Purpose

To evaluate the efficacy and safety of 0.05%, 0.025%, and 0.01% atropine eye drops over 2 years to determine which is the optimal concentration for longer-term myopia control.

Design

Randomized, double-masked trial extended from the Low-Concentration Atropine for Myopia Progression (LAMP) Study.

Participants

Three hundred eighty-three of 438 children (87%) aged 4 to 12 years with myopia of at least –1.0 diopter (D) originally randomized to receive atropine 0.05%, 0.025%, 0.01%, or placebo once daily in both eyes in the LAMP phase 1 study were continued in this extended trial (phase 2).

Methods

Children in the placebo group (phase 1) were switched to receive 0.05% atropine from the beginning of the second-year follow-up, whereas those in the 0.05%, 0.025%, and 0.01% atropine groups continued with the same regimen. Cycloplegic refraction, axial length (AL), accommodation amplitude, photopic and mesopic pupil diameter, and best-corrected visual acuity were measured at 4-month intervals.

Main Outcome Measures

Changes in spherical equivalent (SE) and AL and their differences between groups.

Results

Over the 2-year period, the mean SE progression was 0.55±0.86 D, 0.85±0.73 D, and 1.12±0.85 D in the 0.05%, 0.025%, and 0.01% atropine groups, respectively (P = 0.015, P < 0.001, and P = 0.02, respectively, for pairwise comparisons), with mean AL changes over 2 years of 0.39±0.35 mm, 0.50±0.33 mm, and 0.59±0.38 mm (P = 0.04, P < 0.001, and P = 0.10, respectively). Compared with the first year, the second-year efficacy of 0.05% and 0.025% atropine remained similar (P >0.1), but improved mildly in the 0.01% atropine group (P = 0.04). For the phase 1 placebo group, the myopia progression was reduced significantly after switching to 0.05% atropine (SE change, 0.18 D in second year vs. 0.82 D in first year [P < 0.001]; AL elongated 0.15 mm in second year vs. 0.43 mm in first year [P < 0.001]). Accommodation loss and change in pupil size in all concentrations remained similar to the first-year results and were well tolerated. Visual acuity and vision-related quality of life remained unaffected.

Conclusions

Over 2 years, the efficacy of 0.05% atropine observed was double that observed with 0.01% atropine, and it remained the optimal concentration among the studied atropine concentrations in slowing myopia progression.

中文翻译：

---

低浓度阿托品用于近视进展（LAMP）研究的两年临床试验：2期报告。

目的

为了评估2年内0.05％，0.025％和0.01％阿托品滴眼液的疗效和安全性，以确定哪种是长期近视控制的最佳浓度。

设计

低浓度阿托品用于近视进展（LAMP）研究的随机，双掩蔽试验。

参加者

438名年龄在4至12岁，近视度至少为–1.0屈光度（D）的儿童中，有833名儿童最初随机接受了阿托品0.05％，0.025％，0.01％或安慰剂的双眼每日一次试验。 LAMP 1期研究在此扩展试验中继续进行（2期）。

方法

从第二年随访开始，安慰剂组（第1阶段）的孩子改用0.05％阿托品，而0.05％，0.025％和0.01％阿托品组的孩子继续采用相同的方案。每隔4个月测量一次验光，轴周（AL），适应幅度，明视和中视瞳孔直径以及最佳矫正视力。

主要观察指标

球形当量（SE）和AL的变化及其组之间的差异。

结果

在2年的时间里，在0.05％，0.025％和0.01％的阿托品组中，平均SE进展分别为0.55±0.86 D，0.85±0.73 D和1.12±0.85 D（P  = 0.015，P <0.001 ， 对于成对比较，分别为P = 0.02），两年内的平均AL变化为0.39±0.35 mm，0.50±0.33 mm和0.59±0.38 mm（P  = 0.04，P <0.001和P  = 0.10，分别）。与第一年相比，第二年的阿托品疗效分别为0.05％和0.025％（P  > 0.1），但在0.01％的阿托品组中则略有改善（P = 0.04）。对于1期安慰剂组，近视进展在切换为0.05％阿托品后显着降低（SE改变，第二年为0.18 D，第一年为0.82 D [ P <0.001]；第二年AL相对于第一年延长了0.15 mm。第一年为0.43毫米[ P <0.001]）。在所有浓度下，住宿损失和瞳孔大小变化均与第一年的结果相似，并且耐受性良好。视力和与视力有关的生活质量未受影响。

结论

在2年的时间里，观察到的0.05％阿托品的疗效是0.01％阿托品的两倍，并且在研究的阿托品浓度中仍保持最佳浓度，以减缓近视的进展。