A Retrospective Review of Glueless, Sutureless Pterygium Excision Using Biovance Triple-Layer Decellularized Amniotic Basement Membrane Tissue

Abstract

Introduction

A retrospective analysis was performed to determine if a glueless, sutureless surgical technique utilizing a triple-layer dehydrated, decellularized amniotic basement membrane tissue, combined with short exposure to mitomycin‑C (MMC), can reduce recurrence and complications after pterygium surgery. Surgical excision remains the mainstay of treatment when symptoms such as vision impairment, foreign body sensation, or cosmetic concerns arise. Wide variation in recurrence rates reflects differences in patient populations, follow-up duration, surgical technique nuances, and definition of recurrence. A dehydrated triple-layer decellularized amniotic basement membrane tissue has unique attributes compared to other amniotic membrane tissue (AMT). Decellularization removes the pro-inflammatory chorion and residual donor cellular debris, thereby reducing immunogenicity while preserving extracellular matrix proteins such as collagen, fibronectin, and laminin, which produce anti-inflammatory cytokines and growth factors, promoting epithelial adhesion and migration. In pterygium excision, decellularized basement membrane may contribute to faster, more comfortable recovery, improved cosmesis, and a reduced risk of recurrence.

Methods

A total of 34 eyes from 33 patients underwent pterygium excision using dehydrated, three-layer decellularized basement membrane.

Results

All patients reported minimal postoperative discomfort, and the operative eyes were relatively quiet with minimal subconjunctival injection. Recurrence was 0% (0/34 eyes) at a mean follow-up of 394 days (range, 174–668). In addition, no pyogenic granuloma, infections, dellen, or melts occurred.

Conclusions

Compared with traditional AMT and conjunctival autograft (CAG) methods using glue or sutures, this approach not only reduces operative time, postoperative discomfort, postoperative visits, and topical steroids but also saves costs without compromising outcomes.

Key Summary Points

Why carry out the study?

Pterygium excision remains a common but challenging procedure due to high recurrence rates.

This study was performed to determine whether a glueless, sutureless surgical technique utilizing a triple-layer dehydrated, decellularized amniotic basement membrane tissue, combined with short exposure to MMC, can reduce recurrence and complications after pterygium surgery.

What was learned from the study?

Decellularized basement membrane allows for strong adhesion without the need for tissue glue or sutures and comparatively produces a more robust cell-mediated response, leading to high concentrations of growth factors and anti-inflammatory cytokines.

This study reinforces a simplified, sutureless and glueless technique that maintains excellent safety and efficacy inclusive of low recurrence rates that are comparable to an autograft technique.

By preserving conjunctiva, reducing operative time, and enhancing cosmetic outcomes, this technique may not only save costs but also influence clinical decision-making and patient care in both routine and high-risk cases.

Introduction

A pterygium is a benign, wing-shaped fibrovascular growth of conjunctival tissue that extends onto the cornea, most often arising from the nasal limbus. Its pathogenesis is multifactorial, with ultraviolet (UV) light exposure, chronic ocular surface irritation, and genetic predisposition implicated in its development. The global prevalence of pterygium ranges from approximately 2% to over 30%, with higher rates observed in equatorial and high UV-index regions [1, 2].

Surgical excision remains the mainstay of treatment when symptoms such as vision impairment, foreign body sensation, or cosmetic concerns arise. Multiple surgical techniques exist for pterygium excision, including the bare sclera method, conjunctival autograft (CAG), limbal conjunctival autograft, and amniotic membrane tissue (AMT) transplantation (see Table 1). The success of pterygium surgery is also influenced by surgical technique, including wide excision of Tenon’s fibrovascular tissue [3], smooth scleral bed preparation [4], complete corneal head removal [5], minimal cautery to avoid thermal injury [3], large graft coverage beyond defect margins [6], peripheral dissection under adjacent conjunctiva in recurrent cases [7], preservation or recreation of the limbal barrier [8], and avoidance of bare sclera healing [9]. Adjunctive mitomycin‑C (MMC) has also been shown to further reduce recurrence rates, whether used alone or in combination with AMT.

Table 1.

Surgical techniques

Technique	Clinical impact	Supporting references
Full bare sclera coverage	Complete coverage with conjunctival autograft or AMT reduces fibrovascular regrowth vs. bare sclera	[4, 5]
Fibrin glue fixation	Glue reduces surgical time, inflammation, and postoperative discomfort while maintaining graft stability	[10, 11]
Double-layer AMT	Stacked AMT layers provide sustained anti-fibrotic, anti-inflammatory, and barrier effects in recurrent/aggressive cases	[12]
MMC adjunct	MMC inhibits fibroblast proliferation, synergizing with AMT to further reduce recurrence risk	[13, 14]
Peripheral tucking	Securing the graft under the adjacent conjunctiva prevents fibrovascular tissue from creeping under the graft edge	[7]
Limbal extension	Including the limbal stem cell area in the graft restores the barrier against conjunctival overgrowth	[5, 8]
Oversized graft	Ensuring graft overlaps all high-risk margins reduces recurrence, particularly at horizontal meridians	[3, 4]

AMT amniotic membrane tissue, MMC mitomycin-C

Wide variation in recurrence rates reflects differences in patient populations, follow-up duration, surgical technique nuances, and definition of recurrence (see Table 2). Recurrence rates are typically highest within the first 3–6 months after surgery, with few new recurrences beyond 12 months [15]. Studies with only short follow-up can under- or over-estimate true recurrent rates. Further, recurrent or large pterygia recur more than primary/smaller ones and fixation method (glue vs sutures), surgeon technique (e.g., Tenon’s clearance), and adjuvants also influence recurrence rates [16].

Table 2.

Recurrence rates

Surgical technique	Reported recurrence rate (%)	Key references
Bare sclera excision (no adjunct)	24–89%	[4–5]
CAG	2–39%	[4–5, 17]
AMT	10–40%	[5, 16–19]
CAG + intraoperative MMC	0–15%	[7–8]
AMT + intraoperative MMC	0–12%	[13–14]

CAG conjunctival autograft, AMT amniotic membrane transplantation, MMC mitomycin-C

To mitigate recurrence, closure techniques have primarily relied on CAG and AMT with various adjunctive therapies such as mitomycin. CAG remains the most commonly performed technique, however, limitations include loss of healthy conjunctiva, longer operative times, glue and suture requirement, and postoperative discomfort [3, 4]. AMT is especially advantageous in cases where conjunctiva preservation is desirable, such as in glaucoma suspects or eyes likely to require future filtering surgery.

As an alternative to CAG, AMT provides anti-inflammatory, anti-scarring, and anti-angiogenic properties while serving as a basement membrane scaffold for epithelial migration [5, 20]. AMT inhibits conjunctival overgrowth and provides a good substrate for normal epithelial migration because its basement membrane contains collagens and adhesive glycoproteins found in corneal and conjunctival epithelial basement membranes. Further, it contains numerous growth factors thought to enhance corneal wound healing [21]. Upon activation, AMT extracellular matrix proteins suppress conjunctival transforming growth factor beta (TGF-β) signaling [22] and pterygial fibroblast and myofibroblast differentiation, which can lead to reduced scarring [23].

Complication rates associated with AMT are generally low. Reported issues include mild conjunctival hyperemia, pyogenic granuloma, and dellen formation, with frequencies comparable or lower than those observed with CAG [19, 24]. Clinical evidence supports the effectiveness of AMT in reducing recurrence rates, which range from 0% to 12% depending on technique and adjunctive therapies used [13, 14].

Biovance Ocular 3L (DefEYE, Inc., Sarasota, FL, USA), a dehydrated, amniotic, triple-layer decellularized basement membrane (DBM) tissue, has unique attributes compared to other AMT. Each of its three layers consists of a single layer of DBM, laminated together without heat or freeze-drying. Mechanical decellularization removes the pro-inflammatory chorion and residual donor cellular debris, thereby reducing immunogenicity while preserving extracellular matrix proteins such as collagen, fibronectin, and laminin, which promote epithelial adhesion and migration [20]. This processing facilitates cell adhesion, enhancing the production of anti-inflammatory cytokines and growth factors, while providing a robust scaffold for epithelial migration [25]. Clinically, DBM has shown to effectively resolve persistent corneal epithelial defects in patients with neurotrophic keratitis and severe dry eye [26].

The purpose of this retrospective analysis was to determine whether a glueless, sutureless surgical technique utilizing a triple-layer dehydrated, amniotic DBM tissue, combined with short exposure to MMC, can reduce recurrence and complications after pterygium surgery.

Methods

A retrospective observational study protocol was reviewed by the Institutional Review Board (IRB) at Advarra, and the need for informed consent was determined to be exempt from IRB oversight. The IRB determined that the study met the criteria for a waiver because it was minimal risk to participants, used de-identified data, and was a retrospective study. Furthermore, the research adhered to the ethical standards outlined in the Declaration of Helsinki, ensuring compliance with guidelines for conducting research involving human participants.

Study Population

Inclusion Criteria

• Patients who presented to the study practice with confirmed pterygium surgery using Biovance 3L

• Patients had at least 5 months of follow-up

Exclusion Criteria

• Patients with incomplete medical records or missing follow-up data.

• Patients treated with other forms of amniotic membrane

Intervention

Both nasal and temporal pterygia were evaluated in this study. Each affected eye was subjected to standard sterile preparation and draping. The procedure was performed under topical and peribulbar lidocaine anesthesia. Preservative free subconjunctival lidocaine was placed under the pterygium. Dissection was performed by creating a peristome 3 mm from the limbus, then dissecting underneath the pterygium with blunt scissors, and removing it en bloc, creating 1 × 1 to 1.5 × 1.5 cm bed of bare sclera. A diamond burr was used to polish the cornea defect. A Weck-Cel sponge soaked in MMC 0.02% was placed on the subconjunctival opening for 120 s (2 min). The Biovance amniotic membrane was placed 2–4 mm directly on the cornea to serve as an anchor and then spread across the bare scleral bed with the distal edges tucked under the remaining conjunctiva without the need for glue or sutures. Immediately postoperatively, a bandage contact lens was placed, and the eye was patched until postoperative day 1. The bandage contact lens was usually removed at the postoperative week 1 visit. A single surgeon performed all procedures using a standardized technique. The patients were followed up at 1 month and 3-month intervals through the first year thereafter by the same surgeon.

Postoperative treatment included topical prednisolone four times daily for 1 month in tapering dosage, and a quinolone antibiotic was used four times per day for 1 week. Preservative free tears were also used, at least QID. Patients were examined 1 day, 1 week, 1 month, 3 months, 6 months postoperatively, and as needed thereafter. Complications such as pyogenic granuloma, inclusion cysts, epithelial defects, and dellen formation were recorded. Recurrence was defined as conjunctival if fibrovascular regrowth was limited to the conjunctiva and as corneal if tissue growth extended to the cornea across the limbus.

Cosmetic outcome was defined as the subjective and objective appearance of the ocular surface at the most recent follow-up, including conjunctival injection, corneal clarity at the excision site, and absence of fibrovascular regrowth or visible scarring. A four-point grading scale (adapted from Prabhasawat et al.) was performed by the same surgeon: Grade 1 (Excellent): Normal appearance without vascularization or opacity. Grade 2 (Good): Minimal episcleral vascularity without corneal involvement. Grade 3 (Fair): Mild fibrovascular tissue < 1 mm onto cornea. Grade 4 (Poor/Recurrence): Fibrovascular tissue ≥ 1 mm onto cornea. All eyes in this series achieved Grades 1–2 cosmetic appearance at final visit.

Outcomes

Primary Outcome

• Complete epithelial defect closure and conjunctival healing without recurrence or complications.

Secondary Outcomes

• Time to corneal healing and patient comfort

• Cosmetic outcome

Statistical Analysis

Descriptive statistics were calculated using mean ± standard deviation (SD) or median (interquartile range [IQR]) for continuous variables and counts (percentages) for categorical variables. The primary endpoint—absence of recurrence—was summarized as a binomial proportion with a 95% confidence interval (CI) calculated by the exact Clopper–Pearson method. Follow-up duration was reported as mean ± SD and range. Kaplan–Meier survival analysis was used to illustrate freedom from recurrence over time, with all eyes censored at their last recorded visit. To contextualize results, recurrence rates reported in recent AMT ± MMC and CAG studies were summarized, and exploratory one-sample binomial tests were performed against published recurrence benchmarks (10–15%) [9, 13, 14, 16, 18], recognizing the inherent limitations of indirect, single-arm comparisons.

Recurrence was 0% (0/34 eyes) (0%; exact 95% CI 0–10.3%) at a mean follow-up of 394 days (range, 174–668). No pyogenic granulomas, dellen, melts, or infections were observed. Figure 1 shows the distribution of postoperative follow-up durations across the cohort (mean 394 days). Figure 2 demonstrates a flat Kaplan–Meier curve representing 100% freedom from recurrence, with all 34 eyes censored at final follow-up.

Fig. 1.

Distribution of postoperative follow-up durations. Histogram displaying the range and frequency of postoperative follow-up durations for all 34 eyes that underwent glueless, sutureless pterygium excision using triple-layer decellularized basement membrane. The mean follow-up was 394 ± 126 days (range, 174–668 days). Each vertical line at the X-axis represents an individual eye’s last follow-up visit, illustrating complete patient retention and coverage of long-term (> 600 days) observations

Fig. 2.

Kaplan–Meier recurrence-free survival analysis. Kaplan–Meir curve demonstrating 100% recurrence-free survival throughout the postoperative period. Each “+” symbol represents a censored case at the patient’s final recorded follow-up. Because no recurrence events occurred, the survival curve remains flat at 1.0 and the cumulative hazard is 0, confirming durable freedom from recurrence across all primary and recurrent eyes

To contextualize findings, we summarized recurrence ranges from recent systematic reviews and large cohorts of AMT (with/without MMC) and CAG. We also performed exploratory one-sample binomial tests versus literature benchmarks (e.g., 10–15%) with recognition of limitations inherent to indirect, single-arm comparisons.

Results

A total of 34 eyes from 33 patients underwent pterygium excision using dehydrated, three-layer decellularized basement membrane. Of the patients enrolled, 24 were men and ten female. The average age was 52.8 with a range from 32 to 86 years. The average follow-up was 394 days with a range of 174–668 days.

Of the 34 eyes treated, 88.2% (30/34) were primary pterygia and 11.8% (4/34) recurrent pterygia. The mean patient age was 52.8 years (range, 32–86) and 71% male (24/34) and 29% female (10/34). Notably, 38% of patients (13/34) were younger than 50 years, representing a subgroup typically associated with higher recurrence risk due to more aggressive fibrovascular activity and UV exposure. Moreover, 12% (4/34) represented recurrent pterygium from either autograft or from another (non-Biovance triple-layer) amniotic membrane tissue. Despite this, no recurrences or complications were observed across any age subgroup. All patients reported minimal post operative discomfort and the operative eyes were relatively quiet with minimal subconjunctival injection consistent with either grade 1 (excellent) or grade 2 (good) cosmetic results. The distribution of postoperative follow-up durations is shown in Fig. 1, with a mean of 394 ± 126 days (range, 174–668).

There were no recurrences, pyogenic granuloma, infections, dellen, or melts reported. The contact secured the DBM graft in position and no patients required any postoperative repositioning of the graft.

Compared with a 10–15% benchmark recurrence rate reported in prior literature, the observed rate of 0% (0/34) eyes was not statistically different (p > 0.05, one-sample exact binomial test). These comparisons cannot establish superiority. Kaplan–Meier survival analysis confirmed 100% recurrence-free survival throughout the observation period (Fig. 2).

Discussion

AMT offers compelling biologic and surgical advantages for pterygium excision. Until now, AMT has been primarily used in complex cases involving large, recurrent, or double-headed pterygia, or in populations with higher risk of recurrence, such as younger individuals or those with chronic inflammation [27, 28]. The amniotic membrane basement membrane, in particular, closely resembles the native basement membrane of the conjunctiva and cornea, providing an ideal scaffold for re-epithelialization and wound healing [29]. The amniotic basement membrane supports epithelial cell adhesion, suppresses TGF-β signal transduction: biology, function and TGF-β signaling, and facilitates the production of growth factors and cytokines necessary for tissue regeneration [22, 23].

Compared with conventional or cryopreserved amniotic membrane grafts, DBM scaffolds have been shown to promote more efficient corneal epithelial cell binding, proliferation, and migration while eliciting a reduced inflammatory response [25]. A triple-layer DBM offers additional benefits including enhanced cellular adhesion and longer graft persistence, supporting more robust healing, especially in cases of severe ocular surface disease [25, 30]. It requires no preoperative preparation, has uniform thickness and bidirectional orientation-independent design which simplify surgical placement and improve handling [10, 31]. Recent advances include sutureless and glueless techniques utilizing dehydrated, decellularized basement membrane, simplified surgical procedures and reduced postoperative discomfort [31]. In this series of 34 patients, as well as in the Rivera study, there were no reported pyogenic granulomas or recurrences observed.

Traditional conjunctival CAG and AMT fixation often rely on tissue adhesives or sutures. While effective for graft stabilization, these methods introduce distinct risks. Fibrin glue, though reducing surgical time and inflammation, carries a risk of transmission of blood-borne pathogens and allergic reactions to aprotinin; premature glue dissolution can also cause graft displacement or retraction [19–21]. Sutures may provoke foreign-body sensation, localized inflammation, and induce pyogenic granuloma formation or suture abscess requiring removal [19–22]. By eliminating these materials, the present technique reduces operative complexity, foreign-body irritation, and the risk of granuloma or infection while maintaining secure tissue apposition through biologic adhesion of the decellularized membrane.

Published recurrence rates following pterygium excision vary widely depending on technique, adjuvant use, and follow-up duration. Recent systematic reviews and large series report recurrence ranges of approximately 3.8–40.9% for AMT, 0–12% for AMT with intraoperative MMC, and 2–39% for CAG [9, 13, 14, 16, 18]. In meta-analyses, CAG demonstrated lower recurrence at 6 months, though differences narrowed over longer follow-up [9, 18]. Our 0% (95% CI 0–10.3%) recurrence rate compares favorably with the lowest values reported for AMT ± MMC while using a simplified glueless, sutureless technique that preserves conjunctiva and reduces operative time. Although direct statistical comparisons are limited by the single-arm design, the results suggest that a triple-layer amniotic DBM combined with short MMC exposure achieves similar or better recurrence control with improved comfort and cosmesis.

Younger age and prior recurrence are recognized risk factors for postoperative fibrovascular regrowth. Multiple studies have shown recurrence rates two to three times higher among patients under 50 years of age or those with recurrent pterygia [15, 16]. In our cohort, nearly 40% of patients were younger than 50, and four cases represented recurrent pterygia previously treated with an alternative amniotic membrane, yet no recurrence was observed during a mean follow-up of 394 days. These findings underscore the biologic advantage and sustained anti-fibrotic activity of the triple-layer decellularized basement membrane even in higher-risk populations.

Biovance Ocular 3L’s application in pterygium surgery offers several advantages: (1) placement 2–3 mm onto the cornea over the excision defect, reducing scarring and improving comfort; (2) reduced need and duration for postoperative corticosteroids; (3) enabling glueless, sutureless surgery for reduced cost and operative time; (4) preservation of conjunctiva that would otherwise be sacrificed in autografting; and (5) faster, more comfortable healing with improved cosmetic outcomes.

Optimal surgical technique with Biovance 3L includes using a 15 mm disc or 15 mm × 20 mm rectangle to ensure complete coverage of the scleral bed. This will prevent chronic inflammation from bare sclera exposure and reduce the risk of pyogenic granuloma formation and recurrence. MMC is recommended in younger patients, Hispanic patients, or those with a history of recurrence. Light cautery is applied to reduce bleeding under the tissue. Any subconjunctival steroid injections could be performed before final drying and after MMC application and irrigation. It is critical to thoroughly dry the scleral bed to allow for adequate adherence of the decellularized basement membrane to the bare sclera without glue or sutures. It is important to place the membrane 2–3 mm over the cornea and then spread it out over the bare sclera, making sure it is tucked 1–2 mm under the distal remaining conjunctiva. During this maneuver, a sponge may be used to squeegee out any residual blood from under the tissue. A bandage contact lens can be placed to ensure the graft remains in position and the eye patched for the first 24–48 h to prevent any tissue slippage.

Importantly, AMT patient-reported outcomes suggest superior cosmetic satisfaction and reduced inflammation-related sequelae [32]. An improved cosmetic result is also seen with decellularized basement membrane. Given the mounting evidence supporting its efficacy, safety, and patient-centered benefits, AMT represents a highly viable first option for pterygium surgery.

The quick topical steroid taper is a huge advantage and cannot be overemphasized. Patients on the typical 3-month topical steroid taper should ideally be checked every 2–4 weeks for an intraocular pressure (IOP) check; this technique requires only one IOP check during the first month postoperative, after the first day and first week visit.

This study’s limitations include its retrospective nature, a relatively small sample size (34 patients), potential selection bias in follow-up duration, and absence of masked cosmetic assessment. Nevertheless, the absence of recurrence and pyogenic granulomas in this series is promising and supports further investigation of Biovance 3L in prospective, randomized trials.

Conclusions

In this retrospective series of 34 eyes, glueless and sutureless pterygium excision using a triple-layer decellularized amniotic basement membrane achieved complete epithelial healing with no recurrence or sight-threatening complications over an average follow-up of 394 days. The technique was associated with excellent cosmetic appearance (grades 1–2) and minimal postoperative inflammation allowing for an abbreviated steroid regimen. Compared with traditional AMT and CAG methods using glue or sutures, this approach not only reduces operative time, postoperative discomfort, postoperative visits, and topical steroids but also saves costs without compromising outcomes. These findings support further prospective and comparative trials to validate the clinical and economic advantages of triple-layer decellularized basement membrane in pterygium surgery.

Author Contributions

Marguerite McDonald, MD conceived the study, created the concept and design, collected the data, drafted and edited the manuscript.

Funding

This study was not sponsored or funded. DefEYE, Inc. paid for the journal’s Rapid Service Fee.

Data Availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Conflict of Interest

Marguerite McDonald, MD is a consultant for DefEYE, Inc.

Ethical Approval

This study was conducted in accordance with the Declaration of Helsinki. Institutional review board (IRB) approval was obtained prior to data collection. A retrospective observational study protocol was reviewed by the IRB at Advarra (reference Pro00087862), and the need for informed consent was determined to be exempt from IRB oversight. The IRB determined that the study met the criteria for a waiver because it was minimal risk to participants, used de-identified data, and was a retrospective study. Furthermore, the research adhered to the ethical standards outlined in the Declaration of Helsinki, ensuring compliance with guidelines for conducting research involving human participants. All patient information was de-identified to protect privacy and confidentiality.