To evaluate the effects of adding magnesium sulfate to atracurium with local anesthetic mixture on akinesia of globe and eyelid regarding onset and duration in cataract surgery using peribulbar technique

Regional anesthesia is a preferred technique for ophthalmic surgery. It's safe, inexpensive and provides efficient ocular anesthesia for ophthalmic surgery.

Among regional blocks, peribulbar block is safe to retrobulbar block due to lesser incidence of series complications such as brain-stem anesthesia globe perfusion and retrobulbar hemorrhage .

The effect of non-depolarizing neuromuscular blockers on peribulbar anesthesia has been described in many studies. According to these studies the use of atracurium as adjuvant to peribulbar anesthesia provides early onset of akinesia and improves the quality of anesthesia in absence of any adverse effect.

Magnesium sulphate is non-competitive N-Methyl-D- Aspartate (NMDA) antagonism and calcium channel blocker. Magnesium has endothelium derived Nitric Oxide induced vasodilation. It enhanced the activity of local anesthetic agent and improves the quality of anesthesia .

Inclusion Criteria:

• Patients undergoing elective cataract surgery (phacoemulsification and intraocular lens implantation).

Patients aged 20-80 years. Both sexes. ASA physical status I&II.

Exclusion Criteria:

- Refusal of the patient to participate in the study. Any disorder of neuromuscular system known from history or clinical examination e.g., Guillarian barre syndrome, Myasthenia gravies and Myopathies.

Patients are known to have a history of fits. Patients on medication known to interact with neuromuscular blocking drugs as antipyretics (aminoglycosides and tetracyclines), antiarrhythmic (quinidine).

Local sepsis. Coagulation abnormalities (INR>1.4). High myopia with axial length more than 30 mm or less than 21. Mentally retarded patients and failure of proper communication as in deafness. Morbidly obese patients (BMI>40). Patients with glaucoma (increased IOP>20mmgh). Patients with history of hypersensitivity to study drugs. Very dense or very soft cataract .

Both sexes and from 20 to 80 years