J Korean Ophthalmol Soc.  2010 Feb;51(2):234-240. 10.3341/jkos.2010.51.2.234.

The Morphometric Analysis of Filtering Bleb Using Anterior Segment Optical Coherence Tomography: Pilot Study

• Shin JY
• Kang SY
• Kim NR
• Hong S
• Seong GJ
• Kim CY

• KMID: 2213145
• DOI: http://doi.org/10.3341/jkos.2010.51.2.234

Abstract

PURPOSE
To evaluate intrableb morphology and function after trabeculectomy using anterior segment optical coherence tomography (AS-OCT).
METHODS
Twenty-eight post-trabeculectomy eyes from patients with primary open-angle glaucoma were examined using AS-OCT. Intrableb structures, including bleb wall thickness, subconjunctival fluid, suprascleral fluid and the route under the scleral flap, were measured at the center of the bleb using AS-OCT and were classified according to their slit-lamp appearance. Blebs were classified as successful (IOP< or =18 mmHg without ocular hypotensive medication) and failed (IOP>18 mmHg or use of ocular hypertensive medication.) in order to compare parameters between the two groups.
RESULTS
The blebs were classified as either diffuse filtering (n=17), cystic (n=5), encapsulated (n=3) or flattened (n=3) according to slit lamp appearance and were correlated with AS-OCT images. Blebs were classified as successful and failed in order to compare parameters between the two groups. Significant differences were observed between the two groups in regard to subconjunctival fluid space (p=0.0004). No significant differences were observed in bleb wall thickness (p=0.098), suprascleral fluid space (p=0.87) or the route under the scleral flap (p=0.196).
CONCLUSIONS
AS-OCT images of the intrableb structures were correlated with the appearance of the slit lamp, and a large subconjunctival space was associated with good bleb function. AS-OCT is useful for evaluating blebs; further studies should be performed to verify these findings.

Keyword

Anterior segment OCT; Bleb function; Intrableb morphology

MeSH Terms

Blister
Eye
Glaucoma, Open-Angle
Humans
Pilot Projects
Tomography, Optical Coherence
Trabeculectomy

Figure

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  Figure 1. Morphology of bleb using Visante TM OCT. BW=bleb wall thickness; SF=subconjunctival fluid; SS=scle-rotomy site; SF=scleral flap; R=route under scleral flap; SSF=suprascleral fluid.

• 

  Figure 2. AS-OCT image and corresponding slit-lamp appearance. (A) Diffuse functioning bleb. (B) Cystic bleb. (C) Encapsulated bleb. (D) Flattened bleb

Reference

References

1. Cairns JE. Trabeculectomy. Preliminary report of a new method. Am J Ophthalmol. 1968; 66:673–9.

2. Picht G, Grehn F. Classification of filtering blebs in aberrations: biomicroscopy and functionality. Curr Opin Ophthalmol. 1998; 9:2–8.

3. Hu CY, Matsuo H, Tomita G, et al. Clinical characteristics and leakage of functioning blebs after trabeculectomy with mitomycin-C in primary glaucoma patients. Ophthalmology. 2003; 110:345–52.

4. DeBry PW, Perkins TW, Heatly G, et al. Incidence of lateonset bleb-related complications following trabeculectomy with aberrations. Arch Ophthalmol. 2002; 120:297–300.

5. Soltau JB, Rothman RF, Budenz DL, et al. Risk factors for aberrations filtering bleb infections. Arch Ophthalmol. 2000; 118:338–42.

6. Kronfeld FC. The chemical demonstration of transconjunctival passage of aqueous after antiglaucomatous operations. Am J aberrations. 1952; 35:38–45.

7. Cantor LB, Mantravadi A, WuDunn D, et al. Morphologic aberrations of filtering blebs after glaucoma filtration surgery: the Indiana Bleb Appearance Grading Scale. J Glaucoma. 2003; 12:266–71.

8. Wells AP, Crowston JG, Marks J, et al. A pilot study of system for grading of drainage blebs after glaucoma surgery. J Glaucoma. 2004; 13:454–60.

9. Yamamoto T, Sakuma T, Kitazawa Y. An ultrasound aberrations study of filtering blebs after mitomycin C trabeculectomy. Ophthalmology. 1995; 102:1770–6.

10. Pavlin CJ, Harasiewicz K, Foster FS. Ultrasound biomicroscopy of anterior segment structures in normal and glaucomatous eyes. Am J Ophthalmol. 1992; 113:381–9.

11. Singh M, Chew PT, Friedman DS, et al. Imaging of aberrations blebs using anterior segment optical coherence tomography. Ophthalmology. 2007; 114:47–53.

12. Leung CK, Yick DW, Kwong YY, et al. Analysis of bleb aberrations after trabeculectomy with Visante anterior segment optical coherence. Br J Ophthalmol. 2007; 91:340–4.

13. Kronfeld PC. The mechanism of filtering operations. Trans Pac Coast Oto Ophthalmol Soc Annu Meet. 1949; 33:23–40.

14. Savini G, Zanini M, Barboni P. Filtering blebs imaging by optical coherence tomography. Clin Exp Ophthalmol. 2005; 33:483–9.

15. Zhang Y, Wu Q, Zhang M, et al. Evaluating subconjunctival bleb function after trabeculectomy using slit-lamp optical coherence tomography and ultrasound biomicroscopy. Chin Med J. 2008; 121:1274–9.

16. Theelen T, Wesseling P, Keunen JE, Klevering BJ. A plot study on slit lamp-adapted optical coherence tomography imaging of aberrations filtering blebs. Graefes Arch Clin Exp Ophthalmol. 2007; 245:877–82.

17. Kawana K, Kiuchi T, Yasuno Y, Oshika T. Evaluation of aberrations blebs using 3-dimensional cornea and anterior segment optical coherence tomography. Ophthalmology. 2009; 116:848–55.