INTRODUCTION: Cataract progression is common after trabeculectomy. Subsequent cataract extraction may lead to disappearance of the filtering bleb and may cause an increase in intraocular pressure. Our purpose was to determine the failure rate of functioning filtering blebs after phacoemulsification.
METHODS: In this retrospective study, ten patients with a history of trabeculectomy had undergone phacoemulsification with intraocular lens implantation in the operated eye. Patients with a functioning filtering bleb prior to cataract surgery were included in the study. The recorded data included intraocular pressure measurements and evaluation of the appearance of the filtering bleb 1 week, 1 month, 3 months and up to 1 year after the operation.
RESULTS: The mean time interval between trabeculectomy and cataract surgery was 34.6 ± 12.7 months (range, 15–52 months). After cataract surgery, the mean follow-up time was 5.8 ± 1.5 months (range, 1–24 months). Five of the ten patients had a functioning filtering bleb throughout the follow-up. In the other five patients the bleb disappeared; in three of these patients this happened at the end of the first postoperative week, in one patient after 3 months, and in one after 6 months. The mean intraocular pressures before and after the cataract operation were 10.9 ± 2.67 mmHg (range 6–14 mmHg ) and 11.2 ± 1.23 mmHg (range 9–13 mmHg), respectively.
CONCLUSION: Although flattening of the filtering bleb
occured in 50% of the eyes after phacoemulsification, there was no significant
increase in the mean intraocular pressure in these eyes. However, further studies
should be carried out on a larger group of patients, in order to verify this
conclusion.