Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
J Glaucoma. 2011 Jan;20(1):37-43. doi: 10.1097/IJG.0b013e3181ccb93b.
To assess the effect of cataract on optical coherence tomography (OCT), signal strength (SS), and peripapillary retinal nerve fiber layer (RNFL) thickness measurements.
Peripapillary RNFL thickness measurements were obtained by Stratus OCT scans using the Fast RNFL thickness (3.4) acquisition protocol before and after cataract extraction in 45 patients with cataract, including 23 glaucoma patients. Cataracts were graded according to the Lens Opacities Classification System III.
The postoperative RNFL thickness and SS were 9.3% (P=0.001) and 24.1% (P<0.001) higher than before surgery, respectively. There was greater postoperative change in RNFL thickness measurements in patients with lower preoperative RNFL measurements (r=-0.63, P<0.001) and SS (r=-0.59, P<0.001). Eyes with preoperative SS more than 6 had no significant difference between precataract and postcataract surgery RNFL thickness (P=0.14). There was no significant difference in RNFL thickness change between eyes with cataract only (10.9±20.8 μm) and those with cataract and glaucoma (7.0±14.7 μm; P=0.81).
Cataracts may decrease peripapillary RNFL thickness measurements and the SS on OCT scans. Thinning of the peripapillary RNFL suggestive of glaucomatous progression may be the result of artifact from advancing cataract rather than actual structural changes in the peripapillary RNFL. Peripapillary RNFL thickness measurements should be interpreted with caution in glaucomatous eyes with significant cataract, particularly if the SS is attenuated.
评估白内障对视光学相干断层扫描（OCT）、信号强度（SS）和视盘周围视网膜神经纤维层（RNFL）厚度测量的影响。
45 例白内障患者（包括 23 例青光眼患者）在白内障摘除术前和术后分别使用 Stratus OCT 扫描，采用 Fast RNFL 厚度（3.4）采集方案获取视盘周围 RNFL 厚度测量值。白内障根据 Lens Opacities Classification System III 分级。
术后 RNFL 厚度和 SS 分别增加了 9.3%（P=0.001）和 24.1%（P<0.001）。术前 RNFL 测量值较低的患者术后 RNFL 厚度测量值的变化更大（r=-0.63，P<0.001）和 SS（r=-0.59，P<0.001）。术前 SS 大于 6 的眼在白内障术前和术后的 RNFL 厚度（P=0.14）之间无显著差异。单纯白内障眼（10.9±20.8 μm）和白内障合并青光眼眼（7.0±14.7 μm；P=0.81）之间的 RNFL 厚度变化无显著差异。
白内障可能会降低 OCT 扫描的视盘周围 RNFL 厚度测量值和 SS。提示青光眼进展的视盘周围 RNFL 变薄可能是由于进展性白内障引起的伪影，而不是视盘周围 RNFL 的实际结构变化。在伴有明显白内障的青光眼眼中，应谨慎解释视盘周围 RNFL 厚度测量值，特别是如果 SS 减弱。
