Peribulbar Injection and Direct Infiltration for Vitreoretinal Surgery

To the Editor. —We read with interest the article by Friedberg et al 1 in the November 1991 issue of theArchivesdescribing an alternative technique of local anesthesia for vitreoretinal surgery using a blunt irrigating cannula passed into the posterior sub-Tenon's space. We have been performing this technique in patients since publication of the article by Mein and Woodcock. 2 Our experience has been that procedures requiring considerable manipulation of the recti muscles and pressure on extraconal orbital tissue (when using a tissue retractor) can cause discomfort to the patient despite an adequate intraconal block. The intraconal technique has the advantage of simplicity and relative safety, but our experience is that extraconal orbital tissues are poorly anesthetized by this method. This may not influence vitrectomy cases requiring no scleral buckling, but in cases requiring extensive scleral buckling, poor anesthetization by this method may be a significant limitation. We note