To the Editor
It was with great interest that we read the article by Prajna et al1 entitled, “Conjunctival autograft versus amniotic membrane transplantation after double pterygium excision: a randomized trial.” The issue of recurrence after pterygium excision is an important one that has implications for surgical planning and patient satisfaction, and we congratulate the authors for performing this prospective randomized study to answer this question as it relates to double pterygium. The authors found that nasal and temporal pterygia were both equally likely to recur, and all recurrences occurred when using amniotic membrane transplantation (AMT) rather than conjunctival autograft (CAG), thus confirming the results of previous studies that have found CAG to be superior to AMT in terms of recurrence.2–4
We have similarly observed that when recurrence occurs after double pterygium excision treated with CAG on one side and AMT on the other, recurrence is associated with the use of AMT over CAG, regardless of whether placed nasally or temporally. In 3 consecutive cases of such recurrence seen in our practice, all 3 recurrences were on the side of AMT. The first case was a 43-year-old man with excision of double pterygium in the right eye with CAG temporally and AMT nasally who at 6 years postoperatively was noted to have grade 4 recurrence of nasal pterygium. The second case was a 43-year-old man with double pterygium in both eyes. He underwent pterygium excision with CAG nasally and AMT temporally in the left eye, and was subsequently noted to have grade 4 recurrence temporally in the left eye at the side of the AMT graft at 1.5 years. The third case was a 55-year-old man with double pterygium in both eyes. The right eye underwent double pterygium excision with CAG nasally and AMT temporally, and he experienced grade 4 recurrence of temporal pterygium at 9 months. In all 3 cases in which AMT was used on one side and CAG on the other to treat double pterygium, recurrence was on the side of AMT, not CAG. One recurrence was nasal, and 2 were temporal. In our cases, all recurrences eventually reached grade 4 during the time the patients were observed, and we believe that had the authors' study had an extended follow-up period beyond 1 year that they may have seen some of the observed stage 3 recurrences progress to stage 4.
We, like Prajna et al, conclude from their results and ours that CAG is superior to AMT for the treatment of double pterygium. However, as noted by the authors, AMT is often used in treating double pterygium if there is insufficient normal conjunctival tissue available to serve as an autograft. Currently, we attempt to treat both sides of double pterygium with CAG whenever there is enough normal conjunctiva available. We have generally had good results without recurrences by using this technique. In some instances, we use the inferior conjunctiva in addition to the superior conjunctiva toward this end, and we have not encountered complications with this technique to date. Alternatively, one may wish to treat one side of double pterygium with a conjunctival autograft and then wait for the superior conjunctiva to heal before performing surgery on the opposite pterygium by harvesting conjunctiva from the same area. If the use of AMT is deemed necessary to treat one or both sides of double pterygium, then it may be preferable to apply adjuvant mitomycin-C in these cases, as the recurrence rates with AMT combined with mitomycin-C for primary pterygium are reported to be low.