Express Implant Versus Trabeculectomy After Late Failure Trabeculectomy

Express Implant Versus Trabeculectomy in a Fibrotic Bleb With Late Failure After Previous Trabeculectomy

To compare between outcome of Express implant and subscleral trabeculectomy (SST) in management of glaucoma after previous trabeculectomy with a fibrotic bleb.

Trabeculectomy is the main glaucoma surgery. Despite the good decline in intraocular pressure (IOP) that occur rapidly after the procedure, there is still failure occurring due to progressive subconjunctival fibrosis, with associated increased IOP. If the bleb is revived by needling with adjunctive 5-fluorouracil (5FU) and mitomycin C (MMC) that used intraoperatively for the majority of these cases , the associated rise in IOP was controlled if the revision occured early within the first three months after surgery. But less success occurred if the bleb revision was delayed. If these interventions fail, alternative approaches include new augmented trabeculectomy or aqueous shunt implantation. Express shunt allows aqueous to pass from anterior chamber to subconjunctival space like trabeculectomy .Express shunt is a non valved shunt, It has an advantage of less traumatic, less complications, low diffuse bleb and high success rate.

conjunctival peritomy superior-temporally away from the site of the fibrotic bleb at 12 o'clock, placed on the episclera under the conjunctiva and Tenon's capsule for a contact time of 3 minutes, ,triangular scleral flap , scleral dissection forward to the clear cornea to allow exposure of scleral spur then creation of a pilot hole is fashioned using a sapphire blade (Alcon laboratories,USA) then Express shunt 3 mm long device and external diameter 400 microns was implanted followed by closure of scleral flap and conjunctiva

Trabeculectomy with Mitomycin-C was done in superior-temporal region away from the fibrotic bleb at 12 o, clock. conjunctival peritomy superior-temporally away from the site of the fibrotic bleb at 12 o'clock, placed on the episclera under the conjunctiva and Tenon's capsule for a contact time of 3 minutes, ,triangular scleral flap , scleral dissection forward to the clear cornea to allow exposure of scleral spur then creation of sclerectomy and peripheral iridectomy and closed scleral flab and conjunctiva by nylon 10/0 sutures

Operative technique in group I (Express implant) was as in group II (trabeculectomy) except with no sclerectomy or peripheral iridectomy , the steps included conjunctival peritomy superior-temporally away from the site of the fibrotic bleb at 12 o'clock, placed on the episclera under the conjunctiva and Tenon's capsule for a contact time of 3 minutes, ,triangular scleral flap , scleral dissection forward to the clear cornea to allow exposure of scleral spur then creation of a pilot hole is fashioned using a sapphire blade (Alcon laboratories,USA) then Express shunt 3 mm long device and external diameter 400 microns was implanted followed by closure of scleral flap and conjunctiva. While in group II, Trabeculectomy with Mitomycin-C was done in superior-temporal region away from the fibrotic bleb at 12 o, clock.

IOP measured with Goldmann applanation tonometry: Complete success in IOP considered as IOP less than 20 mmHg without treatment and a qualified success in IOP considered as IOP less than 20 mmHg with medical treatment and a failure in IOP control considered if IOP more than or equal 20 mmHg after surgery

Inclusion Criteria: elevated intraocular pressure (IOP) with fibrotic bleb despite previous SST since more than 4 months follow up 12mo after the second surgery Exclusion Criteria: SST failure other than fibrotic bleb were also excluded follow up less than 4mo after the first surgery, and those less than 12mo after the second surgery