Mark Alford

Predictive value of the initial quantified relative afferent pupillary defect in 19 consecutive patients with traumatic optic neuropathy.

Purpose To study the predictive value of the initial quantified relative afferent pupillary defect (RAPD) in patients with indirect traumatic neuropathy as it relates to final visual outcome. Methods The RAPD was measured and quantified by neutral density filters in patients with unilateral indirect traumatic neuropathy. All patients were treated with megadose methylprednisolone by of the protocol established by the Second National Acute Spinal Cord Injury Study. Patients were followed twice daily during treatment and then at 3-month intervals. Results Nineteen patients were enrolled over a 23-month period. Patients ranged in age from 12 to 78 years old; 18 of the 19 patients were male. No patient with an RAPD of 2.1 log units or greater had visual recovery to better than hand motion vision. The 7 patients with an initial RAPD of less than 2.1 log units showed improvement in their RAPD and were found to have vision of 20/30 or better during the follow-up period. Conclusions In patients treated with megadose methylprednisolone with an initial RAPD of less than 2.1 log units, visual acuity improved to 20/30 or better; however, patients with an initial RAPD of 2.1 or greater showed little visual improvement. The initial quantified RAPD appears to have a predictive value related to final visual outcome.

Persistent visual loss following retrobulbar hemorrhage

R etrobulbar anesthesia is considered both safe and effective by most ophthalmologists and anesthesiologists.1 However, retrobulbar hemorrhage, either arterial or venous, is one of the most devastating complications of local anesthesia, with an incidence of about 0.7% to 1.7%.2-6 Patients usually have sudden onset of proptosis, hemorrhagic chemosis, vision loss and pain. The rapid increase in intraorbital pressure due to the mechanical limitations within the bony orbit may also cause increased intraocular pressure (lOP). This elevated lOP may compromise ocular blood flow, resulting in permanent loss of vision if not recognized and treated early.7·8 The standard therapy for orbital compartment syndrome is immediate lateral canthotomy and cantholysis.3•9 If this is performed adequately and promptly, bleeding within the retrobulbar cavity should no longer be restricted, and the intraorbital pressure and lOP should decrease. We describe a patient with a retrobulbar hemorrhage who, despite adequately performed immediate canthotomy and cantholysis, continued to have progressive visual loss.