Effectiveness of Retrobulbar Block for Analgesia During Ophthalmic Surgery in Patients With Asian and European Eyelid Anatomy: A Single-Center Prospective Controlled Study

BACKGROUND: Retrobulbar block is known to cause varying degrees of upper eyelid edema associated with moderate exophthalmos, which may adversely affect surgical conditions. It has been hypothesized that anatomical differences in the ocular adnexa between patients with Asian and European eyelid anatomy may determine the severity of edema following retrobulbar block.

AIM: This study aimed to evaluate the effectiveness of retrobulbar block and the surgeon’s comfort during surgery in patients with Asian and European eyelid anatomy.

METHODS: A prospective controlled study was conducted involving 80 patients aged 51–75 years who underwent retrobulbar block for anesthesia during vitreoretinal surgery. Group 1 (n = 40) included patients with European eyelid anatomy, and group 2 (n = 40) with Asian eyelid anatomy. Changes in intraocular pressure and upper eyelid thickness were assessed at different stages of the block, along with preparation time for surgery, analgesia level, akinesia, and surgeon’s comfort.

RESULTS: In group 1, the upper eyelid thickness increased by 0.9 ± 0.1 mm, whereas in group 2 it increased by 2.8 ± 0.4 mm (p = 0.000), due to postseptal infiltration of the upper eyelid tissue with local anesthetic. The mean akinesia score was 1.0 ± 0.2 in group 1 and 1.4 ± 0.6 in group 2 (p = 0.021), with higher scores indicating reduced akinesia effectiveness. In group 1, intraocular pressure increased to 17.6 ± 1.9 mm Hg after the retrobulbar block and was 15.9 ± 1.9 mm Hg after compression, which corresponded to the baseline values before the block. In group 2, maximal increase in intraocular pressure was recorded after the retrobulbar block—24.9 ± 6.3 mm Hg (p = 0.0000)—and after compression—21.5 ± 5.4 mm Hg (p = 0.0000), which exceeded the baseline values (16.2 ± 1.3 mm Hg). The presence of ocular hypertension resulted in additional preoperative preparation time aimed at reducing intraocular pressure: in 5% of patients in group 1 and 28.75% of patients in group 2. Pain assessment showed residual pain in group 2 (2.6 ± 1.3 on the numeric rating scale), 1.5 times higher than in group 1 (1.6 ± 1.5, p = 0.0001), requiring additional intraoperative analgesia. Surgeon’s comfort in group 2 was reduced due to decreased palpebral fissure width from 21.4 ± 1.1 mm to 14.8 ± 1.9 mm after the retrobulbar block, associated with anesthetic infiltration of the upper eyelid.

CONCLUSION: Retrobulbar block in patients with Asian eyelid anatomy was associated with a significant increase in eyelid thickness and intraocular pressure, prolonged surgical preparation time, and the need for additional intravenous analgesia, resulting in reduced surgeon comfort during ophthalmic procedures.