INTRODUCTION

Traumatic optic neuropathy (TON) can occur along any level of the optic nerve and results in partial to complete loss of visual acuity. TON can be classified into direct and indirect subtypes. Direct TON results from fractures involving the orbit or optic canal such as those associated with projectiles, facial smashes, or iatrogenic during endoscopic sinus surgery. Conversely, forces transmitted at different levels to the optic nerve after blunt head trauma can cause indirect TON. The damage to the optic nerve is hypothesized to be secondary to intraneural edema, hematoma, shearing of nerve fibers, altered cerebrospinal fluid circulation, and impaired retroaxonal transport of brain-derived growth factors1-3. It occurs in about 2.5% of midface fractures and 10% of craniofacial fractures 4-5. For decades, treatment of compressive optic nerve neuropathy was conservative, with intravenous application of high dose corticoids, and in later years in combination with nerve growth factors6,7 . Surgical treatment for traumatic optic neuropathy was not routinely done in the past as a minimally invasive approach to the optic nerve was not available; also the available intracranial or pterional approaches could add to the morbidity of the patient. However with advent of endoscopic sinus surgeries, a new corridor for optic nerve decompression started to open up. The treatment of TON is controversial; primarily because of absence of a standard treatment protocol- medical as well as surgical. Secondly spontaneous improvement of vision in patients with TON has been reported in 20–38 % of untreated cases 8, 9. The aim of EOND is to decompress the bony optic nerve canal along with removal of bony fragments with or without impingement on the optic nerve as well as reducing the intracanalicular pressure by added fenestration of nerve sheath in selected patients ; expecting restoration of nerve function. High dose corticosteroids administered systemically have a similar effect, resulting in a “medical decompression”. The aim of this study is to assess the role of timing of surgery and pre operative visual status in the prognosis of direct TON undergoing EOND. Current literature lacks a proper grading system for evaluating post operative visual improvement. Hence, we have even developed a quantitative assessment for improvement of vision following EOND.
MATERIALS AND METHODS
During the last 10 years we had 31 patients with traumatic optic neuropathy – direct type; of which one patient had bilateral direct type traumatic optic neuropathy. So totally we had operated on 32 eyes. All the patients in this study were males.