Abstract
Purpose: :
To evaluate blebs after limbus- and fornix- based trabeculectomy using three dimensional cornea and anterior segment optical coherence tomography (OCT, CASIA prototype, Tomey).
Methods: :
A total of 31 eyes from 31 patients (61.5 ± 11.0 years old) (mean ± standard deviation) who had undergone trabeculectomy were evaluated using CASIA prototype 3 months after surgery. Limbus- and fornix-based trabeculectomy was performed on 15 and 16 eyes, respectively. Intraocular pressure (IOP) was 10.7 ± 4.3 mmHg at the time of evaluation. Using a 1.3 um light source and swept-source OCT technology, CASIA can create three-dimensional images of the anterior segment, including internal bleb structure, in 0.3 to 2.2 seconds. The parameters evaluated about the blebs were volume of the internal fluid-filled cavity, volume of reticulated area, wall thickness (minimum and maximum), total height, number of microcysts, and visibility of scleral flap.
Results: :
The rate of eyes with more than 10 microcysts was significantly higher in limbus-based blebs than in fornix-based blebs (P = 0.039, chi-square test). Eyes with limbus-based blebs showed significantly greater data variance in postoperative IOP, volume of the internal fluid-filled cavity, volume of reticulated area, wall thickness (minimum and maximum), and total bleb height (P < 0.05, t-test, Welch’s t-test). There was no significant difference in the visibility of scleral flap between two groups (P = 0.25, chi-square test).
Conclusions: :
More microcysts were found in limbus-based blebs than in fornix based blebs. There were no significant differences in intra-bleb structures between the two groups, but greater data variations were seen in limbus-based blebs.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • imaging/image analysis: clinical • anterior segment