Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.
Can J Ophthalmol. 2010 Feb;45(1):62-6. doi: 10.3129/i09-236.
Preferred retinal loci used for eccentric fixation in patients with age-related macular degeneration (AMD) may be different from the eccentric neighbouring loci of highest retinal sensitivity. This study was designed to highlight the conceptual difference between the 2 and the concept of a functional retinal locus encompassing both the preferred retinal locus and the locus with highest retinal sensitivity.
Prospective, nonrandomized, observational case series.
We recruited 15 adults with documented AMD, low vision, and best-corrected visual acuity of 20/50-20/400 in the better eye.
Automated microperimetry methods were used to assess topographic retinal sensitivity and location of preferred retinal loci.
Mean (SD) age for the group was 85.1 (6.5) years. Mean (SD) best-corrected visual acuity measured was 0.88 (0.25) logMar units (20/150). The mean (SD) eccentricity of the preferred retinal locus used for fixation was different from the eccentricity of the area with highest retinal sensitivity in the same eye (7.53 degrees [2.47 degrees ] vs 9.30 degrees [2.93 degrees ], respectively; p < 0.0003). The oculomotor efficiency score measured 82%. The mean (SD) retinal sensitivity at the preferred retinal loci was inferior to that of loci with highest retinal sensitivity (5.83 [4.26] vs 8.60 [3.06] dB, respectively; p < 0.0007). The highest correlation was measured between potential visual acuity estimates and estimates of retinal sensitivity at the highest retinal sensitivity loci (p < 0.0048).
Preferred retinal loci and highest retinal sensitivity loci are not identical in AMD cases. A new concept of functional retinal locus is proposed to define their relation. A new concept of an oculomotor efficiency score is proposed to define oculomotor abilities when macular function is lost.
与年龄相关性黄斑变性（AMD）患者的偏心固定相关的首选视网膜位置可能与最高视网膜敏感度的偏心相邻位置不同。本研究旨在强调这两者之间的概念差异，并提出一个包含首选视网膜位置和最高视网膜敏感度位置的功能性视网膜位置的概念。
前瞻性、非随机、观察性病例系列。
我们招募了 15 名患有 AMD、低视力且健眼最佳矫正视力为 20/50-20/400 的成年人。
使用自动微视野检查方法评估视网膜敏感度的地形和首选视网膜位置。
该组的平均（标准差）年龄为 85.1（6.5）岁。测量的平均（标准差）最佳矫正视力为 0.88（0.25）logMar 单位（20/150）。用于固定的首选视网膜位置的平均（标准差）偏心度与同一眼中最高视网膜敏感度区域的偏心度不同（分别为 7.53 度[2.47 度]和 9.30 度[2.93 度]；p<0.0003）。测量的眼球运动效率评分为 82%。首选视网膜位置的平均（标准差）视网膜敏感度低于最高视网膜敏感度位置（分别为 5.83[4.26]dB 和 8.60[3.06]dB；p<0.0007）。在最高视网膜敏感度位置测量到的潜在视敏度估计与视网膜敏感度估计之间存在最高相关性（p<0.0048）。
在 AMD 病例中，首选视网膜位置和最高视网膜敏感度位置并不相同。提出了一个新的功能性视网膜位置的概念来定义它们之间的关系。当黄斑功能丧失时，提出了一个新的眼球运动效率评分的概念来定义眼球运动能力。
