查的結果，將患者分成五組，包括沒有視網膜病變組(no diabetic retinopathy, no-DR)、非增殖型視網膜病變組(non-proliferative diabetic retinopathy, NPDR)、增殖型視網膜病變組(proliferative diabetic retinopathy, PDR)、非增殖型視網膜病變併黃斑部水腫組(macular edema，ME)和增殖型視網膜病變合併黃斑部水腫組(PDR&ME)。第一篇研究之對象包括no-DR和NPDR病患，對照組是無罹患糖尿病之受試者。採用心理物理學之典範和方法，評估受試者於無色彩(achromatic)和色彩(chromatic)對比知覺測試之視覺行為反應，以辨識對比閾值為指標，探討糖尿病患者早期視覺訊息傳導之視覺功能表現，包括M-路徑(magnocelllular pathway)、P-路徑(parvocellular pathway)和K-路徑(koniocellular pathway)三部分。測量是使用pulsed pedestal paradigm和pedestal-△-pedestal paradigm比較M-路徑和P-路徑之反應；其次使用chromatic contrast discrimination paradigm評估P-路徑和K-路徑之反應。第二篇研究是使用黃斑部多功能視覺測驗(Macular Multi-Function Assessment, MMFA)評估糖尿病患者和對照組的黃斑部，於辨識不同對比的視覺符號時之視覺功能表現。測驗內容共使用4種不同對比(80 %、25 %、10 %和5 %)的中文視標，受試者需持續注視中央凝視點，然後同時辨識隨機出現在8個軸向的0、1、2、4、6和8度視角之視覺刺激，每次視標呈現的時間為250毫秒。第三篇研究是使用三種視覺功能測驗和視覺相關之生活品質量表，評估糖尿病患者和對照組的視凹之視覺功能，以及分析視覺功能和視覺相關生活品質量表分數之相關性。視覺功能測驗工具包括有ETDRS對比視力測驗(Early Treatment Diabetic Retinopathy Study (ETDRS) contrast acuity charts)、CSV-1000對比敏感度功能測驗和HRR色知覺測驗(Hardy-Rand-Rittler (HRR) pseudoisochromatic test)，視覺相關的生活品質評量是使用NEI-VFQ-25(National Eye Institute 25-Item Visual Function Questionnaire)量表進行評估。
結果: 第一篇研究完成收案的糖尿病患者42人(no-DR: 35、NPDR: 7)、對照組38人。比較糖尿病病患組和對照組，在兩種無色彩對比知覺評量中的平均對比閾值表現，結果達到統計顯著差異。分層探討no-DR和NPDR組在pulsed pedestal paradigm和pedestal-△-pedestal paradigm之對比辨識閾值，NPDR組與對照組之大都達到統計顯著或是邊際顯著差異。比較no-DR組與對照組，只有在pulsed pedestal paradigm達到統計顯著或是邊際顯著差異。而在色彩對比知覺評量中，NPDR組在protan和tritan軸向的對比辨識閾值，與對照組有顯著差異，no-DR組則在tritan軸向，與對照組有邊際顯著差異。第二篇研究完成收案的糖尿病患者77人(no-DR: 37、NPDR: 22、PDR:4、NPDR&ME:8、PDR&ME:6)、對照組45人。NPDR、PDR、NPDR&ME和PDR&ME組在80 %、25 %、10 %和5 %對比測試情境下，相較於對照組，皆達到顯著差異。no-DR組與對照組，在5%有統計顯著差異、80 %則為邊際顯著差異。第三篇研究完成收案的糖尿病患者91人、對照組42人。病患組在ETDRS對比視力測驗、CSV-1000對比敏感度測驗和HRR色覺測驗的表現，皆顯著低於對照組。視覺測驗分數與NEI-VFQ-25量表組合分數呈現統計顯著、輕微至中度的相關性。部分NEI-VFQ-25次項目則與ETDRS對比視力測驗和HRR色覺測驗，達到中度至高度的相關性，例如遠距離活動和獨立性。
結論: 探討糖尿病患者早期視覺功能的研究中，NPDR糖尿病患者在M-路徑、P-路徑和K-路徑的視覺訊息傳導功能，對比辨識閾值大都顯著高於對照組。而no-DR組，只在P-路徑和K-路徑的對比辨識閾值較高於對照組。所以糖尿病對早期視覺P-路徑和K-路徑的影響可能較早產生，隨著早期視網膜病變的發生，也會影響M-路徑的視覺反應。其次評量糖尿病患者黃斑部辨識不同對比的視標方面， no-DR患者在低對比測試中，與對照組也呈現顯著差異，顯示低對比黃斑部視覺測試具有潛力做為協助診斷早期視覺問題的評估工具。視凹的視覺功能，及其與視覺相關的生活品質之相關性部分，糖尿病患者的視覺功能顯著低於對照組，其結果也與生活品質有顯著相關性。本研究同時探討糖尿病患者早期視覺功能、黃斑部視覺功能和視凹之視覺功能，以及後者與生活品質之相關性，結果可以更完整地呈現糖尿病患者之視覺問題，進而提供後續的研究者和臨床工作者，作為日後視覺研究、發展視覺評估工具和視覺復健介入策略之基礎。

關鍵字

糖尿病 ； 視網膜病變 ； 黃斑部水腫 ； 視覺 ； 對比敏感度 ； 色彩知覺 ； 視覺測驗 ； 生活品質

並列摘要

Background and Purposes: The worldwide increase in the prevalence of diabetes mellitus (DM) has become an important public concern in developed and developing countries. Diabetic retinopathy (DR) is one of common complications of DM and the leading cause of visual impairment and blindness in the working-age population. DR is characterized as a microvascular disease, but recent studies have suggested that DM causes not only retinal vaso-occlusion but also retinal neurodegeneration. DR affects diabetic patients’ visual function and their quality of life further, and those of retinal neurodegeneration is the same as the DR and may occur before changes in vascular morphology and visual acuity. Because the effects of DR and neurodegeneration in visual function involve several aspects, the purposes of this study were to investigate the visual function for diabetic patients with different stages of DR from early vision to foveal visual function, and the relations between foveal visual function and quality of life.
Methods: Diabetic patients were prospectively recruited from those who regularly received treatment at the Department of Endocrine and Metabolism, Zhong-Xiao Branch, Taipei City Hospital, and had registered for the Diabetes Share Care Network. Recruited diabetic patients were divided into five groups according to the retinopathy status: no-DR, non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), NPDR combined with clinical significant macular edema (CSME), and PDR with CSME. For the chapter one, study design was to differentiate between magnocelllular (MC), parvocellular (PC), and koniocellular (KC) pathways’ function at achromatic and chromatic contrast processing in a population of the type 2 diabetic patients without diabetic retinopathy (no-DR) and with non-proliferative DR (NPDR). Measurement of achromatic contrast sensitivity through the Pulsed pedestal paradigm and pedestal-△-pedestal paradigm were used to differentiate MC and PC pathways. Chromatic contrast discrimination paradigm which assessed protan, deutan, and tritan color vision was adopted to differentiate the PC and KC pathways. In chapter two, a new functional tests, the Macular Multi-Function Assessment (MMFA), was used to examine the macular function in contrast-dependent word symbol identification under contrast levels of 80 %、25 %、10 % and 5 % for patients with different stages of DR and controls. In chapter three, the following functions were examined: contrast acuity (Early Treatment Diabetic Retinopathy Study (ETDRS) contrast acuity chart), contrast sensitivity function (CSV-1000 test), color vision (Hardy-Rand-Rittler (HRR) color test), and quality of life (National Eye Institute 25-Item Visual Function questionnaire (NEI-VFQ-25)) for diabetic patients and controls.
Results: Fourth-two patients (no-DR: 35, NPDR: 7) and 38 controls completed all tests. Mean thresholds from the diabetic groups were significantly higher than those of controls in six achromatic conditions. For pulsed pedestal paradigm, significant difference was observed in all conditions, except for marginal significance observed at no-DR diabetic group tested at 12 cd/m2 and NPDR diabetic group tested at 7 cd/m2 conditions. For pedestal-△-pedestal paradigm, significant difference was observed at NPDR group tested at 11 cd/m2 and 28 cd/m2 conditions, and marginal significance was shown at 18 cd/m2 condition. Significant chromatic contrast loss was observed in the NPDR group along the protan and tritan axes, and marginal significance level was found in the no-DR group along the tritan axis. Seventy-seven patients (no-DR: 37、NPDR: 22、PDR:4、NPDR&ME:8、PDR&ME:6) and 45 controls received the MMFA test. There were significant differences in MMFA scores between the NPDR, PDR, NPDR&ME, and PDR&ME groups, and controls. Significant and marginal significant difference was observed among no-DR group and controls at 5% and 80% contrast, respectively. Ninety-one patients and 42 controls completed all tests for the third part. Significant differences were observed between the patients and controls at all visual function tests and NEI-VFQ-25. Significant weak to moderate correlation coefficients were shown between visual function test scores and NEI-VFQ-25 composite scores. Part of NEI-VFQ-25 subscale scores displayed moderate to high correlations with the ETDRS charts and HRR test, such as distance activities and dependency subscales.
Conclusions: The findings of this study suggest that the different and independent involvement of the PC-, MC-, and KC-pathways in diabetic patients. The PC- and KC-pathways seems to be more susceptible to DM. For the macular function, diabetic patients with no-DR also showed significant lower MMFA scores than the controls, which indicated that low contrast assessment may be a sensitive method to identify early visual impairment for patients with DM. In addition, patients had significant lower mean scores in all vision tests which assessed foveal visual function and quality of life test. The main characteristics of this study were that it investigated early vision, macular visual function, foveal visual function, and visual-related quality of life at the same time. These results may present more comprehensive information for the overall visual function for patients with diabetes to provide insights for continued study about visual performance during DM, developing vision assessment, and as basis of further visual rehabilitation.

並列關鍵字

Diabetes Mellitus ； Diabetic Retinopathy ； Macular Edema ； Vision ； Contrast Sensitivity ； Color Perception ； Vision Tests ； Quality of Life

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