Minimally Invasive Pterygium Surgery: A New Approach for Prevention of Recurrence

Purpose

To introduce a novel approach for pterygium excision, to report recurrence rates, and to compare with conjunctival autografting. DESIGN. A comparative, prospective clinical case series design was used.

Methods

The study population consisted of 155 patients with unilateral primary or recurrent pterygia. All patients underwent pterygium excision, either by conventional conjunctival autografting (Group A) or by the minimally invasive pterygium excision (MIPE) technique (Group B). The new technique involves making a limbal incision of the conjunctiva through the body of pterygium, removing the head of the pterygium by blunt dissection, keeping the adjacent Tenon capsule intact, and performing a small conjunctival autograft to cover the epithelial defect. The recurrence rate of each technique was compared statistically.

Results

There were 84 patients in Group A and 71 patients in Group B. The recurrence rates were 18% at 1 year after surgery in the conjunctival autografting technique and 4.2% in the MIPE technique. The MIPE technique had significantly lower recurrence rates compared with conjunctival autografting technique (p<0.0001).

Conclusions

The MIPE technique had lower recurrence rate and fewer postoperative complications than the conjunctival autografting technique. Preserving the Tenon capsule and minimizing conjunctival excision in pterygium surgery does not appear to increase the recurrence rate in the 1-year period. However, the effectiveness of this technique in preventing recurrences needs to be proven with more than 1-year results, which we plan to report in the future.

Simultaneous treatment of pterygium complicated with conjunctivochalasis: analysis of pterygium excision and conjunctival autotransplantation combined with sclera fixation

BACKGROUND

This prospective study investigated the safety and efficacy of a therapeutic method of treating pterygium complicated with conjunctivochalasis, using pterygium excision and conjunctival autotransplantation combined with sclera fixation, followed by therapeutic contact lens application.

METHODS

Fifty-seven patients (83 eyes) diagnosed as pterygium complicated with conjunctivochalasis, at our hospital from July 2011 to June 2012, were selected. Patients were treated with pterygium excision and conjunctival autotransplantation combined with sclera fixation surgery, then therapeutic bandage contact lenses were applied. The efficacy of simultaneous surgery was evaluated based on vision changes, tear dynamics, and other complications. Histopathological changes were investigated on removed bulbar conjunctival tissue, using hematoxylin eosin (HE) and Masson's trichrome staining.

RESULTS

(1) Three months after the operation, the success of simultaneous surgery in the treatment of pterygium was 97.6 %, and the recurrence was 2.4 %. Based on subjective evaluation, the success of the simultaneous treatment of conjunctivochalasis was 95.2 %, and failure was 4.8 %. Based on objective evaluation, the success rate was 94.0 % and the recurrence rate was 6.0 %. (2) Visual acuity of the 83 eyes was significantly improved after surgery, and was statistically significant (X 2 = 10.29, P < 0.05). (3) Three months after surgery, the height and integrity of the tear meniscus, tear film break-up time, and chloramphenicol test results of the 83 eyes were significantly improved and there was a statistically significant difference (X 2 the height and integrity of tear meniscus = 147.24, X 2 tear film break-up time = 81.17, X 2 chloramphenicol test = 17.41, P < 0.01). (4) Complications after the operation such as granulation hyperplasia, constrictive fornix, oculomotor defect, and other complications were not observed. (5) Pathological observations, using HE and Masson's trichrome staining of removed bulbar conjunctival tissue, showed several pathological changes, including obvious squamous epithelial hyperplasia, parakeratosis, basal cell pigmentation, lamina propria hemorrhage, infiltration of lymphocytes, and reduction of elastic fibers and collagen fibers.

CONCLUSION

Pterygium excision and conjunctival autotransplantation, combined with sclera fixation followed by therapeutic contact lens use was safe, effective, and suitable for simultaneous treatment of pterygium complicated with conjunctivochalasis.

Uses and complications of mitomycin C in ophthalmology

Mitomycin C is a chemotherapeutic agent that acts by inhibiting DNA synthesis. Its use and application in ophthalmology has been increasing in recent years because of its modulatory effects on wound healing. Current applications include pterygium surgery, glaucoma surgery, corneal refractive surgery, cicatricial eye disease, conjunctival neoplasia and allergic eye disease. Although it has been used successfully in these conditions, it has also been associated with significant complications. This article reviews the current trends and uses of mitomycin C in the eye and its reported complications.

Combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C in the treatment of primary pterygium

PURPOSE

To introduce a new technique of conjunctival reconstruction after primary pterygium excision, and to evaluate the efficacy of combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C application in preventing recurrence of primary pterygium.

METHODS

In a prospective, non-comparative case series, 43 eyes of 41 consecutive patients with primary pterygium were studied. In all patient eyes, after excision of pterygia, 0.02% mitomycin C was applied topically for 2 min over the exposed scleral surface and "symmetrical conjunctival flap transposition" was performed to reconstruct the conjunctival defect. The main outcome measures were pterygium recurrence or any complications related with surgery or mitomycin C.

RESULTS

The mean age of the patients was 47.5 +/- 12.4 years (range 30-70 years). Among the 38 patients who were not lost to follow up, three patient eyes (7.5%) had grade 1, 24 eyes (60.0%) had grade 2 and 13 eyes (32.5%) had grade 3 pterygium. The mean follow up was 12.2 +/- 5.7 months (range 7-28 months). No recurrence or sight-threatening complications were encountered in any patient eye throughout the follow-up period.

CONCLUSION

Combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C application may be an effective surgical alternative in preventing recurrence of primary pterygium. Although the procedure seems to be free from severe complications, surgeons and patients should be well aware of the risk of late radiomimetic complications of mitomycin C. Comparative, randomized trials with more number of patients and longer follow up are required to further establish the safety and efficacy of this treatment strategy.

Tectonic corneal lamellar grafting for severe scleral melting after pterygium surgery

PURPOSE

To describe the technique and review the indications and success of tectonic corneal lamellar grafting for the management of severe scleral melts after pterygium surgery.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Twenty cases of severe scleral necrosis after pterygium surgery (1993-1999).

INTERVENTION

Tectonic corneal lamellar grafting. Surgery involved (1) removal of all devitalized or infected scleral tissue surrounding the melt; (2) use of lamellar or full-thickness donor corneal tissue, fashioned to fit the scleral defect exactly or a 0.25-mm diameter larger; and (3) placement of a pedicled or free conjunctival flap over the corneal lamellar graft.

MAIN OUTCOME MEASURES

Eradication of progressive scleral necrosis, preservation of globe integrity, eradication of infection, and preoperative and postoperative visual acuity.

RESULTS

Sixteen (80%) of 20 cases developed severe scleral necrosis that required tectonic surgery after bare sclera pterygium excision with mitomycin C or beta-irradiation. Surgery was also therapeutic to eradicate progressive infection in 6 cases of infective scleritis that did not respond to maximal medical treatment. Scleral melting presented 1 month to 20 years after initial pterygium surgery in healthy, immune-competent adults. Therapeutic and tectonic success was achieved in 19 cases (95%); in 1 case, recurrence of fusarium fungal infection led to severe graft necrosis and intraocular spread. Among the cases of infectious scleritis, three eyes required repeat lamellar grafting to successfully eradicate infection.

CONCLUSIONS

Tectonic and therapeutic lamellar keratoplasty, combined with aggressive antibiotic therapy, preserved globe integrity and eradicated infection in cases of severe scleral melting after pterygium surgery.

The treatment of pterygium

The treatment of pterygium is still quite controversial, with various treatments being advocated in the scientific literature. Unfortunately, there are very few well-conducted controlled clinical trials of treatments. However, years of anecdotal and noncontrolled studies have confirmed that some methods, such as bare scleral closure, are no longer acceptable in the treatment of pterygium and that other methods are likely to be more useful. In the future it will be important to develop a grading system, and surgeons will need to be conservative in the treatment of pterygium until such time as a single treatment provides a lower recurrence rate and complication rate.

Measures for preventing recurrence after pterygium surgery

PURPOSE

To introduce an improved technique of pterygium surgery and to compare postoperative results between this technique and previous techniques.

METHODS

In a retrospective survey, the records of 216 consecutive eyes with primary pterygium that underwent surgery by three different techniques were reviewed. The new technique (mini-flap technique) involves making a small excision of the pterygium body, removing the pterygium head by scraping with forceps, applying mitomycin C (MMC), and performing a small conjunctival transposition flap. The previous technique (large-flap technique II) involved making a large excision in the pterygium body, removing the pterygium head with a knife, applying MMC, and performing a large transposition flap. Large-flap technique I is the same as large-flap technique II except for the use of intraoperative MMC. The recurrence rate of each technique was estimated by the Kaplan-Meier life table analysis.

RESULTS

The recurrence rates estimated at 1 year after surgery were 15.5% in large-flap technique I, 4.2% in large-flap technique II, and 0% in the mini-flap technique. Large-flap technique II or the mini-flap technique had significantly lower recurrence rates compared with large-flap technique I ( p = 0.02 and p < 0.01, respectively). The mini-flap technique had a significantly lower incidence of conjunctival scarring or granuloma compared with large-flap technique I and large-flap technique II ( p = 0.05 and p = 0.03, respectively.)

CONCLUSIONS

The mini-flap technique was useful for preventing recurrence and was technically easier and induced fewer postoperative complications than large-flap techniques I and II.