Sunness J S, Bressler N M, Maguire M G
Lions Vision Center, Baltimore, MD 21205.
Am J Ophthalmol. 1995 Feb;119(2):143-51. doi: 10.1016/s0002-9394(14)73866-8.
We explored the clinical impression that geographic atrophy of the retinal pigment epithelium, a form of advanced age-related macular degeneration, is perceived by the patient as progressing gradually, even when fixation switches from foveal to extrafoveal.
We analyzed the responses of 60 patients with geographic atrophy to a questionnaire administered as part of a five-year study of the natural course of geographic atrophy, funded by the National Eye Institute. We performed scanning laser opthalmoscope perimetry on all patients. We examined two additional patients with geographic atrophy who reported abrupt visual loss.
No eye with geographic atrophy was reported by any patient to have had sudden visual loss. Although most patients with geographic atrophy show foveal fixation until the fovea is atrophic and then show extrafoveal fixation, scanning laser ophthalmoscope perimetry in three patients with geographic atrophy showed alternation between a foveal and an extrafoveal retinal locus for fixation. Two patients with geographic atrophy who complained of abrupt visual loss were found to have occult choroidal neovascularization, which evolved in one patient to classic choroidal neovascularization. The neovascularization was difficult to detect because of the presence of geographic atrophy and its associated ophthalmoscopic and fluorescein angiographic features.
Visual loss in geographic atrophy is nearly always perceived by the patient as being gradual, even when considerable decreases in visual acuity occur and when foveal vision and fixation are lost. A possible explanation for this perception is that there is a transitional period during which a patient uses both a foveal and extrafoveal site for fixation. The complaint of abrupt visual loss in a patient with geographic atrophy should raise the suspicion of choroidal neovascularization, which may be occult and difficult to detect.
我们探讨了一种临床印象，即视网膜色素上皮的地图样萎缩，一种晚期年龄相关性黄斑变性的形式，即使当注视点从中央凹转移到中央凹外时，患者也感觉其在逐渐进展。
我们分析了60例地图样萎缩患者对一份问卷的回答，该问卷是由美国国立眼科研究所资助的一项关于地图样萎缩自然病程的五年研究的一部分。我们对所有患者进行了扫描激光眼底镜视野检查。我们还检查了另外两名报告有突然视力丧失的地图样萎缩患者。
没有患者报告任何一只患有地图样萎缩的眼睛有突然视力丧失。尽管大多数地图样萎缩患者在中央凹萎缩之前表现为中央凹注视，然后表现为中央凹外注视，但三名地图样萎缩患者的扫描激光眼底镜视野检查显示注视点在中央凹和中央凹外视网膜位点之间交替。两名抱怨突然视力丧失的地图样萎缩患者被发现有隐匿性脉络膜新生血管，其中一名患者的隐匿性脉络膜新生血管发展为典型脉络膜新生血管。由于存在地图样萎缩及其相关的检眼镜和荧光素血管造影特征，新生血管很难被检测到。
即使当视力显著下降以及中央凹视力和注视丧失时，患者几乎总是感觉地图样萎缩导致的视力丧失是逐渐发生的。对此种感觉的一种可能解释是存在一个过渡期，在此期间患者同时使用中央凹和中央凹外位点进行注视。地图样萎缩患者抱怨突然视力丧失应引起对脉络膜新生血管的怀疑，脉络膜新生血管可能是隐匿的且难以检测到。
