Cutting Edge Glaucoma - Issue 2

CHILDHOOD GLAUCOMA SURGERY IN DEVELOPING COUNTRIES • 15  the number of eyes needing medications for the hypertensive phase was close to 46% with flow- restricted and 26% with non-flow-restricted implants (unpublished data). With IOP control, the majority of the corneas are clear (Fig. 1); however, aftercare includes frequent follow-up, not just for IOP evaluation but for tube- and plate-related complications, which are much higher in chil- dren compared to adults [38, 39]. Laser Surgery Cyclodestructive procedures are preferred in patients with limited visual potential, with high risk of intraocular complications with incisional surgery, and with severely scarred conjunctiva pre- cluding GDD surgery or as an adjunct when the GDD surgery is failing. The commonly used cycloablative procedure is contact transscleral cyclophotocoagulation (TSCPC) using Nd:YAG and 810 nm diode laser with a G-probe [40]. The power used is 1500–2000 mW with a soft pop. In children we limit the treatment to 180° or to 20–25 shots to prevent hypotony and phthisis. The laser can be repeated if needed, and repeat laser is not done earlier than 3–4 months after first laser. The placement of the G-probe and laser delivery is based on the limbal anatomy and the globe enlargement. Transillumination to identify the area of the ciliary body helps to deliver the laser appropriately. We avoid the areas of thinning and staphyloma, as well as pigmented areas, to help prevent inadvertent perforations. We also avoid delivering laser at the 3 and 9 o’clock positions to avoid ciliary nerve damage increasing risk of subsequent corneal anesthesia and corneal com- plications. We restrict using TSCPC to eyes with refractory glaucomas and poor visual potential. We also use it as adjunct in treating eyes with failed implants before a second implant is planned. The IOP control is not uniform, with a proportion of children requiring repeat interventions. In conditions where vitreoretinal surgery is needed with refractory glaucoma or those with ciliary staphylomas or in eyes with sclerocorneas, we prefer intraocular cycloablation with endocyclo- photocoagulation. We use a straight or a curved laser probe with endoscopic visualization using much lower energy (250–300 mW) and treat 270° of the ciliary processes. 164 TSCP poor v treatin impla with a ventio is nee ciliary we pr clopho laser much of the Fig. 11.1 Postoperative appearance after Ahmed glau- coma valve implantation in a child with primary congeni- Fig. 1: Postoperative appear- ance after Ahmed glaucoma valve implantation in a child with primary congenital glau- coma. Both eyes show clear corneas and Haab striae in the right eye and well-placed tubes ( arrows ) in a child with failed combined trabeculotomy and trabeculectomy.