Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ont.
Can J Ophthalmol. 2013 Oct;48(5):427-30. doi: 10.1016/j.jcjo.2013.03.001. Epub 2013 Sep 2.
To determine the effect from using prisms for image relocation on fixation stability estimates in low-vision (LV) patients with age-related macular degeneration (AMD).
The study was designed as a prospective, nonrandomized, observational case series. Inclusion criteria included documented AMD, LV with best corrected visual acuity of 20/50 to 20/400 in the better eye, and cases wearing distance glasses with prisms for image relocation incorporated in the glasses. Preferred retinal locus (PRL) and fixation stability were assessed using the Nidek MP1 and MAIA microperimeters. A control group was used to compare results.
We recruited 14 study subjects with AMD and 10 with no retinal pathology serving as a control group. On average, 6 (SD 2) prisms diopters were prescribed to all in distant viewing glasses. Fixation stability was better at 3-month interval from baseline (p = 0.021) in the AMD group and stayed the same for the following 9 months. No change in fixation stability was noticed in the control group. There was no statistically significant difference in PRL eccentricity between the 3- and 12-month intervals in the AMD group (p = 0.39). However, there was a positive correlation between PRL eccentricity and baseline bivariate contour ellipse area in the AMD group (p = 0.052).
Patients with LV with AMD who are using prisms for image relocation toward the peripheral retinal exhibit better fixation stability than those who are not using prisms. Better fixation stability may impact on other visual outcomes. Use of prisms should be considered in any LV rehabilitation attempt and used in conjunction with other modern interventions in LV rehabilitation.
确定在年龄相关性黄斑变性（AMD）的低视力（LV）患者中使用棱镜进行图像重定位对固视稳定性估计的影响。
本研究设计为前瞻性、非随机、观察性病例系列研究。纳入标准包括明确的 AMD、最佳矫正视力为 20/50 至 20/400 的 LV、以及佩戴带有棱镜进行图像重定位的远视眼镜的病例。使用 Nidek MP1 和 MAIA 微视野计评估首选视网膜位置（PRL）和固视稳定性。使用对照组进行比较。
我们招募了 14 名 AMD 患者和 10 名无视网膜病变的对照组患者。平均为所有患者在远距眼镜中处方了 6（标准差 2）棱镜屈光度。AMD 组在基线 3 个月间隔时的固视稳定性更好（p = 0.021），并且在接下来的 9 个月中保持不变。对照组的固视稳定性没有变化。AMD 组在 3 个月和 12 个月间隔之间的 PRL 偏心率没有统计学差异（p = 0.39）。然而，AMD 组的 PRL 偏心率与基线双变量轮廓椭圆面积之间存在正相关（p = 0.052）。
使用棱镜进行图像重定位到周边视网膜的 AMD 合并 LV 患者的固视稳定性优于未使用棱镜的患者。更好的固视稳定性可能会影响其他视觉结果。在任何 LV 康复尝试中都应考虑使用棱镜，并与 LV 康复中的其他现代干预措施结合使用。
