Is retrobulbar or topical anesthesia safer in cataract surgery? Should residents start learning cataract surgery with topical anesthesia?
January's issue of the Journal of Cataract & Refractive Surgery includes an article by Lee and colleagues investigating the question of whether topical or retrobulbar anesthesia is safer for cataract surgery. This topic is of particular interest to young ophthalmologists, especially residents transitioning from retrobulbar to topical anesthesia as they learn cataract surgery.
Advocates of retrobulbar blocks value their longer duration of anesthesia, and the importance of paralyzing the eye to avoid unexpected movements by the patient. Advocates of topical anesthesia cite its safety profile, avoiding risks like globe perforation, optic nerve damage, retrobulbar hemorrhage or posterior pressure.
The authors of this study performed a meta-analysis of fifteens studies, using posterior capsule rupture rates as their metric. The overall rate of posterior capsule rupture was low in both groups: 0.74 percent in the retrobulbar group and 0.80 percent in the topical group. There was no statistically significant difference in rates of posterior capsule rupture between these groups.
Their study suggests that both techniques are equally safe, at least among the experienced surgeons included in these studies. These studies did not include trainees in their analysis, and raises the question of when it is safe for trainees to begin performing topical anesthesia on their cataract cases.
A study by Randleman, et al. (JCRS 2004:30:149-154) reported no difference in PC rupture rates among ophthalmology residents performing either retrobulbar or topical cases during a one-year period. While their study group was divided equally between each technique, more retrobulbar anesthesia was performed by newer surgeons and more topical anesthesia by more experienced surgeons. The authors advocate a swift transition from retrobulbar to topical anesthesia within the trainee's first 50 to100 cases.
An article by Ünal et al. (JCRS 2006;32:1361-5) compared rates of posterior capsule rupture between two groups of residents during their first 50 phacoemulsification surgeries. One group began their training with retrobulbar anesthesia while the other group began with topical anesthesia. Posterior capsule rupture rates were 10 percent in the retrobulbar group and 11 percent in the topical group, a statistically insignificant difference. The authors suggest that with proper supervision, topical anesthesia is equally safe, even for new trainees.
These articles support the continued use of both methods of anesthesia in cataract surgery. For young ophthalmologists who are still learning cataract surgery, most will begin with retrobulbar anesthesia and transition to topical anesthesia. The literature suggests that both techniques are safe, and under proper supervision, trainees may consider earlier transitions to topical anesthesia.