Importance Pathologic myopia due to an excessive increase of axial length is associated with severe visual impairments. Systematic analyses to determine the rate of and the risk factors associated with the axial elongation in adults with high myopia based on long-term follow-up of a large population are needed.

Objective To determine the risk factors associated with axial elongation in adults with high myopia.

Design, Setting, and Participants This cohort study used the medical records of 43 201 patient visits in a single-hospital database that were collected from January 3, 2011, to December 28, 2018. A total of 15 745 medical records with the patients’ sex, best-corrected visual acuity (BCVA), axial length, type of myopic maculopathy, and the presence or absence of choroidal neovascularization (CNV) were reviewed. Data were analyzed from April 3, 2019, to August 5, 2020.

Main Outcomes and Measures Changes in the axial length at each examination were calculated. The significance of the associations between the annual increase of the axial length and age, sex, baseline axial length, types of myopic maculopathy, and a history of CNV was determined. Generalized linear mixed models were used to evaluate the strength of the risk factors associated with an increase of the axial length in high myopia.

Results Among 1877 patients with 9161 visits included in the analysis, the mean (SD) age was 62.10 (12.92) years, and 1357 (72.30%) were women. The mean (SD) axial length was 29.66 (2.20) mm with a mean (SD) growth rate of 0.05 (0.24) mm/y. Among the 9161 visits, 7096 eyes (77.46%) had myopic maculopathy and 2477 eyes (27.04%) had CNV. The odds ratio for inducing a severe elongation of the axial length was 1.46 (95% CI, 1.38-1.55) for female sex, 0.44 (95% CI, 0.35-0.56) to 0.63 (95% CI, 13 0.50-0.78) for older than 40 years, 1.33 (95% CI, 1.15-1.54) for BCVA of less than 20/400, 1.67 (95% CI, 1.54-1.81) to 2.67 (95% CI, 2.46-2.88) for baseline axial length of 28.15 mm or greater, 1.06 (95% CI, 0.96-1.17) to 1.39 (95% CI, 1.24-1.55) for the presence of maculopathy, and 1.37 (95% CI, 1.29-1.47) for prior CNV.

Conclusions and Relevance This cohort study found continuing axial elongation in adults with high myopia. The risk factors for elongation do not appear to be modifiable, so prevention of myopia may be the best approach to reduce the incidence of pathologic myopia and its complications in the future.

重要性 由于眼轴长度过度增加导致的病理性近视与严重的视力障碍有关。需要基于大量人群的长期随访进行系统分析，以确定高度近视成人眼轴伸长率和相关风险因素。

目的 确定成人高度近视眼轴伸长的相关危险因素。

设计、地点和参与者 本队列研究使用了 2011 年 1 月 3 日至 2018 年 12 月 28 日收集的单一医院数据库中 43 201 名患者就诊的医疗记录。共有 15 745 份患者的医疗记录回顾了性别、最佳矫正视力 (BCVA)、眼轴长度、近视黄斑病变类型以及是否存在脉络膜新生血管 (CNV)。数据分析时间为 2019 年 4 月 3 日至 2020 年 8 月 5 日。

主要结果和措施 计算每次检查时轴长的变化。确定了眼轴长度每年增加与年龄、性别、基线眼轴长度、近视黄斑病变类型和 CNV 病史之间关联的重要性。广义线性混合模型用于评估与高度近视眼轴长度增加相关的危险因素的强度。

结果 纳入分析的 1877 例患者共 9161 次就诊，平均 (SD) 年龄为 62.10 (12.92) 岁，其中女性 1357 例 (72.30%)。平均 (SD) 轴向长度为 29.66 (2.20) 毫米，平均 (SD) 增长率为 0.05 (0.24) 毫米/年。在 9161 次就诊中，7096 眼（77.46%）有近视黄斑病变，2477 眼（27.04%）有 CNV。诱发轴向长度严重延长的优势比为 1.46（95% CI，1.38-1.55），女性为 0.44（95% CI，0.35-0.56）至 0.63（95% CI，13 0.50-0.78） 40 岁以上，BCVA 小于 20/400 为 1.33（95% CI，1.15-1.54），基线轴向长度为 1.67（95% CI，1.54-1.81）至 2.67（95% CI，2.46-2.88） 28.15 mm 或更大，1.06 (95% CI, 0.96-1.17) 至 1.39 (95% CI, 1.24-1.55) 用于存在黄斑病变，1.37 (95% CI, 1.29-1.47) 用于先前 CNV。

结论和相关性 本队列研究发现高度近视的成人眼轴持续延长。延长的危险因素似乎无法改变，因此预防近视可能是未来减少病理性近视及其并发症发生率的最佳方法。