Nictitating Membrane Resection in the Horse: A Comparison of Long-Term Outcomes Using Local Versus General Anesthesia

Complete excision of the nictitating membrane can be an effective treatment for primary neoplasia in selected cases and is associated with a low risk of recurrence when performed under general or local anesthesia. Authors’ address: University of Illinois Urbana-Champaign, 1008 West Hazelwood Drive, Champaign, IL 61822. e-mail: [email protected].

1. Purpose

To evaluate the long-term complications of nictitating membrane resection in horses; to evaluate recurrence of neoplasia of the nictitating membrane when nictitating membrane resection is performed under local versus general anesthesia; and to determine if the method of anesthesia influences the recurrence of neoplasia after complete nictitating membrane resection.

2. Methods

Records of 26 horses receiving resection of the nictitating membrane for primary neoplasia of the nictitating membrane were reviewed. Owners were contacted by telephone regarding postoperative outcomes. Data were analyzed using a Fisher exact test (p < 0.05).

3. Results

The most common long-term complication of nictitating membrane excision was mild ocular discharge. Squamous cell carcinoma was the most frequent histopathologic diagnosis. Recurrence of neoplasia was uncommon (2 of 26 horses). No significant difference in the number of horses having recurrence of neoplasia was detected between groups receiving general anesthesia versus those receiving local anesthesia. 

4. Conclusions

Resection of the nictitating membrane in horses under local anesthesia is not associated with increased risk of recurrence of neoplasia compared with excision under general anesthesia. Resection of the nictitating membrane is not associated with any long-term ocular side effects and can be an effective modality for cure of primary neoplasia of the nictitating membrane in selected cases.