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Global Translational Medicine Retrobulbar and sub-Tenon’s local anesthesia

complication rate than other techniques 20-23 , whereas others to inject 3 – 5 mL of 2% xylocaine. An additional 1 cc of
report no significant differences. 2% xylocaine was injected subconjunctivally, with 0.5 cc
Although multiple studies have compared these three administered on each nasal and temporal side at the site
techniques, results on complication rates and efficacy where the sclerotomy incision would be made. Ocular
are inconclusive. 6-8,11,12,20,23-28 Few studies have directly massage at the injection site was performed to promote
compared retrobulbar and sub-Tenon’s anesthesia in faster diffusion of the anesthetic.
vitreoretinal surgeries or assessed postoperative pain, In both groups, additional sedation was administered
surgeon experience, or satisfaction in vitreoretinal and documented if patients experienced discomfort during
cases. 23,27 As sub-Tenon’s anesthesia appears safer, we surgery. Patients were also provided with acetaminophen
aimed to assess its potential as an alternative to retrobulbar tablets during the 24-h postoperative period if they
block. This study aimed to compare sub-Tenon’s and reported pain.
retrobulbar techniques in vitreoretinal surgeries, with A questionnaire designed to assess postoperative pain
a focus on postoperative pain, nausea, vomiting, and and comfort levels were administered to each patient
surgeon experience. twice: once immediately after surgery in the recovery
2. Materials and methods room and again 24 h postsurgery. This dual assessment
helped confirm the reliability of evaluations regarding
This comparative case series involved consecutive patients patients’ pain and satisfaction levels over time (Appendix).
who underwent posterior pars plana vitrectomy under local Questions regarding patient pain and comfort levels
anesthesia, with or without concurrent cataract surgery, during surgery and in the recovery room were analyzed as
at Farabi Eye Hospital. All surgeries included scleral separate items to better assess the overall patient experience
indentation and laser. Participants were nonrandomly in the operating theater. The patient questionnaire, which
assigned to receive either sub-Tenon’s or retrobulbar utilized a Visual Analog Scale, scored responses on a
anesthesia, with the technique alternating daily. Exclusion 4-point scale with ratings of excellent (8 – 10), good (6
criteria included a history of substance use, chronic – 8), fair (3 – 6), and poor (0 – 3). In addition to pain
pain, major psychiatric disorders, and cerebrovascular and comfort assessments, occurrences of intraoperative
or neurologic diseases. The Human Research Ethics and postoperative nausea, vomiting, and ophthalmic
Committee of Tehran University of Medical Sciences complications were recorded through patient and surgeon
approved the study protocol (refer to Appendix). This feedback. The investigator assessing the patients was
study was in accordance with the principles of the Helsinki blinded to the method of local anesthesia used. Surgeon
Declaration. All patients provided oral and written satisfaction factors included surgery duration, adequate
informed consent. akinesia, hemorrhage occurrence, and patient comfort
After transferring the patients to the operating room, during the procedure. All surgeries were performed by
sedative medications (0.02 mg/kg midazolam and 1 mg/kg one expert (N.E.) to ensure consistency in technique and
fentanyl) were administered intravenously in both groups approach. Each surgery involved ocular pathology that
for anxiety reduction and cooperation during injection. In required scleral indentation and laser photocoagulation
the retrobulbar group, we injected 3 – 4 mL of 2% xylocaine during vitrectomy.
(with or without hyaluronidase) in the retrobulbar space Data were entered into SPSS Statistics for Windows,
from the inferotemporal part of the eyelid using a 23- or version 23 (IBM Corp., Armonk, New York) and analyzed
25-gauge needle of 1.5 inches (38 mm) in length before using descriptive statistics, including mean and standard
sterile preparation and draping. Ocular massage was deviation for quantitative values and number and percentage
performed after injection to distribute the drug effectively. for qualitative values. The normality of quantitative
This additional step is crucial in ensuring that the drug data was assessed using the Kolmogorov–Smirnov test.
is adequately dispersed, providing adequate anesthesia Variables with normal distribution were compared using
throughout the surgical procedure. an independent t test, whereas nonparametric variables
In the sub-Tenon’s group, we applied topical anesthetic were analyzed using the Mann–Whitney U test. Spearman
in the eye. This initial step was intended to provide correlation was used to evaluate variable associations. A p
preliminary numbness of the ocular surface and minimize value of <0.05 was considered statistically significant.
discomfort before prepping with betadine, followed by 3. Results
careful sterile preparation and draping. We used a 27-gauge
needle to puncture the conjunctiva in the inferotemporal Fifty-three participants (29 males [55%]) were included in
and/or superotemporal areas of the sub-Tenon’s space the study, with a mean patient age of 64.84 ± 11.6 years

Volume 3 Issue 4 (2024) 3 doi: 10.36922/gtm.3900