Strabismus After Ahmed Glaucoma Valve Implantation

Concurrent adjacent strabismus surgery with glaucoma drainage device placement in childhood glaucomas

BACKGROUND

Determine outcomes of concurrent strabismus surgery with placement of a glaucoma drainage device (GDD) in children.

METHODS

Retrospective review of pediatric patients who underwent simultaneous lateral rectus (LR) muscle surgery with superotemporal GDD placement. Strabismus and GDD success were defined as residual horizontal misalignment < 10 prism diopter (PD) and intraocular pressure (IOP) < 21 mmHg, no visually devastating complications, and no additional IOP-lowering surgeries.

RESULTS

Fifteen eyes of 13 patients (69% male) underwent LR surgery (14 recessions, 1 resection) for exotropia or esotropia simultaneous with GDD placement (13 Baerveldt, 2 Ahmed) at 8.34 ± 5.26 years. Preoperative visual acuity (VA) in operative eye (0.89 ± 0.54) was worse than non-operative eye (0.23 ± 0.44, p = 0.0032). Preoperative horizontal deviation was 38.3 ± 9.4 PD and LR recession was 7.4 ± 1.1 mm. At final follow-up, VA in operative eye (0.87 ± 0.52) was unchanged from preoperative (p = 0.4062). Final IOP was significantly decreased (12.4 ± 4.7 mmHg vs. 31.1 ± 11.4 mmHg, p = 0.0001) as was number of glaucoma medications (2.7 ± 1.7 vs. 1.1 ± 1.3, p = 0.0037). Five (38%) and 9 patients (69%) met criteria for strabismus and GDD success, respectively. Two eyes required tube revision and endoscopic cyclophotocoagulation and 2 eyes had additional strabismus surgery.

CONCLUSIONS

Concurrent strabismus and GDD surgery decreased horizontal deviation and obtained IOP control. It is important to consider correction of strabismus at time of GDD placement to maximize visual development and improve cosmesis in children with glaucoma.

Ahmed Glaucoma Valve Implantation to Reduce Intraocular Pressure: Updated Perspectives

Trabeculectomy and glaucoma drainage device implantation are the most commonly performed glaucoma surgeries worldwide. Although trabeculectomy is the gold standard, at the present time there is an increase in the use of glaucoma drainage devices. The Ahmed glaucoma valve is one of the most widely used glaucoma drainage devices worldwide. Corneal endothelial cell loss and eventually corneal decompensation is one of the serious complication of glaucoma drainage device implantation. To avoid this, drainage tube can be inserted into the ciliary sulcus instead of the anterior chamber, especially in eyes with high risk for corneal decompensation. Tube/plate exposure, hypertensive phase, endophthalmitis, cataract formation, diplopia and ocular hypotony are the other potential complications that can develop after Ahmed glaucoma valve implantation.

Occurrence of motility disorders in patients undergoing tube surgery-consecutive, retrospective follow-up case series analysis

BACKGROUND

The two glaucoma drainage devices (GDD) Ahmed and Baerveldt tubes are most commonly used for the treatment of refractory glaucoma. We noticed a significant number of patients with postoperative motility disorders resulting in diplopia. We investigated the occurrence and patterns of postoperative motility disorders overall and between the two GDD tubes using the Hess Screen Test.

METHODS

Retrospective single-center matched case series of 20 patients undergoing Ahmed and 20 patients undergoing Baerveldt tube implantation with a follow-up of at least 1 year. In order to investigate the dynamic of GDD-induced motility disorder over time, from 25 patients, a follow-up examination from two different time periods (3 to 6 months and 12 to 24 months postoperatively) was available. From these 25 patients, 12 had received an Ahmed and 13 a Baerveldt GDD. To compare the different Hess Screen Tests, we developed nine categories of possible emerging motility disorder in the operated eye as a primary endpoint: Motility restriction in up-gaze, in down-gaze, in abduction, in adduction; combined motility disorders in up-gaze and adduction, up-gaze and abduction, down-gaze and adduction, down-gaze and abduction. If there was no motility disorder, this was also separately classified.

RESULTS

Regardless of the used device, Ahmed or Baerveldt, most patients experienced motility disorders to some extent; mainly down-gaze and adduction were affected. However not every motility disorder resulted in diplopia. Although over time a decrease in ocular misalignment was seen, the incidence of diplopia was stable. Nevertheless, only few required therapy. We noted no difference between Ahmed and Baerveldt tube implant devices.

CONCLUSION

Ocular misalignment and restriction of motility is a common finding after GDD. Although not every motility disorder results in diplopia, it is frequent. Therefore, it needs to be taken into consideration in informed consent.