Combined nasal goniotomy – temporal trabeculotomy (NGTT) for circumferential angle surgery in primary congenital glaucoma

Abstract

Purpose

To assess the safety and efficacy of combining nasal goniotomy with temporal trabeculotomy in the management of primary congenital glaucoma.

Design

Case series

Methods

Fifteen eyes of eleven children (3–12 months old at presentation) were enrolled in this study after the establishment of PCG diagnosis based on the criteria placed by the World Glaucoma Association. Combined nasal goniotomy and temporal trabeculotomy were done on each eye in an attempt to perform almost 360 degrees circumferential angle surgery without disturbing the superior 180 degrees of conjunctiva to preserve it for future filtering glaucoma surgeries.

Results

By first month, average IOP was 10.5 ± 4.3 mmHg with a 65.3% reduction from average pre-operative IOP. Almost the same percentage of reduction was maintained at 3^rd,6^th and 12^th months postoperative visits with average IOP of 11.9 ± 4.65, 11.8 ± 2.77 and 13 ± 2.82 mmHg (60.7%, 61.1% and 57.2% reduction from pre-operative average). According to success rates, complete success has been achieved in all eyes but one (93.3%), with minor complications in 4 out of 15 eyes (26.6%) that did not affect IOP outcome. Nine out of fifteen eyes completed 18 months post-operative follow-up visits with a successfully, maintained target average IOP of 13.3 ± 3.0 mmHg (57.2% reduction). All of the mean IOP readings during post-operative follow-up period were significantly lower when compared to pre-operative IOP (p < 0.0001). Only one eye had persistently elevated IOP of 26 mmHg at 1^st and 3^rd months post-operatively that necessitated a subsequent subscleral trabeculectomy which succeeded in controlling the pressure bringing it down to 15 mmHg on topical medications.

Conclusion

Nasal goniotomy – temporal trabeculotomy (NGTT) is the combination of two well established surgeries that exploits the advantages of circumferential angle surgery while sparing the superior conjunctiva completely for future surgeries if needed. This new procedure was safe and effective in lowering IOP by an average of 60% from pre-operative IOP with a sustained effect till 18 months post-operatively. We believe that this surgery might be added to the armentarium of the surgical management of infantile glaucomas with other circumferential angle surgeries.