Pneumatic trabecular bypass versus trabeculotomy in the management of primary congenital glaucoma

The optimal surgical management in primary congenital glaucoma (PCG) remains a subject of debate. The aim of this study was to assess efficacy of pneumatic trabecular bypass (PTB) in comparison to conventional trabeculotomy (T) in the treatment of PCG.

In a prospective comparative experimental study, one eye per child suffering from PCG underwent either PTB or T. Complete examinations were performed before surgery, postoperatively at one and seven days, then monthly for a minimum of six months. The main outcome measures were the IOP, number of IOP-lowering medications, change in cup/disc ratio, and corneal clarity.

Seventeen eyes (patients) were operated on for PTB compared to 25 eyes (patients) in the T group. The mean (±SD, range) preoperative IOP in the PTB and T groups was 34.7 (6.4, 26–48) mmHg and 26.4 (6.6, 18–44) mmHg, respectively, and these dropped at six months of follow-up to 14.9 (3.6, 11–24) mmHg and 18.8 (8.0, 6–34) mmHg, respectively. The mean reductions of IOP were 55.87 %(±11) and 28.4 %(±28.8), (p = 0.001), where those for cup/disc ratio were 39.0 %(±29) and 17.5 %(±39.7) (p = 0.088) in the PTB and T groups, respectively. The number of IOP-lowering medications had dropped from 1.7 ± 0.5 to 0.7 ± 1.0 in PTB patients, compared to an insignificant change in the T group (0.64 ± 0.9 & 0.62 ± 0.9 pre- and post-operatively respectively). Corneal clarity improved in 13 eyes (76.5 %) in the PTB group, while three eyes (12 %) had worsened in the T group. Total cumulative chances for success were 88.2 % (15 out of 17 eyes), compared to 56 % (14 out of 25 eyes), in the PTB and T groups, respectively (p = 0.027).

PTB is a promising surgical technique for the control of primary congenital glaucoma. A randomized controlled trial with a longer follow-up is recommended.