1. Subtenon’s Anesthesia in Pterygium Excision with Conjunctival Autograft Michael R. Gagnon, M.D. Clinical Instructor, Stanford University Valley EyeCare Center, Pleasanton, California *I have no financial interests in the subject matter.*

2. Introduction Subtenon’s anesthesia has been used in a number of different types of intraocular surgeries including cataract, trabeculectomy, posterior segment, and strabismus surgery. Subtenon’s anesthesia lowers the risks associated with retrobulbar and peribulbar anesthesia including globe perforation, retrobulbar hemorrhage, optic nerve and extraocular muscle damage.

3. Purpose To describe using subtenon’s anesthesia for pterygium excision with conjunctival autograft.

4. Purpose To determine if subtenon’s anesthesia in pterygium surgery provided pain control and akinesia. To determine if subtenon’s anesthesia resulted in sight threatening complications.

5. Methods A retrospective review was conducted of consecutive eyes who had pterygium excision with conjunctival autograft with subtenon’s anesthesia.

6. Methods An incision was made in the inferonasal or inferotemporal quadrant opposite the location of the pterygium. A 23 gauge Corbin subtenon’s anesthesia cannula (Katena) was inserted along the sclera and the 3 ml solution was injected into the subtenon’s space. The 3 ml injection was a 1:1 mixture of lidocaine 1% and bupivicaine 0.75% with 50 units of hyaluronidase.

7. Methods The standard surgical procedure for pterygium excision involved harvesting a free conjunctival graft from the superotemporal conjunctiva with assistance from a corneal traction suture. The conjunctival graft was placed onto the bare sclera and anchored at the limbus with two 9-0 vicryl sutures. Tisseel fibrin glue was used to glue the graft into place.

8. Results A total of 21 eyes in 21 patients were identified. The twenty-one patients included eleven females and ten males and were predominantly left eyes (57%). Average age was 48 years (28-65 years). Eighteen cases were primary pterygia Three were recurrent pterygia.

9. Results Subtenon’s anesthesia provided pain control 21 of 21 eyes and akinesia in 18 of 21 eyes. Three eyes developed subconjunctival hemorrhage. There were no sight threatening complications in these patients.

10. Conclusions Subtenon's anesthesia is a safe and effective technique in pterygium excision with conjunctival autograft and can be used as an alternative to retrobulbar or peribulbar anesthesia.