Tumors of the orbital apex are difficult to approach through a standard lateral 
orbitotomy exposure. The transcranial approach has been described, but it 
requires an open craniotomy as well as dissection through the annulus of Zinn in 
its tight superior segment to reach intraconal and inferior lateral tumors. It 
is well recognized that the transcranial approach is optimal only for tumors of 
the superomedial orbital apex. Our study demonstrates that by enlarging the bony 
incision of a classic lateral orbitotomy to include a generous marginotomy and 
removing the deep sphenoid wing up to the superior orbital fissure, good 
exposure of the lateral orbital apex can be obtained. Tumors of the apex, 
including those that extend slightly into the cavernous sinus, can be removed 
from the cranial nerves and extraocular muscle origins in en face fashion, 
providing optimal ability to identify the delicate neurovascular structures of 
the orbital apex and avoid damage to them. The operating microscope is extremely 
useful for bony and soft tissue dissection. We report four benign tumors of the 
orbital apex removed using this approach. Two tumors encroached slightly into 
the cavernous sinus. Three of four patients were told that they had inoperable 
tumors. By use of the deep orbital apex approach described, all four tumors were 
successfully exposed and removed. Visual and motor function was unchanged or 
improved in all four patients, with the exception of one tumor that incorporated 
the inferior division of the third cranial nerve; in that patient, the 
transected nerve was anastomosed microscopically, and partial return of function 
was noted. The transorbital ophthalmic approach to tumors of the inferolateral 
orbital apex has significant potential advantages in comparison with a frontal 
craniotomy approach.