Abstract
Background
Our study aims to identify anatomical characteristics of glaucoma filtering blebs by means of slit lamp-adapted optical coherence tomography (SL-OCT) and to identify new parameters for the functional prognosis of the filter in the early post-operative period.
Methods
Patients with primary open-angle glaucoma, aged 18 years and older, scheduled for primary trabeculectomy at the Department of Ophthalmology, Radboud University Nijmegen Medical Centre, were considered for our study. All patients underwent standardized trabeculectomy with intra-operative application of mitomycin C. The filtering blebs were evaluated clinically and with SL-OCT on day 1 and 1, 2, 4 and 12 weeks following surgery. The resulting data were analysed and weighed against surgical success. To better understand the SL-OCT data a small comparative histologic study was performed.
Results
The study included 20 eyes of 20 patients. After completion of our study, 15 eyes of 15 patients (mean age±SD 67 ± 16 years) were eligible for data analysis and 5 eyes missed at least one follow-up visit. Filtering surgery was considered successful (intraocular pressure ≤ 21 mmHg without antiglaucomatous medication) in 11 of 15 eyes. SL-OCT frequently demonstrated multiple hypo-reflective layers within Tenon’s capsule (“striping” phenomenon) in the first post-operative week. Presumably, these layers corresponded with drainage channels in the histological specimen. These channels were present in functional filters but not in the failures. In addition, the visualisation of the sclera below the filtering zone was better defined in failures compared with successful filtering blebs (“shading” phenomenon). We observed no differences in the volume and clinical aspect of the blebs in the successful group compared with the unsuccessful group.
Conclusions
Successful filtering blebs show characteristic optical properties on SL-OCT. These phenomena suggest a diffusely enhanced fluid content and the presence of intra-bleb drainage channels in functional filtering blebs.
Similar content being viewed by others
References
Addicks EM, Quigley HA, Green WR, Robin AL (1983) Histologic characteristics of filtering blebs in glaucomatous eyes. Arch Ophthalmol 101:795–798
Cantor LB, Mantravadi A, WuDunn D, Swamynathan K, Cortes A (2003) Morphologic classification of filtering blebs after glaucoma filtration surgery: the Indiana Bleb Appearance Grading Scale. J Glaucoma 12:266–271
Hoerauf H, Wirbelauer C, Scholz C, Engelhardt R, Koch P, Laqua H, Birngruber R (2000) Slit-lamp-adapted optical coherence tomography of the anterior segment. Graefes Arch Clin Exp Ophthalmol 238:8–18
Labbe A, Dupas B, Hamard P, Baudouin C (2005) In vivo confocal microscopy study of blebs after filtering surgery. Ophthalmology 112:1979
Parrish RK II, Folberg R (1996) Wound healing in glaucoma surgery. In: Ritch R, Shields MB, Krupin T (eds) The glaucomas, 2nd edn. Mosby, St. Louis, pp 1636–1637
Picht G, Grehn F (1998) Classification of filtering blebs in trabeculectomy: biomicroscopy and functionality. Curr Opin Ophthalmol 9:2–8
Savini G, Zanini M, Barboni P (2005) Filtering blebs imaging by optical coherence tomography. Clin Experiment Ophthalmol 33:483–489
Schmitt JM, Knuttel A, Yadlowsky M, Eckhaus MA (1994) Optical-coherence tomography of a dense tissue: statistics of attenuation and backscattering. Phys Med Biol 39:1705–1720
Stalmans I, Gillis A, Lafaut AS, Zeyen T (2006) Safe trabeculectomy technique: long term outcome. Br J Ophthalmol 90:44–47
Yamamoto T, Sakuma T, Kitazawa Y (1995) An ultrasound biomicroscopic study of filtering blebs after mitomycin C trabeculectomy. Ophthalmology 102:1770–1776
Acknowledgements
The authors thank Carina F.M. Meulendijks, MS, for statistical calculations, and B. Frits T. Hogewind, MD, for patient recruitment. The slit lamp-adapted optical coherence tomography device was provided to one of the authors (TT) by Medical Workshop, Groningen, Netherlands, under support from the manufacturer, Heidelberg Engineering, Lübeck, Germany. There are no other competing interests of any author.
Author information
Authors and Affiliations
Corresponding author
Additional information
Financial disclosure
Medical Workshop, Groningen, Netherlands, made the slit lamp-adapted optical coherence tomography device available to one of the authors (T. Theelen) with support from the manufacturer, Heidelberg Engineering, Lübeck, Germany. There are no other competing interests.
Rights and permissions
About this article
Cite this article
Theelen, T., Wesseling, P., Keunen, J.E.E. et al. A pilot study on slit lamp-adapted optical coherence tomography imaging of trabeculectomy filtering blebs. Graefe's Arch Clin Exp Ophthalmol 245, 877–882 (2007). https://doi.org/10.1007/s00417-006-0476-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00417-006-0476-2