Current concepts and techniques in pterygium treatment

Ophthalmic pterygium: a stem cell disorder with premalignant features

Pterygia are common ocular surface lesions thought to originate from limbal stem cells altered by chronic UV exposure. Traditionally regarded as a degenerative condition, pterygia also display tumor-like features, such as a propensity to invade normal tissue and high recurrence rates following resection, and may coexist with secondary premalignant lesions. This study was initiated to determine the rate of concurrent ocular surface diseases in patients with pterygia recruited from the practice of a single surgeon operating in a Sydney metropolitan hospital. One hundred pterygium specimens were histopathologically reviewed and selected cases were immunohistochemically assessed to confirm diagnosis. Along with previously documented typical features including epithelial proliferation, goblet cell hyperplasia, angiogenesis, inflammation, elastosis, stromal plaques, and Bowman's membrane dissolution, we identified five cases of ocular surface squamous neoplasia, six cases of primary acquired melanosis, two compound nevi (one suspect invasive melanoma), and one dermoid-like lesion. In 18 specimens, clusters of basal epithelial cells that coexpressed cytokeratin-15/-19 and p63-α were identified at the head of the pterygium, coinciding with clinical observation of Fuchs' flecks. Our data show that significant preneoplastic lesions may be associated with pterygium and that all excised pterygia should undergo histological examination. The presence of p63-α-positive epithelial cell clusters supports the hypothesis that pterygia develop from limbal epithelial progenitors.

Recurrence rate using fibrin glue-assisted ipsilateral conjunctival autograft in pterygium surgery: 2-year follow-up

AIMS

To determine the recurrence rate after pterygium excision with ipsilateral conjunctival autograft using fibrin glue.

METHODS

One hundred eleven eyes of 92 patients operated for primary pterygium were retrospectively evaluated for recurrence rate and intraoperative and postoperative complications. Pterygia were preoperatively divided in atrophic/grade 1 (n = 2; 1.80%), intermediate/grade 2 (n = 85; 76.58%), or fleshy/grade 3 (n = 24; 21.62%) types. All patients were operated using an ipsilateral conjunctival autograft fixed with fibrin glue. Only patients with 2-year follow-up were included in this study.

RESULTS

Two years after surgery, the mean recurrence rate was 4.50% (n = 5). No intraoperative complications were noted. Postsurgical complications were graft pseudoedema (n = 45; 40.54%), graft retraction (n = 3; 2.70%), and donor site granuloma (n = 1; 0.90%).

CONCLUSION

Fibrin glue-assisted ipsilateral conjunctival autograft seems to be safe and efficacious and associated with a low rate of recurrence.

[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.

Bevacizumab and ocular wound healing after primary pterygium excision

PURPOSE

The aim of this study was to evaluate the effect of subconjunctival bevacizumab on early postoperative wound healing in patients with primary pterygium excision.

METHODS

In this randomized, double-blind, placebo-controlled study, the patients were randomized into 2 groups. Group 1 (G1) received a total of 7.5  mg bevacizumab (5  mg/0.2  mL on the day of surgery and 2.5  mg on the fourth day after surgery). Group 2 received 0.2  mL balanced salt solution at the end of surgery. Postoperatively, patients were examined at 1 day, 1 week, and 1 month. The following parameters were evaluated: horizontal length of the corneal epithelial defect (in millimeters), conjunctival erythema, conjunctival flap edema, subconjunctival hemorrhage, lacrimation, and photophobia. Any complications of conjunctival flaps such as retraction and melting or wound infection were recorded.

RESULTS

There were no statistically significant differences for age, sex, operated eye, and horizontal size of pterygium among 44 eyes of 44 patients, 22 in each group. No patient had conjunctival flap melting or retraction, keratitis, or nonhealing corneal epithelial defect. No statistically significant differences were observed between the groups for the evaluated measures except for conjunctival erythema at the first postoperative day (P = 0.005), which was more common in G1. Although the horizontal length of corneal epithelial defect in G1 was twice that of group 2 on the seventh postoperative day (average 0.09 vs. 0.04  mm, range 0-1 vs. 0-0.3  mm), the difference was not statistically significant (P = 0.45).

CONCLUSION

No adverse effect on early postoperative wound healing of excised primary pterygium was observed in patients who received subconjunctival bevacizumab.

[Pterygium surgery. Complication following adjuvant radiotherapy]

Scleromalacia is a rare but serious complication following excision of an atypical pterygium and postoperative radiation which needs immediate action and treatment. In this case report we describe a successful method for treating this condition with amniotic membrane transplantation. Despite severe blepharoconjunctivitis the patient is now free of recurrence of pterygium for 3 years supporting the use of amnion membranes for covering scleromalacia in inflammatory conditions.

Sutureless and glue-free conjunctival autograft in pterygium surgery: a case series

AIMS

Foreign materials used in ocular surface surgery may lead to local complications such as discomfort, scarring, or infection. Plasma-derived products such as fibrin glue may produce possible hypersensitivity reactions whereas the risk of viral transmission remains. We describe a simple method of achieving conjunctival autograft adherence during pterygium surgery avoiding potential complications associated with the use of fibrin glue or sutures.

METHODS

After pterygium excision and fashioning of the autologous conjunctival graft, the recipient bed is encouraged to achieve natural haemostasis and relative dessication before graft placement. Excessive haemorrhage in the graft bed is tamponaded. Graft adherence and positioning is examined 20 min after surgery.

RESULTS

A total of 15 eyes of 12 patients (mean (SD) age 73.7 (11.2) years), 8 females underwent SGF autologous conjunctival graft post-pterygium excision. Mean graft area was 24(1.5)mm(2). Mean follow-up time was 9.2 (2.2) months. Cosmesis was excellent in all cases and visual acuity improved in one patient. There were no intra- or post-operative complications requiring further treatment.

CONCLUSION

This simple technique for pterygium surgery may prevent potential adverse reactions encountered with the use of foreign materials and in this small series provided safe and comparable results to current methods.

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.

Oxidative stress in diseases of the human cornea

Intense exposure to light, robust metabolic activity, and high oxygen tension render the human eye particularly vulnerable to oxidative damage and the list of ophthalmological disorders implicating reactive oxygen and nitrogen species is rapidly expanding. Here, we review the roles of oxidative stress in the etiopathogeneses and pathophysiology of diseases of the human cornea including pterygium, keratoconus, trauma and chemical injury, and a host of inflammatory, metabolic, degenerative, and iatrogenic conditions. Data from animal and tissue culture experimentation germane to these conditions are also adduced.

Surgical strategies for fornix reconstruction based on symblepharon severity

PURPOSE

To identify surgical strategies of fornix reconstruction for symblepharon graded according to the length from the limbus to the lid margin, to the width, and to associated inflammation.

DESIGN

Retrospective, comparative, interventional case series.

METHODS

In 61 eyes with symblepharon, cicatrix lysis and amniotic membrane transplantation (AMT) were performed with sutures (n = 34) or fibrin glue (n = 27) together with (n = 47) or without (n = 14) intraoperative mitomycin C (MMC), plus fornix reconstruction using anchoring sutures without (n = 30) or with (n = 7) oral mucosal graft or with conjunctival autograft (n = 4). Overall, success was defined as an outcome of complete success (restoration of an anatomically deep fornix) or partial success (focal recurrence of scar), and failure was defined as the return of symblepharon.

RESULTS

For a follow-up of 25 +/- 10.8 months, the overall success was achieved by the first attempt in 52 eyes (85.2%) and failure resulted in nine eyes (14.8%); however, the success rate improved to 59 eyes (96.7%) with additional attempts. At the first attempt, AMT alone achieved overall successes in 92.8% of grade I eyes and in 100% of grade II eyes. Additional anchoring sutures achieved successes in 100% of grade I eyes, 70% of grade II eyes, and 71.4% of grade III/IV eyes. Additional oral mucosa or conjunctival autograft achieved successes in 100% of grade III/IV eyes. The complete success was correlated positively with lower grades of symblepharon or intraoperative use of MMC, but negatively correlated with younger ages, canthal involvement, or use of anchoring sutures. Anatomic improvement was accompanied by reduction of preoperative conjunctival inflammation (n = 40), improved visual acuity (n = 14), improved ocular motility (n = 18), improved eyelid closure (n = 3), and feasibility of contact lens wear (n = 10).

CONCLUSIONS

Successful outcome can be achieved by selectively deploying cicatrix lysis and AMT, intraoperative MMC, anchoring sutures, and oral mucosal or conjunctival autograft based on the severity of pathogenic symblepharon.