Bagga Harmohina, Greenfield David S, Knighton Robert W
Department of Ophthalmology, University of Miami School of Medicine, Bascom Palmer Eye Institute, Miami, FL, USA.
J Glaucoma. 2005 Oct;14(5):358-63. doi: 10.1097/01.ijg.0000176930.21853.04.
To evaluate structural asymmetry in the macula using optical coherence tomography (OCT) in glaucomatous eyes with visual field defects localized to one hemifield.
Complete examination, standard automated perimetry (SAP), and OCT imaging (512 A-scans) of the peripapillary retina and macula were performed. Exclusion criteria were visual acuity <20/40, diseases other than glaucoma, and SAP defects localized to both hemifields. Macular OCT images were obtained using four 5-mm radial scans centered on the foveola and passing obliquely through the macula (15 degrees superotemporally and inferotemporally). Macular measurements temporal to the fovea (T) were sub-divided into nasal (T1) and temporal (T2) segments. Macular symmetry testing (MST) was performed in T, T1, and T2 segments by comparing the mean macular thickness of the perimetrically abnormal and perimetrically normal hemi-zones (macular thickness in perimetrically normal hemi-zone/macular thickness in perimetrically abnormal hemi-zone x 100), and superior and inferior hemi-zones in normal subjects (macular thickness in superior hemi-zone/macular thickness in inferior hemi-zone x 100). MST measurements were considered to be abnormal if they exceeded the 95% limits of normal variability.
Forty eyes of 40 patients (20 normal, 20 glaucoma) were enrolled (mean age 60 +/- 19 years, range 21-89). All eyes with glaucoma had associated hemifield defect (average MD = -7.23 +/- 4.8 dB, range -0.9 to -15.4). In glaucomatous eyes, mean retinal thickness in T, T1, and T2 within the perimetrically abnormal hemi-zone (222 +/- 14 microm, 224+/- 17 microm, 221 +/-13 microm, respectively) was significantly less (P = 0.002, 0.008, 0.001, respectively) than the corresponding segments in the perimetrically normal hemi-zone (235 +/- 17 microm, 237 +/- 18 microm, 233 +/- 17 microm, respectively). Normal eyes showed no difference (P = 0.17, 0.20, 0.35) in T, T1, and T2 measurements within the superior hemi-zone (254 +/- 11, 249 +/- 14, 258 +/- 14) and inferior hemi-zone (252 +/- 11, 250 +/- 13, 255 +/- 13), respectively. MST values in glaucomatous eyes were outside 95% limits of normal variability in 17/20 (85%) T segments, 16 /20 (80%) T1 segments, and 16/20 (80%) T2 segments.
Localized macular thickness changes exist in glaucomatous eyes with regional visual field loss. The MST may represent a novel strategy for glaucoma diagnosis.
使用光学相干断层扫描（OCT）评估视野缺损局限于一个半视野的青光眼患者黄斑部的结构不对称性。
对患者进行全面检查、标准自动视野计（SAP）检查以及视乳头周围视网膜和黄斑部的OCT成像（512次A扫描）。排除标准为视力<20/40、青光眼以外的疾病以及视野缺损累及两个半视野。使用以中心凹为中心、倾斜穿过黄斑部（颞上和颞下各15度）的四条5毫米径向扫描获取黄斑部OCT图像。黄斑部中心凹颞侧（T）的测量值分为鼻侧（T1）和颞侧（T2）节段。通过比较视野异常半区和视野正常半区的平均黄斑厚度（视野正常半区的黄斑厚度/视野异常半区的黄斑厚度×100）以及正常受试者上半区和下半区的平均黄斑厚度（上半区的黄斑厚度/下半区的黄斑厚度×100），在T、T1和T2节段进行黄斑对称性测试（MST）。如果MST测量值超过正常变异性的95%限值，则认为异常。
纳入40例患者的40只眼（20例正常，20例青光眼）（平均年龄60±19岁，范围21 - 89岁）。所有青光眼患者均伴有半视野缺损（平均MD = -7.23±4.8 dB，范围 -0.9至 -15.4）。在青光眼患者中，视野异常半区内T、T1和T2节段的平均视网膜厚度（分别为222±14微米、224±17微米、221±13微米）显著低于视野正常半区内相应节段（分别为235±17微米、237±18微米、233±17微米）（P分别为0.002、0.008、0.001）。正常眼在上半区（254±11、249±14、258±14）和下半区（252±11、250±13、255±13）的T、T1和T2测量值无差异（P分别为0.17、0.20、0.35）。青光眼患者中，17/20（85%）的T节段、16/20（80%）的T1节段和16/20（80%）的T2节段的MST值超出正常变异性的95%限值。
视野局部缺损的青光眼患者存在黄斑部局部厚度变化。黄斑对称性测试可能代表一种青光眼诊断的新策略。
