This prospective study found that ocular surface squamous neoplasia (OSSN) did not commonly coexist with pterygium in a cohort of patients in south Florida. However, it had a prevalence greater than that of Sidney, Australia, which has a higher UV index, and lower than that of Canada, with a lower UV index.
Investigators retrospectively evaluated the prevalence of OSSN in 2,005 patients with surgically excised pterygia at the Bascom Palmer Eye Institute. The prevalence of coexistent OSSN was 1.7 percent. The authors note that south Florida has a UV index of 6 to 7. The prevalence of OSSN with pterygia was reported to be 11.5 percent in Sidney, which has a UV index of 8 to 9, and 0 percent in Canada, with a UV index of 2 to 3.
The authors write that the above data may support the theory that UV radiation is involved in the pathophysiology of OSSN and suggests that surgeons in zones with high UV radiation should have a higher index of suspicion for OSSN when evaluating and treating pterygia.
They say that 41 percent of OSSN cases were clinically suspected preoperatively and 59 percent were unexpectedly found on histopathology. Clinically suspected OSSN with pterygia was generally treated with wide surgical margins and cryotherapy, whereas unexpected OSSN with pterygia was treated with simple excision, followed by adjuvant interferon treatment in six cases.
The prognosis of suspected OSSN with pterygia was excellent. After a mean follow-up of two years, there were no recurrences in the suspected OSSN group and two recurrences in the unexpected OSSN group. The recurrence rate in the latter group was 11 percent at one year and 24 percent at two years. They note that the recurrence rates for unexpected OSSN with pterygia were comparable to those for isolated OSSN, highlighting the need for vigilant and long-term follow-up.
Patients with coexistent OSSN and pterygia were older than patients with simple pterygia. The authors also note that although location data for the cohort were incomplete, inferiorly located lesions were seen more often in the suspected OSSN group. This finding highlights the need to increase the suspicion for malignancy when a lesion does not present at the nasal or temporal position.
They conclude that future investigations with larger patient numbers are needed to study whether adjuvant measures for unsuspected OSSN with pterygia can significantly decrease the recurrence rate.