Visualization of blebs using anterior-segment optical coherence tomography after glaucoma drainage implant surgery.
OBJECTIVE
The current study investigated the internal structure of blebs using anterior-segment optical coherence tomography (AS-OCT) in patients who had undergone Ahmed glaucoma valve (AGV) (New World Medical Inc, Rancho Cucamonga, CA) implantation and compared the differences between successful and failed surgeries.


METHODS
Cross-sectional, observational study.


METHODS
A total of 76 patients who had undergone AGV implantation.


METHODS
The blebs after AGV implantation were examined using AS-OCT. The relationship between intraocular pressure (IOP) or the number of glaucoma medications and intrableb parameters was evaluated. Success was defined as IOP ≤ 21 mmHg with a maximum of 2 glaucoma medications, and the remaining cases were assigned to the "failed surgery group." Logistic regression was used to determine the predictive value of various bleb parameters measured by AS-OCT for bleb success.


METHODS
The bleb wall thickness (minimum and maximum) and the reflectivity of the bleb wall (mean, modal value, minimum, and maximum).


RESULTS
Blebs from 46 successful (60.5%) and 30 failed (39.5%) AGV implantation surgeries were analyzed. The AS-OCT imaging of the intrableb configuration revealed a relatively regular surface and a homogeneous and hyperreflective bleb wall. The maximum and minimum bleb wall thicknesses were significantly different between the 2 groups (P<0.001, P<0.005). No significant differences were observed between the 2 groups in mean, modal, maximum, or minimum reflectivity of the bleb wall. The maximum and minimum bleb wall thicknesses were significantly correlated with the postoperative maximum IOP (r = 0.402, P<0.001; r = 0.280, P = 0.014). The maximum and minimum bleb wall thicknesses showed a significant correlation with the number of postoperative glaucoma eye drops (r = 0.452, P<0.001; r = 0.327, P = 0.004). Maximum bleb wall thickness was significantly associated with the success of AGV surgery by multivariate analysis (P<0.001).


CONCLUSIONS
Anterior-segment OCT can be used for bleb imaging after glaucoma valve implantation. The AS-OCT results revealed that the maximum bleb wall was significantly thinner in successful AGV implant surgeries compared with unsuccessful AGV implant surgeries. This technique may facilitate the investigation of surgical outcomes and pathogenesis in patients receiving glaucoma valve implants.


BACKGROUND
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Department of Ophthalmology and Visual Science, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Kyoung In
KI
Jung
Sung A
SA
Lim
Hae-Young L
HY
Park
Chan Kee
CK
Park
D000328:Adult; D000368:Aged; D000869:Anterior Eye Segment / Q000601:surgery*; D001768:Blister / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000473:pathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*