Background/Aims To investigate clinical characteristics and risk factors for glaucoma conversion of the contralateral eye in unilateral normal-tension glaucoma (NTG) patients. Methods A retrospective observational cohort study was conducted on a total of 76 subjects who had been diagnosed with unilateral NTG at the baseline and followed up for more than 5 years. Glaucoma conversion in the contralateral eye was defined as increased thinning of neuro-retinal rim, development of retinal nerve fibre layer defect and/or development of glaucomatous visual field defect. Results During the mean follow-up period of 7.3±2.4 years, 21 of 76 (27.6%) subjects were confirmed to have developed glaucoma in the non-glaucomatous contralateral eye. The 5-year rate of glaucoma conversion in contralateral eyes was 19.7%. The maximum width of β-zone parapapillary atrophy (MWβPPA)-disc diameter (DD) ratio at the baseline and the presence rate of disc haemorrhage during follow-up period were significantly greater in the contralateral eyes of the conversion group than in those of the non-conversion group (p = 0.011, <0.001, respectively). A multivariate Cox-proportional hazard model revealed intraocular pressure (IOP) over 17 mm Hg (HR 5.05, p=0.031), central corneal thickness (CCT) under 491 μm (HR 4.25, p=0.025) and MWβPPA-DD ratio over 0.32 (HR 6.25, p=0.003) in contralateral eye at the baseline as the independent risk factors for glaucoma conversion. Conclusions Among unilateral NTG patients, those with low CCT and high MWβPPA-DD ratio as well as high IOP in the contralateral eye are more likely to develop glaucoma in that eye during long-term follow-up.

中文翻译：

---

单侧正常眼压青光眼患者对侧眼的青光眼转化：一项为期 5 年的随访研究

背景/目的 研究单侧正常眼压性青光眼 (NTG) 患者对侧眼青光眼转化的临床特征和危险因素。方法 对基线时诊断为单侧 NTG 并随访 5 年以上的 76 名受试者进行回顾性观察性队列研究。对侧眼的青光眼转化被定义为神经视网膜边缘变薄、视网膜神经纤维层缺损和/或青光眼视野缺损的发展。结果在7.3±2.4年的平均随访期内，76名受试者中有21名（27.6%）被证实在非青光眼对侧眼发生青光眼。对侧眼的 5 年青光眼转化率为 19.7%。基线时β区视乳头旁萎缩最大宽度（MWβPPA）-椎间盘直径（DD）比值和随访期间椎间盘出血的存在率在转换组的对侧眼中显着大于转换组的对侧眼。非转换组（分别为 p = 0.011，<0.001）。多变量 Cox 比例风险模型显示眼压 (IOP) 超过 17 mm Hg (HR 5.05, p=0.031)，中央角膜厚度 (CCT) 低于 491 μm (HR 4.25, p=0.025) 和 MWβPPA-DD 比率超过 0.32 (HR 6.25, p=0.003) 在基线时对侧眼作为青光眼转化的独立危险因素。结论 单侧NTG患者中，CCT低、MWβPPA-DD比值高、对侧眼压高的患者在长期随访中更易发生该眼青光眼。