Abstract
Purpose: :
To visualize and characterize on ultrasound biomicroscopy (UBM) the filtering bleb after X-200 Ex-PRESSTM implantation in a modified minimally penetrating deep sclerectomy.
Methods: :
Twenty patients with uncontrolled primary open angle glaucoma underwent a modified deep sclerectomy with X-200 implantation in the scleral bed. After performing a standard deep sclerectomy, the tube was inserted 2 mm behind Schlemm’s canal into the anterior chamber. The tube was covered with the superficial scleral flap to prevent from eroding the conjunctiva. Comprehensive slit lamp examinations including Goldmann applanation intraocular pressure (IOP) measurements, best corrected visual acuity (BCVA) assessments and fundus observation were performed before surgery and every week for 1 month then every month for a 9 months follow-up. Outcome data were mean IOP, BCVA, number of medications and complication rates. UBM imaging was performed 6 months after surgery and subconjunctival, intrascleral and subchoroidal spaces were analyzed using digital imaging software.
Results: :
The preoperative IOP was 23.1 ± 7.4 mmHg, the BCVA was 0.55 ± 0.3, and the number of medication was 2.8 ± 1.1 (mean ± SD). At the end of the follow-up (7.5 ± 1.0 months) the IOP was lowered to 11. 2 ± 2.7 mmHg, the BCVA was 0.45 ± 0.4, and the number of medication was reduced to 0.97 ± 0.38. On UBM imaging the subconjunctival bleb was barely visible. The mean intrascleral bleb volume measured was 0.64 ± 0.64 mm3. The subchoroidal space was visible for 11 (55%) patients only. One case of malignant glaucoma was reported. The complete success rate was 70%. No tube was removed or went blocked. Needling of the bleb was required in 6 (30%) cases to prevent durable fibrosis of the filtering bleb.
Conclusions: :
The subconjunctival filtering bleb after deep sclerectomy using X-200 is rather shallow and the main bleb visible is located into the intrascleral space. The new technique of minimally penetrating deep sclerectomy reduces the subconjunctival bleb thickness without compromising on the IOP control.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • outflow: trabecular meshwork • anterior segment