Anterior chamber angle measurements using Schwalbe's line with high-resolution fourier-domain optical coherence tomography

Bing Qin, Brian A. Francis, Yan Li, Maolong Tang, Xinbo Zhang, Chunhui Jiang, Catherine Cleary, David Huang

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


PURPOSE:: To use Fourier-domain optical coherence tomography (OCT) to measure the angle opening distance at Schwalbe's line (AOD-SL) and determine its value in anterior chamber angle assessment. METHODS:: Horizontal scans of the nasal and temporal anterior chamber angles in glaucoma subjects were performed at 830 nm wavelength Fourier-domain OCT. Images were graded by 2 ophthalmologists who assessed the visibility of Schwalbe's line (SL), anterior limbus (AL), scleral spur (SS), and angle recess (AR). AOD-SL was measured with computer calipers. SL was manually identified by the termination of the corneal endothelium. Gonioscopy was used to classify anterior chamber angles according to a modified Shaffer system. Spearman ρ analysis was performed to assess correlation between AOD-SL and modified Shaffer grade. A cutoff value of AOD-SL for diagnosing occludable angles (modified Shaffer grade ≤1) was determined by receiver operating characteristic (ROC) analyses. RESULTS:: Thirty-five glaucoma subjects (65 eyes) were enrolled. SL, AL, AR, and SS were visible by OCT in 97.7%, 99.2%, 87.3%, and 80.8% of eyes, respectively. Nasal and temporal AOD-SLs were 322.6±200.2 μm and 341.4±197.4 μm, respectively. Correlation coefficients between AOD-SL and modified Shaffer grade were 0.80 (nasal) and 0.81 (temporal). The diagnostic cutoff value of AOD-SL for occludable angles was 290 μm. The areas under the ROC curve, sensitivity, specificity values were 0.90, 0.80, 0.87 (nasal) and 0.90, 0.85, 0.77 (temporal), respectively. CONCLUSIONS:: The measurement of AOD-SL by Fourier-domain OCT is highly correlated with gonioscopy and may be a useful noncontact method for assessing angle closure risk.

Original languageEnglish (US)
Pages (from-to)684-688
Number of pages5
JournalJournal of Glaucoma
Issue number9
StatePublished - Dec 2013
Externally publishedYes


  • anterior chamber angle imaging
  • glaucoma
  • optical coherence tomography

ASJC Scopus subject areas

  • Ophthalmology


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