Department of Clinical Science/Ophthalmology, Umeå University, Umeå, Sweden.
Acta Ophthalmol. 2021 Aug;99(5):519-526. doi: 10.1111/aos.14669. Epub 2020 Nov 16.
To assess the effect of two high-oxygen epi-on PiXL treatments for low-grade myopia.
This prospective, randomized, intra-individually comparing, single-masked study included 23 healthy volunteers (46 eyes) aged 18-35 years with mild myopia, -0.75 to -2.50 D manifest refractive spherical equivalent (MRSE). One eye was randomized to a 4.0-mm homogenous treatment zone and the fellow eye to a 4.0-mm annular zone (16:40 min at 30 mW/cm , fluence 15 J/cm ). Uncorrected distance visual acuity (UDVA), MRSE, best spectacle-corrected visual acuity (BSCVA), Scheimpflug light scattering depths, mean keratometry (K ) and endothelial cell count (ECC) were assessed through 24 months.
Similar improvements in UDVA were seen for the homogeneous and annular protocols at 1 month: -0.52 (-0.59, -0.39) and -0.49 (-0.59, -0.39) logMAR, respectively (medians and interquartile ranges, IQR), p = 0.91, and MRSE: +1.0 D (0.94, 1.31) and +1.0 D (0.69, 1.25), p = 0.17. Light scattering depths were 496 (465, 527) and 349 (247, 378) µm, respectively, and the reduction in mean keratometry was -0.8 D (-1.1, -0.7) and 0 D (-0.1, 0.1), p < 0.001. The treatment effect remained stable throughout 24 months. At 1 week, the participants reported less ocular discomfort with the annular protocol. No reductions were seen in BSCVA or ECC. No adverse events were reported.
PiXL can reduce low-grade myopia and improve uncorrected vision in healthy eyes. The initial ocular discomfort may be reduced with an annular treatment zone. Further studies are needed to optimize PiXL treatment parameters.
评估两种高氧 epi-on PiXL 治疗低度近视的效果。
这是一项前瞻性、随机、个体内比较、单盲研究，纳入了 23 名年龄在 18-35 岁的轻度近视（-0.75 至-2.50 D 等效球镜屈光度）的健康志愿者（46 只眼）。一只眼随机接受 4.0-mm 均匀治疗区治疗，另一只眼接受 4.0-mm 环形治疗区治疗（30 mW/cm 时 16:40 min，剂量 15 J/cm ）。未矫正远视力（UDVA）、等效球镜屈光度（MRSE）、最佳矫正远视力（BSCVA）、Scheimpflug 光散射深度、平均角膜曲率（K ）和内皮细胞计数（ECC）在 24 个月时进行评估。
在 1 个月时，均匀和环形方案的 UDVA 均有相似的改善：-0.52（-0.59，-0.39）和-0.49（-0.59，-0.39）logMAR，中位数和四分位间距（IQR），p=0.91，MRSE 也有相似的改善：+1.0 D（0.94，1.31）和+1.0 D（0.69，1.25），p=0.17。光散射深度分别为 496（465，527）和 349（247，378）µm，平均角膜曲率降低分别为-0.8 D（-1.1，-0.7）和 0 D（-0.1，0.1），p<0.001。治疗效果在 24 个月内保持稳定。在 1 周时，参与者报告环形方案的眼部不适程度较低。BSCVA 和 ECC 无降低。无不良事件报告。
PiXL 可降低低度近视并改善健康眼的未矫正视力。环形治疗区可能会减轻初始眼部不适。需要进一步研究来优化 PiXL 治疗参数。
