Pseudopapilledema associated with abnormally small optic discs.

Using Littmann's method for correcting the magnification of central fundus photographs, we determined the absolute size of 35 unselected optic discs with pseudopapilledema. The optic disc area (1.95 +/- 0.33 mm2 (mean and SD)) was significantly (P less than 0.001, Student's t-test ) smaller than standard values of normal unselected optic nerve heads (2.73 +/- 0.76 mm2). There was no cupping in the discs with pseudopapilledema. Coefficients of variation for intraobserver re-evaluation were 0.045, and for interobserver re-evaluation 0.08. The markedly reduced optic disc size coincide with an abnormally small optic nerve scleral canal may inhibit the intraaxoplasmatic flow with secondary swelling of the juxtapapillary optic nerve fibers. This may lead t o prominence and indistinct borders of the optic disc. Pseudopapilledema might be related to optic nerve head drusen, which are also associated with abnormally small optic discs.