CLINICAL SCIENCE Autologous Blood Versus Fibrin Glue in Pterygium Excision With Conjunctival Autograft Surgery Gaayathri Nadarajah, MBBS,* Vanitha Hema Ratnalingam, MD(USM), MSurg(UKM),† and Hazlita Mohd Isa, MBChb, MS(Ophthal), AM(Mal), PhD‡ Purpose: To evaluate graft stability and recurrence rate between fibrin glue and autologous blood in pterygium conjunctival autograft surgery. Methods: A prospective, randomized, single-blinded clinical trial to assess the efficacy of autologous blood in place of fibrin glue in pterygium surgery. A total of 120 eyes of 111 patients were randomized according to pterygium morphology, to undergo pterygium surgery with autografting using either autologous blood or fibrin glue. All patients were operated by a single surgeon; 58 eyes were operated using fibrin glue and 62 eyes had a conjunctival autograft with autologous blood. Patients were seen on postoperative day 1, 1 week, 1 month, 6 months, and 1 year after surgery. Graft stability and pterygium recurrence were graded by an independent observer who was masked to the method of treatment. Results: All 120 eyes completed the 1-year follow-up. Graft loss was seen only in the autologous blood group. Of the 62 eyes in this group, a total of 15 (24.2%) grafts dislodged. Recurrence was calculated after excluding grafts that were dislodged. Of the 105 patients, there were a total of 7 recurrences, 2 (3.4%) from the fibrin adhesive method and 5 (10.6%) from the autologous blood method. This was not statistically significant (P = 0.238). Conclusions: Autologous blood does not exhibit similar graft stability seen with fibrin glue. Although the recurrence rate may not be significant, careful patient selection and a standard method needs to be laid out before the use of this method is widely accepted. Key Words: pterygium, autologous blood, recurrence, graft stability (Cornea 2017;36:452–456) O ver the years, a wide range of modalities of treatment has emerged in the world of pterygium surgery, from beta-irradiation to sutureless surgeries with fibrin glue. These Received for publication August 7, 2016; revision received October 3, 2016; accepted October 21, 2016. Published online ahead of print December 8, 2016. From the *Ophthalmology Department, Pusat Perubatan Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia; †Ophthalmology Department, Hospital Sungai Buloh, Selangor, Malaysia; and ‡Ophthalmology Department, PPUKM, Cheras, Kuala Lumpur, Malaysia. The authors have no funding or conflicts of interest to disclose. Reprints: Hazlita Mohd Isa, MBChb, MS(Ophthal), AM(Mal), PhD, Consultant Ophthalmologist and Senior Lecturer, Pusat Perubatan Universiti Kebangsaan Malaysia, Jalan Yaakob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia (e-mail: drhdmi@yahoo.co.uk). Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. 452 | www.corneajrnl.com methods primarily aim at curtailing the undesired complication of recurrence. Of these methods, fibrin glue has proven to champion over other methods in both recurrence rates and patient comfort.1 However, because fibrin glue is fractionated from pooled human plasma, it has been reported to be associated with a very small risk of transmission of certain diseases and hypersensitivity reaction.2 Furthermore, fibrin glue is costly in certain countries, equating and sometimes more expensive than that of an intraocular lens. Unfortunately, the majority of the patients who would benefit from this technique belong to a lower socioeconomic stratum, hence limiting the application of this method to an advantaged few. To overcome both concerns mentioned above, a handful of studies have emerged over these last few years comparing the efficacy of autologous blood with fibrin glue. The latest study is by Kurian et al3 that demonstrated autologous blood to be as adherent as fibrin glue with comparably low recurrence rates. Nevertheless, most reports illustrating the benefits of autologous blood for pterygium surgery are singlearm studies, have a small sample size, or lack proper randomization technique.4,5 Many landmark studies have proven that the morphology of pterygium is instrumental in predicting recurrence of pterygium.6 None of the above studies randomized the patients according to the pterygium morphology. This study not only is comparable in terms of the sample size but also has taken the morphology of pterygium into consideration during randomization. METHODOLOGY A prospective randomized single-blind clinical trial was conducted at 2 tertiary centers in Kuala Lumpur between November 2014 and August 2015, after receiving ethical approval by the Research Ethics Committee of the National University of Malaysia. Patients with pterygium who attended the ophthalmology clinic and fulfilled the inclusion criteria were recruited into the study, after providing written informed consent. The sample size was determined by the standard sample size calculation formula, with an 80% power for demonstrating reduction in the current recurrence rate of pterygium surgery by 15%. The recurrence rate was determined after extensive research on the current available studies. Patients were examined under the slit lamp and had their pterygium graded by a single preoperative investigator, Cornea ! Volume 36, Number 4, April 2017 Copyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Cornea ! Volume 36, Number 4, April 2017 Autologous Blood Versus Fibrin Glue following a grading system devised by Tan et al. Patients who had bilateral pterygium had each eye randomized separately according to the grade of pterygium. Pterygium was graded by a single preoperative investigator into 3 categories based on fleshiness of pterygium and visibility of the underlying episcleral vessels, which could predict the likelihood of recurrence, T1 being least likely to recur and T3 having the highest possibility to recur (Table 1). Patients were then stratified according to their pterygium morphology by a single preoperative investigator. Every 20 patients in the subcategory were then randomized into either the autologous blood or fibrin glue method by a blockpermuted sampling with differing block sizes of 4 and 6, by the same preoperative investigator. The outcome of this randomization was not revealed to the masked independent observer, designated to grade recurrence. conjunctiva was dissected carefully without swelling it up with subconjunctival anesthesia, as it may lead to dissection in the wrong plane. Once a thin Tenon-free graft with a fair limbal rim was obtained, it was oriented correspondingly on the cornea adjacent to the wound. Preoperative Assessment Conjunctival Autograft With Autologous Blood Before surgery, all patients underwent Snellen visual acuity documentation, intraocular pressure assessment, slitlamp biomicroscopy, and fundus examination. Refraction and keratometry assessment was done whenever required, and the size of all pterygium was documented after measuring at the slit lamp and photographed. All surgeries were performed by the same surgeon to ensure consistency in the technique and time allocated for graft adherence. Topical proparacaine 0.5% was instilled into the eye to be operated. The surgical field was cleaned with povidone–iodine 5%, the area draped, and a lid speculum inserted into the eye. Subconjunctival lidocaine was injected into the head of pterygium at the start of surgery. Intraoperative Steps The head of pterygium was dissected from the cornea toward the limbus using a Took knife. A maximum of 5 mm of the body of pterygium was excised (measured with a Vernier caliper), and the surrounding Tenon tissue was removed as much as possible, with care taken not to damage the underlying recti. Hemostasis was secured by applying pressure with only a cotton bud. Cautery was not used. Residual fibrous tissue on the cornea was removed with a Colibri or Beaver blade. The area of bare sclera was measured with a Vernier caliper, and a corresponding 1-mm oversized graft was harvested from the superior bulbar conjunctiva. The bulbar Conjunctival Autograft With Fibrin Adhesive The thrombin and fibrinogen components prepared at the start of surgery were drawn into 2 separate 1-mL syringes. One drop of the thrombin component followed by a drop of the protein solution was placed on the scleral bed.2 The graft was slid over the bare sclera, ensuring epithelium side up and the limbal edge toward the cornea. The graft was then pressed gently, edges crimpled together, and left to dry for 1 to 2 minutes before removing the lid speculum. A homogenous blood film was allowed to form on the scleral bed. In cases in which the blood film was exceptionally thin or clot formation was premature, a fresh blood film was created by purposefully pricking the scleral capillaries with a 20-G needle. The graft was then slid over the bare sclera, taking into consideration the orientation of the graft at all times, pressed gently and left for a minimum of 7 minutes, using the normal clotting time of 4 to 10 minutes as a guide. The graft was left on for another few minutes, in cases in which the graft was still found to be mobile after this time. The edges of the graft were also crimpled together. For all cases, the graft was checked and confirmed to be intact after removal of the lid speculum. Dexamethasone/ polymyxin B ointment (Maxitrol) was applied into the eye, and the eye was double-padded until review the next day. Follow-up All patients were reviewed by the same investigator at postoperative day 1, 1-month, 6-month, and 1-year follow-up. Graft stability was assessed on post operative day 1. Grafts were noted on whether they were intact or not and documented together with anterior segment photographs. Fluorescein staining of the eye was performed to assess the area of bare sclera exposed in cases of partial or total dislodgement of the graft. Grades 1 to 3 were considered partial dislodgment, whereas grade 4 was considered total dislodgement (Table 2). After TABLE 1. Classification of Pterygium Morphology TABLE 2. Graft Stability Assessment Grade Graft Stability Grade T1 (atrophic) Grade T2 (intermediate) Grade T3 (fleshy) Description Episcleral vessels underlying the body of pterygium were unobscured and clearly distinguished Episcleral vessels not indistinctly seen or partially obscured Episcleral vessels underlying the body of pterygium were totally obscured Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Grade 1 Grade 2 Grade 3 Grade 4 An area of fluorescein staining less than or equivalent to 1/4th of the area of bare sclera An area of fluorescein staining more than 1/4th but less than or equivalent to 1/2 of the area of bare sclera An area of fluorescein staining more than 1/2 but less than or equivalent to 3/4 of the area of bare sclera Graft completely dislodged from the area of bare sclera www.corneajrnl.com | 453 Copyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Nadarajah et al Cornea ! Volume 36, Number 4, April 2017 assessment, all patients were administered Maxitrol eyedrops every 2 hours for a week, 4 times a day for 3 weeks, and twice a day for another 2 weeks. Chloramphenicol ointment was prescribed at night for the whole 6 weeks. Complete or total graft dislodgement (grade 4 graft stability) was assessed at day 1 up to the 1-week postoperative period, using a slit lamp and photography. At 1 month, 6 months, and 1 year, patients were assessed for recurrence, and anterior segment photographs were taken at each visit. Recurrence was defined as true recurrence with fibrovascular tissue invading the cornea.7 These photographs were evaluated by a single independent observer who was masked to the randomization method and hence the method used for each patient. Statistical Analysis The data were tabulated and analyzed using SPSS for Windows version 20. The data were analyzed for graft stability, and the recurrence rate between both methods was analyzed using the x2 test and Fisher exact test. RESULTS Patient Characteristics Analysis was performed on 120 eyes of 111 patients who completed the 1-year follow-up. The demographic data of the patients in the study are summarized in Table 3. Of the total 111 patients who were recruited, 62 were male and 49 were female. This difference was not found to have any significance (P = 1). The mean age in the fibrin adhesive group was 62.3 6 1.7 years and 53.6 6 1.8 years in the autologous blood group. Although these values were found to be statistically significant (P = 0.006), it was not relevant because we did not randomize patients according to age in this study. The race distribution was as follows: 57.7% of the study population was Malay, 34.2% Chinese, 5.4% Indian, and 2.7% were other races. There were no significance of the racial distribution between both methods (Malay, P = 0.18; Chinese, P = 0.43; Indian and other races, P = 1) (Table 3). In the fibrin adhesive method, there were 13 (10.8%) patients in the T1 grade, 31 (25.8%) in T2 grade, and 14 (11.7%) in the T3 grade. Similar numbers were seen in the autologous blood method, 14 (11.7%), 30 (25%), and 18 (15%), in grades T1, T2, and T3, respectively. As randomization was done meticulously, there was no significant difference in the TABLE 3. Patient Characteristics Characteristics Fibrin Glue, n (%) Autologous Blood, n (%) Sex Male Female Race Malay Chinese Indian Others 454 Total 30 (27) 23 (20.7) 32 (28.8) 26 (23.4) 62 (55.9) 49 (44.1) 25 23 3 2 39 15 3 1 64 38 6 3 (22.5) (20.7) (2.7) (1.8) | www.corneajrnl.com (35.1) (13.5) (2.7) (0.9) (57.7) (34.2) (5.4) (2.7) number of patients seen between both methods in all the three grades (Table 4). Graft Dislodgement Partial dislodgement was seen in both fibrin glue (n = 1, 1.7%) and autologous blood groups (n = 6, 9.7%). This result was not found to be statistically significant (P = 0.116). In the fibrin group, partial dislodgement of the graft was seen in 1 case in grade 3 pterygium (T3). However, in the autologous blood group, graft instability was seen in all 3 grades; 1 in T1, and 3 in T2 and T3 each. Nevertheless, there were no significant differences between both methods in the T3 grade (P = 0.62). On analyzing all the 3 grades in the autologous blood group, we also found that these differences were not statistically significant (P = 0.42), as shown in Table 4. In contrast, complete graft dislodgement (grade 4 graft stability) was seen only in the autologous blood method, and occurred in all three grades (Table 4). Of the 15 (24.2%) grafts that completely dislodged within the first postoperative week, 3 (21.4%) were seen in T1, 6 (20%) in T2, and 6 (33.3%) in T3. This rate of dislodgement between the groups however was not statistically significant. Recurrence Recurrence was calculated after excluding all grafts that were dislodged. Of the 105 patients, there were a total of 7 recurrences, 2 (3.4%) from the fibrin adhesive method and 5 (10.6%) from the autologous blood method. However, there was no statistical significance seen in recurrence between these two methods (P = 0.238). In both methods, recurrence was seen only in the T3 grade, as depicted in Table 4. It is worth noting that recurrence was documented as early as the 1-month postoperative period. Two of the 5 recurrences in the autologous blood group were seen at 1 month but none was seen in the fibrin adhesive group. At the 6-month postoperative period, 3 recurrences were seen in the autologous blood group (4.8%), and 1 (1.7%) recurrence was detected in the fibrin adhesive group. Nevertheless, these numbers were also not statistically significant (P = 0.327). Postoperative Complications A total of 3 patients developed a Tenon granuloma at the 1-month postoperative period in the autologous blood group. Two of them were excised with no recurrence thereafter, and the other resolved with topical application of Maxitrol ointment for a week. The conjunctival autograft of one patient was inadvertently placed epithelium side down and graft necrosis was noted at 1-week follow-up. The conjunctival autograft was reharvested from inferior bulbar conjunctiva, and no recurrence was seen thereafter. The esthetic value of surgery done with autologous blood is comparable to that of Tisseel glue, as shown in Figures 1 and 2. DISCUSSION Pterygium is a very common condition faced by ophthalmologists in Malaysia and neighboring countries, because it is more commonly seen in countries close to the Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Copyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Cornea ! Volume 36, Number 4, April 2017 Autologous Blood Versus Fibrin Glue TABLE 4. Number of Patients, Partial and Complete Dislodgement, and Recurrence at 1 Year in All 3 Grades Between Both Methods Grade 1 Characteristics Number of patients Partial dislodgement Complete dislodgement Recurrence at 1 yr Grade 2 Grade 3 Fibrin Glue Autologous Blood Fibrin Glue Autologous Blood Fibrin Glue Autologous Blood 13 0 0 0 14 1 3 0 31 0 0 0 30 3 6 0 14 1 0 2 18 3 6 5 equator.8 Although it is easy to diagnose and treat, recurrence is a persistent problem and can cause visionthreatening complications. There are countless studies and trials that have postulated that recurrence is multifactorial. Although surgery is the treatment for this condition, it may be a double-edged sword. A few studies have proven that inflammation during the postoperative period causes proliferation of not only vascular cells and fibroblasts but also subconjunctival fibroblast tissue, and overexpression of matrix metalloproteinases may result in invasive pterygium.9 The most reliable predictor of recurrence is still the morphology of pterygium. As seen in many studies, thick fleshy pterygia are more likely to recur in contrast to their atrophic counterparts.10 This could also be the reason why recurrence is more likely to occur in younger age groups as they tend to have thicker pterygium at presentation. We found that of the 111 patients who were recruited in this study, 55.9% were male and 44.1% were female. This is consistent with the majority of the existing studies, as males are exposed to more outdoor activities than females are. Regarding the ethnic distribution, the bulk of our patients were Malays (57.7%), undeviating from the racial distribution in Klang Valley, where the study was conducted. As mentioned earlier, there was no statistical significance in sex and racial distribution between both groups. In this study, we found that the majority of the patients were aged between 50 and 60 years, with the fibrin glue group having an older mean age of 62.3 6 1.7 years and the autologous blood group having a younger age range with a mean of 53.6 6 1.8 years. Age was not considered in the process of randomization, as many studies have undisputedly proven that pterygium prevalence increases with age, with the majority occurring above age 40, as seen in our immediate FIGURE 1. Day 1 (left) and 6 months (right) postoperative period appearance of pterygium excision and a conjunctival autograft with autologous blood. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. neighbors, Singapore (12.3% Malays and 6.9% Chinese),11,12 Sumatera (16.8%),13 and Meiktila, Myanmar (19.6%).14 Our study area encompasses largely an urban area and a small area at the fringe of a rural district, which probably accounts for a smaller number of younger patients, who mostly work in offices, in contrast to the older subjects who are still involved in agricultural work under the sun. In terms of the pterygium grade, the majority of the patients had the intermediate grade T2 (50.8%), 22.5% were of the atrophic variety, and 26.7% belong to the fleshy grade T3. These numbers are similar to those of a study in the same geographical region.15 Partial dislodgement occurred when the graft was still stuck to the bulbar conjunctiva but variable amounts of bare sclera were exposed. A total of 8 grafts were reported to have partial dislodgement, 1 (1.7%) in the fibrin glue method and 7 (11.3%) in the autologous blood method. No complications were seen in one patient in the fibrin glue method; but in the autologous blood method, 2 patients developed a Tenon granuloma and another developed recurrence. As autologous blood contains more naturally occurring growth factors, this could be the reason for more complications due to an exacerbated fibrovascular response. In contrast, complete dislodgment was seen only in the autologous blood method, a total of 15 (24.2%) grafts were completely dislodged within the first postoperative week. No grafts in the fibrin glue group dislodged. It is unlikely that autologous blood is not as adhesive as fibrin adhesive. In fact, fibrin glue simply mimics the last few stages of the coagulation cascade that concludes with formation of a stable fibrin clot.2 Our numbers were comparable to the dislodgement rate in a similar study.5 There were a few shortcomings encountered during the autologous blood method in which it was difficult to control the amount of subgraft blood. When more blood oozes, a larger clot is expected to form beneath the graft, the contraction of which will probably cause dislodgement of the graft. Hence, it is recommended that another study be conducted to gauge the appropriate amount of blood to cover the scleral bed before sliding over the graft, with a suitable technique to achieve this. The duration to leave the graft to adhere on the scleral bed is based on the normal clotting time of 4 to 10 minutes. The minimum duration of 7 minutes used in this study fell in this range and seemed to allow for sufficient graft adhesion. A further few minutes was allocated in cases in which the graft was still mobile after 7 minutes. Hence, we believe that this technique may be a little more time consuming than www.corneajrnl.com | 455 Copyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Nadarajah et al Cornea ! Volume 36, Number 4, April 2017 FIGURE 2. Day 1 (left) and 6-month (right) postoperative period appearance of pterygium excision and a conjunctival autograft with fibrin glue. a conjunctival autograft with fibrin glue that ensured graft adherence within 2 to 3 minutes. Fibrin glue may be a more feasible method in centers with a large number of patients with pterygium. The recurrence rate at 1 year after excluding patients whose grafts were completely dislodged was more in the autologous blood group, 5 (10.6%), compared with 2 (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 (T3) in both methods. The recurrence rate found in this study is comparable to that of similar studies performed previously.3–5 This is consistent with virtually all existing studies that emphasize the risk of recurrence to be associated with a more severe morphology of pterygium.6 Recurrence was noted as early as 1 month in the autologous blood group, possibly due to more growth factors present in fresh blood, in contrast to that found in the fractionated plasma of Tisseel glue. From this trial, although autologous blood seems to be a promising new technique in pterygium excision with conjunctival autograft surgery, more careful patient selection is warranted to prevent aggressive recurrence. Autologous blood is likely to be more beneficial in older patients with more atrophic pterygium, compared with other age groups and pterygium morphologies. Fibrin adhesive therefore still remains the mainstay for pterygium surgery until a more comprehensive recommendation on the use of autologous blood emerges. REFERENCES 1. Koranyi G, Seregard S, Kopp ED. Cut and paste: a no suture, small incision approach to pterygium surgery. Br J Ophthalmol. 2004;88: 911–914. 456 | www.corneajrnl.com 2. Panda A, Kumar S, Kumar A, et al. Fibrin glue in ophthalmology. Indian J Ophthalmol. 2009;57:371. 3. Kurian A, Reghunadhan I, Nair KG. Autologous blood versus fibrin glue for conjunctival autograft adherence in sutureless pterygium surgery: a randomized controlled trial. Br J Ophthalmol. 2014;99:464–470. 4. Sirisha G, Jyothi S. Autologous blood for conjunctival autograft fixation in pterygium surgery. Indian J Appl Res. 2016;6:328–330. 5. Boucher S, Conlon R, Teja S, et al. Fibrin glue versus autologous blood for conjunctival autograft fixation in pterygium surgery. Can J Ophthalmol. 2015;50:269–272. 6. Tan DT, Chee SP, Dear KB, et al. Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision. Arch Ophthalmol. 1997;115: 1235–1240. 7. Prabhasawat P, Barton K, Burkett G, et al. Comparison of conjunctival autografts, amniotic membrane grafts, and primary closure for pterygium excision. Ophthalmology. 1997;104:974–985. 8. Jap A, Chan C, Lim L, et al. Conjunctival rotation autograft for pterygium: an alternative to conjunctival autografting. Ophthalmology. 1999;106:67–71. 9. Solomon A, Pires RT, Tseng SC. Amniotic membrane transplantation after extensive removal of primary and recurrent pterygia. Ophthalmology. 2001;108:449–460. 10. Shimazaki J, Kosaka K, Shimmura S, et al. Amniotic membrane transplantation with conjunctival autograft for recurrent pterygium. Ophthalmology. 2003;110:119–124. 11. Wong TY, Foster PJ, Johnson GJ, et al. The prevalence and risk factors for pterygium in an adult Chinese population in Singapore: the Tanjong Pagar survey. Am J Ophthalmol. 2001;131:176–183. 12. Cajucom-Uy H, Tong L, Wong TY, et al. The prevalence of and risk factors for pterygium in an urban Malay population: the Singapore Malay Eye Study (SiMES). Br J Ophthalmol. 2010;94:977–981. 13. Gazzard G, Saw SM, Farook M, et al. Pterygium in Indonesia: prevalence, severity and risk factors. Br J Ophthalmol. 2002;86:1341–1346. 14. Durkin SR, Abhary S, Newland HS, et al. The prevalence, severity and risk factors for pterygium in central Myanmar: the Meiktila Eye Study. Br J Ophthalmol. 2008;92:25–29. 15. Ratnalingam V, Eu AL, Ng GL, et al. Fibrin adhesive is better than sutures in pterygium surgery. Cornea. 2010;29:485–489. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Copyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.