Fibrin glue versus sutures for conjunctival autografting in primary pterygium surgery

The effect of cyclosporine a in pterygium surgery using fibrin glue

BACKGROUND/OBJECTIVES

To evaluate the effect of topical cyclosporine A (CsA) 0.05% in patients with pterygium surgery using fibrin glue (FG).

SUBJECTS/METHODS

Patients with primary nasal pterygium were retrospectically analyzed and categorized into two groups: Group 1 with 41 eyes from 38 patients as a control group and group 2 with 39 eyes from 36 patients who received topical CsA twice a day for 6 months. Patients were assessed for recurrence rate, tear film parameters, side effects, and complications at postoperative intervals of 1-7 days; 1st, 3rd, 6th and 12th months. The follow-up period was 1 year.

RESULTS

The two groups were age (p = 0.934) and sex (p = 0.996) matched. CsA drop was discontinued in one patient due to burning sensation and conjunctival hyperemia after 1 week. There was no statistically significant difference between the mean preoperative and postoperative 1st year Schirmer I and tear break-up time (TBUT) values in group 1 (p = 0.136; p = 0.069). Although the difference between the mean preoperative and postoperative 1st year TBUT values in group 2 was not statistically different (p = 0.249), Schirmer I results were higher postoperatively (p = 0.003). There was no statistically significant difference between preoperative Schirmer (p = 0.496), postoperative Schirmer (p = 0.661), preoperative TBUT (p = 0.240) and postoperative TBUT (p = 0.238) results of the two groups. Recurrence was observed in only one patient from group 1.

CONCLUSION

No recurrent pterygium cases were observed in group 2. Schirmer I values were higher postoperatively in group 2; thus,topical CsA treatment may improve lacrimal secretion and be effective after pterygium surgery with FG.

Intermittent sliding-lock-knot suture for limbal conjunctival autograft fixation in pterygium surgery: a technique note

AIM

To report a technique used with intermittent sliding-lock-knot (ISLK) fixation for limbal conjunctival autografts in pterygium surgery and compared with those of routine intermittent (RI) fixation.

METHODS

Consecutive patients with primary pterygium who had undergone pterygium excision combined with limbal conjunctival autograft transplantation between March 2021 and March 2022 at our institute were retrospectively analyzed. Primary outcome measures were mean duration of surgery and suture removal, degree of conjunctival hyperemia on postoperative day 1, pain score at suture removal, postoperative symptoms at 6mo, including conjunctival hyperemia, foreign body sensation, and graft stability.

RESULTS

Ninety-eight patients underwent monocular surgery and were divided into ISLK (51 eyes) and RI (47 eyes) groups according to the type of conjunctiva autograft fixation method planned. There was no significant difference in mean duration of surgery between the two groups (18.59±2.39min vs 18.15±2.20min, P=0.417); however, compared to the RI group, shorter suture removal times were observed in the ISLK group [0.58min (0.42-0.87) vs 3.00min (2.21-4.15), P<0.001]. The degree of conjunctival hyperemia on postoperative day 1 was milder in the ISLK group (P<0.001). Pain scores at suture removal were lower in the ISLK group than in RI group [1 (0-3) vs 2 (1-4), P<0.001]. Postoperative symptoms at 6mo were comparable between the groups (P=0.487), with no recurrence.

CONCLUSION

ISLK is an innovative method for limbal conjunctival autograft fixation after pterygium excision. Compared to RI fixation, ISLK facilitates suture removal and reduces discomfort, with comparable surgery duration and less conjunctival hyperemia.

The effect of different pterygium surgery techniques on the ocular surface parameters in different durations: a systematic review and meta-analysis

PURPOSE

To evaluate the effects of different pterygium surgery techniques on ocular surface (OS) in different follow-up periods.

METHODS

PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wan Fang, and China Biology Medicine disc were searched for studies reporting pre- and post-operative OS parameters in pterygium.

RESULTS

A total of 33 articles were finally included. Three OS parameters showed relatively consistent changing trends after surgery including ocular surface disease index (OSDI), tear film break-up time (BUT), and score of corneal fluorescein staining (SCFS). They worsened significantly at 1w post-operation and then gradually improved: OSDI and BUT showed obvious improvement in 1 m post-operation (SMD =  - 0.58, 95%CI = [- 1.04, - 0.13]; SMD = 0.42, 95%CI = [0.06, 0.78]); SCFS was restored to preoperative levels in 3 m after surgery (SMD =  - 0.54, 95%CI = [- 1.16, 0.07]). Another parameter, Schirmer test without anesthesia (SIT), presented transient increase at 1w post-operation (SMD = 0.87, 95%CI = [0.27, 1.47]) and presented a relatively stable improvement after 1 m post-operation (SMD = 0.52, 95%CI = [0.16, 0.89]). All parameters in amniotic membrane graft (AMT) showed better improvement in early stage and they showed non-inferior improvements in the long term compared with conjunctival autograft (CAG). Limbal-conjunctival autograft (LCAG) made excellent improvement to OS in the long term while pterygium excision (PE) showed the worst OS. The type of pterygium (primary and secondary), diabetes mellitus (DM) status, and fixation method had certain effects on the results.

CONCLUSIONS

OS of pterygium is deteriorated at 1w post-operation then gradually improved to preoperative levels after 1 m post-operation. Among various surgery techniques, LCAG had the best improvement to OS which especially displayed in the long-term outcomes.

Andrias Davidianus Mucus-Based Bioadhesive with Enhanced Adhesion and Wound Healing Properties

The skin secretion of Andrias davidianus (SSAD) is a novel biological adhesive raw material under development. This material exhibits robust adhesion while maintaining the flexibility of the wound. It also has the potential for large-scale production, making it promising for practical application explore. Hence, in-depth research on methods to fine-tune SSAD properties is of great importance to promote its practical applications. Herein, we aim to enhance the adhesive and healing properties of SSAD by incorporating functional components. To achieve this goal, we selected 3,4-dihydroxy-l-phenylalanine and vaccarin as the functional components and mixed them with SSAD, resulting in a new bioadhesive, namely, a formulation termed "enhanced SSAD" (ESSAD). We found that the ESSAD exhibited superior adhesive properties, and its adhesive strength was improved compared with the SSAD. Moreover, ESSAD demonstrated a remarkable ability to promote wound healing. This study presents an SSAD-based bioadhesive formulation with enhanced properties, affirming the feasibility of developing SSAD-based adhesive materials with excellent performance and providing new evidence for the application of SSAD. This study also aims to show that SSAD can be mixed with other substances, and addition of effective components to SSAD can be studied to further adjust or improve its performance.

The use of commercial fibrin glue in dermal replacement material reduces angiogenic and lymphangiogenic gene and protein expression in vitro

BACKGROUND

Commercial fibrin glue is increasingly finding its way into clinical practice in surgeries to seal anastomosis, and initiate hemostasis or tissue repair. Human biological glue is also being discussed as a possible cell carrier. To date, there are only a few studies addressing the effects of fibrin glue on the cell-molecular level. This study examines the effects of fibrin glue on angiogenesis and lymphangiogenesis, as well as adipose-derived stem cells (ASCs) with a focus on gene and protein expression in scaffolds regularly used for tissue engineering approaches.

METHODS

Collagen-based dermal regeneration matrices (DRM) were seeded with human umbilical vein endothelial cells (HUVEC), human dermal lymphatic endothelial cells (LECs), or adipose-derived stem cells (ASC) and fixed with or without fibrin glue according to the experimental group. Cultures were maintained for 1 and 7 days. Finally, angiogenic and lymphangiogenic gene and protein expression were measured with special regard to subtypes of vascular endothelial growth factor (VEGF) and corresponding receptors using Multiplex-qPCR and ELISA assays. In addition, the hypoxia-induced factor 1-alpha (HIF1a) mediated intracellular signaling pathways were included in assessments to analyze a hypoxic encapsulating effect of fibrin polymers.

RESULTS

All cell types reacted to fibrin glue application with an alteration of gene and protein expression. In particular, vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor B (VEGFB), vascular endothelial growth factor C (VEGFC), vascular endothelial growth receptor 1 (VEGFR1/FLT1), vascular endothelial growth receptor 2 (VEGFR2/KDR), vascular endothelial growth receptor 3 (VEGFR3/FLT4) and Prospero Homeobox 1 (PROX1) were depressed significantly depending on fibrin glue. Especially short-term fibrin effect led to a continuous downregulation of respective gene and protein expression in HUVECs, LECs, and ASCs.

CONCLUSION

Our findings demonstrate the impact of fibrin glue application in dermal regeneration with special regard to angiogenesis and lymphangiogenesis. In particular, a short fibrin treatment of 24 hours led to a decrease in gene and protein levels of LECS, HUVECs, and ASCs. In contrast, the long-term application showed less effect on gene and protein expressions. Therefore, this work demonstrated the negative effects of fibrin-treated cells in tissue engineering approaches and could affect wound healing during dermal regeneration.

The use of fibrin glue in pterygium surgery with amniotic membrane transplantation: Systematic review and meta-analysis

PURPOSE

To compare the outcomes of fibrin glue versus sutures in pterygium surgery with amniotic membrane transplantation.

METHODS

A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses Guidelines. An electronic search identified all studies comparing the outcomes of using fibrin glue versus sutures in pterygium surgery with amniotic membrane transplantation. Conjunctival inflammation, postoperative pain and discomfort, pterygium recurrence, pyogenic granuloma, and surgical time were primary outcome measures. Secondary outcome measures included amniotic membrane transplant outcomes, time to recurrence, graft loss, and subconjunctival hemorrhage. Fixed and random-effects models were used for the analysis.

RESULTS

Four studies enrolling 180 patients were identified. Conjunctival inflammation (odds ratio [OR] 0.21, P = 0.0005) demonstrated a significant difference favoring the fibrin glue group. Despite the trend favoring the use of fibrin glue, there were no significant differences in terms of postoperative pain and discomfort (OR = 0.46, P = 0.25), pterygium recurrence (OR = 0.74, P = 0.48), pyogenic granuloma (OR = 0.47, P = 0.38), and surgical time (mean difference = -17.52, P = 0.13). For secondary outcomes, fibrin glue had significantly fewer cases of graft loss compared with sutures. No statistically significant difference was found in amniotic membrane graft outcomes, time to recurrence, and subconjunctival hemorrhage.

CONCLUSION

Fibrin glue is comparable to the sutures used in pterygium surgery with amniotic membrane transplantation as it significantly improves conjunctival inflammation and does not increase postoperative pain and discomfort, pterygium recurrence, pyogenic granuloma, and surgical time.

Autologous fibrin glue versus sutures for conjunctival autograft in primary pterygium: a randomized clinical trial

PURPOSE

To describe and compare the autologous fibrin glue and traditional sutures for conjunctival graft attachment in patients undergoing primary pterygium excision surgery.

METHOD

A randomized clinical trial included patients who underwent pterygium surgery with conjunctival autologous graft (CAG). Using randomization, a single-trained surgeon performed graft fixation with autologous glue or sutures. The glue was prepared immediately before the surgery, using the patient's blood components. After centrifugation, the plasma was collected and enhanced with calcium gluconate. Postoperative assessments were performed on Days 1, 7, 21, 30 and 180. The study evaluated postoperative edema and pain and complications. The mean surgical time was compared. Recurrence of the pterygium was assessed 6 months postoperatively.

RESULTS

The study evaluated 61 eyes. Thirty-three eyes underwent pterygium surgery using the glue technique, and 28 underwent the traditional suture technique. Fifty-one patients (83.60%) had successful graft adhered to at the end of follow-up. Ten patients (10/33) lost their graft in the glue group, and only 69.70% maintained graft presence in the fourth week versus 100% of the patients in the suture group (p = 0.001). Pain scores were lower in the glue group, and clinical edema was significantly higher. There was no significant difference in graft retraction or the presence of granuloma, necrosis or postoperative infection.

CONCLUSION

Autologous fibrin glue is an affordable option for CAG fixation in particular contexts where commercial fibrin glue is unavailable, and it could offer advantages compared to sutures. A higher graft loss rate was observed and might be related to topical anesthesia, and improvements to the technique are needed.

CLINICALTRIALS

gov Identifier: NCT04151017. https://clinicaltrials.gov/ct2/show/NCT04151017?term=20170467&draw=1&rank=1 .

Advances in biomaterials as a retinal patch for the repair of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is the most common retinological emergency that can cause blindness without surgical treatment. RRD occurs when liquefied vitreous accumulates between the neurosensory retina and the retinal pigment epithelium via retinal breaks, which are caused by the separation of the vitreous from the retina with aging. Currently, the main treatment option is pars plana vitrectomy, which involves surgical removal of the vitreous and laser photocoagulation around retinal breaks to generate firm chorioretinal adhesion, as well as subsequent filling of the vitreous cavity with long-lasting substitutes (expansile gas or silocone oil) to prevent the connection between the subretinal space and the vitreous cavity via the breaks before the chorioretinal adhesion firm enough. However, the postoperative face-down position and the not very satisfactory first retinal reattachment rate place a heavy burden on patients. With the development of technology and materials engineering, researchers have developed biomaterials that can be used as a retinal patch to seal retinal breaks and prevent the connection of subretinal space and vitreous cavity via breaks, thus replacing the long-lasting vitreous substitutes and eliminating the postoperative face-down position. Preclinical studies have demonstrated that biomaterial sealants have enough biocompatibility and efficacy in the in vitro and in vivo experiments. Some sealants have been used in clinical trials on a small scale, and the results indicate promising application prospects of the biomaterial sealants as retinal patches in the repair of RRD. Herein, we review the recent advances in biomaterials as retinal patches for the repair of RRD, focusing on the biomaterial categories, methods, and procedures for sealing retinal breaks, as well as their biocompatibility and efficacy, current limitations, and development perspectives.

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.

Bindehautdegenerationen und -neoplasien

Erhabenheiten der Bindehaut entstehen durch Gewebevermehrung, die entweder degenerativ oder neoplastisch, aber auch entzündlich sein können. In diesem Artikel werden degenerative (Pterygium und Pinguecula) sowie benigne und maligne neoplastische Bindehautveränderungen (epitheliale, melanozytäre und vaskuläre Tumoren, Choristome sowie Metastasen) bezüglich der Pathogenese, Symptome, Diagnostik und aktuellem Stand der Behandlung dargestellt.

[Conjunctival Degeneration and Neoplasia]

Conjunctival tumors result from gain of tissue, which can be either degenerative or neoplastic, but also inflammatory. In this article, degenerative (pterygium and pinguecula) as well as benign and malignant neoplastic conjunctival changes (epithelial, melanocytic and vascular tumors, choristomas as well as metastases) are discussed with regard to pathogenesis, symptoms, diagnostics and current status of treatment.

Polymerizable Skin Hydrogel for Full Thickness Wound Healing

The skin is the largest organ in the human body, comprising the main barrier against the environment. When the skin loses its integrity, it is critical to replace it to prevent water loss and the proliferation of opportunistic infections. For more than 40 years, tissue-engineered skin grafts have been based on the in vitro culture of keratinocytes over different scaffolds, requiring between 3 to 4 weeks of tissue culture before being used clinically. In this study, we describe the development of a polymerizable skin hydrogel consisting of keratinocytes and fibroblast entrapped within a fibrin scaffold. We histologically characterized the construct and evaluated its use on an in vivo wound healing model of skin damage. Our results indicate that the proposed methodology can be used to effectively regenerate skin wounds, avoiding the secondary in vitro culture steps and thus, shortening the time needed until transplantation in comparison with other bilayer skin models. This is achievable due to the instant polymerization of the keratinocytes and fibroblast combination that allows a direct application on the wound. We suggest that the polymerizable skin hydrogel is an inexpensive, easy and rapid treatment that could be transferred into clinical practice in order to improve the treatment of skin wounds.

Α Novel Sutureless Pterygium Excision Surgery Using Human-Derived Dehydrated Amniotic Membrane

There are many surgical techniques available for the management of pterygium. Excision with limbal conjunctival autograft is currently the most popular surgical procedure and has been shown to have low recurrence rate and fewer complications. The fixation of limbal conjunctival autograft is performed with either sutures or fibrin glue. The use of sutures results in longer operating time and intense postoperative irritation and epiphora. We describe a new technique for pterygium excision using a human amniotic membrane-derived dry matrix (Omnigen®; Nottingham, UK: Nu-Vision Biotherapies). The use of Omnigen instead of conjunctival autograft in pterygium surgery is a new promising technique and results in shorter operation time, easier graft fixation, reduction in complications, and less postoperative discomfort. This is a simple technique for pterygium surgery with dry amniotic membrane matrix and without the need for anchoring limbal sutures or an assistant holding the graft whilst it is glued in place.

Surgical Preferences in the Management of Primary Pterygium among Anterior Segment Specialists

Purpose:

The purpose of this study is to reflect anterior segment specialists’ current practice pattern regarding the management of primary pterygium.

Methods:

A 24-item survey regarding indications for surgery, different surgical techniques, use of adjuvant pharmacological therapy, type of intraoperative and postoperative pharmacological therapy, and the preferred treatment of early recurrences was sent to members of the Saudi Ophthalmological Society (SOS) and practicing cornea experts including consultants, specialists, and fellows in Saudi Arabia.

Results:

A total of 61 cornea specialists completed the questionnaire (response rate 49%). More than 95% considered the proximity of the pterygium to the visual axis an indication for excision. The most frequent technique for pterygium excision was extensive head and conjunctival resection, including the base (69%) and intermediate resection of the Tenon's capsule (53%). For conjunctival replacement, conjunctival autograft was preferred by 79%, amniotic membrane (54%), and simple conjunctival closure (46%). Interrupted vicryl sutures, fibrin glue, and combined sutures and tissue adhesive were the preferred graft fixation conveyed by 85%, 46%, and 34% of our experts, respectively. An estimated recurrence rate of 1-5% was stated by 29% of respondents and 46% reported recurrence within 6 to 12 months. Half of the respondents specified using mitomycin C intraoperatively to prevent early pterygium recurrences. When recurrence occurred, corticosteroid was the agent of choice.

Conclusion:

This study set out to reflect the practice pattern of anterior segment specialists regarding the management of primary pterygium, and it may serve as an insight for further studies to define the optimal management of pterygium.

Impact of fibrin glue versus suture closure on double-headed pterygia in Asian eyes - a 7-year study in a tertiary institution

BACKGROUND

To compare the recurrence rate and outcomes of double-headed pterygia using fibrin glue versus suture closure of conjunctival autograft.

METHODS

All patients with double-headed pterygia who underwent pterygia excision with conjunctival autograft from January 2012 to January 2019 in the National University Hospital of Singapore were included. Patients were divided into 2 groups depending on whether fibrin glue or sutures were used to secure the conjunctival autograft in place. All patients had a minimum of 6 months follow-up.

RESULTS

A total (26 patients) of 22 eyes had fibrin glue, while eight eyes underwent suture closure of their conjunctival autograft. Fibrin glue group had 4.5% recurrence rate, while suture group had 37.5% recurrence rate (p = .021). There is statistically significant improvement for overall visual acuity (p = .009) and cylinder (p = .002). There is also statistically significant improvement for visual acuity in the glue group (p = .026), but not in the suture group. Fibrin glue group had a shorter operation duration time compared to suture group (p < .001).There were no cases of graft dislocation, contraction or limbal stem cell deficiency.

CONCLUSIONS

Low recurrence rates and good postoperative visual outcomes can be achieved with the split conjunctival autograft technique. Our study suggests that fibrin glue has an additional benefit over the use of sutures in the management of these complex cases.

Refractive Outcomes of Simultaneous Pterygium and Cataract Surgery With Fibrin Glue

Introduction

Pterygium is commonly reported in India because of its tropical location. It is often accompanied by senile cataract. The current study aimed to evaluate the refractive outcomes of patients undergoing simultaneous pterygium and cataract surgery.

Materials and methods

A total of 12 patients with cataract and pterygium underwent simultaneous phacoemulsification with a foldable intraocular lens (IOL) followed by pterygium excision with conjunctival limbal autograft secured with fibrin glue under peribulbar anesthesia. Nasal pterygium was present in all the cases, and its size ranged from 2.5 to 3.5 mm from the limbus. All the patients exhibited nuclear sclerotic cataract of grades 2 and 3.

Results

The results of the patients were analyzed retrospectively. We determined the best-corrected visual acuity ([BCVA] in logMAR), manifest astigmatism, and mean corneal astigmatism before operation and after 12 months of surgery. We also analyzed the correlation between the prediction error (calculated by subtracting the predicted postoperative refraction from the actual postoperative spherical equivalent) and changes in the mean keratometry and prediction errors and pterygium size. The mean age of the patients was 61.9 ± 7.14 years (range: 50-70 years). The mean BCVA at presentation was 0.67 ± 0.24 logMAR units, which significantly increased after surgery to 0.01 ± 0.03 logMAR units (p < 0.001, Wilcoxon signed-rank test). The mean manifest corneal astigmatism significantly reduced from −1.98 ± 0.84 diopters (D) preoperatively to −0.54 ± 0.18 D postoperatively (p < 0.001). Mean corneal keratometry increased from 43.81 ± 1.77 D preoperatively to 44.19 ± 1.76 D postoperatively (p < 0.05). At 12 months, 58.33% and 41.66% of the eyes were within  ±0.5 D and  ±1.0 D, respectively. A significant correlation was observed between the prediction errors and changes in the mean keratometry (Spearman signed-rank test, r = −0.65, p < 0.05) and pterygium size (Spearman correlation coefficient, r = −0.75, p < 0.05).

Conclusion

The simultaneous pterygium and cataract surgery with conjunctival autograft and fibrin glue was safe and effective in providing excellent and predictable refractive outcomes. Steepening of the cornea after combined surgery results in myopia; therefore, the IOL power should be selected appropriately. The use of fibrin glue in surgeries reduces the operative time and postoperative pain and results in early postoperative rehabilitation of patients.

Adhesive Tissue Engineered Scaffolds: Mechanisms and Applications

A variety of suture and bioglue techniques are conventionally used to secure engineered scaffold systems onto the target tissues. These techniques, however, confront several obstacles including secondary damages, cytotoxicity, insufficient adhesion strength, improper degradation rate, and possible allergic reactions. Adhesive tissue engineering scaffolds (ATESs) can circumvent these limitations by introducing their intrinsic tissue adhesion ability. This article highlights the significance of ATESs, reviews their key characteristics and requirements, and explores various mechanisms of action to secure the scaffold onto the tissue. We discuss the current applications of advanced ATES products in various fields of tissue engineering, together with some of the key challenges for each specific field. Strategies for qualitative and quantitative assessment of adhesive properties of scaffolds are presented. Furthermore, we highlight the future prospective in the development of advanced ATES systems for regenerative medicine therapies.

Profile of complications in pterygium surgery - A retrospective analysis

Purpose:

Analysis of complication profile after pterygium excision, in primary and recurrent pterygia.

Methods:

Retrospective analysis of all the patients who had undergone pterygium excision in a tertiary center in South India from 2010 to 2018 was analyzed. A total of 2356 eyes in 2028 patients were included in the study. Patients who had undergone conjunctival autografting for primary pterygium, conjunctival limbal autografting for recurrent pterygium, vertical split conjunctival autografting for double head pterygium were included in the study. In all the surgical procedures fibrin glue was used for fixation of the autograft. The follow-up period ranged from 6 months to 75 months, with an average of 17 months. Patients with less than 6 months of follow-up were excluded from the study.

Results:

The following postoperative complications were noted, Sub-conjunctival hemorrhage in 912 eyes (38.7%), edema of the graft in 522 cases (22.15%), graft loss in 22 cases (0.93%), graft retraction in 692 cases (29.37%) and sliding of the graft was seen in 9 cases (0.38%). Granuloma was seen in 4 cases (0.16%) at the host site and 5 cases (0.21%) at the donor site. Recurrence was seen in 34 patients (1.44%). Other severe complications like corneal melt were seen in only 1 case (0.04%) who was operated on for recurrent pterygium. In comparison between primary and recurrent pterygia; subconjunctival hemorrhage, edema of the graft, graft loss, and recurrence was significantly (P < 0.05%) higher in recurrent pterygia.

Conclusion:

Various complications can occur post pterygium surgery as listed above. Selecting a proper procedure for a particular type of pterygium with a proper graft fixation technique will improve the outcome with minimal complications.

Bibliometric analysis and mapping knowledge domain of pterygium: 2000-2019

AIM

To track the knowledge structure, topics in focus, and trends in emerging research in pterygium in the past 20y.

METHODS

Base on the Web of Science Core Collection (WoSCC), studies related to pterygium in the past 20y from 2000-2019 have been included. With the help of VOSviewer software, a knowledge map was constructed and the distribution of countries, institutions, journals, and authors in the field of pterygium noted. Meanwhile, using co-citation analysis of references and co-occurrence analysis of keywords, we identified basis and hotspots, thereby obtaining an overview of this field.

RESULTS

The search retrieved 1516 publications from WoSCC on pterygium published between 2000 and 2019. In the past two decades, the annual number of publications is on the rise and fluctuated a little. Most productive institutions are from Singapore but the most prolific and active country is the United States. Journal Cornea published the most articles and Coroneo MT contributed the most publications on pterygium. From co-occurrence analysis, the keywords formed 3 clusters: 1) surgical therapeutic techniques and adjuvant of pterygium, 2) occurrence process and pathogenesis of pterygium, and 3) epidemiology, and etiology of pterygium formation. These three clusters were consistent with the clustering in co-citation analysis, in which Cluster 1 contained the most references (74 publications, 47.74%), Cluster 2 contained 53 publications, accounting for 34.19%, and Cluster 3 focused on epidemiology with 18.06% of total 155 co-citation publications.

CONCLUSION

This study demonstrates that the research of pterygium is gradually attracting the attention of scholars and researchers. The interaction between authors, institutions, and countries is lack of. Even though, the research hotspot, distribution, and research status in pterygium in this study could provide valuable information for scholars and researchers.

Cosmetic outcome of femtosecond laser-assisted pterygium surgery

Background

To examine the cosmetic outcome of femtosecond laser-assisted pterygium surgery (FLAPS) with conjunctival autograft (CAG) and its potential predictive factors.

Methods

This was a prospective interventional case series (NCT02866968). We included 29 patients (29 eyes) with primary pterygium who underwent FLAPS. Cosmetic outcome was graded by two graders (an ophthalmology resident and an experienced ophthalmologist) using Hirst classification system (1–4 = excellent–poor). Weighted Cohen’s kappa analysis was performed to examine the intra- and inter-rater reliability. The relationship between cosmetic outcome and various factors were determined by Spearman’s correlation coefficients (r).

Results

The preoperative severity of pterygium (Tan grading system) was mild/atrophic (7%), moderate/intermediate (62%), and severe/fleshy (31%). An ultrathin CAG (mean thickness of 74.5 ± 9.8 μm) was fashioned intraoperatively. An excellent cosmetic outcome of FLAPS (median ± IQR) was observed at 3 months (1.0 ± 1.0) and remained similar at 6 months (1.0 ± 0.0) and 12 months (1.0 ± 0.0) postoperatively. At final follow-up, 27 (93%) patients achieved good-to-excellent cosmetic outcome, with 1 (3%) patient having a poor outcome due to incomplete pterygium removal. Weighted kappa analysis of Hirst grading system showed excellent intra-rater (κ = 0.86–0.95) and inter-rater reliability (κ = 0.84–0.88). There was a weak and borderline significant correlation between good cosmetic outcome and reduced postoperative CAG thickness (r = 0.38, P = 0.06) but not with age, gender, preoperative pterygium severity, or intraoperative CAG thickness.

Conclusions

FLAPS can result in an excellent cosmetic outcome, which may be attributed to the beneficial effect of an ultrathin CAG.

Trial registration

ClinicalTrials.gov, NCT02866968. Registered in July 2016,

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-021-00230-w.

Repeated Freezing Procedures Preserve Structural and Functional Properties of Amniotic Membrane for Application in Ophthalmology

For decades, the unique regenerative properties of the human amniotic membrane (hAM) have been successfully utilized in ophthalmology. As a directly applied biomaterial, the hAM should be available in a ready to use manner in clinical settings. However, an extended period of time is obligatory for performing quality and safety tests. Hence, the low temperature storage of the hAM is a virtually inevitable step in the chain from donor retrieval to patient application. At the same time, the impact of subzero temperatures carries an increased risk of irreversible alterations of the structure and composition of biological objects. In the present study, we performed a comprehensive analysis of the hAM as a medicinal product; this is intended for a novel strategy of application in ophthalmology requiring a GMP production protocol including double freezing–thawing cycles. We compared clinically relevant parameters, such as levels of growth factors and extracellular matrix proteins content, morphology, ultrastructure and mechanical properties, before and after one and two freezing cycles. It was found that epidermal growth factor (EGF), transforming growth factor beta 1 (TGF-β1), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), hyaluronic acid, and laminin could be detected in all studied conditions without significant differences. Additionally, histological and ultrastructure analysis, as well as transparency and mechanical tests, demonstrated that properties of the hAM required to support therapeutic efficacy in ophthalmology are not impaired by dual freezing.

Comparison and application of commercially available fibrin sealants in ophthalmology

Fibrin glues carry many advantages over traditional suture as a tissue adhesive and have been increasingly used in a variety of ophthalmic procedures over the past 15 years. Several fibrin sealants are commercially available worldwide, each of which differs slightly in its composition and mechanism of delivery. The focus of our review is to briefly discuss the reported uses of fibrin in ophthalmic surgery and provide a broad overview of the properties associated with each commercially available fibrin sealant.

Conduct and reporting of citation searching in Cochrane systematic reviews: A cross-sectional study

BACKGROUND

The search for studies for a systematic review should be conducted systematically and reported transparently to facilitate reproduction. This study aimed to report on the conduct and reporting of backward citation searching (ie, checking reference lists) and forward citation searching in a cross section of Cochrane reviews. Citation searching uses the citation network surrounding a source study to identify additional studies.

METHODS

Cochrane reviews were identified by searching the Cochrane Database of Systematic Reviews using the wildcard symbol and date limiting to the 3-month period November 2016 to January 2017. Cochrane reviews thus identified were screened for mention of citation searching. Descriptive detail on the conduct and reporting of citation searching was captured in data extraction forms and described and evaluated.

RESULTS

Two hundred fifteen Cochrane reviews were identified. One hundred seventy-two reviews reported backward citation searching, and 18 reviews reported forward citation searching. Web of Science was the most frequently reported citation index. The studies used for backward citation searching consisted mainly of studies meeting the inclusion criteria. One-third of reviews that reported forward citation searching used selected studies of importance. Reporting of citation searching was compliant with the Methodological Expectations of Cochrane Intervention Reviews (MECIR) standards, but full transparency requires additional detail that only a minority of reviews reported.

CONCLUSION

The conduct of backward citation searching was more uniform than forward citation searching. This might be due to lack of MECIR guidance for forward citation searching. Reporting was generally compliant with MECIR, but this is not always sufficient to ensure full transparency.

Evaluation of antimitotic and antiangiogenic effect of preoperative subconjunctival application of mitomycin C in primary pterygium: a randomized trial

PURPOSE

To evaluate the influence of preoperative mitomycin C (MMC) on the proliferative behavior of fibroblasts and fibrovascular tissue derived from the primary pterygium using the immunohistochemical method (Ki67 and CD34).

DESIGN

Randomized clinical trial.

SUBJECTS, PARTICIPANTS AND/OR CONTROLS

Sixty-five patients with primary pterygium were randomly selected and divided into one of three groups. The control group had 29 patients that were only submitted to pterygium removal. The group that received the MMC injection a month before surgery had 16 patients, and the group that received the MMC 2 weeks before surgery had 20 patients. Each patient only had one eye operated on.

METHODS

Sixty-five patients were selected to undergo pterygium excision surgery. We randomly placed the patients into three groups: one without MMC (n = 29), one with MMC application 1 month before surgery (n = 16) and another with MMC application 2 weeks before surgery (n = 20). Subconjunctival injection was applied with 0.1 ml of 0.02% MMC in the pterygium body, and patients were followed for 2 years.

MAIN OUTCOME MEASURES

Proliferative behavior of fibroblasts and fibrovascular tissue using the immunohistochemical method (Ki67 and CD34) comparing the three groups.

RESULTS

Of the total 29 patients (44.6%) in the control group (without MMC application), 11 cases had recurrence (37.9%), of which seven (63.6%) were within 3 months of follow-up and four (36.3%) within 6 months of follow-up. The mean proliferation index of the recurrent cases was 4.5%, and of the cases without recurrence, it was 6.1%. There were 16 patients (24.6%) in the MMC application group 1 month before surgery, in which one case (6.25%) recurred at 6 months. In the group with MMC application 2 weeks before surgery, of the total of 20 patients (30.7%), there was one case of recurrence (5%) at 6 months. The proliferation index of the group that had MMC administered and did not have a recurrence was 7.2%, and in the group with recurrence, it was 6.4%. The CD34-labeled cell count was 5.8% among cases with recurrence and 5.6% in cases without recurrence. No side effects of MMC application were reported during the study follow-up period.

CONCLUSION

MMC was efficient to reduce the recurrence index despite the absence of a direct relation with its antimitotic and antiangiogenic effect in the samples that were analyzed.

Conjunctival Autograft With Fibrin Glue for Pterygium: A Long Term Recurrence Assessment

Pterygium is an old challenge for ophthalmic surgeons. Its final resolution is surgical intervention. New surgical techniques have been introduced to improve the outcome, however, the possibility of recurrence always exists. The purpose of this study was to evaluate the pterygium recurrence rate with a long-term follow-up, after surgery was performed with conjunctival autograft and fibrin glue as a biological adhesive. A retrospective case-series study was performed, reviewing cases operated from May 2008 to May 2018 with at least 1 year of follow-up in a private clinic in Buenos Aires, Argentina. The evaluation time-points were at 1 day, 20 days, 6 months, 1 year after surgery and then every year. All the procedures were performed by the same surgeon in single center. Topical Mitomycin C (MMC), 5-Fluorouracil (5-FU), cauterization and/or amniotic membrane were not used in any case. From a total of 159 operated eyes (82/77 women/men), pterygium was recurred in 7 eyes (4.4%); all of them detected at the second follow-up time-point (at day 20). Intraoperative complications did not occur, but at the postoperative stage, one case presented a conjunctival granuloma, which was surgically resolved. In conclusion, a low pterygium recurrence rate was observed after conjunctival autograft with fibrin glue. In our study, recurrence was found at the postoperative first month and did not recur until the end of follow-up for 10 years.

Glue and glide: a novel technique for pterygium conjunctival autograft

Conjunctival autograft adhesion with fibrin glue has gained rapid popularity in pterygium excision surgery and is now the technique of choice in many centers worldwide. It has enabled a suture-free technique, reducing surgical time and postoperative pain. However, the adhesive’s components form a fibrin clot 10 seconds after mixing, and in this time, the surgeon must complete glue application, grabbing of the instruments and adequate placement of the conjunctival patch. This easy and new technique explains how separate application of glue components on the receiving site and cornea with subsequent sliding of graft results in even mixing of the components on site. It enables the surgeon to spend all 10 seconds in adjusting the position of the conjunctival autograft, resulting in an easier and more precise surgery.

How to minimize pterygium recurrence rates: clinical perspectives

The main treatment for pterygium is surgical removal. However, pterygium surgery is concerned with high rates of postoperative recurrence. Predicting factors of recurrence are not fully understood, yet, but they probably depend on a multitude of patient-related, clinical, and/or surgical factors. Several adjuvant treatments have been proposed to reduce postoperative pterygium recurrence, including different antimetabolites, antiangiogenetic factors, and radiation therapy. The purpose of this review is to collect the current evidence regarding application and limits of different therapeutic approaches for preventing postoperative recurrence of pterygium, giving insights and perspectives for better management of this disease. In the light of the current evidence, pterygium surgery cannot disregard wound coverage with conjunctival autografting or rotational flap combined with adjuvant treatments. The rotational flap technique is associated with shorter surgical time rates and prevents graft displacement and necrosis, given its vascular pedicle. Amniotic membrane may still be reserved in case of great conjunctival defects or insufficient conjunctiva. Repeated subconjunctival antivascular endothelial growth factor injections can be considered as an effective and safe adjuvant treatment. Moreover, management of postoperative pain is crucial. Innovative treatment strategies will probably target different molecular pathways, considering recent findings regarding pterygium pathogenesis, to improve better understanding and develop universally shared guidelines. Great importance shall be dedicated to the identification of novel molecular biomarkers and favoring factors of recurrence, in order to achieve a customized surgical treatment for each patient and obtain maximal reduction of postoperative recurrence.

Cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery (CAGE CUP): study protocol of a randomised controlled trial

INTRODUCTION

Pterygium is a non-cancerous growth of the conjunctival tissue over the cornea that may lead to visual impairment in advanced stages, restriction of ocular motility, chronic inflammation and cosmetic concerns. Surgical removal is the treatment of choice, but recurrence of pterygium is a frequent problem. It has been previously shown that fibrin glue may result in less recurrence and may take less time than sutures for fixing the conjunctival graft in place during pterygium surgery. However, fibrin glue is a biological material and it carries the risk of transmitting infectious agents from pooled and single-donor blood donors and anaphylaxis in susceptible individuals. Cauterisation is another surgical option, and it would be advantageous to know whether cauterisation may be superior surgical option compared with fibrin glue. This protocol describes the rationale and design of the randomised controlled trial (RCT) in which we will compare cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery.

METHODS AND ANALYSES

This will be a parallel group RCT comparing cauterisation versus fibrin glue for conjunctival autografting in primary pterygium surgery. Computer-generated randomisation will be used, and allocation concealment will be conducted using sequentially numbered opaque sealed envelopes. Surgeons will not be blinded to the procedures, but participants, other investigators and outcome assessors will be blinded. Adult participants with primary pterygium operated in a tertiary hospital in Split, Croatia, will be included. Primary outcome will be recurrence of pterygium, defined as any regrowth of tissue from the area of excision across the limbus onto the cornea after 180 days.

ETHICS AND DISSEMINATION

The trial was approved by the ethics review board of the University Hospital Split (500-03/17-01/68). Results will be disseminated at conferences and through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03321201; Pre-results.

Conjunctival Autograft Versus Amniotic Membrane Transplantation for Treatment of Pterygium: Findings From a Cochrane Systematic Review

PURPOSE

To summarize key findings from a systematic review of the effectiveness and risks of conjunctival autograft (CAG) compared with amniotic membrane transplant (AMT) for pterygium.

DESIGN

Cochrane systematic review.

METHODS

We included only randomized controlled trials (RCTs) in which CAG and AMT had been compared for primary or recurrent pterygia. The primary outcome was recurrence of pterygium ≥1 mm onto the cornea by 3 and 6 months post surgery. We adhered to Cochrane methods for trial selection, data extraction, risk of bias evaluation, and data synthesis.

RESULTS

Twenty RCTs with 1866 participants (1947 eyes) were included. Pterygium recurrence 6 months after surgery ranged from 3.3% to 16.7% in the CAG group and 6.4% to 42.3% in the AMT group based on data from 1021 eyes in 10 RCTs. Estimated risk ratios from meta-analysis indicated that CAG-treated eyes had a 47% lower risk of recurrence 6 months after surgery compared with the AMT group (RR, 0.53, 95% confidence interval [CI], 0.33-0.85). For 96 eyes with recurrent pterygium, the risk of recurrence 6 months after CAG was reduced by 55% compared with AMT (risk ratio [RR], 0.45, 95% CI, 0.21-0.99). Three-month recurrence rates were similar for CAG and AMT based on data from 538 eyes (6 RCTs).

CONCLUSIONS

CAG was more effective than AMT to prevent pterygium recurrence by 6 months post surgery, especially in recurrent pterygia. CAG-treated eyes had half the recurrence rates of AMT-treated eyes. Future RCTs should assess changes in patient-reported outcomes (symptoms, cosmesis) and visual acuity, and evaluate effects of surgical variations.

Self-made cryopreservative fibrin glue applied in pterygium surgery: a novel practical technique

PURPOSE

To introduce a novel practical technique of self-made cryopreservative fibrin glue (SMC) applied in pterygium surgery and to assess its safety and efficacy.

METHODS

Forty-eight eyes of 48 patients with nasal primary pterygium were enrolled. The patients were equally assigned to 6 groups. Self-made fibrin glue was subpackaged and, respectively, cryopreserved for 3, 7, 15 days and 1, 2 and 3 months. At each time point, the asepsis of SMC was confirmed by bacterial culture and colony counting. In each group, corresponding SMC was applied to fix the autograft after the pterygium was removed (e.g., SMC 3d for group 1 and SMC 3m for group 6). All the patients were followed up postoperatively on days 1, 3, 7 and 14 and then at months 1, 3, 6. The main outcome measures included fixation success rate within two tries, postoperative discomfort, recurrence rate and complications.

RESULTS

No colony growth was observed in all the fibrinogen and thrombin tubes sent. Five patients needed a second try with respective SMC during the autograft fixation, and there were no significant differences in SMC use times among the groups (P = 0.885). There were no significant differences in postoperative discomfort (day 1, 3, 7; P = 0.651, P = 0.269, P = 0.180, respectively) among the groups. By the end of 6-m follow-up, no infections and severe complications were observed in any group. The total recurrence rate was 3/48 (6%), and there were no significant differences in recurrences among the groups (P = 1.000).

CONCLUSION

SMC is safe and effective for autograft fixation in pterygium surgery. This new practical technique will benefit the patients and surgeons in developing and underdeveloped country.

Comparison of autologous fibrin glue versus nylon sutures for securing conjunctival autografting in pterygium surgery

PURPOSE

To compare the safety, operating time, postoperative ocular signs, symptoms, overall patient satisfaction, complications rate and recurrence rate of autologous fibrin glue (AFG) and nylon suturing (NS) for attaching conjunctival autografts in pterygium surgery.

METHODS

A prospective, randomized, interventional study was performed among 120 patients (120 eyes) with primary pterygium. Superior conjunctival autograft was harvested and transferred on to bare sclera after pterygium excision. For attaching the autograft, AFG (n = 60 eyes) and NS (n = 60 eyes) were used. The patients were followed up for 12 months. The groups were compared for the safety, operative time, postoperative ocular signs, symptoms, overall patient satisfaction, recurrence and complications rate.

RESULTS

All conjunctival autografts in both groups were successfully attached. The average operating time for the AFG group was significantly shorter (P < 0.001). Postoperative symptoms were fewer for the AFG group than the suture group. After 12 months of follow-up, no recurrence was reported for the AFG group, but 8.3% of patients experienced recurrence in the NS group.

CONCLUSIONS

Our study demonstrated the superiority of AFG to NS in saving operating time and elimination of recurrence without any complications in pterygium surgery. AFG can obviate the need for suturing and increases the viability of tissue flaps. Additional studies are necessary to determine the long-term effects considering factors such as primary or recurrent status of pterygium, age and sex of patient, dose and duration of treatment for mitomycin C.

Fibrin glue versus sutures for conjunctival autografting in primary pterygium surgery

BACKGROUND

Pterygium, a growth of the conjunctiva over the cornea, is a progressive disease leading in advanced stages to visual impairment, restriction of ocular motility, chronic inflammation and cosmetic concerns. Surgical removal is the treatment of choice, but recurrence can be a problem. Currently the best surgical option in terms of recurrence is conjunctival autograft. To date the most common surgical methods of attaching conjunctival autografts to the sclera are through suturing or fibrin glue. Each method presents its own advantages and disadvantages. Sutures require considerable skill from the surgeon and can be associated with a prolonged operation time, postoperative discomfort and suture-related complications, whereas fibrin glue may give a decreased operation time, improve postoperative comfort and avoid suture-related problems.

OBJECTIVES

To assess the effectiveness of fibrin glue compared to sutures in conjunctival autografting for the surgical treatment of pterygium.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2016), Embase (January 1980 to October 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 14 October 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in any setting where fibrin glue was compared with sutures to treat people with pterygium.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, assessed trial quality, and extracted data using standard methodological procedures expected by Cochrane. Our primary outcome was recurrence of pterygium defined as any re-growth of tissue from the area of excision across the limbus onto the cornea. The secondary outcomes were surgical time and complication rate. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We included 14 RCTs conducted in Brazil, China, Egypt, India, Malaysia, New Zealand, Philippines, Saudi Arabia, Sweden and Turkey. The trials were published between 2004 and 2016, and were assessed as a mixture of unclear and low risk of bias with three studies at high risk of attrition bias. Only adults were enrolled in these studies.Using fibrin glue for the conjunctival autograft may result in less recurrence of pterygium compared with using sutures (risk ratio (RR) 0.47, 95% CI 0.27 to 0.82, 762 eyes, 12 RCTs; low-certainty evidence). If pterygium recurs after approximately 10 in every 100 surgeries with sutures, then using fibrin glue may result in approximately 5 fewer cases of recurrence in every 100 surgeries (95% CI 2 fewer to 7 fewer cases). Using fibrin glue may lead to more complications compared with sutures (RR 1.92; 95% CI 1.22 to 3.02, 11 RCTs, 673 eyes, low-certainty evidence). The most common complications reported were: graft dehiscence, graft retraction and granuloma. On average using fibrin glue may mean that surgery is quicker compared with suturing (mean difference (MD) -17.01 minutes 95% CI -20.56 to -13.46), 9 RCTs, 614 eyes, low-certainty evidence).

AUTHORS' CONCLUSIONS

The meta-analyses, conducted on people with pterygium in a hospital or outpatient setting, show fibrin glue may result in less recurrence and may take less time than sutures for fixing the conjunctival graft in place during pterygium surgery. There was low-certainty evidence to suggest a higher proportion of complications in the fibrin glue group.