Serious complications of topical mitomycin-C after pterygium surgery

[Evaluation of topical vasoconstrictors in pterygium surgery and their role in reducing intraoperative bleeding]

OBJECTIVE

To reduce vascularisation before surgery through the application of topical vasoconstrictors, decreases the rate of intraoperative bleeding, improves the dynamics of the surgery and reduces the difficulty in surgical performance.

METHODS

Only patients with primary pterygium were included in the study. A prospective randomized clinical trial was designed to compare intraoperative bleeding, need for cauterization and surgical time a group that was administered phenylephrine. preoperatively and one which did not receive it. The sample was divided into two groups: 1st (n=27) received topical phenylephrine (F) 0.1 ml (10%), twice in 5 minutes before surgery. 2nd (n=30) did not receive phenylephrine (NoF). The technique was similar in both groups using conjunctival autograft suturing. In both groups, the subconjunctival aneasthesia was performed with 0.5% bupivacaine hydrochloride with epinephrine 1:200,000.

RESULTS

A total of 57 patients were included in the study. The mean operation time for group F was 15.57 minutes (SD: 1.8 min) and the NoF group 16.51 min (SD to 1.82 min, P=.057). In the group F, it was necessary to use diathermy in 2 patients (7.4%) and in the NoF group cauterisation was used in 14 patients (46.7%, Chi-Square=10.848, P=.001. There is a relative risk 6.3 (95% CI 1.57 - 25.27) times greater than having to cauterise without phenylephrine when used phenylephrine.

CONCLUSIONS

The use of topical vasconstrictors prior to pterygium surgery reduces the rate of bleeding and the time of surgery.

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

PURPOSE

The purpose of this study is to evaluate and compare recurrence rates upon using mitomycin C (MMC) with limbal-conjunctival autograft for treating recurrent pterygia.

METHODOLOGY

An interventional, prospective, comparative clinical study was performed in 30 eyes (26 patients) with recurrent pterygia, allocated into two groups: Group A (19 eyes) operated by pterygium excision and limbal-conjunctival autograft transplantation (L-CAT) without MMC and Group B (20 eyes) operated with injection of 0.1 mL of MMC 0.15 mg/mL 1 month before L-CAT surgery. Exclusion criteria included patients with symblepharon, cicatricial conjunctival diseases, limbal stem cell deficiency, and other intraocular diseases.

RESULTS

A total of four cases of recurrences for Group A (P = 0.012) and one case of recurrence for Group B (P < 0.001) were recorded.

CONCLUSIONS

Preoperative injection of MMC in low dose and concentration improves the results of L-CAT in recurrent pterygium.

Phototherapeutic keratectomy for the treatment of corneal opacities after epidemic keratoconjunctivitis

PURPOSE

To assess visual results and compare methods of measuring central corneal thickness (CCT) and corneal opacity thickness (COT) in patients with corneal opacities induced by epidemic keratoconjunctivitis (EKC) and treated with phototherapeutic keratectomy (PTK) using low-dose mitomycin C (MMC).

DESIGN

Prospective consecutive case series.

METHODS

Patients with chronic adenoviral corneal opacity underwent transepithelial PTK with MMC 0.002% for 1 minute. The presence of photophobia, the best spectacle-corrected visual acuity (BSCVA), and the contrast sensitivity were evaluated. CCT measurements were obtained with ultrasound pachymeter (US), ultrasound biomicroscopy (UBM), Scheimpflug tomography (Pentacam Oculus), and optical coherence tomography (OCT Visante). COT measurements were obtained with UBM, Pentacam, and OCT.

RESULTS

Thirty-one eyes of 23 patients, comprising 15 women (65.2%) and 8 men (34.8%), mean age 41.8 years, were enrolled in the study. Duration of visual disturbance was 19.1 ± 14 months. The number of patients with photophobia was reduced from 100% to 29% after surgery. BSCVA improved 2 or more lines in 78% of the patients at 12 months. A hyperopic shift of 1.52 ± 0.91 diopters was achieved. Contrast sensitivity improved in both photopic and mesopic conditions. For each of the instruments, the CCT postoperative mean was significantly smaller than the preoperative measurement (P < .0001) and COT values were significantly reduced in comparison to the preoperative values (P < .001).

CONCLUSION

Improvements in photophobia, BSCVA, and contrast sensitivity were observed in patients treated using excimer laser PTK with low-dose MMC for subepithelial infiltrates.

Inhibitory effect of PPARγ agonist on the proliferation of human pterygium fibroblasts

The effects of DK2, a peroxisome proliferator-activated receptor γ agonist, on cultured human pterygium fibroblasts (HPFs) in virto were studied. The HPFs were incubated with 0-200 μmol/L DK2 for 12-72 h. The MTT method was used to assay the bio-activity of DK2 at different doses and time. The cytotoxic effect of DK2 was measured by LDH release assay. The cell cycle distribution and apoptosis were flow cytometrically detected. The expression of proliferating cell nuclear antigen (PCNA) in each group was detected by real-time PCR (RT-PCR) and Western blotting. The results showed that administration of 1-75 μmol/L DK2 for 12-72 h could significantly inhibit HPF proliferation in a dose- and time-dependent manner. DK2-treated cells did not release significant amount of LDH as compared with rosiglitazone-treated cells. After treatment with DK2 at concentrations of 15, 25 μmol/L for 24 h, the number of HPFs in G(0)/G(1) phase was significantly increased while that in S phase was significantly decreased (P<0.05), leading to arrest at G(0)/G(1) phase. The apoptosis rates of HPF cells in drug-treated groups were significantly higher than the rate of control group (P<0.05). At the dosage range between 15-25 μmol/L, DK2 could inhibit the expression of PCNA mRNA and protein in HPFs in a dose-dependent fashion (P<0.05). It was concluded that PPARγ agonist can significantly inhibit HPF proliferation, resulting in the arrest at G(0)/G(1) phase, induce the apoptosis of HPFs, and suppress the synthesis of PCNA, in dose- and time-dependent manners.

Effectiveness of amniotic membrane transplantation combined with mitomycin C in the treatment of pterygium: a meta-analysis

AIM

To evaluate the recurrence rate and safety of amniotic membrane transplantation (AMT) augmented with mitomycin C (MMC) compared with amniotic membrane transplantation alone during the pterygium excision.

METHODS

We took a meta-analysis on this program. Pertinent studies were selected through extensive searches of the Cochrane Library, MEDLINE, EMBASE, CBMdisc, CNKI. Pooled estimates were carried out in RevMan software v.4.2.

RESULTS

Six trials reported postoperative recurrence rate of pterygium, included 882 eyes, three trials reported the complications. The results of meta-analysis showed that recurrence rate of AMT plus MMC group was 5.41%, AMT alone group was 16.89%, RR was 0.32, 95%CI ranged from 0.19 to 0.56, Z was 4.06, P<0.001. Two trials reported early complication as punctata keratitis, the incidence rate of AMT plus MMC group and AMT alone group were 17.14% and 0.00%, RR was 12.11, 95%CI ranged from 1.62 to 90.76.

CONCLUSION

Amniotic membrane transplantation with MMC was associated with lower recurrence rate compared with amniotic membrane transplantation alone in pterygium excision, whether accompanied a higher risk with adverse events need more investigation.

[Operative techniques for surgical treatment of primary and recurrent pterygia]

Surgical treatment of pterygia is indicated when there is a reduction of visual acuity secondary to the development of irregular astigmatism and an (impending) obscuration of the visual axis by the tumor. Poor cosmetic appearance and an insufficient corneal lubrication are more rare indications. The most popular surgical technique in this country appears to be a free conjunctival autograft which, depending on the priority of the surgeon, is combined with adjunctive antimetabolite therapy applied either in primary or recurrent cases. A simultaneous transplantation of conjunctival and limbal stem cell autografts is an excellent method to be considered particularly in cases of recurrent pterygia. In the case of non-existing healthy autologous tissue the resection bed can be covered by preserved amniotic membrane. A lamellar sectorial corneal graft might become necessary if there is a deep corneal defect. The well established technique of suturing the graft has been replaced by fibrin glue in some surgical centers.

Study on the optimal concentration of topical mitomycin-C in preventing postlaminectomy epidural adhesion

There is increasing evidence that topical application of mitomycin-C can be beneficial in reducing epidural scar adhesion. However, the ideal concentration of mitomycin-C is unknown. The purpose of this study was to verify its efficacy for preventing epidural adhesion and the immediate electrophysiological responses caused by it in a laminectomy model. Seventy rats underwent laminectomy at L-1 and L-2. Cotton pads soaked with saline and various concentrations of mitomycin-C (0.1 mg/ml, 0.3 mg/ml, 0.5 mg/ml and 0.7 mg/ml) were applied to the exposed dura for 5 min. Spine somatosensory evoked potentials (SSEP) were monitored in preoperative and the immediate electrophysiological responses of mitomycin-C used. Four weeks postlaminectomy the rats were killed. The area of epidural scar tissue and degree of epidural adhesion were determined by 7.0 T Micro MR imaging. Macroscopic evaluations were performed according to the Rydell standard. The results showed that severe epidural adhesion was formed in the saline group and no dural adherence or incomplete adhesions were found in the mitomycin-C group. The Rydell classification and the degree of epidural adhesion and the area of the scar in 0.5 mg/ml group and 0.7 mg/ml mitomycin-C group revealed a significant decrease compared with the control group and 0.1 mg/ml group and 0.3 mg/ml mitomycin-C group. The spine sensory evoked potentials did not alter obviously in both preoperative and the immediate electrophysiological responses of mitomycin-C used. In conclusion, locally applied mitomycin-C in a concentration of 0.5 mg/ml and 0.7 mg/ml mitomycin-C may be the optimal concentration in preventing postlaminectomy epidural adhesion.

Boston Ocular Surface Prosthesis for persistent epitheliopathy after treatment of conjunctival melanoma

PURPOSE

To report two cases of persistent epitheliopathy after treatment of conjunctival melanoma and review management options for this condition.

METHODS

Case report and literature review.

RESULTS

Persistent epitheliopathy, presumably resulting from limbal stem cell deficiency, is an uncommon complication of treatment of conjunctival malignant melanoma with surgical excision, cryotherapy, and mitomycin C. The Boston Ocular Surface Prosthesis was successful in improving vision, comfort, and epithelial status in our patients.

CONCLUSION

Persistent epitheliopathy is a rare complication of treatment of conjunctival melanoma. The Boston Ocular Surface Prosthesis is a viable treatment option in this situation.

Scleral ulceration after vitreoretinal surgery

Scleral ulceration after ocular surgery is a rare but serious complication. Determination of the underlying systemic and local causes is critical for treatment. An unusual case of ischemic scleral ulceration after vitreoretinal surgery in a diabetic patient is reported. Patient was successfully treated with a pedicle conjunctival graft.

Prospective study of exclusive strontium-/yttrium-90 beta-irradiation of primary and recurrent pterygia with no prior surgical excision. Clinical outcome of long-term follow-up

PURPOSE

To evaluate the consecutive treatment results regarding pterygium recurrence and the efficacy of exclusive strontium-/yttrium-90 beta-irradiation for primary and recurrent pterygia and to analyze the functional outcome.

PATIENTS AND METHODS

Between October 1974 and December 2005, 58 primary and 21 recurrent pterygia were exclusively treated with strontium-/yttrium-90 beta-irradiation with doses ranging from 3,600 to 5,500 cGy. The follow-up time was 46.6 +/- 26.7 months, with a median of 46.5 months.

RESULTS

The treatment led to a size reduction in all pterygia (p < 0.0001). Neither recurrences nor side effects were observed during therapy and follow-up in this study. Best-corrected visual acuity increased (p = 0.0064). Corneal astigmatism was reduced in recurrent pterygia (p = 0.009).

CONCLUSION

Exclusive strontium-/yttrium-90 beta-irradiation of pterygia is a very efficient and well-tolerated treatment, with remarkable aesthetic and rehabilitative results in comparison to conventional treatments, especially for recurrent lesions which have undergone prior surgical excision.

Mitomycin C aqueous humor concentration after photorefractive keratectomy: an experimental study

PURPOSE

To evaluate mitomycin C (MMC) aqueous humor concentration after photorefractive keratectomy (PRK).

METHODS

In this experimental study, twenty-four eyes of 12 male pigmented rabbits were divided into 4 groups and studied at the Institute of Vision and Optics, Department of Medicine, University of Crete, Greece. Eyes in groups 1 and 2 underwent PRK to correct -5 diopters (D) in a 6-mm optical zone, while sponges soaked with 0.02% MMC were applied on the exposed corneal stroma for 60 and 120 seconds, respectively. Similarly, eyes in groups 3 and 4 underwent PRK to correct -10 D in a 6-mm optical zone, while sponges soaked with 0.02% MMC were applied on the exposed corneal stroma for 60 and 120 seconds, respectively. Aqueous humor was extracted from all rabbit eyes 10 minutes after MMC application and high-performance liquid chromatography was performed immediately to detect and quantify MMC levels.

RESULTS

The mean aqueous humor concentration of MMC was 0.23+/-0.03 microg/mL, 0.39+/-0.05 microg/mL, 0.28+/-0.04 microg/mL, and 0.52+/-0.16 microg/mL in groups 1, 2, 3, and 4, respectively. The effect of application time and correction on aqueous humor MMC concentration was significant (p<0.0001 and p=0.019), while the exposure time had a greater impact on aqueous humor MMC concentration when compared with the attempted correction.

CONCLUSIONS

Both exposure time of MMC on the corneal stroma and the attempted correction was correlated with MMC aqueous humor concentrations.

Treatment of primary pterygium: role of limbal stem cells and conjunctival autograft transplantation

PURPOSE

The limbus and its stem cells are important in the pathogenesis of pterygium. In this study, the usefulness of limbal stem cells and conjunctival autograft transplantation for the treatment of primary pterygium is assessed.

METHODS

In this prospective noncomparative cohort study, 42 eyes of 42 patients with grade I-III primary pterygium underwent pterygium excision followed by superotemporal limbal stem cells and conjunctival autograft transplantation. Pterygium recurrences and complications within a mean follow-up period of 18.26 months (range, 10-28 months) were assessed.

RESULTS

There were no recurrences of pterygium growth except in 2 cases (4.75%). In addition, no significant complications were noted. No further surgical interventions were needed in any case except for reoperation in the 2 recurrent cases.

CONCLUSIONS

Although limbal stem cells and conjunctival autograft transplantation is a time-consuming procedure, it is a safe and effective technique for the treatment of different grades of pterygium. It is useful in prevention of pterygium recurrence, which is a major problem in pterygium surgery.

Recurrent pterygium surgery using pterygium extended removal followed by extended conjunctival transplant: recurrence rate and cosmesis

OBJECTIVE

To assess the rate of recurrence, complications, and cosmesis after recurrent pterygium removal with P.E.R.F.E.C.T. for PTERYGIUM (Pterygium Extended Removal Followed by Extended Conjunctival Transplant).

DESIGN

A case series study of P.E.R.F.E.C.T. for PTERYGIUM was conducted by 1 surgeon with a 1-year follow-up to assess the recurrence, complication rate, and cosmesis.

PARTICIPANTS

A total of 111 consecutive patients with recurrent pterygium removals.

INTERVENTION

A major modification of conjunctival autograft surgery was used to treat recurrent pterygia.

MAIN OUTCOME MEASURES

The recurrence rate, complications, and cosmesis after excision of recurrent pterygia using P.E.R.F.E.C.T. for PTERYGIUM.

RESULTS

There were no patients with recurrence in 111 consecutive patients, and all but 2 patients were followed for at least 1 year. One patient developed an exotropia that required no treatment, and 1 patient lost 4 lines of vision as a result of a corneal ulcer.

CONCLUSIONS

In this series, P.E.R.F.E.C.T. for PTERYGIUM resulted in a zero recurrence rate (2 patients lost to follow-up) with few complications and a good cosmetic appearance.

Effect of human RAD50 gene therapy on glaucoma filtering surgery in rabbit eye

PURPOSE

To investigate the antiproliferative effects of the subconjunctival injection of human RAD50 (hRAD50) on fibroblasts after glaucoma filtering surgery.

METHODS

After glaucoma filtering surgery in normal rabbit eye, the subconjunctival injection of hRAD50 was performed. Morphologic changes in the subconjunctival area of hRAD50-treated eyes were compared with those of mitomycin C (MMC)-treated and control eyes using light and electron microscopy. Results. Two weeks after hRAD50 treatment (2 microg), the conjunctival epithelium increased in thickness and had many tonofilaments, but the basal lamina was intact. The subconjunctival fibroblasts exhibited a granular endoplasmic reticulum without distension. Most of the collagen bundles and fibers around the fibroblasts disappeared, and apoptotic cells with many fragmented nuclei and condensed chromatin were observed. Four weeks after hRAD50 treatment, the findings were similar with those of 2 weeks except for a slight increase in the number of collagen bundles and fibers and the appearance of macrophages. In MMC-treated eyes, the conjunctival epithelium also increased in thickness and had many tonofilaments. However, intercellular spaces were widened and the basal lamina was interrupted in some areas. Most of the collagen bundles and fibers were shortened, and apoptotic cells were also observed.

CONCLUSIONS

These results demonstrate that the histologic antiproliferative effects of local hRAD50 on the conjunctival fibroblasts are similar to those of MMC, but without damage to the basal lamina of the conjunctival epithelium, and suggest that hRAD50 may be useful as a possible antifibroblastic agent for glaucoma filtering surgery. However, further investigations are needed to test for possible systemic complications, which so far have not been reported.

Identification of monoclinic calcium pyrophosphate dihydrate and hydroxyapatite in human sclera using Raman microspectroscopy

Raman microspectroscopy was first used to determine the composition of a calcified plaque located at the pterygium-excision site of a 51-year-old female patient's left nasal sclera after surgery. It was unexpectedly found that the Raman spectrum of the calcified sample at 1149, 1108, 1049, 756, 517, 376 and 352/cm was similar to the Raman spectrum of monoclinic form of calcium pyrophosphate dihydrate (CPPD) crystal, but differed from the Raman spectrum of triclinic form of CPPD. An additional peak at 958/cm was also observed in the Raman spectrum of the calcified plaque, which was identical to the characteristic peak at 958/cm of hydroxyapatite (HA). This is the first study to report the spectral biodiagnosis of both monoclinic CPPD and HA co-deposited in the calcified plaque of a patient with sclera dystrophic calcification using Raman microspectroscopy.

Corneal and conjunctival findings after mitomycin C application in pterygium surgery: an in-vivo confocal microscopy study

PURPOSE

To perform a qualitative assessment of the topical side-effects of mitomycin C on cornea after pterygium surgery.

METHODS

In-vivo confocal microscopy (Heidelberg Retina Tomograph II in combination with the Rostock Cornea Module) was performed in 10 patients with unilateral primary pterygium. Mitomycin C 0.02% was applied topically to seven eyes for 5 min intraoperatively and twice daily for 5 days postoperatively. Three eyes underwent surgery without application of cytostatic agent. Patient follow-up was 1 month.

RESULTS

After application of mitomycin C, complete epithelialization of the operated zone was found 2 weeks after surgery. In-vivo confocal microscopy revealed signs of superficial punctate keratitis for 2 weeks in the central cornea only after application of mitomycin C. The presence of epithelial and stromal oedema in this group was noted for up to 2 weeks in the central cornea and for up to 4 weeks in the operated zone. In the control group, complete epithelialization was found after 1 week; there were no signs of oedema after 1 week in the central cornea or after 2 weeks in the operated zone. Leucocyte infiltration and increased Langerhans cell density were noted in both groups in the operated and central zones. Analysis of the conjunctiva revealed a decrease in goblet cell density following cytostatic application.

CONCLUSION

Local application of mitomycin C delays corneal epithelialization, and prolongs postoperative epithelial and stromal oedema in both the centre and periphery. Moreover, signs of punctate keratitis were noted 2 weeks after surgery in central intact cornea. Nevertheless, in-vivo confocal microscopy shows that these changes are reversible 4 weeks after application of mitomycin C 0.02%.

Intraoperative mitomycin C use during filtration surgery and lacrimal drainage system obstruction

PURPOSE

To evaluate the effect of intraoperative mitomycin C (MMC) application during filtration surgery on lacrimal drainage system.

DESIGN

Prospective, nonrandomized, comparative, observational case series.

METHODS

All glaucomatous patients with previous filtration surgery with or without intraoperative MMC application were included. An ophthalmology resident took a detailed history and performed a general eye examination. Patients with ocular and periocular diseases and previous procedures that could affect the lacrimal drainage system were excluded. Diagnostic probing and irrigation of lacrimal drainage system were performed by a masked oculoplastic surgeon.

RESULTS

There were 76 eyes from 60 patients with intraoperative MMC (MMC group) and 35 eyes from 24 patients without intraoperative MMC (non-MMC group) application. Two groups were matched for all the variables except for significantly longer duration of being on topical anti-glaucoma medications in the non-MMC group. Lacrimal drainage system obstruction was found in 18.4% of MMC and 22.8% of non-MMC group (P = .61). Upper lacrimal drainage system obstruction was insignificantly more in the MMC group. Duration of MMC application (one to five minutes) did not have significant impact on lacrimal drainage system obstruction. Patients with lacrimal drainage system obstruction were significantly more symptomatic (wet eye).

CONCLUSION

Intraoperative MMC application during filtration surgery did not have a statistically significant impact on the rate of lacrimal drainage system obstruction.

Trichostatin a inhibits corneal haze in vitro and in vivo

PURPOSE

Trichostatin A (TSA), a histone deacetylase inhibitor, has been shown to suppress TGF-beta-induced fibrogenesis in many nonocular tissues. The authors evaluated TSA cytotoxicity and its antifibrogenic activity on TGF-beta-driven fibrosis in the cornea with the use of in vitro and in vivo models.

METHODS

Human corneal fibroblasts (HSFs) were used for in vitro studies, and New Zealand White rabbits were used for in vivo studies. Haze in the rabbit cornea was produced with photorefractive keratectomy (PRK) using excimer laser. Trypan blue exclusion and MTT assays evaluated TSA cytotoxicity to the cornea. Density of haze in the rabbit eye was graded with slit lamp biomicroscopy. Real-time PCR, immunoblotting, or immunocytochemistry was used to measure alpha-smooth muscle actin (SMA), fibronectin, and collagen type IV mRNA or protein levels. TUNEL assay was used to detect cell death.

RESULTS

TSA concentrations of 250 nM or less were noncytotoxic and did not alter normal HSF morphology or proliferation. TGF-beta1 treatment of HSF significantly increased mRNA and protein levels of SMA (9-fold), fibronectin (2.5-fold), and collagen type IV (2-fold). TSA treatment showed 60% to 75% decreases in TGF-beta1-induced SMA and fibronectin mRNA levels and 1.5- to 3.0-fold decreases in protein levels but had no effect on collagen type IV mRNA or protein levels in vitro. Two-minute topical treatment of TSA on rabbit corneas subjected to -9 D PRK significantly decreased corneal haze in vivo.

CONCLUSIONS

TSA inhibits TGF-beta1-induced accumulation of extracellular matrix and myofibroblast formation in the human cornea in vitro and markedly decreases haze in rabbit cornea in vivo.

Conjunctivolimbal autograft using a fibrin adhesive in pterygium surgery

Purpose

To evaluate the efficacy and safety of fibrin bioadhesive in conjunctivolimbal autograft surgery for primary pterygium.

Methods

Thirty-six eyes in 34 patients were reviewed with nasal primary pterygium who were treated with pterygium excision with superior conjunctivolimbal transplantation with fibrin bioadhesive. Surgical durations were recorded and the patients were followed up on the first day after surgery and then at 1, 2, 4, 8 and 12 weeks postoperatively. The graft-recipient site attachments were examined and subjective symptoms of patients were recorded at every follow-up examinations.

Results

The mean patient age was 57.9±10.1 (ranging from 33 to 83) years. The mean follow-up period was 22.05±5.78 weeks. The mean surgery time was 18.04±5.65 minutes. The subjective symptoms (pain, foreign body sensation, tearing and discomfort) disappeared in 23 of 36 eyes (64%) in one week after surgery, and all discomforts subsided within two weeks after surgery in all patients. The conjunctivolimbal autograft was correctly positioned and fixed in 34 of 36 eyes (94.4%) throughout the follow-up period. Graft dehiscence was seen in two eyes (5.6%), one eye was treated with remedial sutures, and the other eye showed a spontaneous healing without remedial sutures. Transient graft edema occurred in four eyes (11.2%) but subsided spontaneously within a month. There were no cases of pterygium regrowth or complications due to the fibrin bioadhesive.

Conclusions

The use of fibrin bioadhesive in conjunctivolimbal autograft surgery in primary pterygium simplifies surgical techniques, shorten surgical duration, and produce less postoperative subjective symptoms. Therefore, the fibrin bioadhesive is a safe and effective tool to attach conjunctivolimbal autograft in primary pterygium surgery.