Laterally and inferiorly the limits of safe dissection are approximately 25mm. The anterior aspect of the inferior orbital fissure is about 25 mm posterior to the infraorbital foramen. Superiorly and medially dissection is safe for approximately 30 mm from the superior orbital rim and anterior lacrimal crest. The distance from the anterior lacrimal crest to the optic canal is 42 mm. From the superior orbital rim to the superior orbital fissure the distance is 40mm.
Photographic documentation is important.
B. Visual acuity. Measurement with a hand near card or Snellen wall chart. Ophthalmologic consultation should be obtained for more accurate assessment. C. Extraocular muscle range of motion should be examined in all cardinal directions. Document any diplopia.