Tuck in versus cauterisation of graft edge in pterygium management: A comparative retrospective interventional analysis.

PURPOSE: To compare and evaluate surgical outcome between tuck in and cauterisation in the management of primary pterygium.
MATERIALS AND METHODS: Two groups of 56 eyes and 58 eyes with primary pterygium underwent pterygium excision with conjunctival autograft fixation by tucking in alone (Group 1) and with cauterization (Group 2), respectively. A retrospective comparative analysis was done between the two groups.
RESULTS: This study included a total of 114 eyes in the final analysis. The recurrence was noted in 3 eyes in Group 1 (5.35%), whereas only 1 eye (1.72%) in Group 2. Other complications included graft edema in 25 eyes (44.64%), in Group 1 and 29 eyes (50%) in Group 2, subconjunctival hemorrhage seen in 28 eyes (50%) in Group 1 and 32 eyes (55.17%) in Group 2, graft retraction observed in 28 eyes (50%) in Group 1 and 13 eyes (22.4%) in Group 2, granuloma formation was seen only in one patient (1.72%) in Group 2, graft loss was observed in four patients (7.14%) in Group 1 and 2 patients (3.44%) in Group 2.
CONCLUSION: Graft fixation in pterygium surgery using low-cost procedures with tuck in or cauterization proves to be tolerable, safe and successful method. An additional step of fixing the graft to the cut conjunctival margin using bipolar cautery proves to be safer. Copyright:

Introduction

Pterygium is a wing-shaped elastotic degenerative sub-conjunctival overgrowth over the cornea which arises commonly from nasal bulbar conjunctiva, prevailing mainly around the equatorial regions. Etiology of pterygium is thought because of long-term exposure to ultraviolet rays.[1]

Multiple techniques have been evolved for its management in order to overcome the complications such as recurrence, graft loss, and infection. These techniques included bare sclera, conjunctival autograft with sutures, conjunctival autograft with glue, conjunctival autograft with autologous blood serum, and amniotic membrane transplantation. Also, mitomycin C application over bare sclera has proven benefits in overcoming recurrence.[23] In 1985, Kenyon et al., discovered the technique of conjunctival autograft placement over bare sclera which decreases the recurrence rate and also overcomes cosmetic unacceptability post bare sclera technique; Conjunctival autograft transplantation initiated by them significantly affected the recurrence rate, which dropped from 89% in case of bare sclera technique to 2% in conjunctival autograft transplantation technique.[4]

In this study, we analyzed and observed the outcomes of two techniques of graft fixation, first tucking the graft edge along the sides under the conjunctiva and second by cauterizing the graft edges. Hopefully, this study updates our knowledge in cost effective management of pterygium.

Materials and Methods

This is a retrospective comparative study including two groups of 56 eyes in 55 patients (Group 1) and 58 eyes in 55 patients (Group 2) diagnosed with primary pterygium which underwent pterygium excision and conjunctival autograft fixation by tuck in and with cauterization of the edges, respectively. It was held at a tertiary care center.

Pterygium was graded based on the following grading: Grade 1 is when pterygium crosses limbus, Grade 2 is midway between limbus and pupil, Grade 3 reaching upto pupillary margin, and Grade 4 crossing pupillary margin.[5] Patients with primary pterygium Grade 1 and 2 and patients with primary pterygium having symptoms of irritation, watering, redness and for cosmetic reasons were included [Figure 1].

Figure 1

Preoperative Grade 2 primary pterygium

Patients with recurrent pterygium, fleshy pterygium accompanied by symblepharon or limitation of duction, double-headed pterygium, glaucoma filtering bleb, and glaucoma suspects were excluded from the study. Informed consent was obtained from all patients. The study protocol was adhered to the tenets of the Declaration of Helsinki. The study was approved by the institutional ethics committee and review board.

Surgical technique

A single experienced surgeon performed all the surgeries. Topical proparacaine hydrochloride was applied three times at an interval of 10 min before the start of the surgery. A 0.5–1cc of 2% xylocaine (Astra Zeneca, UK) was injected subconjunctivally into the pterygium tissue. The pterygium was avulsed from the apex using a toothed forceps and an iris spatula, pterygium body and the underlying fibrovascular tissues were delineated from the conjunctiva and excised using conjunctival scissors. The subconjunctival degenerated tissue was trimmed from the margins and adherent residual tissue was scraped off from the cornea using a crescent blade, size of the defect was measured using a vernier calliper and slightly oversized graft was harvested from supero-temporal conjunctiva. In order to harvest conjunctival graft, 1–2 cc of 2% xylocaine was injected in the supero-temporal conjunctiva to separate it from Tenon capsule below which was further dissected using conjunctival scissors and then a tenon free graft was harvested. In Group 1 a thin homogenous blood film coagulates and forms a natural thin fibrin clot on the scleral bed, any active bleeding site was avoided and the graft was slided over the bed and subsequently was pressed and ironed out along its surface using an iris spatula, after that the edges were tucked inside the conjunctiva along all the sides. On the other side, Group 2 patients underwent similar procedure as described above in addition the edges of the graft were cauterized with conjunctiva along all the sides using a bipolar cautery [Figures 2 and 3].

Figure 2

Intraoperative photographs of pterygium excision with Conjunctival Autograft (CAG) tucked inside conjunctiva (a) pterygium excision (b) tuck-in method (c) lid movement done to check graft fixation

Figure 3

Intraoperative photos of pterygium excision with CAG fixation with cauterization (a) pterygium excision (b) graft harvestation (c) graft fixation with cauterization

After the procedure patients were patched overnight and were seen on postoperative day 1, 1 week, 6 weeks, 6 months and every year thereafter. All the patients were started on steroid-antibiotic combination and preservative free tear substitutes for four weeks [Figure 4].

Figure 4

Postoperative photographs of the procedure at (a) Day 1 (b) 6 weeks

Results

This study included a total of 114 eyes in the final analysis (Group 1) 56 eyes (Group 2) 58 eyes. The mean age was 46.2 ± 9.4 (Group 1) and 43.2 ± 11.3 (Group 2). The male: female ratio was 25:30 (Group 1) and 20:35 (Group 2). Table 1 shows the demography of the study population and Table 2 demonstrates duration of the surgery. The average time taken for surgery in Group 1 was 11.17 ± 2.10 min and 10.22 ± 1.8 min in Group 2. Complications in both the groups were noted, and statistical analysis was conducted using Chi-square test to obtain the P value for significance. The rate of recurrence following pterygium surgery was 3 eyes (5.35%) in Group 1 after 6 months, 7 months and 8 months and 1 eye (1.72%) in Group 2 after 6 months, and the P value obtained was 0.6188 i.e., >0.05 which shows no significance. Graft retraction was observed in 28 eyes (50%) in Group 1 and 13 eyes (22.4%) in Group 2 with P - 0.0021 i.e., <0.05 which shows significance. Other complications included graft edema in 25 eyes (44.64%) in Group 1 and 29 eyes (50%) in Group 2, subconjunctival hemorrhage seen in 28 eyes (50%) in Group 1 and 32 eyes (55.17%) in Group 2, granuloma formation was seen only in one patient (1.72%) in Group 2, graft loss was observed in four patients (7.14%) in Group 1 and two patients (3.44%) in Group 2; P value calculated for all the complications were >0.05, hence were not considered significant. Table 3 shows complications in both the groups. Figure 5 shows complications in both the groups with the help of a bar diagram.

Table 1

Demography of the study population (n=114)

	Group 1 (n=56 eyes) 55 patients	Group 2 (n=58 eyes) 55 patients
Age	46.2±9.4	43.2±11.3
Male: female	25:30	20:35

Table 2

Comparison of mean duration between the study groups (n=114)

Parameter	Tuck in	Cauterization
Duration (min)	11.17±2.10	10.22±1.8

Table 3

Comparison of complications between the study groups (n=114)

	Number of eyes		P
	Tuck in, n (%)	Cauterization, n (%)
Recurrence	3 (5.35)	1 (1.72)	0.2919
Retraction	28 (50)	13 (22.4)	0.002153
Graft edema	25 (44.64)	29 (50)	0.5668
Graft loss	4 (7.14)	2 (3.44)	0.3771
Subconjunctival hemorrhage	28 (50)	32 (55.17)	0.5803
Granuloma	0	1 (1.72)	NA

NA: Not available

Figure 5

Bar diagram showing complications in Group 1 and Group 2

Discussion

Conjunctival autograft fixation in pterygium surgery holds significant role in overcoming unwanted postoperative complications. Graft loss has been one of the major causes for recurrence and so in this study the surgical technique was focused on evaluation of different fixation techniques in order to decrease recurrence and hence, patients have been followed up for 1 year in order to note for any evidence of recurrence.

Recurrent pterygium has been divided into three grades: Grade 1 – regrowth of fibrovascular pterygium like tissue crossing the limbus onto the cornea, Grade 2 – fibrovascular recurrence attaining the same degree of corneal encroachment as the original lesion, Grade 3 – or regrowth exceeding 1 mm onto the cornea.[6] According to this criteria, even though Group 1 showed recurrence in three eyes and Group 2 showed in only one eye it was not statistically significant. Retraction of the graft is considered one of the significant causes of graft loss, as in Group 1 cauterization was not done at the graft edges, and it resulted into increased graft retraction compared to Group 2.

Also, there are number of studies conducted in order to evaluate, compare and analyze different techniques of graft fixation.

Suzuki et al. described conjunctival inflammation post conjunctival autograft fixation with sutures. This study concluded that despite being safe and effective procedure, suturing conjunctival autograft required surgical expertise, technical abilities, more surgical time, and need of their removal at times. Patients always complain of pain, grittiness, and watering postoperatively, especially if 10-0 MFN sutures were used. Sutures are thought to be not actively participating in wound healing; it can result in additional trauma to surgical site, acts as a nidus for infection, and carries the risk of suture-related complications such as granuloma formation. Silk, nylon, and particularly, vicryl sutures placed in the conjunctiva are thought to cause inflammation and migration of the Langerhans cells to the cornea, thus favoring recurrence.[7]

Nadarajah et al. conducted a study between conjunctival autograft fixation with fibrin glue and autologous blood. The results of this study were that the recurrence rate at 1 year was more in the autologous blood group, five eyes (10.6%), compared with two eyes (3.4%) in the fibrin adhesive group. Nevertheless, these were not found to be statistically significant. The recurrence occurred only in patients with the fleshy morphology of pterygium in both methods. The recurrence rate found in this study is comparable to that of similar studies performed previously.[8910] This is consistent with virtually all existing studies that emphasize the risk of recurrence to be associated with a more severe morphology of pterygium.[11]

Choudhury et al. compared conjunctival autograft fixation with sutures and with autologous blood which concluded that the duration of surgery was significantly less in patients undergoing graft fixation with autologous blood (mean duration 15 ± 2 min) than with sutures (mean duration 67 ± 2 min). Postoperative symptoms were fewer for autologous blood than sutures. The rate of recurrence was equal in both groups (one patient in each group, 6.25%). Howevere, complications regarding graft failure and graft retraction were more common in autologous blood (two patients, 12.5%) than sutures (one patient, 6.25%); however, the difference was not statistically significant (Z = 0.61). Thus, autologous in situ blood coagulum is a useful method for graft fixation in pterygium surgery with shorter operating time and less postoperative discomfort.[12] Similar results were obtained with other comparable studies.[13141516]

Cha et al. compared fibrin glue with sutures which concluded that the operation duration was 27.71 min (5.22 min) in the fibrin glue group and 43.30 min (8.18 min) in the suture group (P = 0.000). Seven days after the operation, the fibrin glue group showed milder conjunctival inflammation than the suture group (P = 0.000). Postoperative complications and corneal recurrence rates were not statistically different between the two groups.[17] This study is backed up with other similar studies giving comparable results.[181920]

An analysis was conducted by Kodavoor et al. between three most common types of graft fixation which are sutures, fibrin glue, and autologous blood. The outcomes showed that all the three techniques are equally comparable and can be offered to the patients with equally good results.[21] These results were found comparable with another similar study.[22]

A study was conducted by Lešin et al. between cauterization and sutures in graft fixation, which the only study in our literature research which compared between these techniques. However, the results were inconclusive in this study.[23]

In comparison to previous studies, our study turns out to be one of its own. This study describes significant differences between study groups with respect to postoperative complications which are noticeable.

The surgical technique followed in both the groups included graft fixation by allowing capillary ooze to form thin blood clot on the bare sclera along with either tuck in or cauterization of the graft edge. We observed in this study that time duration required to perform pterygium excision with conjunctival autograft fixation in Group 1 was higher than Group 2 which describes that graft fixation by tucking in the edges of the graft only and took more time to check the stability of the graft in place because of weak fixation as compared to cauterization but was not found statistically significant. Also, graft retraction was observed higher in Group 1 than Group 2, this proves that graft retraction is more when the edges are tucked in the conjunctiva and are not adhered to it, because of comparatively weak fixation than when fixed with cauterization. Graft retraction, graft loss, and subsequent recurrence were more with tuck in fixation alone. All the four cases of recurrence in both the groups were observed because of graft loss. However, all other complications observed were comparable in both the groups and had no significance in the final outcome of the surgery.

Conclusion

The study concludes that graft fixation in pterygium surgery using low-cost procedures with tuck in or with cauterization proves to be tolerable, safe and successful method. Both the study groups show comparable complications except tuck in alone showing increased chances of graft loss and consequently recurrence. An additional step of fixing the graft to the cut conjunctival margin using bipolar cautery proves to be safer, effective and can be considered in primary pterygium surgery.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.