Abstract
Purpose:
To study the recurrence rate of pterygium using amniotic membrane graft (AMG) with or without cryotherapy for the treatment of primary pterygium.
Methods:
This is a prospective study in patients with primary pterygium causing visual deterioration, defined as loss of BCVA or discomfort that interferes with activities of daily life. Other inclusion criteria are a pterygium extending more than 2mm beyond the limbus. Exclusion criteria are a history of any previous ocular surgery, any history of ocular inflammation from any cause or history of systemic inflammatory disease, or a histologic specimen not consistent with pterygium. The cases were randomly assigned to two groups. In group 1, 9 patients had pterygium removed and closed by AMG with fibrin glue. In group 2, 12 patients had pterygium removed, cryotherapy applied, and the defect closed by AMG with fibrin glue. One patient presented with a double-headed pterygium (both nasal and temporal). In this case, one pterygium was treated with AMG and cryotherapy; the other was treated with amniotic membrane graft alone. Surgery was performed by two surgeons; the surgical technique did not deviate from protocol. Pterygia were dissected off the cornea, then away from the cornea before being removed in total. Cryotherapy was applied to the defect at the base of the pterygium and areas of tenon’s capsule with a cryoprobe for 10 seconds using a double freeze-thaw technique. Histopathology was performed on removed pterygia to ensure the absence of malignancy and confirm the diagnosis. Postoperatively, patients received a standardized eyedrop regimen, and post-operative photos were taken. The primary endpoint was recurrence of pterygium. A masked observer graded the outcomes for recurrence with standardized criteria.
Results:
A total of 12 patient underwent pterygium excision with amniotic membrane graft and application of cryotherapy to date. There have been no cases of recurrence in this treatment group. A total of 9 patients underwent pyerygium excision with amniotic membrane graft, with one case of recurrence.
Conclusions:
The double freeze-thaw cryotherapy treatment in conjunction with pterygium excision and amniotic membrane graft appears to offer a significantly reduced rate of recurrence.