Evaluation of Topical Lignocaine Jelly 2% for Recurrent Pterygium Surgery with Glue-free Autologous Conjunctival Graft.

AIM: This study aims to evaluate the efficacy of lignocaine 2% jelly as a topical anesthesia in recurrent pterygium surgery with glue-free conjunctival limbal autograft.
MATERIALS AND METHODS: A prospective, nonrandomized, observational study, comprising of 51 patients (51 eyes) having recurrent pterygium, was conducted at a tertiary eye care center in central India. Pterygium excision with glue-free autologous conjunctival grafting was done under 2% lignocaine jelly. The visual analog scale was utilized to record the intra- and post-operative pain score. Patient comfort, intraoperative painful sensations perceived by the patient, supplemental anesthesia, complications, and surgeon discomfort were noted. Anesthetist also noted vital parameters and any intravenous drugs required.
RESULTS: No difference in intra- and post-operative pain score (P = 0.24) was observed in the patients. Zero score, i.e. no pain was noticed in 30 patients (58.8%) patients. The average surgical time was 29.20 min (+1.11). The average surgeon discomfort score was 0.18 + 0.51. Inadvertent eye movement was seen in 3 patients (5.9%). Lid squeeze was noted in 45 patients (88.2%) during placement of lid speculum. Forty-eight patients (94.1%) gave preference to the topical anesthesia of 2% lignocaine jelly compared to the previous mode of anesthesia.
CONCLUSION: Pterygium surgery with glue-free autogenous conjunctival grafting can be performed successfully by preoperative local application of 2% lignocaine jelly. The ease of application, lack of toxicity and sufficient effect to complete the surgery make it an efficient alternative to injectable anesthetics.

Introduction

Pterygium is a common ocular diseases characterized by triangular-shaped conjunctival overgrowth extended to cornea. The standard treatment of this disease is surgical excision. The major drawback associated with pterygium surgery is high recurrence rates (2.1%–87%).[12345] Several techniques have been tested to reduce the fibrovascular activity aiming to reduce the recurrence such as β-irradiation, conjunctival and limbal autografting, antimitotic drugs, and amniotic membrane transplantation.[67] Conjunctival autograft transplantation is currently the most frequently used procedure for the treatment of both primary and recurrent pterygium. This technique has been associated with little complications and recurrence rates, as well as with improved postoperative comfort and favorable cosmetic results.[89]

Various anesthetic techniques have been tried to perform primary pterygium surgery. These include peribulbar, retrobulbar block anesthesia, subconjunctival injection of 2% lignocaine hydrochloride,[1011] ropivacaine eye drops,[12] benoxinate 0.4% drops,[13] and 2% lignocaine jelly.[1415] Performing pterygium surgery under topical drops may need frequent instillation and may be a painful experience to the patient. Peribulbar and retrobulbar injection is associated with globe perforation, retrobulbar hemorrhage,[16] and central retinal artery occlusion;[17] subconjunctival injection of local anesthetic agent has become a technique of choice for the majority of patients undergoing pterygium surgery. However, subconjunctival anesthesia is also not free from the complications. It may cause hemorrhage, chemosis, and globe perforation.

Recurrent pterygium is characterized by the presence of extensive scarring from the previous surgical procedure, excessive fibrovascular growth, and corneal thinning. Surgical procedure for recurrent pterygium requires meticulous dissection of the fibrovascular growth and the protection of the underlying structures.

The role of lignocaine jelly has already been established in chalazion;[18] cataract;[19] and primary pterygium excision surgery.[1415] We designed this prospective, interventional case series to establish its role in recurrent pterygium surgery with glue-free conjunctival grafting.

Materials and Methods

Approval of the study was obtained from the ethical committee of the hospital and adhered to the tenets of the Declaration of Helsinki. Written informed consent was obtained from each patient. The study comprised 51 consecutive patients having recurrent pterygium presented from January 2015 to December 2015 scheduled for excision and conjunctival autograft. Patients who were previously treated with bare sclera technique and had recurrence having records of previous surgical procedure were included in the study. The exclusion criteria were primary pterygium, allergy to the topical anesthetics, deafness, nystagmus, barrier to the communication, extreme anxiety, neurological disorders, and patients unable to understand visual analog scale (VAS). Nonsteroidal anti-inflammatory drugs were not used preoperatively. None of the patients received pre- or intraoperative sedation.

Surgical technique

A single surgeon operated all the patients. The lignocaine 2% jelly (Xylocaine Jelly 2% Astra Zeneca India Ltd.) was instilled in the conjunctival sac 10 min before the surgery. A vertical incision was given over the body of pterygium 2 mm behind the limbus. The head of the pterygium was dissected from the cornea with blunt dissection. The subconjunctival tissue under the body of the lesion was removed. Bleeding points were cauterized with wet field cautery. The area was dried with a cotton bud. A free conjunctival autograft was excised from the superior bulbar area. The size of the graft was determined by measuring the area of exposed sclera with caliper. The graft was positioned over the bare sclera in the nasal area with limbus-to-limbus orientation for 10 min by applying gentle pressure with a sponge. After a drying period, the redundant margins of the graft were excised with Vannas scissors and the lid speculum was removed. The eye was bandaged for 24 h. We did not use bandage contact lenses. After completion of surgery, the patient was taken to the recovery room. A standard 10-point VAS was used to assess intra- and post-operative pain.[20] A score of “0” represented no pain at all and score “10” represented the worst pain ever. Postoperative pain was assessed 30 min after the completion of the surgery. A trained para-ophthalmic technician performed the job. Surgeon was not present during the assessment of pain score. Patients were also asked about the satisfaction level as to the type of anesthesia used compared to the previous surgery. The surgeon's subjective impression on discomfort during the surgery (grade 0-nil, 1 = mild, 2 = moderate, and 3 = severe), supplemental anesthesia, lid squeezing, and the inadvertent ocular movements were noted. Total surgical time was also recorded from first conjunctival incision to the removal of a lid speculum, i.e. the time taken from the excision of pterygium to the time to secure the graft on the bed. Anesthetist also noted vital parameters such as blood pressure, pulse rate, and oxygen saturation during the surgery and any supplemental intravenous sedation required.

Statistical analysis

Statistical analysis was performed using a Chi-squared test and P < 0.05 was considered statistically significant. The statistical analyses were performed using Statistical Package for Social Sciences (SPSS– 23, Chicago, USA).

Results

The study included 51 eyes of 51 patients. There were 28 females (54.9%) and 23 males (45.1%). The mean age was 50.2 + 9.1. All patients had nasal vascularized and fleshy pterygium. In three patients, pterygium was covering pupil. From the previous records, forty patients (78.4%) underwent pterygium excision with bare sclera under peribulbar anesthesia, nine patients (17.6%) under subconjunctival injection of 2% lignocaine hydrochloride, and two patients (3.9%) under lignocaine jelly supplemented by subconjunctival injection of 2% lignocaine.

The average intraoperative pain score on VAS was 1.17 + 1.50 (range 0–7). The average postoperative pain score was 0.99 + 1.4 (range 0–7). This difference was not statistically significant (P = 0.24). Zero score, i.e. no pain was seen in 30 patients (58.8%) patients. The average surgical time was 29.20 min + 1.106. No corneal epithelial or ocular surface complications, either intra- or post-operative were observed. None of the patients required suturing of the graft. There were no complications during anesthetics administration. There were no surgical complications, which could compromise the visual outcome. The average surgeon discomfort score was 0.18 + 0.51.

Inadvertent eye movement was seen in 3 patients (5.9%). Lid squeezing was noted in 45 patients (88.2%) during placement of lid speculum. Intraoperative painful sensations and the supplemental anesthesia required during the various steps of the surgery are shown in Table 1.

Table 1

Steps during the surgery

Average blood pressure measured was systolic 130 + 5 mm of Hg and diastolic 85 + 3 mm of Hg. Average pulse rate was 78 + 3.5, and oxygen saturation was maintained at 99%–100%. Patients were asked to give their preference between the anesthetic technique used in the previous and present pterygium surgery. Forty-eight patients (94.1%) preferred the jelly technique, whereas only two patients (3.9%) did not bother about the anesthetic technique. Only one patient (2%) was unaware of the previous technique.

Discussion

Recurrence of fibrovascular tissue is a common concern after primary pterygium surgery. Removal of recurrent pterygium is more difficult due to corneal thinning, symblepharon, and extension of the scar tissue to recti muscles.[19] It requires meticulous dissection of fibrovascular growth from the underlying structures. Pain and bleeding from the vascular growth could be a challenge during surgery. Adequate anesthesia is essential for patient cooperation and surgical procedure. There have been studies on primary pterygium excision under retrobulbar or peribulbar block, subconjunctival injection of lignocaine hydrochloride beneath the head of pterygium, topical application of ropivacaine or benoxinate 0.4% eye drops and lignocaine 2% gel.[101112131415] However, there is a sparse literature on recurrent pterygium excision with glue-free autologous conjunctival graft performed under lignocaine gel.

Our study showed preoperative instillation of 2% lignocaine hydrochloride gel provided satisfactory patient comfort to conduct the safe removal of recurrent pterygium with glue-free conjunctival grafting. There was no significant difference between intra- and post-operative pain score (P = 0.24). Oksuz and Tamer. Studied the role of lignocaine jelly in excision of primary pterygium with conjunctival autograft.[15] The mean pain score in their study was 4.0 ± 1.01, which was higher than our study (1.17 + 1.50). Moreover, they started the procedure 5 min after the instillation of the gel. The low pain score in our study could be due to longer contact time (10 min) between the instillation of jelly and commencement of the excision and no use of sutures to secure the graft. Mithal et al.[14] have also studied the role of lignocaine gel in the excision and glue-free conjunctival grafting in primary pterygium. The mean pain score in their study was 0.70 ± 0.97, lower than our study. The lower pain score in Mithal et al. study could be due to the method of evaluation of pain score, which was done before opening the dressing and no use of sutures to secure the graft. However, the contact time between the gel and conjunctiva was 5 min in Mithal et al. study. Intraoperative pain score gives an idea about the effect of anesthetic agent on the ocular structures. It also serves as a guide to the pain management in the subsequent patients. In this study, none of the patients required intravenous sedation during the procedure. Postoperative VAS score was assessed 30 min after the surgery. We considered this period as the anesthetic effect of the gel will start to weir off, and the patient may experience pain. Postoperative score was lower than the intraoperative pain score. Thirty patients (58.8%) had zero pain score on the scale. None of the patients required injectable analgesics. Anbari et al. compared autologous conjunctival graft by suture and glue prepared by cryoprecipitate and had found postoperative VAS was considerably lower in glue group than the sutured group.[21] However, pterygium excision was performed under subconjunctival injection of 2% lignocaine hydrochloride. We could not compare postoperative VAS as there has been no study in the literature on postoperative pain score in the recurrent pterygium surgery operated under lignocaine gel.

The efficacy of any anesthetic agent also depends on the surgeons comfort in performing the procedure. Lignocaine gel causes surface anesthesia and does not block the movements of the eye. In the present study, inadvertent eye movement was seen in three patients (5.88%) and did not interfere with the surgical steps. The movements were controlled by the verbal command. Moreover, patient's ability to move the eye in a particular direction was helpful to bring the area into the surgical field. This was particularly useful when the graft was kept apposed to the scleral bed for 10 min. Lid squeezing is another phenomena, which was observed when some foreign body intrudes into the eye. Forty-five patients (88.2%) had lid squeeze during the application of the lid speculum. Talking to the patients during this stage may alleviate anxiety and increase their cooperation during the procedure. Intravenous sedation is another option. However, it may affect the intra- and post-operative pain score assessment.

Normally, patients perceive touch sensation during excision and dissection of pterygium, cauterization of the episcleral vessels and making of the conjunctival flap. In this study, seven patients perceived pain sensation; however, it did not affect the surgical steps. Instillation of 0.5% proparacaine hydrochloride alleviated the pain sensation. Intraoperative subconjuctival, retrobulbar and peribulbar injection of lignocaine are options available to alleviate the intra-operative painful sensations. However, subconjunctival hemorrhage, chemosis, and globe perforation can occur with injectable anesthetic agents. Joshi has reported that a single drop instillation of proparacain hydrochloride is sufficient for clear corneal phacoemulsification.[22] In our study, no patient complained discomfort of the microscope light. Putting the illumination of the microscope light to the minimum and increasing it as the surgical steps advances does help.

Due to prolonged contact of gel with the cornea, it can cause corneal epithelial or ocular surface complications. Lignocaine gel has a short duration of action and needs to be instilled repeatedly in case of lengthy surgical procedure potential for cumulative toxicity. We did not observe any intra- or post-operative complications related to the lignocaine gel.

The average surgical time was 29.20 min (+1.106). Anbari et al. compared suture and cryoprecipitate for attaching autologous conjunctival graft in primary and recurrent pterygium. The median surgical time was 11 min (range 9–15) in glue group, which was less than our study.[21] Anbari et al. did not consider the preparation time of cryoprecipitate. The average surgical time noted by Oksuz and Tamer. in the study on primary pterygium under lignocaine gel was 25.3 ± 4.6 min.[15] In their study, Sharma et al. performed pterygium excision with glue-free conjunctival graft under peribulbar anesthesia and had a mean surgical time 23.20 (±1.55) min which was less than our study.[23] Dissection of pterygium and control of episcleral bleed does take time in recurrent pterygium. We did not use commercially available glue. Serum from small bleeding vessels acted as an adhesive. The overall operating conditions as rated by the surgeon were good. Anesthetist noted vital parameters of all the patients. None of the patients had drastic changes in the pulse rate and the oxygen saturation.

This study involves a single surgeon. Involving two or more surgeons and conducting multicenter trial would add more weight age to the study.

Conclusion

The study result demonstrates recurrent pterygium surgery with glue-free autogenous conjunctival grafting can be performed under instillation of 2% lignocaine gel preoperatively without compromising the results. The Ease of application procedure, lack of toxicity, and sufficient effect to complete the surgery make it an efficient alternative to injectable anesthetics. However, it is prudent to individualize the anesthetic technique according to the patient and surgeon need.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.