The use of mitomycin C with autologous limbal-conjunctival autograft transplantation for management of recurrent pterygium

Pharmacological treatment strategies of pterygium: Drugs, biologics, and novel natural products

Pterygium is a fibrovascular tissue growth invading the cornea. Adjunctive treatment post-surgery includes conventional immunosuppressants as well as antiviral drugs. The use of large- and small-molecule antivascular endothelial growth factor (VEGF) agents remains an integral part of pterygium treatment as well as other neovascular conditions of the eye. Naturally occurring polyphenolic compounds have favorable characteristics for treating neovascular and inflammatory eye conditions, including good efficacy, stability, cost-effectiveness, and the versatility of their chemical synthesis. In this review, we discuss pharmacological treatments of pterygium. Natural products, such curcumin, ellagic acid, and chalcones, are reviewed, with emphasis on their potential as future pterygium treatments.

Recurrent pterygium: A review

Purpose:

To summarize the recent evidence regarding different aspects of pterygium recurrence.

Methods:

Human-based studies from PubMed, Scopus, and Google Scholar were identified using the following keywords: conjunctival disease, pterygium, recurrent pterygium, pterygium recurrence, pterygium management/surgery, conjunctival autograft (CAU), amniotic membrane graft/transplant, and adjuvant therapy (January 2009 to February 2021). We reviewed risk factors associated with the recurrence of pterygium, timing of recurrence, medical treatments to prevent from recurrence, and nonsurgical and surgical alternatives for management of recurrence.

Results:

Dry eye disease, black race, and young age are considered definite risk factors for recurrence. However, fleshy appearance of the pterygium and preoperative size remain controversial. Surgical techniques such as excessive suturing, insufficient conjunctival graft size, thick conjunctival graft with remained Tenon tissue, and postoperative graft retraction are considered possible risk factors for recurrence. Using fibrin glue instead of sutures can further reduce recurrence rates. Although recurrence could occur even after many years, most recurrences happen in the first 3–6 months after surgery. Multiple kinds of adjuvant medications are used before, during, or after the operation including mitomycin C (MMC), 5-fluorouracil (5-FU), corticosteroids, and anti-vascular endothelial growth factors (anti-VEGFs). Multiple weekly subconjunctival 5-FU injections are shown to be safe and effective in halting the progression of recurrent pterygium. Although topical bevacizumab is found to inhibit the growth of impending recurrent pterygium, the effect is mostly temporary. CAU is superior to amniotic membrane transplantation in the treatment for recurrent pterygia.

Conclusions:

There is yet to be a panacea in treating recurrent pterygium. Currently, there is not a globally accepted recommendation for treating recurrent pterygium with anti-VEGFs or 5-FU as a nonsurgical treatment. We strongly recommend using MMC as an adjunct to surgery in recurrent cases, with consideration of its specific complications. CAU is the most effective surgical treatment for recurrent pterygium, and other new surgical therapies need further investigation.

Anti-fibrotic, anti-VEGF or radiotherapy treatments as adjuvants for pterygium excision: a systematic review and network meta-analysis

Background

Anti-fibrotic, anti-VEGF (vascular endothelial growth factor) medications, or radiotherapy, as adjuvant for pterygium surgical procedure, has been suggested for reducing recurrence, but difficulties may be experienced in deciding which treatment to use. The purpose of this study was to compare the efficacies of these different adjuvants for preventing recurrence following pterygium surgery.

Methods

We conducted a systematic review to identify randomized controlled trials of patients with primary or recurrent pterygium who received anti-fibrotic, anti-VEGF medication, or radiotherapy as adjuvants in combination with surgical procedure. The surgical procedure contained bare sclera technique or petrygium excision combination with tissue grafting. The primary outcome of this study was recurrence. Direct-comparison and Bayesian network meta-analyses were performed to assess direct and indirect evidence of efficacy.

Results

We obtained data from 34 randomized controlled trials, representing a total of 2483 patients. Adjuvants included bevacizumab, 5-FU (5-fluorouracil), MMC (mitomycin C), and β-RT (beta-radiotherapy). Compared with placebo, we found distinguishable improvement in recurrence with bevacizumab (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.18–0.80), MMC (0.12, 95% CI 0.06–0.21), and β-RT (0.17, 95% CI 0.04–0.69), but not with 5-FU (0.41, 95% CI 0.12–1.39). MMC significantly reduced recurrence when compared to bevacizumab (0.31, 95% CI 0.13–0.77) and 5-FU (0.28, 95% CI 0.08–0.99). The probability of having the most recurrences after excision was lowest for MMC, followed by bevacizumab and β-RT. Similar results were found in subgroup analyses, including for primary pterygium, and the patients receiving bare sclera technique or conjunctival autograft.

Conclusions

Adjuvants such as MMC, bevacizumab, and β-RT could effectively prevent recurrence following pterygium excision. However, their efficacy and acceptability require further clarification in future randomized controlled trials.

Electronic supplementary material

The online version of this article (10.1186/s12886-017-0601-5) contains supplementary material, which is available to authorized users.

Limbal conjunctival versus amniotic membrane in the intraoperative application of mitomycin C for recurrent pterygium: a randomized controlled trial

PURPOSE

This study compared the outcomes of a limbal conjunctival autograft (LCAG) with those of an amniotic membrane graft (AMG) followed by intraoperative 0.02 % mitomycin C (MMC) to treat recurrent pterygium.

METHODS

In this randomized controlled trial, ninety-six eyes with recurrent pterygium were enrolled and randomly allocated into two groups using a computer-generated random number table. Pterygium removal was followed by intraoperative 0.02 % MMC for 3 min and then either LCAG or AMG transplantation. The major outcomes were recurrence rate, conjunctival inflammation grade, healing time of the corneal epithelial defect, eye-movement amplitude (EMA), uncorrected distance visual acuity (UDVA), and complications.

RESULTS

A follow-up of 12 months was conducted for 93 eyes of 82 patients. Grade D (recurrence) presented in one eye of the LCAG group and five eyes of the AMG group, with no between-group difference (p = 0.196). However, Grades A, B, and C presented in 46, zero and zero eyes of the LCAG group respectively, and in 37, two and two eyes of the AMG group respectively, with the surgical bed generally showing a better appearance in the LCAG group than in the AMG group (p = 0.008). Compared with baseline values, the postoperative EMA improved significantly in both groups (p < 0.001 for the LCAG group; p = 0.001 for the AMG group), as did UDVA (p = 0.005 for the LCAG group; p = 0.012 for the AMG group). No between-group differences were found in terms of the healing time for epithelial defect, conjunctival inflammation grade, or the frequency of complications such as punctate epithelial keratitis, episcleral melting, corneal pannus, and delayed corneal epithelium healing.

CONCLUSIONS

LCAG transplantation with intraoperative 0.02 % MMC is as efficacious in treating recurrent pterygium as AMG transplantation with MMC. The former procedure results in an attractive cosmetic appearance but might result in limbal damage in some eyes. The surgeon's familiarity with these procedures should determine the method of treatment.

Intraoperative Fluorescein Staining of Cryopreserved Amniotic Membrane Grafts to Improve Visualization During and After Pterygium Surgery: A Novel Technique

Supplemental Digital Content is Available in the Text.

Purpose:

To describe a new method of enhancing the visualization of amniotic membrane grafts with fluorescein staining during pterygium surgery.

Methods:

Pterygium excision surgery using intraoperatively stained cryopreserved amniotic membranes was performed on 346 eyes. A sterile 0.6 mg sodium fluorescein strip was placed directly onto the amniotic membrane in the manufacturer's original packaging, and the stained allograft was then transplanted onto the planned site. Staining intensities, at 3, 5, and 10 minutes of dye immersion, were compared. Immediate postoperative pain rating (scale 0–10), visibility of the fluorescein-stained amniotic membrane graft, and conjunctival autograft and amniotic membrane graft elevation, dehiscence, retraction, or displacement were recorded. The recurrence rate of the study population was compared with that of a previous cohort of 121 patients who underwent pterygium excision with conjunctival autograft without stained amniotic membrane.

Results:

Direct contact of the fluorescein strip on the amniotic membrane at 3, 5, and 10 minutes showed no differences in subjective staining intensity. Fluorescein-stained amniotic membrane was easily detected on the ocular surface during and 24 hours after pterygium surgery. The average immediate postoperative pain rating was 0.8 ± 1.8. No intraoperative complications or postoperative amniotic membrane graft dehiscence, retraction, or displacement occurred. The recurrence rate using fluorescein-stained amniotic membrane (3 patients, 0.9%, mean follow-up time 31.8 ± 18.6 weeks) did not differ from that of the previous cohort without the stained amniotic membrane (2.5%; χ²(1) = 1.837, P = 0.183).

Conclusions:

Fluorescein strip staining of the amniotic membrane is a novel and safe intraoperative method to enhance visualization and handling of the graft during and after ocular surgeries.

Topical Mitomycin-C enhances subbasal nerve regeneration and reduces erosion frequency in the debridement wounded mouse cornea

Corneal epithelial basement membrane dystrophies and superficial injuries caused by scratches can lead to recurrent corneal erosion syndrome (RCES). Patients and animals with reduced corneal sensory nerve innervation can also develop recurrent erosions. Multiple wild-type mouse strains will spontaneously develop recurrent corneal erosions after single 1.5 mm debridement wounds. Here we show that this wound is accompanied by an increase in corneal epithelial cell proliferation after wound closure but without a commensurate increase in corneal epithelial thickness. We investigated whether excess corneal epithelial cell proliferation contributes to erosion formation. We found that topical application of Mitomycin C (MMC), a drug used clinically to improve healing after glaucoma and refractive surgery, reduces erosion frequency, enhances subbasal axon density to levels seen in unwounded corneas, and prevents excess epithelial cell proliferation after debridement wounding. These results suggest that topically applied MMC, which successfully reduces corneal haze and scarring after PRK, may also function to enhance subbasal nerve regeneration and epithelial adhesion when used to treat RCES.

Surgical management of corneal limbal dermoids: retrospective study of different techniques and use of Mitomycin C

PURPOSE

We retrospectively studied the efficacy and safety of different surgical approaches to treating pediatric limbal dermoids with regard to intra and postoperative complications.

METHODS

The data of 12 consecutive patients (14 eyes), who underwent monocentric surgery of a limbal demoid in the past 9 years, were retrospectively analyzed for intra and postoperative complications. Group one consists of eleven eyes: seven eyes with a bare-sclera deep lamellar excision of the dermoid and four eyes with an additional amniotic membrane transplantation subsequent to excision. Group two consists of three eyes: two eyes treated with Mitomycin C 0.02% over 2 min following the excision, and one eye treated with Mitomycin C and amniotic membrane transplantation after removal of the dermoid. Follow-up ranged from 2 to 53 months (median 17 months).

RESULTS

Intraoperative complications did not occur in any of the patients. Postoperatively, all patients showed corneal reepithelialization within a week. Limbal stem cell deficiency with a pseudopterygium developed in four eyes, one treated with bare-sclera excision and the others with amniotic membrane transplantation. One pseudopterygium had to be removed surgically because of visual acuity deterioration. Not a single eye treated with Mitomycin C developed a pseudopterygium.

CONCLUSIONS

The transplantation of amniotic membrane following removal of a limbal dermoid cannot prevent the occurrence of a pseudopterygium. However, the use of Mitomycin C seems to have a protective effect.

Pterygium recurrence, astigmatism and visual acuity following bare-sclera excision and conjunctival autograft with or without additional phototherapeutic keratectomy

BACKGROUND

Treatment outcome in patients with pterygium following bare-sclera excision and conjunctival autograft (CAG) with and without phototherapeutic keratectomy (PTK).

METHODS

Retrospective comparative analysis of 81 eyes, with primary and recurrent pterygia, that were analyzed for recurrence, best-corrected visual acuity (BCVA) and astigmatism in primary (P1 without PTK, P2 with PTK) and recurrent pterygia (R1 without PTK, R2 with PTK). BCVA and astigmatism were compared in patients with simple CAG alone (group I) or in combination with PTK (group II).

RESULTS

Recurrence rates were 4.7, 11.6, 16.2, 23.2 and 32.5% at 3, 6, 12, 24 and >24 months (P1), 7.1% at >24 months (P2). Recurrence rates were 5.3, 10.5, 21.1, 21.1 and 26.3% at 3, 6, 12, 24 and >24 months (R1) and 1 recurrence (7.7%) till month 24, and 3 (23.1%) thereafter (R2). BCVA increased from logarithm of the minimal angle of resolution 0.095 ± 0.141 (mean ± SD) at baseline to 0.066 ± 0.09 (group I), and from 0.090 ± 0.164 to 0.054 ± 0.124 (group II). Astigmatism decreased from -1.01 ± 0.90 dpt at baseline to -0.97 ± 1.24 dpt (group I), and from -1.19 ± 1.55 to -0.75 ± 0.87 dpt (group II).

CONCLUSION

In comparison to CAG alone, additional excimer smoothing with PTK tends to increase BCVA and reduces recurrence rates in patients with primary pterygia.

Ten-year results of a randomized controlled trial comparing 0.02% mitomycin C and limbal conjunctival autograft in pterygium surgery

OBJECTIVE

To compare the long-term outcome of pterygium surgery and the long-term effect on endothelial counts after mitomycin C (MMC) or limbal conjunctival autograft (LCAU) in pterygium surgery.

DESIGN

We performed a 10-year follow-up study of a randomized controlled trial.

PARTICIPANTS

A total of 115 eyes of 114 patients with primary pterygium were treated with intraoperative MMC (n = 63) or LCAU transplants (n = 52). A total of 76 patients completed the current 10-year long-term follow-up (47 in the MMC group, 29 in the LCAU group).

METHODS

This is a follow-up study of a randomized controlled trial of a cohort of 114 patients in 2 groups that was performed at the Prince of Wales Hospital 10 years ago: group 1, intraoperative 0.02% MMC for 5 minutes; group 2, LCAU. Consecutive patients enrolled in the original study (recruitment began in February 2001) were invited back for a detailed clinical examination to document the long-term outcome of both surgical groups.

MAIN OUTCOME MEASURES

The main outcome measures included the recurrence rate, residual conjunctival bed status, complications, and corneal endothelial cell density (ECD) differences.

RESULTS

A total of 115 eyes of 114 patients were enrolled and randomized in our previous study. For the current study, 76 of the 114 patients (47 in the MMC group, 29 in the LCAU group) were contacted, whereas 18 patients were lost to follow-up and 20 patients had died. The mean follow-up period was 138 ± 2 months in the MMC group and 137 ± 2 months in the LCAU group. Twelve of 47 patients (25.5%) in the original MMC group and 2 of 29 patients (6.9%) in the LCAU group had recurrent pterygium (P = 0.021). The mean ECD was 2,39 2 ± 342 cells/mm(2) in the MMC group and 2,390 ± 388 cells/mm(2) in the LCAU group (P = 0.978). There was no significant difference in the ECD between the operated eyes and the fellow eyes in both groups (P = 0.926 MMC, P = 0.468 LCAU). No other significant ocular complications were observed in either group at the 10-year postoperative follow-up.

CONCLUSIONS

Limbal conjunctival autograft was more effective than intraoperative MMC in minimizing pterygium recurrence at the 10-year follow-up. Treatment with intraoperative MMC was not associated with long-term corneal endothelial cell loss.

[Conjunctival limbal autograft versus simple excision with intra-operative mitomycin C in pterygium surgery: a comparative study]

PURPOSE

The purpose of our study is to evaluate the long-term anatomical and functional results of conjunctival-limbal autograft (AGCL) compared to simple excision with intraoperative mitomycin C.

PATIENTS AND METHODS

We conducted a prospective comparative study of 60 eyes of 60 patients presenting with primary pterygium. These patients were divided into two groups, matched according to the age and the stage of the pterygium. Thirty eyes of 30 patients were treated with conjunctival limbal autograft (AGCL group), and 30 eyes of the other 30 patients were treated with simple excision with intraoperative mitomycin C (MMC group). Minimum follow-up was 24 months.

RESULTS

The mean age of our patients was 50.6 and 51.3 years in the AGCL and MMC groups, respectively. A male predominance with male to female ratio of 1.5 was noted in both groups. We found more pterygium recurrences in the MMC group. Indeed, seven patients (23.3%) in the MMC group experienced a recurrence. In comparison, we found only a single recurrence (3.33%) in the AGCL group with a statistically significant difference (P=0.026). With regard to postoperative complications, we noted three inflammatory granulomas in the AGCL group (10%). In the MMC group, we observed two cases (6.66%) of delayed corneal healing with superficial punctate keratitis and epithelial defect and one case (3.33%) of symblepharon. There was no statistically significant difference in mean visual acuity gain between the two groups (AGCL: 1.76 lines; MMC: 2.82 lines; P=0.133).

CONCLUSION

Pterygium surgery by excision with conjunctival limbal autograft is an effective technique offering a low rate of long-term recurrences and few complications.

Randomized trial of pterygium surgery with mitomycin C application using conjunctival autograft versus conjunctival-limbal autograft

PURPOSE

To compare the outcomes of free conjunctival autograft (CAU) versus conjunctival-limbal autograft (CLAU) in the prevention of recurrence after pterygium surgery with adjunctive mitomycin C application in patients with primary or recurrent pterygia.

DESIGN

Prospective, randomized study.

PARTICIPANTS AND CONTROLS

Eighty-seven eyes of 86 patients with primary or recurrent nasal pterygia were included.

METHODS

All eyes underwent pterygium excision followed by removal of subconjunctival fibrovascular tissue and application of 0.02% mitomycin C for 3 minutes. The eyes then were assigned randomly to receive either CAU (44 eyes) or CLAU (43 eyes).

MAIN OUTCOME MEASURES

Rate of conjunctival or corneal recurrence of pterygium after surgery.

RESULTS

A follow-up of at least 12 months (mean, 14 ± 2.2 months) was achieved in 78 eyes of 78 patients, including 39 eyes in the CAU group (31 primary and 8 recurrent pterygia) and 39 eyes in the CLAU group (33 primary and 6 recurrent pterygia). After surgery, no eye in the CLAU group developed pterygium recurrence; however, recurrence was seen in 2 eyes (5.1%) in the CAU group, including 1 of 31 patients (3.2%) with primary pterygia and 1 of 8 patients (12.5%) with recurrent pterygia. There was no statistically significant difference in recurrence rates between the 2 groups or in the primary and recurrent subgroups. In the CLAU group, a localized pannus formation at the donor site of the limbal graft was noted in 5 eyes (12.8%), with the appearance of pseudopterygium in 1 eye.

CONCLUSIONS

There was no significant difference in recurrence rates of pterygium after surgery with mitomycin C application between the CAU and CLAU groups, more remarkably in primary cases. Limbal damage was seen in some eyes with CLAU.