目的：探讨正常眼压性青光眼(normal tension glaucoma，NTG)患者睡眠体位与其双眼不对称损害的关系。方法：纳入2014年1月至2018年9月在温州青光眼进展研究(Wenzhou Glaucoma Progression Study，WGPS)项目中的NTG患者。眼部主要检查有视野和光学相干断层扫描(optical coherence tomography，OCT)。睡眠体位数据通过基线睡眠体位问卷获得。根据侧卧位睡眠偏好，将NTG患者眼部参数分为卧位高侧眼和卧位低侧眼进行讨论；根据双眼不对称损害，将患者眼部参数分为较好眼和较差眼讨论。双眼不对称损害定义为双眼视野平均偏差(mean deviation，MD)差值>6 dB或杯盘比差值>0.2。结果：共纳入158例NTG患者，最长随访时间为48个月，其中122例(77.22%)患者存在睡眠偏好；存在睡眠偏好的患者中，83例(68.03%)患者存在侧卧位偏好；存在侧卧位偏好的患者中，大多数患者偏好右侧卧位[右vs左：59 (71.1%) vs 24 (28.9%)，P<0.001]。对存在侧卧位偏好的患者进行分析，发现卧位高侧眼与卧位低侧眼眼部参数之间，差异无统计学意义(P>0.05)；卧位低侧眼的视野进展速率[视野指数(visual field index，VFI)、MD]慢于卧位高侧眼(0.48%±1.66%/年 vs ?0.45%±3.07%/年；0.54±0.96 dB/年 vs 0.2±1.15 dB/年)，差异无统计学意义(P=0.086，P=0.308)。对同时存在侧卧位偏好及双眼不对称损害的患者进行分析，发现卧位高侧眼与卧位低侧眼的眼部参数之间，差异无统计学意义(P>0.05)；卧位低侧较好眼的个数及占比高于卧位低侧较坏眼[23 (57.5%) vs 17(42.5%)]，但差异无统计学意义(P=0.132)；卧位低侧眼的视野进展速率(VFI、MD)也慢于卧位高侧眼(1.19%±1.65%/年 vs ?0.86%±3.65%/年；0.71±1.13 dB/年 vs0.13 dB/年)，但差异无统计学意义(P=0.064，P=0.419)。结论：存在睡眠体位偏好的NTG患者中，约68%存在侧卧位偏好；存在侧卧位偏好的患者中，约70%偏好右侧卧位。但本研究并未发现睡眠体位与青光眼患者双眼不对称损害及其疾病进展存在相关性。

Objective: To investigate the association between lateral decubitus position (LDP) and asymmetric loss in normal tension glaucoma (NTG) patients. Methods: NTG patients were enrolled from Wenzhou Glaucoma Progression Study (WGPS) in Jan. 2014 to Sep. 2018. The main eye examinations included visual field test and optical coherence tomography (OCT). A questionnaire to determine the preferred sleeping position was administered to each patient in the baseline. According to the LDP, the eye parameters were divided into non-dependent eyes(higher lateral eyes) and dependent eyes (lower lateral position eyes) for discussion. According to the asymmetric damage, the ocular parameters of the patients were divided into the better eyes and the worse eyes for analysis.Asymmetric loss was defined as a difference in mean deviation (MD) between the 2 eyes of at least 6 dB or disc/cup >0.2. Results: One hundred and twenty-two patients (77.22%) had sleep preferences among the 158 NTG patients who was finally recruited and the longest follow up time was 48 months. Among the patients with sleep preference, 83 patients (68.03%) preferred the lateral decubitus position. Patients who had the lateral decubitus position mostly preferred the right lateral position [59 (71.1%) vs 24 (28.9%), P<0.001]. For patients who had the lateral decubitus position, the ocular parameters between the dependent eyes and the non-dependent eyes had no statistical difference(P>0.05); the rate of visual field progression in the dependent eyes was slower than that in non-dependent eyes, but there was no statistical difference between the two groups (0.48%±1.66%/year vs ?0.45%±3.07%/year; 0.54±0.96 dB/year vs 0.2±1.15 dB/year; P=0.086, P=0.308, respectively). For patients who had the lateral decubitus position and asymmetric damage, the ocular parameters between the dependent eyes and the non-dependent eyes had also no statistical difference (P>0.05); the number and ratio of the dependent-better eye and the dependent-worse eye were 48 and 41, respectively [23 (57.5%) vs 17 (42.5%), P=0.132]; the rate of visual field progression in the dependent eyes was also lower than that in non-dependent eyes, but there was no statistical difference between the two groups (1.19%±1.65%/year vs ?0.86%±3.65%/year; 0.71±1.13 dB/year vs 0.13 dB/year; P=0.064, P=0.419 respectively). Conclusion: About 68% of NTG patients with sleep preferences preferred the lateral decubitus position; and about 70% of patients with the lateral decubitus position preferred the right side sleeping. However, this study did not find a correlation between lateral decubitus position and asymmetric visual field loss.