Use of A-scan Ultrasound and Optical Coherence Tomography to Differentiate Papilledema From Pseudopapilledema

Optom Vis Sci. 2017 Dec;94(12):1081-1089. doi: 10.1097/OPX.0000000000001148.


Significance: Differentiating papilledema from pseudopapilledema reflecting tilted/crowded optic discs or disc drusen is critical but can be challenging. Our study suggests that spectral-domain optical coherence tomography (OCT) peripapillary retinal nerve fiber layer thickness and retrobulbar optic nerve sheath diameter (ONSD) measured by A-scan ultrasound provide useful information when differentiating the two conditions.

Purpose: To evaluate the use of A-scan ultrasound and spectral-domain OCT retinal nerve fiber layer thickness (RNFLT) in differentiating papilledema associated with idiopathic intracranial hypertension from pseudopapilledema.

Methods: Retrospective cross-sectional analysis included 23 papilledema and 28 pseudopapilledema patients. Ultrasound-measured ONSD at primary gaze, percent change in ONSD at lateral gaze (30° test), and peripapillary RNFLT were analyzed. Receiver operating characteristic curves were constructed using one eye from each subject.

Results: Compared with pseudopapilledema, papilledema eyes showed larger mean ONSD (5.4 ± 0.6 vs. 4.0 ± 0.3 mm, P < .0001), greater change of ONSD at lateral gaze (22.4 ± 8.4% vs. 2.8 ± 4.8%, P < .0001), and thicker retinal nerve fiber layer (219.1 ± 104.6 vs. 102.4 ± 20.1 μm, P < .0001). Optic nerve sheath diameter and 30° test had the greatest area under the receiver operating characteristic curve, 0.98 and 0.97, respectively; followed by inferior quadrant (0.90) and average RNFLT (0.87). All papilledema eyes with Frisén scale greater than grade II were accurately diagnosed by ONSD, 30° test, or OCT. In mild papilledema (Frisén scale grades I and II, n = 15), area under the receiver operating characteristic curve remained high for ONSD (0.95) and 30° test (0.93) but decreased to 0.61 to 0.71 for RNFLT. At 95% specificity, sensitivities for ONSD, 30° test, and RNFLT were 91.3%, 91.3%, and 56.5%, respectively, for the entire papilledema group and 80.0%, 86.7%, and 13.3% for the mild papilledema subgroup.

Conclusions: Retinal nerve fiber layer thickness can potentially be used to detect moderate to severe papilledema. A-scan may further assist differentiation of mild papilledema from pseudopapilledema.

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Diagnosis, Differential
  • Eye Diseases, Hereditary / diagnosis*
  • Female
  • Humans
  • Male
  • Nerve Fibers / pathology*
  • Optic Disk / pathology*
  • Optic Nerve Diseases / diagnosis*
  • Papilledema / diagnosis*
  • ROC Curve
  • Retinal Ganglion Cells / pathology*
  • Retrospective Studies
  • Tomography, Optical Coherence / methods*
  • Ultrasonography / methods*

Supplementary concepts

  • Pseudopapilledema