SUMMARY
Alterations of the corneal and conjunctival epithelii and also of the tear film were studied in 40 patients with clinic diagnosis of pterygium who were divided at random in two groups (group without Thio-tepa and group with Thio-tepa), through the biomicroscopy, corneal sensitivity measure, Schirmer test I, break-up time of the precorneal tear film and rose bengal teste.
In the group without Thio-tepa an eye was submitted to the excision of the pterygium and got until the 25th post-operative day one drop 3 times a day of collirium of dexamethasone 1 mg and choramphenicol 5 mg, being the contralateral eye the control one. Significativy variations of corneal sensitivity measure and of the eye rose bengal test occurred only on the 15th post-operative day, and were considered to be caused by surgery trauma.
ln the group with Thio-tepa an eye was submitted to the excision of pterygium and got a collirium of dexamethasone 1 mg and chloramphenicol 5 mg, one drop 3 times day until the 25th post-operative day and also 1 drop of Thio-tepa 1 : 2000,5 times a day until the 40th post-operative day, being the contralateral eye the control one. The variations of the corneal sensitivity, Schirmer test I, break-up time of the precorneal tear film and rose bengal test were significative during the 40 days of use of Thio-tepa and, for the majority of the individuals, these parameters were normaliized between the 1st and 3rd weeks after the discontinuation of the drug. In the contralateral eye alterations of the corneal sensitivity and of break-up the precorneal tear film were significative suggesting effects of systemic absortion of the drug.
The research demonstrates that the alterations of the corneal sensitivity, though transitory, as well as the ones of the volume and stability of the tear film, besides the vitality of the corneal and conjunctival epithelium are related to the use of Thio-tepa.