The most common cause of reversible blindness in the globe, cataracts continue to be a serious public health issue, especially for the elderly. Cataract extraction is one of the most popular and successful surgical treatments in ophthalmology due to advancements in intraocular lens implantation and surgical techniques that have greatly improved visual outcomes. In order to ensure patient comfort, reduce intraoperative pain and anxiety, enable surgical precision, and enhance overall patient satisfaction, adequate anaesthesia is essential [1, 2]. Because it offers efficient analgesia and ocular akinesia without the dangers of general anaesthesia, regional ophthalmic anaesthesia is frequently utilised during cataract surgery. Peribulbar block and Sub-Tenon's block are two of the most widely used regional anaesthetic methods in clinical practice. In order to execute cataract surgery in a safe and comfortable manner, both methods seek to deliver sufficient anaesthesia of the globe and surrounding tissues [3, 4]. A local anaesthetic is injected via the lower eyelid into the extraconal orbital space during a peribulbar block. It is regarded as a reasonably safe and efficient method that produces adequate akinesia and analgesia. Although globe perforation, retrobulbar haemorrhage, optic nerve injury, extraocular muscle trauma, and vascular injury are rare when carried out by skilled clinicians, the procedure necessitates inserting a needle into the orbital cavity and may result in complications [5, 6]. Effective analgesia promotes early recovery, patient satisfaction, and decreased postoperative discomfort, making postoperative pain management a crucial part of cataract surgery. Different anaesthetic procedures may affect postoperative analgesic outcomes, despite the fact that cataract surgery is often associated with less postoperative discomfort. Peribulbar and Sub-Tenon's blocks have been compared in a number of studies in terms of anaesthesia onset, intraoperative analgesia, akinesia, patient comfort, and complication rates. Regarding their relative efficacy in reducing postoperative pain, however, conflicting findings have been documented [7, 8]. In order to examine the effectiveness of Sub-Tenon's block and Peribulbar block for postoperative analgesia in patients having cataract surgery, this study was conducted. The study's objectives were to evaluate both anaesthetic procedures' postoperative pain scores, anaesthesia onset, patient comfort, surgical conditions, patient satisfaction, and procedure-related complications. The results could direct the choice of anaesthetic and improve perioperative care for cataract surgery patients [9, 10].

This prospective comparative study was conducted in the Department of Anaesthesiology, Kanya Kumari Medical Missions Medical College, Kanyakumari, Tamil Nadu, between April 2024 and March 2025. A total of 25 patients scheduled for elective cataract surgery under regional ophthalmic anesthesia were included in the study after obtaining written informed consent. Ethical approval for the study was obtained from the Institutional Ethics Committee prior to commencement. Patients were allocated into two groups: Peribulbar Block Group (n=13) and Sub-Tenon's Block Group (n=12). Methods: Patient demographics, duration of cataract, associated systemic illnesses, type of cataract surgery performed, onset of anesthesia, degree of ocular akinesia, intraoperative pain, postoperative pain scores, need for supplemental anesthesia, patient satisfaction, and procedure-related complications were recorded. In the Peribulbar block group, local anesthetic solution was administered into the extraconal orbital space using standard peribulbar injection techniques. In the Sub-Tenon's block group, local anesthetic was administered through a blunt cannula into the episcleral space beneath Tenon's capsule. Postoperative pain was assessed using the Visual Analog Scale (VAS) at 1, 4, 8, and 24 hours after surgery. Ocular akinesia was evaluated before surgery using standard movement scoring systems. Inclusion Criteria: • Patients aged 40 years and above undergoing elective cataract surgery. • Patients scheduled for cataract extraction with intraocular lens implantation under regional anesthesia. • Patients classified as American Society of Anesthesiologists (ASA) Grade I–III. • Patients willing to participate and provide written informed consent. • Patients able to understand and respond to postoperative pain assessment scales. Exclusion Criteria: • Patients unwilling to participate in the study. • Known allergy or hypersensitivity to local anesthetic agents. • Coagulation disorders or patients receiving anticoagulant therapy. • Active ocular infection or severe orbital pathology. • Previous ocular surgery affecting anesthetic administration. • Patients requiring general anesthesia for cataract surgery. Statistical Analysis: We used SPSS version 26.0 to analyse the data that had been entered into Microsoft Excel. Mean ± standard deviation (SD) was used to represent continuous variables, whilst frequencies and percentages were used for categorical variables. We used the Chi-square test or Fisher's exact test to compare categorical variables such as patient satisfaction, requirement for supplemental anesthesia, and incidence of complications between the two groups. The Student's t-test was used to compare continuous variables including onset time of anesthesia, postoperative pain scores, and duration of surgery. A p-value less than 0.05 was considered statistically significant.

A total of 25 patients undergoing elective cataract surgery were included in the study. Of these, 13 patients received Peribulbar block (Group A) and 12 patients received Sub-Tenon's block (Group B). Demographic characteristics, anesthetic efficacy, postoperative analgesia, patient satisfaction, and complications were evaluated and compared between the two groups. Table 1: Baseline Characteristics of Study Participants Variable Group A (Peribulbar) (n=13) Group B (Sub-Tenon's) (n=12) p-value Mean Age (Years) 64.1 ± 8.5 63.4 ± 8.9 0.82 Male 7 (53.8%) 7 (58.3%) 0.81 Female 6 (46.2%) 5 (41.7%) 0.81 ASA Grade I–II 10 (76.9%) 9 (75.0%) 0.91 ASA Grade III 3 (23.1%) 3 (25.0%) 0.91 Table 1 shows that both groups were comparable with respect to age, gender distribution, and ASA grading, with no statistically significant differences. Table 2: Comparison of Anesthetic Characteristics Parameter Group A (Peribulbar) Group B (Sub-Tenon's) p-value Onset of Anesthesia (Minutes) 5.1 ± 1.2 2.8 ± 0.9 0.001 Adequate Ocular Akinesia 12 (92.3%) 11 (91.7%) 0.95 Need for Supplemental Anesthesia 2 (15.4%) 1 (8.3%) 0.58 Table 2 demonstrates that the onset of anesthesia was significantly faster in the Sub-Tenon's block group. Adequate ocular akinesia was achieved in the majority of patients in both groups. Table 3: Intraoperative and Postoperative Pain Scores (VAS) Time Interval Group A (Peribulbar) Group B (Sub-Tenon's) p-value Pain During Block Administration 2.4 ± 0.8 1.1 ± 0.5 0.001 1 Hour Postoperative 1.8 ± 0.7 1.2 ± 0.5 0.03 4 Hours Postoperative 2.0 ± 0.7 1.2 ± 0.6 0.01 8 Hours Postoperative 1.5 ± 0.6 1.0 ± 0.4 0.04 24 Hours Postoperative 0.8 ± 0.4 0.6 ± 0.3 0.18 Table 3 shows that patients receiving Sub-Tenon's block experienced significantly less pain during block administration and lower postoperative pain scores during the early postoperative period. Table 4: Patient Satisfaction Satisfaction Level Group A (Peribulbar) Group B (Sub-Tenon's) Excellent 5 (38.5%) 8 (66.7%) Good 5 (38.5%) 3 (25.0%) Fair 2 (15.4%) 1 (8.3%) Poor 1 (7.6%) 0 (0.0%) Table 4 demonstrates higher patient satisfaction in the Sub-Tenon's block group, with two-thirds of patients rating their experience as excellent. Table 5. Procedure-Related Complications Complication Group A (Peribulbar) Group B (Sub-Tenon's) Chemosis 0 (0.0%) 2 (16.7%) Subconjunctival Hemorrhage 0 (0.0%) 1 (8.3%) Ecchymosis 1 (7.7%) 0 (0.0%) Globe Perforation 0 (0.0%) 0 (0.0%) Retrobulbar Hemorrhage 0 (0.0%) 0 (0.0%) Serious Complications 0 (0.0%) 0 (0.0%) Table 5 shows that only minor complications were observed in both groups. Chemosis was more common with Sub-Tenon's block, whereas transient ecchymosis occurred in one patient receiving Peribulbar block. No serious adverse events were encountered.

For cataract surgery to be effective, adequate regional anaesthesia is necessary because it guarantees patient comfort, creates ideal operating conditions, and improves postoperative results. Peribulbar block and Sub-Tenon's block are two of the most popular ocular anaesthetic methods due to their efficacy and safety. In the current study, these two methods were evaluated in terms of postoperative analgesia, anaesthesia onset, patient satisfaction, and complications in cataract surgery patients [11, 12]. Age, gender distribution, and preoperative clinical parameters were similar across the two groups in this study. This resemblance reduced any confounding variables and enabled a trustworthy comparison of the anaesthetic methods. Nearly all patients in both groups received adequate anaesthesia and excellent operative conditions, proving that Peribulbar and Sub-Tenon's blocks are both successful cataract surgery techniques [13, 14]. The much quicker onset of anaesthesia with Sub-Tenon's block as opposed to Peribulbar block was one of the study's key conclusions. The quick onset of Sub-Tenon's anaesthesia could be explained by the local anaesthetic being deposited directly into the episcleral space, which allows for effective diffusion throughout the globe and extraocular muscles. Prior to surgery, a quicker start might lessen patient anxiety and increase operating room efficiency [15, 16]. Additionally, the Sub-Tenon's group showed better postoperative analgesia in the current study. In comparison to the Peribulbar group, postoperative pain scores at 1, 4, and 8 hours were considerably reduced. Good postoperative pain management improves patient comfort, speeds up recuperation, and increases overall satisfaction with the surgical procedure. Sub-Tenon's block may provide a longer-lasting analgesic effect because the anaesthetic drug is distributed more evenly throughout the ocular tissues [17-19]. Patients who received Sub-Tenon's block reported higher levels of satisfaction. This group's greater satisfaction levels were probably caused by a combination of less procedural discomfort, quick anaesthesia onset, and better postoperative comfort. In contemporary ophthalmic treatment, patient-centered results have grown in significance, and methods that enhance the overall surgical experience are greatly sought for [20, 21]. There are certain restrictions on the current investigation. The study was carried out at a single institution and had a somewhat limited sample size, which would restrict how broadly the results can be applied. Furthermore, postoperative long-term results were not assessed. More information about the relative efficacy and safety of these anaesthetic methods may be obtained from larger multicenter studies with longer follow-up [22, 23].

For cataract surgery, both the peribulbar block and the sub-tenon's block were safe and effective anaesthetic options. When contrasted with the Peribulbar block, the Sub-Tenon's block showed a number of advantages, including a quicker start to anaesthesia, less postoperative pain, and more patient satisfaction. Since the risks associated with Sub-Tenon's block are low and tend to go away on their own, it could be a good option for cataract surgery patients seeking better postoperative pain relief.

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