Comparative study between medial canthus episcleral block versus peribulbar block in intracapsular cataract surgery

Background
Ophthalmic regional anesthesia is now the most common anesthetic technique used for eye surgeries. There are various modes of needle-based ophthalmic anesthesia which are retrobulbar, peribulbar, and episcleral. The sub-Tenon episcleral anesthesia technique became a potential alternative to the retrobulbar and peribulbar anesthesia in most of the anterior and posterior segment eye surgeries; this is due to its better safety profile and tolerability than the other blocks. The aim of this study was to compare between medial episcleral block and peribulbar block in intracapsular cataract surgery as regards anesthesia and akinesia of the eye, the need of supplementation of local anesthetic, and finally the safety profile of each block. This was a prospective, comparative, randomized, double-blinded clinical study. It was carried out on 60 patients that were scheduled for intracapsular cataract surgery in ophthalmic surgery unit. The patients were randomly allocated into two equal groups; group A received medial canthus episcleral block technique and group B received peribulbar block technique.
Results
Results of this prospective, comparative, randomized, double-blinded study showed no statistical difference between the two groups as regards demographic and vital data. As regards Akinesia score, the ESA group had better akinesia score at 1, 5, and 10 min and at the end of surgery than PBA group ( value, 0.001). No patient in the ESA group received supplemental injection via inferotemporal peribulbar block technique, while 66.7% of PBA group was in need of supplementation. Regarding time to onset of acceptable akinesia score; ESA group had a faster onset with high statistical significance ( value, 0.001). Numeric pain scale was better in ESA group than PBA group with high statistical significance. There were chemosis after injection in two of the ESA group (6.6%). On the other hand, slight pricking pain at the end pf surgery developed in two cases in the PBA group.
Conclusion
Medial canthal episcleral technique proved to be superior in motor akinesia score, time to onset of acceptable akinesia score, and numeric pain scale in comparison to peribulbar anesthesia with high statistical significance between the two groups. Both techniques proved to be safe with no incidence of major complications.