Abstract
Purpose:
In a previously published study, we found a significant correlation between endothelin-1 in the aqueous humor of glaucoma patients obtained during cataract surgery or trabeculectomy and immediately pre-operative intraocular pressure. The aim of this chart-review study was to assess, whether the previously recorded ET-1 concentrations had any influence on IOP development or surgical outcome during up to five years of follow-up.
Methods:
Clinical records of the patients enrolled in the original study were reviewed, post surgical IOP development, number of 5-FU treatments, bleb revisions, further glaucoma surgeries, glaucoma medications and complications were compared between patients with high (above median) and low (below median) ET-1 concentrations in aqueous humor.
Results:
Of the 56 glaucoma patients originally enrolled, 51 came into our clinic for further consultations. Median follow-up time was 24 months (range 1 to 59 months). There were no significant differences in IOP at any time point during follow-up. In the subpopulation of patients who had undergone trabeculectomy (n=36), both groups needed the same number of 5-FU injections (5.5±3.7 high vs. 5.1±3.1 low, p=0.74), needlings (0.2±0.7 vs. 0.2±0.7, p=0.82) and suture lyses (0.4±0.8 vs. 0.3±0.7, p=0.65 ) during the post-operative phase. Complication rates and number of revision procedures were equally low in both groups, although all 4 recorded bleb revisions were necessary in the high ET-1 group . At the end of follow-up, the number of glaucoma medications was not significantly different (0.3±0.8 vs. 0.2±0.5, p=0.88).
Conclusions:
ET-1 concentrations in aqueous humor do not appear to have any influence on long term outcome or IOP development after filtration surgery. While several animal models as well as our previous clinical study suggest a role for ET-1 in IOP control by inducing contraction of trabecular meshwork (TM), this influence on IOP development is likely reduced once the TM has been shunted. Its predictive value for long term outcome of filtering surgery therefore is limited.
Keywords: 427 aqueous •
464 clinical (human) or epidemiologic studies: risk factor assessment •
568 intraocular pressure