Purpose
To provide by prospective spectral-domain anterior segment optical coherence tomography (AS-OCT) assessment, morphological details of blebless filtering glaucoma surgeries (nonpenetrating deep sclerectomy (NPDS) and combined phacoemulsification + NPDS) and analyze the correlation of intraocular pressure (IOP) reduction with any of the OCT parameters.
Methods
A total of 111 eyes were included in this study. All surgeries were performed with antimetabolite agent (mitomycin C 0.2 mg/ml) avoiding any scleral implant. 69 NPDS and 42 combined phacoemulsification + NPDS. IOP and morphological bleb features were prospectively analyzed by AS-OCT in 1 week, 1, 3, 6 and 12 months follow-up. Blebs were imaged with a commercially available AS-OCT system and the presence or absence of 3 qualitative parameters was analyzed: subconjunctival microcysts (SMC), posterior episcleral fluid (PEF) and anterior episcleral fluid (AEF).
Results
Postsurgical prospective analysis by AS-OCT of the bleb morphological features at each time point shows statistical differences in the frequency of these parameters. Presence of SMC, PFE decays progressively in first 6 months (from 82.7% and 85.3% in first week to 28.9% and 51.1% in 6 month follow-up respectively); whereas presence of AEF shows a converse evolution beyond the third month. It is present only in 4.8% of surgeries in first week and in 77.8% of cases in 6 month follow-up. Intraocular pressure and medication use reduction in all eyes were significantly decreased from baseline (IOP 23.8±7.4 mm Hg) at every time point (p<.001) with a mean IOP of 15.5±4.3 mm Hg in 12 month postoperative follow up. Nevertheless, greater IOP reduction levels were not statistically correlated with any of the 3 qualitative bleb parameters analyzed in each of the follow-up.
Conclusions
AS-OCT is a useful tool for the assessment of the filtering function in blebless glaucoma surgeries as NPDS and phacoemulsicication + NPDS. Morphological features of the filtering bleb changes dynamically in the first months of the glaucoma surgery and to monitor by new imaging techniques permits a comprehensive study of the ocular tissues responses to the wound healing process.
Keywords: 550 imaging/image analysis: clinical •
421 anterior segment •
765 wound healing