Ocular surgery may be performed under topical, regional, or general anesthesia. The first recorded use of regional anesthesia for surgery was the instillation of cocaine into the conjunctival sac in 1884 by an Austrian ophthalmologist.~Davis and Mandel in 1986 described the peribulbar block, peribulbar block has delayed onset and need a higher volume of local anesthetic (LA) than a retrobulbar block. But the peribulbar block is away from intra-conal space and so produce fewer complication.~Dexmedetomidine is used as adjuvant to LA drugs in peripheral nerve block, brachial plexus block and intrathecal anesthesia with satisfactory results. A more recent study using dexmedetomidine (50 μg) with the peribulbar block before cataract surgery demonstrated an IOP decrease similar to IV dexmedetomidine administration and greater than a peribulbar block without dexmedetomidine.
The aim of this study is to compare efficacy of dexmedetomidine as an additive to topical versus peribulbar anesthesia for cataract surgery