Study on filtering blebs imaging by anterior segment optical coherence tomography / 眼科研究

ABSTRACT

Objective To seak a available way of evaluating morphology of filtering blebs after trabeculectomy is very important for forecasting the successful rate of surgery.At the present time,filtering blebs were commonly evaluated by using the slim lamp microscope,but it did not to exactly reflect the filtering passage.This study aimed to evaluate the morphology of filtering blebs after trabeculectomy with anterior segment optical coherence tomography (AS-OCT).MethodsThis was a prospective study.Sixty-nine eyes of 53 patients who had previously undergone trabeculectomy were selected in this study,including 25 eyes with open-angle glaucoma,38 eyes with close-angle glaucoma and 6 eyes with secondary glaucoma.These filtering blebs were classified into functional type (typeⅠandⅡ) and nonfunction type (type Ⅲ and Ⅳ) under the slit lamp microscope based on the van Buskirk grading scales.Intra-bleb morphology and structure were characterized as diffuse-like,cystic-like,encapsulating-like and flatten-like by AS-OCT in reference to the Leung method.The consistency between the two methods was evaluated by the Chi-Square test.Written informed consent was obtained from all the patients before surgery.ResultsThe average follow-up time was 10.78±11.0 months.All the patients finished the examination during the follow-up duration.The average intraocular pressure was(14.9±4.5)mmHg during the observation period.There were 38/69 (55.1%) functioning blebs and 31/69 (44.9%) non-function blebs under the slim lamp microscope.AS-OCT imaging showed diffuse-like blebs in 26 eyes (15.9%),cystic-like blebs in 11 eyes (27.5%),encapsulating-like blebs in 19 eyes (18.8%) and flatten-like in 13 eyes with the intraocular pressure of(13.16±3.77)mmHg,(15.36±2.92)mmHg,(15.77±5.07)mmHg and (16.62±5.33)mmHg,respectively,showing a significant difference among them (F=3.32,P＜0.05).These patterns of different OCT presented a good consistency with the clinical outcome (χ~2=0.03,P=0.86).ConclusionAS-OCT allows the observation of filtering blebs after glaucoma surgery.It is probably to visualize the internal structure of filtering bleb and deep sclerectomy.Functional and dysfunctional filtering blebs delivery gives different OCT patterns.This could be a new way to assess the postoperative healing process.