Abstract

Background: To determine whether thermography can be used to evaluate bleb function.

Methods: The surface temperatures of filtering blebs from 39 eyes of 33 post-trabeculectomy patients were measured using thermography. We introduced a new parameter: the temperature decrease in the filtering bleb (TDB) [TDB = (Mean temperature of the temporal and nasal bulbar conjunctiva)-(Temperature of the filtering bleb)]. The eyes were classified into good and poor intraocular pressure (IOP) control groups according to the patients;Epostoperative IOP, and the morphological appearance of the filtering blebs were classified by slit-lamp images according to the Indiana Bleb Appearance Grading Scale. The differences in TDB were analyzed statistically.

Results: Mean ± standard deviation overall scores were as follows. The TDB were 0.54 ± 0.20°C and 0.21 ± 0.18°C for the good and poor IOP control groups, respectively. The difference between the TDB of the two IOP control groups was significant (P <0.0001), but there was no significant relationship between morphological classification and TDB.

Conclusions: Thermographic measurements suggest that functional blebs have lower temperatures than non-functional blebs, and their morphological appearances are not affected by their temperature. Thermography may be useful for the evaluation of bleb function.