Pathology of canine cataract surgery complications

To compare pathological complications arising from 2 methods of canine cataract surgery, manual extracapsular cataract extraction (MECCE) and the more automated phacoemulsification and aspiration (PA).

Case material presented to the Comparative Ophthalmic Pathology Laboratory, University of North Carolina over the previous 20 years (1979-1999) was searched for cases with a history of prior cataract surgery. Data were obtained from the pathology accession forms, and submitting veterinarians were contacted to verify and complete missing data where possible. The slides were re-examined, histological features of surgical complications were noted and secondary changes recorded.

Fourteen canine post-cataract-surgery cases were reviewed, the average age of the group being 7.7 years. Of the 14 eyes, 7 had surgery performed using MECCE, and 7 using PA. Of the 7 eyes that underwent MECCE surgery, 5 were enucleated and diagnosed on both clinical and pathological grounds with glaucoma. Of the 7 eyes that underwent PA, 4 were diagnosed with infectious endophthalmitis.

Complications observed were related to the surgical technique performed. Failures of manual extracapsular surgical procedures were more commonly associated with postoperative synechia and glaucoma, compared with failures of phacoemulsification, which were more commonly associated with infection and rhegmatogenous retinal detachments.

To minimise post surgical complications, MECCE should be accompanied by rigorous efforts to reduce surgically induced inflammation, while PA should be performed using excellent aseptic technique. It is important with both techniques to totally remove cortical material while maintaining the integrity of the posterior capsule.