Abstract
Purpose: :
Our study aims to identify anatomical assessment of filtering blebs in the early post-operative period after glaucoma surgery.
Methods: :
We performed a prospective,observational study on 14 eyes of 12 patients(mean age 65 years old)consecutively scheduled for trabeculectomy.42% of eyes were in therapy with 3 topical medications,58% with 2 topical medications.All patients underwent standardized limbus-based trabeculectomy with intra-operative application of Mitomicin C(0.2 mg/ml/3 min).The filtering blebs were evaluated by slit-lamp examination,Intra Ocular Pressure(IOP)measurement and with Anterior Segment Module SD-OCT Spectralis (Heidelberg Engineering, Heidelberg) at day 1 and 30 after surgery.The blebs were classified with reference to slit lamp morphology and bleb function.
Results: :
Mean IOP before surgery was 20.6 mmHg,after 1 day 10.7 mmHg and 11 .4 mmHg one month after.Following the Wurzburing Filtering Bleb Classification we classified six diffuse,four mild encapsulated and four flattened filtering bleb types. Intrableb morphologies and structures, including bleb wall thickness,Tenon’s capsule,subconjunctival fluid space, scleral flap and sub flap space were characterised after 1 month from the surgery day. Subepithelial fluid collections and subconjunctival fluid-filled pseudo-cystic space characterized diffuse blebs.Subscleral fluid space was identified in 50% of cases.Encapsulated blebs were composed of a thickened Tenon’s capsule and an enclosed fluid filled space covered by a thin layer of conjunctiva.Subscleral fluid space was identified in 25% of cases.Flattened blebs demonstrated high scleral flap reflectivity and iporeflective subscleral fluid.The route between subscleral space and subconjunctival fluid was identified in 100% of cases.
Conclusions: :
Anterior Segment Module for Heidelberg Spectralis OCT with the enhanced depth imaging (EDI) system may contribute to study the deeper structures and the non contact approach makes it possible to monitor the anterior segment structures non invasively,above all in the early post-operative period following trabeculectomy.This technique may help to identify new criteria to recognize failing filtering blebs at a very early stage.
Keywords: imaging/image analysis: clinical • intraocular pressure • outflow: trabecular meshwork