Abstract
Purpose: :
To determine the incidence of occult ocular surface squamous neoplasia (OSSN) among clinically normal–appearing pterygia excised by a university–based cornea service in San Antonio, Texas.
Methods: :
All pterygia excised over thirty–four months (January 21, 2003 through November 16, 2005) by a university–based cornea service were submitted to the University Eye Pathology Laboratory for pathologic examination. Patients in whom OSSN was suspected pre–operatively were excluded. Pathology reports were reviewed and the incidence of occult OSSN was calculated. Patient age and pterygium size were analyzed using a t–test to identify differences between the group without occult OSSN (Group I) and the group with occult OSSN (Group II). Fisher's exact test was used to determine significant difference in the rate of "double" pterygia (two pterygia in one eye) between the two groups.
Results: :
Of eighty patients, six (or 7.5%) were found to have occult OSSN. The mean age of patients in Group I was 52.2, while the mean age in Group II was 51.3. Mean areas were 13.4 mm2 and 12.8 mm2 for Groups I and II, respectively. Significant differences were not identified when Group I and Group II were compared for mean patient age and mean pterygium size (p=0.87 and 0.89 respectively). Of seventy–four patients in Group II, four (or 5.4%) had "double" pterygia. Of the six patients in Group Two, two (or 33%) had "double" pterygia. Although large, this difference was not statistically significant (p = 0.06).
Conclusions: :
This study demonstrates that pterygia can occasionally harbor neoplasia and that clinical signs of such growth may be absent. Although the differences in patient age, pterygium size and rates of "double" pterygia were not found to be statistically significant between the pterygia with occult OSSN and those without occult OSSN, it is possible that a larger sample size might find a difference. To our knowledge, there have been no previous reports of the incidence of occult OSSN among clinically normal–appearing pterygia. We found a frequency of unexpected OSSN in 7.5% of routine pterygium excisions, thus supporting the importance of routine pathological evaluation of excised pterygia.