RÉSUMÉ
PURPOSE: Describe and compare the effects of intraoperative application of Polyvinylpyrrolidone Collagen (PVP) versus Mitomycin C (MMC) on the pattern of change in mean IOP reduction and mean number of medications over 36-months follow-up in patients with primary open angle glaucoma (POAG) undergoing trabeculectomy. METHODS: Prospective, randomized, comparative study. Twenty-six eyes of 26 patients with POAG and no previous incisional glaucoma surgery underwent trabeculectomy and were randomized to PVP or MMC and completed a 36-month follow-up. Main outcome measures were IOP and number of glaucoma medications. Multivariate longitudinal analysis was performed by fitting a linear trend model adjusting for baseline response for the IOP outcome and a log-linear regression model with within-subject associations for the number of hypotensive medications outcome. Sensitivity analysis was performed to assess lower and higher order polynomial trends over time in IOP. RESULTS: The univariate analysis revealed that the mean IOP reduction from baseline to 36 months was 7.62mmHg (3.05; 12.18) in the MMC group and 8.15mmHg (-0.64; 16.95) in the PVP group. Mean percentage IOP reduction from baseline was 37.09% (15.93; 58.17) and 36.08% (5.16; 67.20) in the PVP group. Mean change in number of medications from baseline to 36 months was -0.92 medications (-3.38; +1.54) for the MMC group and -1 medication (-3.12; +1.12) for the PVP group. Both groups had a statistically significant decline in mean IOP over the follow-up period (p<0.001) but there was no discernible difference between the two exposure groups in the rate of change in IOP (p=0.5975). Sensitivity analysis showed that a linear trend model is adequate to describe the IOP reduction over the follow-up period. Both groups had a statistically significant change in the number of hypotensive medications used between baseline and month 36 (p<0.05) but there was no discernible difference between exposure groups (p=0.2917). Both the PVP and MMC groups showed an initial reduction in number of medications until month 12 and a relatively linear increase towards month 36. A longer follow-up may be warranted to reveal differences in the number of medications between the two exposure groups. Postoperative complications were less frequent in the PVP group. CONCLUSIONS: The use of PVP during trabeculectomy achieves and maintains a statistically significant IOP reduction from baseline to 36 months and decreases the number of glaucoma medications. Secondary outcome measures showed a lower incidence of adverse events in the PVP group.
RÉSUMÉ
To compare intraocular pressure (IOP) measurements obtained with Goldmann applanation (GAT) and dynamic contour tonometry (DCT) in a Mexican population. 40 glaucoma patients were included in this cross-sectional observational cohort study. IOP measurements were performed in the following order: DCT, ultrasonic pachymetry and GAT, with a 5-minute difference between each measurement, between 8 am and 2 pm. Only DCT measurements of good quality (Q ≤ 3) were accepted. GAT measurements were made three times with the same Goldmann tonometer, previously checked for calibration errors, and the mean was used for statistical purposes. The IOP (mean [standard deviation], 95 % confidence interval [CI]) measured with the Goldmann tonometer (13.2 [2.4], 12.4-14.0 mmHg) was significantly lower than that obtained with the DCT (18.4 [3.3], 17.0-19.2 mmHg), p < 0.0001. Pearson's correlation coefficients between CCT and IOP measured with GAT and DCT were (r = 0.24, 95 % CI = 0.07-0.52, p = 0.133) and (r = 0.13, 95 % CI = -0.19 to 0.43, p = 0.412), respectively. The concordance correlation coefficient between GAT and DCT was r c = 0.3, 95 % CI = 0.17-0.41). DCT seems to overestimate the IOP as compared to GAT. Additionally, although there was a good correlation between the IOP measurements assessed with either GAT or DCT, the agreement was poor.